To see the other types of publications on this topic, follow the link: Crayfish.
Journal articles on the topic 'Crayfish'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Crayfish.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Gao, Jian, Cheng Yang, Zehui Zhang, Zhengwen Liu, and Erik Jeppesen. "Effects of co-occurrence of invading Procambarus clarkii and Pomacea canaliculata on Vallisneria denseserrulata-dominated clear-water ecosystems: a mesocosm approach." Knowledge & Management of Aquatic Ecosystems, no. 422 (2021): 29. http://dx.doi.org/10.1051/kmae/2021029.
Full textAbstract:
Single invaders often substantially alter ecosystems, but the potential impacts by multiple invaders remain understudied. The golden apple snail (Pomacea canaliculata) and the red swamp crayfish (Procambarus clarkii) are two widespread coinvaders. To test the effects of co-occurrence of the two species on a clear-water macrophyte state, we performed a 20-day experiment in 16 mesocosms (4 contained only two snails, 4 contained only two crayfishes, 4 contained two snails and two crayfishes, and 4 controls). Comparing with the control, the leaf length, number, and biomass of Vallisneria denseserrulata had decreased in the snail-only and crayfish-only treatments. In the crayfish-only treatment, total nitrogen, total phosphorus and total suspended solids had increased compared with the control, while they did not differ between the snail-only and the control treatment. Nutrients and turbidity concentrations did not differ between the snail + crayfish and the crayfish-only treatment, and plant biomass did not differ between the snail + crayfish and the snail-only treatment. These findings suggest that golden apple snails mainly affected the lake ecosystem by plant grazing, while red swamp crayfishes disturbed the sediment by increasing nutrients in the water and through resuspension. These snail and crayfish together had mainly additive effects on macrophyte and the physico-chemical variables studied.
2
Ludlam, John P., Brandon T. Banks, and Daniel D. Magoulick. "Density-dependent effects of omnivorous stream crayfish on benthic trophic dynamics." Freshwater Crayfish 21, no. 1 (December 31, 2015): 165–70. http://dx.doi.org/10.5869/fc.2015.v21-1.165.
Full textAbstract:
Abstract Crayfish are abundant and important consumers in aquatic food webs and crayfish invasions have demonstrated strong effects of crayfish on multiple trophic levels. Density may be an important factor determining the role of omnivorous crayfish in benthic communities, especially if density alters the strength of trophic interactions. The effect of crayfish density on a simple benthic food web using ceramic tiles was examined in three treatments (crayfish exclusion cage, cage control (open to crayfish), and exposed ceramic tiles) in mesocosms stocked with 6, 12, or 18 crayfish·m-2. We hypothesized that at low densities crayfish consumption of herbivorous chironomids would increase algal abundance, but at high densities crayfish would reduce both periphyton and invertebrates. In the experiment, periphyton and chironomid abundance increased with declining crayfish biomass on day 30 but not day 15. The magnitude of crayfish effects on day 15 periphyton chlorophyll a abundance increased with crayfish biomass, but crayfish effects on day 30 periphyton chlorophyll a or chironomid biomass did not increase with crayfish biomass. In this experiment there was little evidence for a trophic cascade at low crayfish densities and strong omnivory by crayfish dominated trophic dynamics.
3
Dobrzycka-Krahel, Aldona, and Maria Leonor Fidalgo. "Euryhalinity and Geographical Origin Aid Global Alien Crayfish Invasions." Water 15, no. 3 (February 1, 2023): 569. http://dx.doi.org/10.3390/w15030569.
Full textAbstract:
Salinity tolerance is a determinant of a narrow or wide distribution range of organisms. Crayfishes are important key species in many aquatic environments so require a better understanding of their ability to live in different saline regimes. We identified all alien crayfish and examined their habitats (freshwater and/or saline) and origins to test whether these factors predict their dispersal. We used contingency tables populated with raw frequency data with χ2—tests and assessed statistical significance at α of 0.05. We identified 21 alien crayfishes and we found that alien crayfish species were disproportionately freshwater (71%), with significantly lower proportions of euryhaline crayfishes inhabiting freshwater to saline environments (29%). Alien crayfishes also significantly disproportionally originate from America (67% of these taxa) when compared to all ‘other’ grouped regions (33%). In total, 36% of American crayfishes represent euryhaline species inhabiting freshwater to saline habitats against only 14% of crayfishes from all “other” grouped regions. This suggests that binomial euryhalinity/origin can help understand the potential of spread. We discussed obtained results with known experimental data on salinity tolerance, osmoregulation, growth, and reproduction of American alien crayfish. The paper will help in the management of crayfish spread.
4
Wang, Jianguo, Gang Li, and Yongjun Bao. "Effects of Ammonia Nitrogen, Nitrite and pH on Embryo In Vitro Incubation of Red Crayfish." Journal of Biobased Materials and Bioenergy 17, no. 6 (December 1, 2023): 663–71. http://dx.doi.org/10.1166/jbmb.2023.2324.
Full textAbstract:
As an important economic aquatic animal, red crayfish’s reproduction and incubation can affect its breeding efficiency. With aquaculture developing, the study of factors affecting aquaculture species growth has gradually become an important research direction. To study the effects of ammonia nitrogen, nitrite and pH on red crayfish embryos, the In Vitro incubation experiment of red crayfish embryos was conducted. The residual module was used to design the embryo counting method of red crayfish. And different ammonia nitrogen, nitrite and PH gradients were set to analyze the hatching rate and emergence rate of red crayfish’s embryo development.When conducting research method performance testing, the training loss value of the research method decreased to 84 after 200 iterations. On the 6th day in an ammonia nitrogen environment, the number of water microbiota was only 4.74 M. The emergence rate of red crayfish decreases to a lower level when the ammonia nitrogen concentration is above 0.6 mg/L. The emergence rate of red crayfish decreased with the increase of nitrite concentration, and decreased to 0 when the nitrite concentration reached 1.25 mg/L. When the pH value of water body is 8.1, the emergence rate of red crayfish reaches the highest value of 68.92%. Ammonia nitrogen and nitrite concentration will inhibit the In Vitro hatching of crayfish embryos, and the appropriate PH value can improve the emergence rate of crayfish hatching In Vitro.
5
Egly, Rachel M., and Eric R. Larson. "Distribution, habitat associations, and conservation status updates for the pilose crayfish Pacifastacus gambelii (Girard, 1852) and Snake River pilose crayfish Pacifastacus connectens (Faxon, 1914) of the western United States." PeerJ 6 (September 27, 2018): e5668. http://dx.doi.org/10.7717/peerj.5668.
Full textAbstract:
Our study evaluates the distribution, habitat associations, and current conservation status of the Snake River pilose crayfish Pacifastacus connectens (Faxon, 1914) and pilose crayfish Pacifastacus gambelii (Girard, 1852), two little-studied and data-deficient species endemic to the western United States. We first developed a species distribution model (SDM) for the pilose crayfishes based on their historical occurrence records using boosted regression trees and freshwater GIS data layers. We then sampled 163 sites in the summers of 2016 and 2017 within the distribution of these crayfishes, including 50 where these species were observed historically. We next compared our field results to modeled predictions of suitable habitat from the SDM. Our SDM predicted 73 sites (45%) we sampled as suitable for the pilose crayfishes, with a moderate AUC value of 0.824. The pilose crayfishes were generally predicted to occur in larger streams and rivers with less extreme upstream temperature and precipitation seasonality. We found the pilose crayfishes at only 20 (12%) of the 163 total sites we sampled, 14 (20%) of the 73 sites predicted as suitable for them by our SDM, and 12 (24%) of 50 historical sites that we sampled. We found the invasive virile crayfish Faxonius virilis (Hagen, 1870) at 22 sites total and 12 (24%) historical sites for the pilose crayfishes, and we found the “native invader” signal crayfish Pacifastacus leniusculus (Dana, 1852) at 29 sites total and 6 (12%) historical sites for the pilose crayfishes. We subsequently used a single classification tree to identify factors associated with our high rate of false positives for contemporary pilose crayfish distributions relative to our SDM. This classification tree identified the presence of invasive crayfishes, impairment of the benthic community, and sampling method as some of the factors differentiating false positives relative to true positives for the pilose crayfishes. Our study identified the historical distribution and habitat associations for P. connectens and P. gambelii using an SDM and contrasted this prediction to results of contemporary field sampling. We found that the pilose crayfishes have seemingly experienced substantial range declines, attributable to apparent displacement by invasive crayfishes and impairment or change to stream communities and habitat. We recommend increased conservation and management attention to P. connectens and P. gambelii in response to these findings.
6
Diehl, Kaine M., Nicoleena M. Storer, Hogan D. Wells, Destinee A. Davis, Zachary J. Loughman, and Zackary A. Graham. "On the surface or down below: Field observations reveal a high degree of surface activity in a burrowing crayfish, the Little Brown Mudbug (Lacunicambarus thomai)." PLOS ONE 17, no. 10 (October 14, 2022): e0273540. http://dx.doi.org/10.1371/journal.pone.0273540.
Full textAbstract:
Opposed to most crayfish species that inhabit permanent bodies of water, a unique burrowing lifestyle has evolved several times throughout the crayfish phylogeny. Burrowing crayfish are considered to be semi-terrestrial, as they burrow to the groundwater—creating complex burrows that occasionally reach 3 m in depth. Because burrowing crayfishes spend most of their lives within their burrow, we lack a basic understanding of the behavior and natural history of these species. However, recent work suggests that burrowing crayfishes may exhibit a higher level of surface activity than previously thought. In the current study, we conducted a behavioral study of the Little Brown Mudbug, Lacunicambarus thomai using video surveillance to determine their degree of surface activity and behavioral patterns. Throughout 664 hrs of footage, we observed a surprisingly high amount of activity at the surface of their burrows—both during the day and night. The percentage of time that individual crayfish was observed at the surface ranged from 21% to 69% per individual, with an average of 42.48% of the time spent at the surface across all crayfish. Additionally, we created an ethogram based on six observed behaviors and found that each behavior had a strong circadian effect. For example, we only observed a single observation of foraging on vegetation during the day, whereas 270 observations of this behavior were documented at night. Overall, our results suggest that burrowing crayfishes may exhibit higher levels of surface activity than previously thought. To increase our understanding of burrowing crayfish behaviors ecology, we encourage the continued use of video-recorded observations in the field and the laboratory.
7
Perry, W. L., D. M. Lodge, and G. A. Lamberti. "Impact of crayfish predation on exotic zebra mussels and native invertebrates in a lake-outlet stream." Canadian Journal of Fisheries and Aquatic Sciences 54, no. 1 (January 1, 1997): 120–25. http://dx.doi.org/10.1139/f96-255.
Full textAbstract:
To test the hypothesis that Orconectes spp. crayfishes could be a significant source of zebra mussel (Dreissena polymorpha) mortality in streams, we conducted a laboratory experiment and a field experiment. In the laboratory experiment, maximum zebra mussel size consumed increased with increasing crayfish size for Orconectes rusticus, Orconectes propinquus, and Orconectes virilis. Slopes differed among crayfish species but not between O. rusticus sexes. To quantify crayfish impacts on seminatural zebra mussel populations, we placed 16 enclosures (0.2 m2) lined with artificial cobble substrata in a midwestern lake-outlet stream (mean width 17 m). Zebra mussels were stocked in each cage (20000 individuals/m2) 14 days before male O. rusticus (20 individuals/m2) were stocked in each of eight enclosures. Densities of all sizes of zebra mussels were reduced in enclosures, with a total density reduction of 31% over the 28 days of the experiment, relative to the exclosures. Crayfish also reduced gastropod densities by 54%, but did not significantly affect other invertebrates. Laboratory and field results suggest that predation by Orconectes crayfishes may significantly reduce zebra mussel populations in streams.
8
Russ, William T., and Stephen J. Fraley. "Status Update for Six Rare Crayfishes (Decapoda: Cambaridae) in Western North Carolina." Journal of North Carolina Academy of Science 130, no. 2 (June 1, 2014): 25–39. http://dx.doi.org/10.7572/2167-5880-130.2.25.
Full textAbstract:
Abstract From 2009–2012 detailed distribution data, information to update conservation status, and additional life history and habitat observations were obtained for six rare crayfishes in Western North Carolina. The Hiwassee Headwaters Crayfish, Cambarus (Puncticambarus) parrishi, continues to occupy a very limited range in Clay County, with most known occurrences from the Tusquitee Creek system. The Chauga Crayfish, C. (P.) chaugaensis, appears to be abundant throughout much of its range in the upper Savannah River Drainage, in Transylvania, Jackson, and Macon counties. The French Broad River Crayfish, C. (P.) reburrus, has declined in Madison and Buncombe counties, while populations in Transylvania County appear to have remained relatively stable. The Broad River Stream Crayfish, C. (Cambarus) lenati continues to occur primarily in the upper First Broad River drainage where it is common in some streams in Rutherford County. The Broad River Spiny Crayfish, C. (P.) spicatus is rare but continues to exist in two isolated populations: upper First Broad and North Pacolet river drainages. The Little Tennessee River Crayfish, C. (P.) georgiae continues to occupy Jackson and Macon counties where it is most abundant in the upper Little Tennessee River Drainage. No range expansions were observed for any of these crayfish species.
9
Figiel, Chester R., and Sandra Bohn. "Laboratory experiments for the detection of environmental DNA of crayfish: Examining the potential." Freshwater Crayfish 21, no. 1 (December 31, 2015): 159–63. http://dx.doi.org/10.5869/fc.2015.v21-1.159.
Full textAbstract:
Abstract We examined methods for detecting environmental DNA of the invasive white river crayfish Procambarus zonangulus. In a laboratory experiment, we investigated detection capability in benthic sediment samples and in water samples in six flow-through tanks. Additionally we determined whether crayfish density (low = 0.67 or high = 2.69 crayfish·m-2) or crayfish time in tanks influenced DNA detectability (collection of samples on Days 2, 5, 8 and 15). Species-specific primers and probes were designed for P. zonangulus and their specificity was tested against other crayfish species. Limits of detection and quantification were specified for the target DNA sequence by means of quantitative PCR amplifications on dilution series of known amounts of P. zonangulus DNA. We detected crayfish DNA in 14 of the 24 benthic sediment samples and in two of the 24 water samples. DNA detection was found in benthic sediment samples in at least two tanks at every sampling period, while DNA detection was found in water samples only on Day 8. Crayfish DNA was detected in benthic sediment and water samples independently of crayfish density. Crayfish at both densities were observed to ‘explore’ all areas of the tank and move irrespective of diurnal time or conspecific presence. These behavior patterns were observed throughout the 15 day experiment and likely resulted in the positive detections, especially in benthic sediment samples. We believe that these methods could benefit monitoring of invasive crayfish species, although there is no doubt that further optimization and more research is needed to evaluate these techniques in the wild.
10
Smith, Bradley J. "Density-Dependent Escapement of Rusty Crayfish from Modified Minnow Traps with Varying Throat Configurations." Journal of Fish and Wildlife Management 11, no. 1 (November 25, 2019): 22–32. http://dx.doi.org/10.3996/032019-jfwm-015.
Full textAbstract:
Abstract Modified minnow traps are the most widely used gear for collecting tertiary burrowing crayfishes. The throats of modified minnow traps are often widened more than 60% to accommodate the capture of larger crayfish. However, widening this crucial chokepoint into the trap may facilitate easier escape of captured individuals, especially as density in the trap increases. Increased escapement rates may reduce catch rates and corresponding estimates of relative abundance and lower detection probability. Incorporating a design feature, that is, throat restriction, that allows entry of all sizes of crayfish while reducing escapement would be an improvement over current designs. Here, I present the results of a paired field and laboratory experiment comparing the effectiveness of modified minnow traps with a throat restriction (restricted) and without such a feature (unrestricted) under varying crayfish densities. I chose rusty crayfish Faxonius rusticus as a study organism because it is widespread and abundant in the Laurentian Great Lakes region and commonly the focus of research and removal efforts. Rusty crayfish capture and escapement were strongly influenced by throat design and crayfish densities. The field component demonstrated that both traps performed similarly under low-to-moderate densities; however, at high densities catch in unrestricted traps plateaued at approximately 50 crayfish/trap, while restricted traps kept accumulating catch up to 155 crayfish/trap. Laboratory trials demonstrated that escapement for both trap types was negligible at low density and slightly higher at medium density: 0.8% for restricted and 11.5% for unrestricted. However, at high density, escapement from restricted traps was 8.8 vs. 45.3% for unrestricted traps. Our findings suggest that inclusion of a throat restriction may increase catch of rusty crayfish by reducing escapement and may be of particular use in removal projects or when sampling in high-density populations.
11
SCHUSTER, GUENTER A. "Review of crayfish color patterns in the Family Cambaridae (Astacoidea), with discussion of their possible importance." Zootaxa 4755, no. 1 (March 23, 2020): 63–98. http://dx.doi.org/10.11646/zootaxa.4755.1.3.
Full textAbstract:
The use of color photographs in crayfish species descriptions, state faunal books and popular articles is relatively recent. Except for verbal color descriptions, color and color patterns have not often been explored by crayfish researchers. Carotenoids and carotenoproteins are responsible for much of the color found in the integument and exoskeleton of crayfishes and other crustaceans. Research has shown variation in color may be the result of the environment, diet, molt stage and age, genetics, or a combination of these. Crayfishes possess color vision, may use polarization vision, and have the possibility of fluorescent vision. They also have very good low light vision. Crayfishes have a multichromatic range in color sensitivity; it ranges from blue to red, with no UV sensitivity. Color vision may be an important factor in intraspecific and interspecific competition, territoriality, camouflage, sexual selection, and communication. A distinction is made between base or background colors displayed in crayfishes and their exhibited color patterns. While actual base or background colors may vary among individual crayfishes, a case is made that color patterns show much less intraspecific variation. Distinct color patterns are the result of highly contrasting colors on appendages or parts of appendages such as chelae, leg joints, tail fan, spines, and tubercles. Body regions like the carapace and abdomen may also have contrasting spots, bands or stripes. Color patterns may be useful in better understanding crayfish taxonomy, phylogeny, and evolutionary convergence, and examples are provided.
12
Khairunnisah, Rachmawati Rusydi, Eva Ayuzar, Salamah, and Munawwar Khalil. "Growth performance of freshwater crayfish (Cherax quadricarinatus) as the effect of prebiotic-feed from sweet potato." E3S Web of Conferences 442 (2023): 02023. http://dx.doi.org/10.1051/e3sconf/202344202023.
Full textAbstract:
Good growth of freshwater crayfish (Cherax quadricarinatus) is supported by an excellent intestinal digestion process in the absorption of feed nutrition. Implementing prebiotics from sweet potatoes is expected to maximize the nutrient absorption inside the digestive tract of freshwater crayfish. This research aims to evaluate the growth performance of freshwater crayfish in implementing sweet potatoes in feed. The research was conducted for one month, from March to April 2021, in the Laboratory of Hatchery and Cultivation Technology, Agriculture Faculty, Malikussaleh University. The experimental design was a non-factorial, completely randomized design (CRD) with four treatments and three replications. The experimental factor was different percentages of sweet potato in feed, namely A: 0% (Control), B: 1%, C: 2%, D: 3%. This research showed that prebiotic feed from sweet potatoes had a significant effect (p<0.05) on freshwater crayfish's growth and feed efficiency. The best result was demonstrated by treatment D, namely adding sweet potato 3% in feed at length growth of 2.64±0.035 cm and weight growth of 3.155±0.078 g. Meanwhile, the feed efficiency value of freshwater crayfish was 69.023±7.118%. The water quality parameters during the research were optimal for crayfish cultivation.
13
GLON, MAEL G., SUSAN B. ADAMS, ZACHARY J. LOUGHMAN, GREG A. MYERS, CHRISTOPHER A. TAYLOR, and GUENTER A. SCHUSTER. "Two new species of burrowing crayfish in the genus Lacunicambarus (Decapoda: Cambaridae) from Alabama and Mississippi." Zootaxa 4802, no. 3 (June 24, 2020): 401–39. http://dx.doi.org/10.11646/zootaxa.4802.3.1.
Full textAbstract:
While sampling for the Rusty Gravedigger, Lacunicambarus miltus, Taylor et al. (2011) found one or more potentially undescribed burrowing crayfish species in the genus Lacunicambarus inhabiting the area between the Pascagoula River and Mobile Bay in southern Alabama and Mississippi. Molecular analyses by Glon et al. (2018) confirmed that samples from this area were genetically distinct from other Lacunicambarus crayfishes. These findings prompted a dedicated sampling trip in January 2020. We used morphological and molecular analyses to investigate the specimens we collected and, based on our results, we describe two new crayfish species: the Lonesome Gravedigger, L. mobilensis sp. nov. and the Banded Mudbug, L. freudensteini sp. nov. Lacunicambarus mobilensis sp. nov. is sister to the Rusty Gravedigger, L. miltus, while L. freudensteini sp. nov. is sister to the Painted Devil Crayfish, L. ludovicianus. Both new species are currently known from a small number of sites in southern Alabama and Mississippi and may require conservation attention. In addition, we provide an updated key to Lacunicambarus crayfishes that includes these new species.
14
Owen, Christopher L., Heather Bracken-Grissom, David Stern, and Keith A. Crandall. "A synthetic phylogeny of freshwater crayfish: insights for conservation." Philosophical Transactions of the Royal Society B: Biological Sciences 370, no. 1662 (February 19, 2015): 20140009. http://dx.doi.org/10.1098/rstb.2014.0009.
Full textAbstract:
Phylogenetic systematics is heading for a renaissance where we shift from considering our phylogenetic estimates as a static image in a published paper and taxonomies as a hardcopy checklist to treating both the phylogenetic estimate and dynamic taxonomies as metadata for further analyses. The Open Tree of Life project ( opentreeoflife.org ) is developing synthesis tools for harnessing the power of phylogenetic inference and robust taxonomy to develop a synthetic tree of life. We capitalize on this approach to estimate a synthesis tree for the freshwater crayfish. The crayfish make an exceptional group to demonstrate the utility of the synthesis approach, as there recently have been a number of phylogenetic studies on the crayfishes along with a robust underlying taxonomic framework. Importantly, the crayfish have also been extensively assessed by an IUCN Red List team and therefore have accurate and up-to-date area and conservation status data available for analysis within a phylogenetic context. Here, we develop a synthesis phylogeny for the world's freshwater crayfish and examine the phylogenetic distribution of threat. We also estimate a molecular phylogeny based on all available GenBank crayfish sequences and use this tree to estimate divergence times and test for divergence rate variation. Finally, we conduct EDGE and HEDGE analyses and identify a number of species of freshwater crayfish of highest priority in conservation efforts.
15
Luzardo, Amanda, Nicole M. Johnson, Julia Custelcean, Sophie Prevost, Christie Sampson, Steven M. Vamosi, and Emily Baumgartner. "Observations of claw differences in an invasive crayfish (Orconectes virilis)." Biodiversity Observations 13 (February 6, 2023): 106–12. http://dx.doi.org/10.15641/bo.1222.
Full textAbstract:
The Northern Crayfish (Orconectes virilis) is a relatively new invasive species to Calgary, Alberta Canada. We observed unique morphological characteristics concerning the claws (cheliped) of four (3 males and 1 female) out of 31 crayfish captured using a sweep sampling method from a creek in Calgary, Canada. These specimens exhibited a notable difference in claw size between the right and left claws. Differences in claw sizes can be attributed to an ongoing process of regeneration due to loss of the crayfish’s cheliped.
16
DiDonato, Guy T., and David M. Lodge. "Species Replacements among Orconectes Crayfishes in Wisconsin Lakes: The Role of Predation by Fish." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 7 (July 1, 1993): 1484–88. http://dx.doi.org/10.1139/f93-169.
Full textAbstract:
To test the role of size- and species-selective predation by fishes in species replacements among congeneric crayfishes in northern Wisconsin lakes, we tethered the same three sizes of each of three species of Orconectes at six sites in the littoral zone of Trout Lake, Vilas County, Wise. Small crayfish (15–18 mm carapace length) were removed by fish at significantly higher rates than medium (23–25 mm) and large (33–35 mm) crayfish. Orconectes virilis was removed at significantly higher rates than O. propinquus and O. rusticus. These species-selection results suggest that predation by native fishes contributes to the previously documented replacement of the native crayfish O. virilis by the exotic crayfishes O. propinquus and O. rusticus. In combination with the observations of others that adult size of O. rusticus is typically larger than that of O. propinquus in northern Wisconsin lakes, our size-selection results suggest that fish predation may also hasten the ongoing replacement of O. propinquus by O. rusticus. Thus, fish predation is probably an important mechanism driving the replacement of O. virilis by O. propinquus and the replacement of both congeners by O. rusticus.
17
Taylor, Christopher A., Bryan S. Engelbert, and Robert J. DiStefano. "Site specific assessments of burrow- and lentic-dwelling crayfish communities: A proposed sampling design." Freshwater Crayfish 21, no. 1 (December 31, 2015): 63–69. http://dx.doi.org/10.5869/fc.2015.v21-1.63.
Full textAbstract:
Abstract We conducted a study to investigate methods to assess crayfish populations typically found in low gradient, lentic, floodplain habitats in Missouri. We used a random site selection process that allowed us to capture all known species from this region of Missouri. We compared two sampling methods for primary burrowing crayfishes at our sampling sites: hook-and-line capture technique and burrow excavation. Adjacent standing water habitats at sites were also sampled using a timed search method. Hook-and-line capture success was substantially less than reported in the literature (0.7% versus 80%), while burrow excavation was higher than reported (64% versus 40.7%). We successfully captured six crayfish species using burrow excavation, whereas lentic timed search sampling captured nine species in adjacent standing waters at our sampling sites. Our results suggest that additional efforts sampling lentic habitats rather than additional time searching for and excavating burrows is more likely to capture total community richness. We found a seasonal influence on burrow occupancy surveys, as Julian day was positively correlated to finding active crayfish burrows. Crayfish capture in standing water was positively affected by soil temperature, and negatively correlated to Julian day.
18
Guiaşu, Radu C. "Range expansion of the vulnerable crayfish Creaserinus fodiens (Cottle, 1863) (Decapoda, Cambaridae) in Ontario, Canada, with added notes on the distribution, ecology and conservation status of this species in North America." Crustaceana 94, no. 4 (April 13, 2021): 467–86. http://dx.doi.org/10.1163/15685403-bja10104.
Full textAbstract:
Abstract The distribution of the semi-terrestrial burrowing crayfish Creaserinus fodiens (Cottle, 1863) in Ontario was updated based on the examination of the records stored in the crayfish database of the Royal Ontario Museum in Toronto and specimens collected during field studies. New Ontario locality records are reported for this crayfish species from MacGregor Point Provincial Park and other nearby sites in Bruce County, along the shores of Lake Huron. These are among the northernmost locality records reported for this species in North America. These new records represent a northwestern range expansion for this crayfish species in southern Ontario. As a result of these new records, the revised distribution of this species in Ontario is estimated to cover an area of about 32 620 km2. This is an increase of 7620 km2 over a previous 1996 estimate of this range. Creaserinus fodiens is a vulnerable species in Ontario, mainly due to the loss of suitable wetland habitats. Thus, the new locations and the range expansion reported here provide some hopeful news about the long-term future of burrowing crayfishes in this Canadian province. At some of the new locations, C. fodiens was found together with Faxonius immunis (Hagen, 1870), another burrowing crayfish species. However, this analysis of all the relevant records found in the collections of the Royal Ontario Museum (Toronto) and the Canadian Museum of Nature (Ottawa) shows that our knowledge of the distribution of C. fodiens in Ontario remains quite incomplete. A survey of the conservation status and challenges for this crayfish species in various regions of North America was also undertaken.
19
Mazlum, Yavuz, Metin Yazıcı, Çiğdem Ürkü, and Seval Bahadır Koca. "Effects of black cumin and grape powder mix on growth performance and hepatopancreas histology in third instars of Pontastacus leptodactylus." Aquatic Research 6, no. 3 (2023): 166–74. http://dx.doi.org/10.3153/ar23017.
Full textAbstract:
This study investigated the effects of dietary supplementation of combined black cumin (BC) and grape seed (GS) powder at different rates (0%, 1%, 2%, and 4%, respectively) on growth performance and hepatopancreas histology of third instar Turkish narrow-clawed crayfish (Pontastacus leptodactylus). A total of 180 third instar of crayfish with an initial mean weight of (0.06 g ±0.01 g) and mean length (11.0 mm ±0.01) were randomly assigned to four treatment groups with three replications in each group and at a density of 15 crayfish per replicate. Crayfish were fed an experimental diet rate of at 10% of total body weight for 84 days. Growth performance parameters were improved significantly with BC and GS powder supplementation (P<0.05), while survival rates did not differ among all groups (P>0.05). Weight gain, specific growth rate and feed conversion rate of the 1% group tended to be better than the other groups, with significant differences among groups (P<0.05). The number and volume of B cells increased significantly with the increase in the amount of (BC and GS) added to the feed (1, 2, and 4%) in the hepatopancreas. In addition, it was determined that the R cells, which absorb nutrients, are dense in the hepatopancreas tissue of the crayfish fed with 1% (BC and GS) added feed compared to the other groups. The results showed that dietary supplementation of 1% BC and GS could benefit third-instar crayfish's growth and histological data. Therefore, combining BS and GS can be recommended as a promising new feed additive for narrow-clawed crayfish culture.
20
Quebedeaux, Kathleen B., Christopher A. Taylor, Amanda N. Curtis, and Eric R. Larson. "A multi-method approach for assessing the distribution of a rare, burrowing North American crayfish species." PeerJ 11 (February 20, 2023): e14748. http://dx.doi.org/10.7717/peerj.14748.
Full textAbstract:
Primary burrowing crayfishes face high extinction risk, but are challenging to study, manage, and conserve due to their difficult-to-sample habitat (i.e., terrestrial burrows) and low population densities. We apply here a variety of methods to characterize the distribution, habitat associations, and conservation status of the Boston Mountains Crayfish Cambarus causeyi (Reimer, 1966), an endemic burrowing crayfish found only in the Ozark Mountains of Arkansas, United States. We used species distribution modeling (SDM) on historic occurrence records to characterize the distribution and macro-scale habitat associations of this species. We then ground-truthed SDM predictions with conventional sampling, modeled fine-scale habitat associations with generalized linear models (GLM), and lastly developed and tested an environmental DNA (eDNA) assay for this species in comparison to conventional sampling. This represents, to our knowledge, the first successful eDNA assay for a terrestrial burrowing crayfish. Our MaxEnt-derived SDM found a strong effect of average annual precipitation on the historic distribution of C. causeyi, which occurred most frequently at locations with moderately high average annual precipitation (140–150 cm/yr) within our study region. Cambarus causeyi was difficult to detect by conventional sampling in 2019 and 2020, found at only 9 of 51 sites (17.6%) sampled by searching for and manually excavating crayfish burrows. Surprisingly, habitat suitability predicted from our MaxEnt models was not associated with contemporary C. causeyi occurrences per GLMs. Instead, C. causeyi presence was negatively associated with both sandy soils and the presence of other burrowing crayfish species. Poor SDM performance in this instance was likely caused by the omission of high resolution fine-scale habitat data (e.g., soils) and biotic interactions from MaxEnt models. Finally, our eDNA assay detected C. causeyi from six of 25 sites (24.0%) sampled in 2020, out-performing conventional surveys by burrow excavation for this species. Given the difficulty of studying primary burrowing crayfishes and their high conservation need, we propose that eDNA may become an increasingly important monitoring tool for C. causeyi and similar species.
21
Florey, Cassidy L., and Paul A. Moore. "Analysis and description of burrow structure in four species of freshwater crayfishes (Decapoda: Astacoidea: Cambaridae) using photogrammetry to recreate casts as 3D models." Journal of Crustacean Biology 39, no. 6 (October 10, 2019): 711–19. http://dx.doi.org/10.1093/jcbiol/ruz075.
Full textAbstract:
Abstract Freshwater crayfishes use burrows for predator avoidance, desiccation prevention, foraging, and brood care. Based on their burrow ecology, crayfishes can be categorized as tertiary, secondary, or primary burrowers, with primary burrowers being semi-terrestrial and highly dependent on burrows for survival; secondary and tertiary burrowers have decreased burrow dependence and complexity. There has been limited investigation into the specifics of burrow structure. We investigated the factors that influence the structure of crayfish burrows including habitat structure and crayfish through the use of burrow casting and photogrammetry to recreate casts as 3D models. Examined species include the primary burrowing Lacunicambarus aff. diogenesGirard, 1852 and Creaserinus fodiens (Cottle, 1863), and the tertiary burrowing Faxonius rusticus (Girard, 1852) and Faxonius propinquus (Girard, 1852). Crayfish burrows (N = 17) were filled with polyester resin and cured burrow casts were excavated, and photogrammetry was used to recreate casts as 3D models. Burrow depth, number and widths of openings, number and widths of chambers, and number of ancillary tunnels were recorded. Differences in burrow features were analyzed by field site/habitat and crayfish species using stepwise linear regression, MANOVAs, and multiple factor analysis (MFA). From stepwise linear regression, “species” was a better predictor than “habitat of burrow structure.” Burrows constructed by L. aff. diogenes were significantly larger and have more chambers than burrows constructed by the other species examined; burrows of C. fodiens were significantly deeper than those of tertiary burrowers. Each species also created a stereotyped burrow shape. The morphometric differences between burrows of primary and tertiary species illustrate the relevance of these informal classifications. Differences between primary and tertiary species may be related to the species social behavior and ecology.
22
Chilton, Joe, Amanda E. Rosenberger, and Robert J. DiStefano. "Habitat associations and distributions of two endemic crayfishes, Cambarus (Erebicambarus) maculatus Hobbs & Pflieger, 1988 and Faxonius (Billecambarus) harrisonii (Faxon, 1884) (Decapoda: Astacoidea: Cambaridae), in the Meramec River drainage, Missouri, USA." Journal of Crustacean Biology 40, no. 4 (June 20, 2020): 351–63. http://dx.doi.org/10.1093/jcbiol/ruaa033.
Full textAbstract:
Abstract Understanding the habitat associations and distributions of rare species is important to inform management and policy decisions. Cambarus (Erebicambarus) maculatusHobbs & Pflieger, 1988, the freckled crayfish, and Faxonius (Billecambarus) harrisonii (Faxon, 1884), the belted crayfish, are two of Missouri’s endemic crayfish species. Both species are listed as Vulnerable (S3) on Missouri’s Species and Communities of Conservation Concern Checklist due to their limited range within the Meramec River drainage (MRD) and the impact of anthropogenic activities therein. Their distributional overlap offers an opportunity for multi-species research to address gaps in information required for conservation. We sampled 140 sites throughout the MRD during the summers of 2017 and 2018 for crayfishes and associated habitat variables, which we related to crayfish presence in an occupancy modeling framework. We found that C. maculatus occupancy was associated with larger stream size, boulder substrate, dolomite lithology, aquatic vegetation beds, dissolved oxygen, and pool mesohabitat. Faxonius harrisonii occupancy increased with boulder substrate, aquatic vegetation beds, the presence of C. maculatus, and decreased in third-order streams. We also expanded the known range for both species within the MRD. Range estimates (watershed area) for C. maculatus and F. harrisonii were 4,347 km2 and 3,690 km2, respectively. This study demonstrates the importance of targeted rather than opportunistic sampling for species distribution.
23
Bezrodnykh, Evgeniya A., Oxana V. Vyshivannaya, Boris B. Berezin, Inesa V. Blagodatskikh, and Vladimir E. Tikhonov. "A Walkway from Crayfish to Oligochitosan." Applied Sciences 13, no. 5 (March 6, 2023): 3360. http://dx.doi.org/10.3390/app13053360.
Full textAbstract:
Edible crayfish are an object of local fishing and artificial breeding in many countries. This industry is very promising in terms of production of healthy foods and byproducts, such as biologically active polyaminosaccharide—chitosan and its derivatives. However, crayfishing is far from being at the level at which it could be. This laboratory scale protocol describes a walkway from crayfish Actacus leptodactylus to chitin, chitosan, and oligochitosan hydrochloride, with the main emphasis on the way of getting rid of the impurities (residual heavy metals, proteins and other residues) commonly present in commercial chitosan and its derivatives, as well as the characterization of the products by means of inductively-coupled plasma mass spectrometry (ICP-MS), energy-dispersive X-ray spectroscopy (EDXS), protein and elemental analysis, proton magnetic resonance spectroscopy (1H NMR), and chromatography methods. The protocol includes the preparation of crude shell waste; the extraction of proteins from crude shell waste and preparation of deproteinated shell waste, demineralization and decolorization of the deproteinated crayfish shell waste, deacetylation of chitin, and depolymerization of chitosan. EDXS shows the presence of Al and Si residues in chitin is found when the deproteination of crayfish waste is carried out in an alumosilicate glass vessel. In contrast, these residues are absent when deproteination is carried out in the borosilicate glass flask. Analytical data show that the content of residues in chitosan and oligochitosan hydrochloride meets pharmaceutical requirements. The study demonstrates crayfish waste a promising for the purification of chitosan, for the preparation of pharmaceutical grade oligochitosan hydrochloride, and can improve commercialization of crayfishes.
24
Scholz, Stephan, Torben Göpel, Stefan Richter, and Christian S. Wirkner. "High degree of non-genetic phenotypic variation in the vascular system of crayfish: a discussion of possible causes and implications." Zoomorphology 140, no. 3 (August 12, 2021): 317–29. http://dx.doi.org/10.1007/s00435-021-00536-2.
Full textAbstract:
AbstractIn this study, the hemolymph vascular system (HVS) in two cambarid crayfishes, i.e. the Marbled Crayfish, Procambarus virginalis Lyko, 2017 and the Spiny Cheek Crayfish, Faxonius limosus (Rafinesque, 1817), is investigated in regard of areas of non-genetic phenotypic variation. Despite their genetic identity, specimens of P. virginalis show variability in certain features of the HVS. Thus, we describe varying branching patterns, sporadic anastomoses, and different symmetry states in the vascular system of the marbled crayfish. We visualize our findings by application of classical and modern morphological methods, e.g. injection of casting resin, micro-computed tomography and scanning electron microscopy. By comparing our findings for P. virginalis to the vasculature in sexually reproducing crayfishes, i.e. F. limosus and Astacus astacus, we discuss phenotypic variation of the HVS in arthropods in general. We conclude that constant features of the HVS are hereditary, whereas varying states identified by study of the clonal P. virginalis must be caused by non-genetic factors and, that congruent variations in sexually reproducing F. limosus and A. astacus are likely also non-genetic phenotypic variations. Both common causal factors for non-genetic phenotypic variation, i.e., phenotypic plasticity and stochastic developmental variation are discussed along our findings regarding the vascular systems. Further aspects, such as the significance of non-genetic phenotypic variation for phylogenetic interpretations are discussed.
25
Logarbo, Jordan R., and Christopher P. Bonvillain. "Thermal stress responses of two sympatric crayfishes in Louisiana, Procambarus clarkii Girard, 1852 and Procambarus zonangulus Hobbs & Hobbs, 1990 (Decapoda: Astacoidea: Cambaridae)." Journal of Crustacean Biology 40, no. 6 (September 12, 2020): 734–38. http://dx.doi.org/10.1093/jcbiol/ruaa066.
Full textAbstract:
Abstract Water temperature is an important abiotic component in farmed and wild crayfish habitats as it influences individual and population characteristics including growth, metabolic activity, and overall population vigor. Thermal limits, however, have not been established for the two commercially important crayfishes in Louisiana, the red swamp crayfish Procambarus clarkii (Girard, 1852) and the southern white river crayfish P. zonangulus (Hobbs & Hobbs, 1990). We aimed to determine the thermal stress responses for the two species. Thermal stress was examined by the critical thermal maxima (CTmax) for crayfish acclimated to 24, 27, or 30 °C for two weeks prior to experimentation. Water temperature in all acclimation trials was increased 1 °C h–1 and the end-point temperature for an individual was determined by the failure of righting response within 30 seconds. CTmax values (±SD) for P. clarkii acclimated at 24, 27, and 30 °C were 39.5 ± 0.5, 39.1 ± 0.3, and 39.4 ± 0.7 °C respectively, and 39.8 ± 0.8, 38.8 ± 0.8, and 39.0 ± 0.6 °C for P. zonangulus. CTmax did not differ significantly between species in any of the acclimation treatments. Thermal stress was also examined by measuring P. clarkii and P. zonangulus hemolymph glucose concentration every two hours for crayfish acclimated at 26 °C for two weeks and water temperature increased 1 °C h–1. Hemolymph glucose concentration began to increase at 36 °C in P. zonangulus and 38 °C in P. clarkii. Large increases in mean hemolymph glucose concentration (±SE) were observed in both P. clarkii (67.19 mg–dl ± 24.55) and P. zonangulus (74.11 mg–dl ± 18.04) at 40 °C.
26
Hurt, Carla R., Roger F. Thoma, David I. Withers, Carl E. Williams, and Robert T. R. Paine. "Extensive regional endemism and cryptic diversity in the Tennessee and Kentucky, USA populations of the burrowing crayfish Cambarus deweesae (Bouchard & Etnier, 1979) (Decapoda: Astacidea: Cambaridae) as revealed by molecular genetics." Journal of Crustacean Biology 39, no. 4 (June 4, 2019): 440–49. http://dx.doi.org/10.1093/jcbiol/ruz027.
Full textAbstract:
Abstract The southeastern United States is a global hotspot for crayfish biodiversity, with more than 300 described species in the region. Some of this diversity is unfortunately being threatened by anthropogenic activities and nearly one fifth of the North American crayfish species are currently threatened with extinction. Efforts to protect crayfish species have been hindered by a lack of information regarding their taxonomy, distribution, and conservation status. Here we target populations of the burrowing valley flame crayfish, Cambarus deweesae (Bouchard & Etnier 1979) for molecular taxonomy investigation. This species was originally known from the Clinch and Emory subdrainages in eastern Tennessee but it is currently listed as state endangered. The reporting of additional populations in Tennessee and Kentucky, however, has led to uncertainty about its conservation status. We analyzed sequence data from three mitochondrial genes (COI, 12S rRNA, and 16S rRNA) and from one nuclear gene (GAPDH) to decipher taxonomic questions regarding 15 crayfish populations, including 13 populations that are morphologically similar to C. deweesae (type locality sensu stricto). Combined analysis of all four genes demonstrated reciprocal monophyly for 14 out of 15 populations surveyed. Species delimitation methods, including GMYC and ABGD, identified between 11 and 13 new distinct genetic entities based on sequence divergence at the mitochondrial COI gene. Molecular results are combined with information on morphology and distribution in order to resolve taxonomic uncertainties within C. deweesae and its close relatives. The study highlights the need for fine-scale investigations into the phylogeography of North American burrowing crayfishes.
27
Herleth-King, Shawna S., Hayden T. Mattingly, and Robert J. DiStefano. "Habitat use of Orconectes meeki meeki and Orconectes williamsi in an intermittent Ozark stream." Freshwater Crayfish 21, no. 1 (December 31, 2015): 103–14. http://dx.doi.org/10.5869/fc.2015.v21-1.103.
Full textAbstract:
Abstract Relatively few studies have examined fine-scale habitat use of crayfish in headwater streams, despite increasing awareness of the importance of such habitats. Orconectes meeki meeki, Meek’s crayfish, is endemic to the upper White River drainage of Missouri and Arkansas, and Orconectes williamsi, Williams’ crayfish, occurs only there and in the Arkansas River drainage. Our objective was to describe speciesspecific habitat use of these crayfishes at two spatial scales (pool-riffle and microhabitat) within a seasonally intermittent stream. From May through August 2008, we sampled ten riffles and five pools in Rock Creek, Missouri, to quantify surface and hyporheic environmental variables. Density of O. m. meeki was similar between riffles and pools; O. williamsi density was greater in riffles. At the riffle scale, O. m. meeki was positively associated with wetted channel width and upwelling hyporheic zones; O. williamsi was negatively associated with surface and hyporheic water temperatures. At the microhabitat scale within riffles, O. m. meeki was positively associated with wetted depth and pebble-cobble substrates; O. williamsi was positively associated with surface velocity and pebble-cobble substrates. Habitat use was relatively static for both species as surface flows waned from May through August. Our research provides detailed, fine-scale habitat associations of the crayfish to complement existing knowledge of these species at coarser spatial scales.
28
Adams, Susan B., Scott G. Hereford, and Chaz Hyseni. "Burrow Densities of Primary Burrowing Crayfishes in Relation to Prescribed Fire and Mechanical Vegetation Treatments." Water 13, no. 13 (July 2, 2021): 1854. http://dx.doi.org/10.3390/w13131854.
Full textAbstract:
Fire suppression and other factors have drastically reduced wet prairie and pine savanna ecosystems on the Coastal Plain of the southeastern United States. Restoration of these open-canopy environments often targets one or several charismatic species, and semi-aquatic species such as burrowing crayfishes are often overlooked in these essentially terrestrial environments. We examined the relationship between primary burrowing crayfishes and three vegetation treatments implemented over at least the past two decades in the Mississippi Sandhill Crane National Wildlife Refuge. Vegetation in the 12 study sites had been frequently burned, frequently mechanically treated, or infrequently managed. Creaserinus spp., primarily C. oryktes, dominated the crayfish assemblage in every site. We counted crayfish burrow openings and coarsely categorized vegetation characteristics in 90, 0.56-m2 quadrats evenly distributed among six transects per site. The number of active burrow openings was negatively, exponentially related to both the percent cover of woody vegetation and the maximum height of woody vegetation in quadrats, and to the number of trees taller than 1.2 m per transect, indicating that woody plant encroachment was detrimental to the crayfishes. Results were consistent with several other studies from the eastern US, indicating that some primary burrowing crayfishes are habitat specialists adapted to open-canopy ecosystems.
29
Manjarrez, Javier, Constantino Macías Garcia, and Hugh Drummond. "Congenital feeding response to a novel prey in a Mexican gartersnake." PeerJ 8 (March 5, 2020): e8718. http://dx.doi.org/10.7717/peerj.8718.
Full textAbstract:
In this study, we explored chemosensory, ingestive and prey-catching responses of neonate Mexican Black-bellied Gartersnakes (Thamnophis melanogaster) to crayfish (Cambarellus montezumae). By comparing snakes from a recently discovered crayfish-eating population and a typical non-crayfish-eating population, we asked which behavioral components change as a species enlarges its feeding niche. In the crayfish-eating population chemosensory responsiveness to crayfish was not enhanced but its heritability was higher. Neonates of both populations showed similar preference for freshly-molted versus unmolted crayfish, and whereas the tendency to ingest both crayfish stages remained stable between ages 15 and 90 days in the non-crayfish-eating population, in the crayfish-eating population it actually decreased. Techniques to catch and manipulate molted crayfish were similar in the two populations. We discuss the possibility that there is no increase in the behavioral response to eat crayfish by the neonates of the crayfish-eating populations, possibly due to the absence of ecological and spatial isolation between the two T. melanogaster populations. The crayfish ingestion in some population of T. melanogaster can be explained by environmental differences between populations, or by recent origin of crayfish ingestion in T. melanogaster.
30
Jussila, Japo, and Lennart Edsman. "Relaxed attitude towards spreading of alien crayfish species affects protection of native crayfish species: case studies and lessons learnt from a Fennoscandian viewpoint." Freshwater Crayfish 25, no. 1 (April 15, 2020): 39–46. http://dx.doi.org/10.5869/fc.2020.v25-1.039.
Full textAbstract:
Abstract The spreading of the alien signal crayfish (Pacifastacus leniusculus) is posing an ongoing threat to native European crayfish species in Fennoscandia, like the native noble crayfish (Astacus astacus). The signal crayfish is commonly a chronic carrier of the crayfish plague (Aphanomyces astaci), thus, in addition to being more competitive than noble crayfish, it also has a competitive advantage in this disease over the noble crayfish. The challenges rising from the introduction of the alien signal crayfish to Sweden, Finland and finally also Norway, are similar in nature. The licensed and unlicensed spreading of this species also has a similar history in these countries. In this paper we describe some of the patters of the spread of alien signal crayfish and highlight the detrimental nature of an alien crayfish, accompanied by a highly virulent disease, to native Fennoscandian crayfish and also to native Fennoscandian ecosystems. A halt to the further spreading of alien signal crayfish in Fennoscandia is the only means to ensure successful conservation outcomes for the noble crayfish.
31
Faria, Larissa, Jean R. S. Vitule, and Julian D. Olden. "Predation risk by largemouth bass modulates feeding functional responses of native and non-native crayfish." NeoBiota 87 (October 4, 2023): 191–212. http://dx.doi.org/10.3897/neobiota.87.108457.
Full textAbstract:
Context-dependency is prevalent in nature, challenging our understanding and prediction of the potential ecological impacts of non-native species (NNS). The presence of a top predator, for example, can modify the foraging behaviour of an intermediate consumer, by means of non-consumptive effects. This raises the question of whether the fear of predation might modulate consumption rates of NNS, thus shaping the magnitude of ecological impacts. Here, we quantified the functional feeding responses of three non-native crayfish species – red swamp crayfish Procambarus clarkii, rusty crayfish Faxonius rusticus and virile crayfish Faxonius virilis – compared to the native analogue signal crayfish Pacifastacus leniusculus, considering the predation risk imposed by a top fish predator, the globally invasive largemouth bass Micropterus salmoides. We applied the comparative functional response (FR) approach using snails as prey and exposing crayfish to water containing predator and dietary chemical cues or not. All crayfish species presented a destabilising Type II FR, regardless of the presence of chemical cues. Predation risk resulted in significantly longer handling times or lower attack rates in non-native crayfish; however, no significant differences were observed in signal crayfish. We estimated per capita impacts for each species using the functional response ratio (FRR; attack rate divided by handling time). The FRR metric was lower for all crayfish species when exposed to predation risk. Rusty crayfish demonstrated the highest FRR in the absence of chemical cues, followed by signal crayfish, virile crayfish and red swamp crayfish. By contrast, the FRR of signal crayfish was nearly twice that of rusty crayfish and virile crayfish and ten times greater than red swamp crayfish when chemical cues were present. The latter result agrees with the well-recognised ecological impacts of signal crayfish throughout its globally-introduced range. This study demonstrates the importance of considering the non-consumptive effects of predators when quantifying the ecological impacts of intermediate non-native consumers on prey. The direction and magnitude of the modulating effects of predators have clear implications for our understanding of NNS impacts and the prioritisation of management actions.
32
Mouser, Joshua, David Ashley, Douglas Zentner, and Shannon Brewer. "Seasonal context of Bristly Cave Crayfish Cambarus setosus habitat use and life history." Journal of Cave and Karst Studies 84, no. 3 (September 30, 2022): 85–95. http://dx.doi.org/10.4311/2021lsc0110.
Full textAbstract:
Cave crayfishes are important members of groundwater communities, but many cave crayfishes are threatened or endangered. Unfortunately, we lack basic life history and ecological data that are needed for developing conservation plans for most cave crayfishes, especially the role of seasonal and annual fluctuations in structuring populations. Therefore, we determined the seasonal life history and habitat use of Cambarus setosus in Smallin Civil War Cave, Christian County, Missouri, United States. We conducted visual crayfish surveys over a 400 m section of the cave from 2006 to 2019. We used multinomial logit, multiple linear regression, and logistic regression models to estimate crayfish substrate, water depth, and water velocity use, respectively. All models included sex, carapace length, season, distance into the cave, and interactions between all variables and sex as predictor terms. We also used t-tests to assess morphometric differences between male and female crayfish. Six mark-recapture events (2010 to 2019) were used to estimate population sizes using a nil-recapture model. We attempted to age eight individuals using gastric mill bands, but annual bands were not discernable. We found reproductively active males during all seasons. We captured one ovigerous female during the spring, though ovigerous females were observed during show cave tours during spring, summer, and autumn. Male C. setosus were more likely to use homogenous and heterogeneous rock substrates and shallower and calmer water when compared to females; however, these relationships varied based on distance into the cave and season. Females sampled were significantly larger than males, and males regenerated chelae more often. Minimum population size estimates ranged from 9 to 159 individuals and indicated the population was relatively stable. Our data provide both a baseline population estimate for comparison with future studies and valuable trait information that is often lacking but useful for developing conservation efforts.
33
Dorn, Nathan J., and Gary G. Mittelbach. "Effects of a native crayfish (Orconectes virilis) on the reproductive success and nesting behavior of sunfish (Lepomis spp.)." Canadian Journal of Fisheries and Aquatic Sciences 61, no. 11 (November 1, 2004): 2135–43. http://dx.doi.org/10.1139/f04-158.
Full textAbstract:
While crayfish are traditionally considered fish prey, they are capable of feeding on substrate-bound fish eggs and their introductions have been blamed for the decline in fish populations in Europe and North America. To investigate their potential effects on fish reproductive success we measured the effects of a native crayfish (Orconectes virilis) on the reproductive success of two substrate-nesting sunfish, pumpkinseed (Lepomis gibbosus) and bluegill (Lepomis macrochirus), in replicated pond experiments. Crayfish were observed feeding on eggs in both experiments. Crayfish presence delayed successful reproduction by pumpkinseeds in densely vegetated ponds, resulting in lower young-of-the-year biomass in ponds with crayfish. In the second experiment, with bluegills in less-vegetated ponds, crayfish prevented successful reproduction entirely. However, when we added crayfish-proof exclosures to the crayfish ponds late in the summer, bluegills located the crayfish-free habitat and successfully reproduced inside the exclosures (1 month after first successful reproduction in control ponds). The results of these experiments demonstrate the potential strong negative effects of crayfish on sunfish reproduction and suggest that the spatial distribution of crayfish and other egg predators may influence fish nesting behaviors and habitat choices. Further studies are needed to determine the magnitude of crayfish effects in natural lakes and ponds where sunfish and crayfish co-occur.
34
Peng, Fangjun, Jiawen Li, Zhiyong Gong, Bing Yue, Xueli Wang, Anne Manyande, and Hongying Du. "Investigation of Bioaccumulation and Human Health Risk Assessment of Heavy Metals in Crayfish (Procambarus clarkii) Farming with a Rice-Crayfish-Based Coculture Breeding Modes." Foods 11, no. 3 (January 19, 2022): 261. http://dx.doi.org/10.3390/foods11030261.
Full textAbstract:
Due to the rapid development of the crayfish (Procambarus clarkii) industry in Chinese catering, people are paying more attention to the bioaccumulation of heavy metals in crayfish. To evaluate the health risks associated with the consumption of crayfish, nine types of heavy metals in both crayfish and abdominal muscles of crayfish were investigated. Crayfish samples were collected from rice-crayfish-based coculture breeding modes from different areas located in the middle and lower reaches of the Yangtze River. The average concentrations of heavy metals in the whole crayfish were much higher than the abdominal muscle of crayfish. The estimated daily intake (EDI) of heavy metals in the abdomen of crayfish was calculated to assess the noncarcinogenic risk and the overall noncarcinogenic risk including the target hazard quotient (THQ), the hazard index (HI) and carcinogenic risk (CR). The results of the present study showed that the consumption of crayfish may not present an obvious health risk to human associated with heavy metals. However, the THQ values of As in the abdominal muscles of crayfish for adults in EnShi (ES) and children in JiaYu (JY) should be of concern due to the higher contribution to the potential health risks of crayfish compared to other metals. Through X-ray photoelectron spectroscopy (XPS) detection of heavy metal As, it is found that As in crayfish culture environment mainly exists in the form of As3+.Therefore, the quality and quantity of crayfish consumption should be moderated to prevent the bioaccumulation of As. The results indicate that crayfish cultured in different areas may have similar pollution levels and/or emissions from the same pollution sources.
35
JAMES, J., S. NUTBEAM-TUFFS, J. CABLE, A. MRUGAŁA, N. VIÑUELA-RODRIGUEZ, A. PETRUSEK, and B. OIDTMANN. "The prevalence of Aphanomyces astaci in invasive signal crayfish from the UK and implications for native crayfish conservation." Parasitology 144, no. 4 (January 12, 2017): 411–18. http://dx.doi.org/10.1017/s0031182016002419.
Full textAbstract:
SUMMARYThe crayfish plague agent, Aphanomyces astaci, has spread throughout Europe, causing a significant decline in native European crayfish. The introduction and dissemination of this pathogen is attributed to the spread of invasive North American crayfish, which can act as carriers for A. astaci. As native European crayfish often succumb to infection with A. astaci, determining the prevalence of this pathogen in non-native crayfish is vital to prioritize native crayfish populations for managed translocation. In the current study, 23 populations of invasive signal crayfish (Pacifastacus leniusculus) from the UK were tested for A. astaci presence using quantitative PCR. Altogether, 13 out of 23 (56·5%) populations were found to be infected, and pathogen prevalence within infected sites varied from 3 to 80%. Microsatellite pathogen genotyping revealed that at least one UK signal crayfish population was infected with the A. astaci genotype group B, known to include virulent strains. Based on recent crayfish distribution records and the average rate of signal crayfish population dispersal, we identified one native white-clawed crayfish (Austropotamobius pallipes) population predicted to come into contact with infected signal crayfish within 5 years. This population should be considered as a priority for translocation.
36
Weiperth, András, Martin Bláha, Bettina Szajbert, Richárd Seprős, Zsombor Bányai, Jiří Patoka, and Antonín Kouba. "Hungary: a European hotspot of non-native crayfish biodiversity." Knowledge & Management of Aquatic Ecosystems, no. 421 (2020): 43. http://dx.doi.org/10.1051/kmae/2020035.
Full textAbstract:
There is a long history of crayfish introductions in Europe and numbers keep increasing. In Hungary, spiny-cheek crayfish Faxonius limosus, signal crayfish Pacifastacus leniusculus, red swamp crayfish Procambarus clarkii, marbled crayfish P. virginalis and Mexican dwarf crayfish Cambarellus patzcuarensis have become established. Here we report on monitoring at two localities with novel crayfish assemblages closely linked to releases associated with the pet trade. Florida crayfish Procambarus alleni were recorded from the Gombás brook near Vác living in syntopy with the established spiny-cheek crayfish. Dozens of Florida crayfish individuals including egg-carrying females have been detected. The short lifespan of this species and its documented presence including two overwintering in at least two years suggests possible establishment. However, the lack of juvenile records calls for further monitoring as long-term propagule pressure cannot be ruled out. We also identified a single marbled crayfish in the Danube floodplain at the end of the monitoring campaign. The second locality (Városliget thermal pond in Budapest) harbours an even more diverse crayfish assemblage. Here, we identified numerous red swamp and marbled crayfish in syntopy with dozens of monitored redclaws Cherax quadricarinatus and seven individuals of New Guinean Cherax species − C. holthuisi, C. snowden, as well as two scientifically undescribed species. These findings clearly indicate the attractiveness of urban and, especially, thermal waters for the release of even expensive aquatic pets and highlight the hitherto poorly known biodiversity of New Guinean crayfish species.
37
Nyström, Per, Eva Axelsson, Johan Sidenmark, and Christer Brönmark. "Crayfish predation on amphibian eggs and larvae." Amphibia-Reptilia 18, no. 3 (1997): 217–28. http://dx.doi.org/10.1163/156853897x00107.
Full textAbstract:
AbstractWe experimentally evaluated the impact of the introduced signal crayfish (Pacifastacus leniusculus) and the native noble crayfish (Astacus astacus) on eggs and larvae of seven species of amphibians, likely to co-occur with crayfish in southern Sweden. In aquarium experiments eggs and tadpoles of all amphibian species were consumed by both crayfish species. The consumption of amphibian eggs by signal crayfish increased with temperature. The noble crayfish consumed more tadpoles than the signal crayfish, but the latter caused more sub-lethal damage to tadpoles. Tadpoles of the common toad (Bufo bufo) were sometimes killed but left uneaten by both crayfish species. In pool experiments, signal crayfish consumed more tadpoles of Hyla arborea in a less complex habitat and significantly reduced survival of Hyla tadpoles and the biomass of aquatic macrophytes.
38
PARPET, JEAN-FRANÇOIS, and STUART R. GELDER. "North American Branchiobdellida (Annelida: Clitellata) or Crayfish Worms in France: the most diverse distribution of these exotic ectosymbionts in Europe." Zoosymposia 17, no. 1 (February 17, 2020): 121–40. http://dx.doi.org/10.11646/zoosymposia.17.1.12.
Full textAbstract:
Crayfishes and other invertebrates were collected during 2010 to 2016 from 519 sites located in the river basins of the Adour, Charente, Dordogne, Garonne, Loire, Seine, Rhône and Sélune in France. North American species included Pacifastacus leniusculus at 255 sites, Faxonius limosus at 206 sites, Procambarus clarkii at 56 sites, and the endemic Austropotamobius pallipes at two sites. However, branchiobdellidans were only recorded from 100 sites with 23 of these being sampled more than once, resulting in a total of 127 collections. The widely distributed western North American, P. leniusculus carried four of its endemic branchiobdellidan species: Cambarincola gracilis, C. okadai, Triannulata magna and Xironogiton victoriensis. X. victoriensis was found at the majority of sites, with C. okadai, C. gracilis, and T. magna at fewer locations. Although F. limosus was the second most numerous crayfish species collected, it did not carry any of its endemic North American branchiobdellidan species. However, it was found cohabiting with P. leniusculus at four sites but carried X. victoriensis at only one of these. European A. pallipes only occurred at two sites with individuals harboring X. victoriensis, although no cohabiting exotic crayfish were found. Crayfish were also absent from three sites where free-living X. victoriensis were recovered from substrate samples. Procambarus clarkii appeared at sites scattered across the country, while specimens with C. mesochoreus were restricted to the Adour drainage. This study has shown the widespread distribution of exotic branchiobdellidans in the wild and the virtual extinction of endemic species in France. In addition, we have provided the first European record of T. magna, and the first record of C. mesochoreus in France; the latter being only the second recording in Europe. With this comprehensive survey of their crayfish hosts in France, monitoring future exotic range expansions and endemic contraction or extinction can be traced. These data will be available to authorities for future planning in maintaining healthy freshwater bodies by reducing the damaging effects caused by exotic crayfishes.
39
Meade, Mark, Lindsay White, Rahim Zettili, Megan Meade, Saad Almani, and Abdurehman Qureshi. "Metabolic physiology of the southeastern USA crayfish, Cambarus latimanus (LeConte), in response to different temperatures." Freshwater Crayfish 21, no. 1 (December 31, 2015): 171–77. http://dx.doi.org/10.5869/fc.2015.v21-1.171.
Full textAbstract:
Abstract Variable crayfish, Cambarus latimanus (LeConte), were collected and acclimated to four temperatures, 15, 20, 25, and 30°C. Following a two-week acclimation period, mean standard metabolic rates (SMR), as determined using oxygen consumption rates, were measured using an intermittent-flow, closed-loop respirometer. For ~10g mean weight C. latimanus, mean weight specific oxygen consumption rates (MO2) at 15, 20, 25, and 30°C were 73.4 ± 0.18, 81.6 ± 0.10, 103 ± 0.11, and 205 ± 0.12 mg O2·kg-1·h-1 (±SE), respectively. Calculated Q10 values of 1.25, 1.61, and 3.92 for the change in metabolic rate from 15 – 20°C, 20 – 25°C, and 25 – 30°C suggest the crayfish were responding normally to temperature increases and were metabolically stressed when temperatures increased above 25°C. Daily caloric energy budgets of 58 (15°C), 65 (20°C), 82 (25°C), and 164 (30°C) calories·day-1 were estimated for crayfishes using SMR data and suggested that crayfish standard (resting) energy requirements nearly tripled when acclimated to 15 versus 30°C. Overall, these data suggest that increased temperatures have substantial effects on C. latimanus energy demands which may reduce potential growth and reproduction.
40
Phillips, Iain D., Rolf D. Vinebrooke, and Michael A. Turner. "Experimental reintroduction of the crayfish species Orconectes virilis into formerly acidified Lake 302S (Experimental Lakes Area, Canada)This paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”." Canadian Journal of Fisheries and Aquatic Sciences 66, no. 11 (November 2009): 1892–902. http://dx.doi.org/10.1139/f09-118.
Full textAbstract:
Reintroduction of functionally important species is considered a key strategy for restoring damaged ecosystems. However, the sudden reappearance of an extirpated species may have adverse ecological impacts, degrading ecosystem services. Therefore, we experimentally reintroduced the crayfish Orconectes virilis into a biologically recovering, formerly acidified Boreal Shield lake (Lake 302S, Experimental Lakes Area, Canada) to determine its effect on the littoral food web following a 17-year absence. In June 2004, a single-factor experimental design consisting of two treatment levels (crayfish-less control versus 1.8 introduced crayfish·m–2) was replicated five times for a total of 10 littoral cages (4 m2). Orconectes virilis significantly (P < 0.05) suppressed the total biomass of other benthic invertebrates by 70% primarily because of declines in larval damselflies and midges. In addition, crayfish reduced periphytic biomass by 90% (P < 0.001). Stable isotopic analyses of the mesocosm food webs further indicated that O. virilis likely functioned as an omnivore, exerting direct and possibly indirect effects on other invertebrates and periphyton. Our findings highlight how the reintroduction of O. virilis must be balanced with adequate fish predation to prevent this species from becoming an invader and negatively affecting the productive capacity of boreal lakes.
41
Radtke, Grzegorz, Rafał Bernaś, Piotr Dębowski, Dariusz Ulikowski, and Andrzej Kapusta. "Three crayfish species of different origin in a medium-sized river system: a new state of affairs." Knowledge & Management of Aquatic Ecosystems, no. 422 (2021): 26. http://dx.doi.org/10.1051/kmae/2021025.
Full textAbstract:
In view of contemporary changes in aquatic environments, determining the distribution of both native and emerging invasive crayfish species is increasingly important. In central Europe, the three invasive crayfish species of the signal crayfish Pacifastacus leniusculus (Dana, 1852), the spiny-cheek crayfish Faxonius limosus (Rafinesque, 1817) and the red swamp crayfish Procambarus clarki (Girard, 1852) are of North American origin. The spiny-cheek crayfish was first brought to the southern Baltic basin at the end of nineteenth century, and its expansion ensued rapidly. At the same time, the indigenous species of the noble crayfish Astacus astacus (Linnaeus, 1758) began to disappear. The spread of the signal crayfish started in the second half of twentieth century; however, it has progressed strongly in recent years. Latest studies of fish fauna in the Drwęca River system, a tributary of the lower Vistula River, have simultaneously revealed new information on the occurrence of crayfish. The most widespread was spiny-cheek crayfish found at ten sites throughout the river basin. The second alien species, the signal crayfish, was noted in four locations in the upper part of the river system, but no mixed populations were noted. A particularly valuable result of the study was the discovery of an unknown site of noble crayfish in a small stream.
42
Ruokonen, Timo J., Rosanna Sjövik, Esa Erkamo, Jouni Tulonen, Fabio Ercoli, Harri Kokko, and Japo Jussila. "Introduced alien signal crayfish (Pacifastacus leniusculus) in Finland − uncontrollable expansion despite numerous crayfisheries strategies." Knowledge & Management of Aquatic Ecosystems, no. 419 (2018): 27. http://dx.doi.org/10.1051/kmae/2018016.
Full textAbstract:
In Finland, massive signal crayfish introductions started towards the end of 1980s, with an estimated total of 2.2 million signal crayfish been stocked before year 2016. During that period, Finnish fisheries authorities have implemented three national management strategies setting guidelines for the crayfish introductions. The main aims of the strategies have been conservation of native noble crayfish stocks and a controlled spreading of the alien signal crayfish within a designated region. In this study, we report the current distribution of signal crayfish in Finland in comparison to the guidelines set in these three national strategies. The present distribution area of the signal crayfish covers most of the Southern Finland. The signal crayfish has been introduced with a stocking permits to over 480 water bodies. In addition, there have been numerous stockings without permits, which are often next to the region designated for the signal crayfish. Based on the results, we conclude that crayfish management strategies adopted in Finland have only had limited effect on the spread of signal crayfish. We presume that main causes for the uncontrolled spreading of the signal crayfish in Finland have been lack of strict official supervision and general lack of awareness about the risks associated with the alien species spreading.
43
Hasrun, Hasrun, and Kasmawati Kasmawati. "HUBUNGAN PANJANG BERAT DAN NISBAH KELAMIN UDANG KARANG MUTIARA (Panulirus ornatus) DI SEKITAR PULAU SALEMO KABUPATEN PANGKEP." JOURNAL OF INDONESIAN TROPICAL FISHERIES (JOINT-FISH) : Jurnal Akuakultur, Teknologi Dan Manajemen Perikanan Tangkap, Ilmu Kelautan 5, no. 1 (June 28, 2022): 110–22. http://dx.doi.org/10.33096/joint-fish.v5i1.117.
Full textAbstract:
The purpose of this study is 1) The composition of the type of catch of crayfish caught in the water around the island of Salemo. 2) Long-weight crayfish pearl (P. ornatus) and Sex ratio. This research will be conducted on October 1, 2021 to February 28, 2022 in the Salemo Island Waters in the Kabupatan Pangkep area. The research method used to identify the type of crayfish was carried out visually by looking at the color patterns found in the body segments based on the book Moosa and Aswandy (1984), identification of crayfish types was carried out using the identification key from William. The results of this study showed that there were 3 types of crayfish or lobsters, namely pearl crayfish (P. ornatus) as many as 38.23 heads or 38.23%, pearl crayfish (P. versicolor) as many as 218 heads or 41.05%, and batik crayfish (P. longipes) as many as 110 heads or 20.72%. With the largest size is pearl crayfish (P. ornatus). The sex ratio of male and female crayfish pearl crayfish (P. ornatus) is 0.45 : 0.55 or a ratio of 1 : 1. The relationship between the length and weight of pearl crayfish is classified as a minor allometric growth pattern.
44
Roessink, Ivo, Karina A. E. van der Zon, Sophie R. M. M. de Reus, and Edwin T. H. M. Peeters. "Native European crayfish Astacus astacus competitive in staged confrontation with the invasive crayfish Faxonius limosus and Procambarus acutus." PLOS ONE 17, no. 1 (January 27, 2022): e0263133. http://dx.doi.org/10.1371/journal.pone.0263133.
Full textAbstract:
The European native, noble crayfish (Astacus astacus) has suffered from a serious and long term population decline due to habitat destruction, water pollution and the impact of the invasive North American crayfish that are carriers of the crayfish plague (Aphanomyces astaci). The latter being the major factor currently confining noble crayfish to uninvaded (parts of) waterbodies. However, recently wild populations of apparently healthy noble crayfish carrying the crayfish plague have been found. As crayfish are known for their inter- and intraspecific agonistic behaviour which may be key for their competitive success, this raised the interesting question what would happen if the crayfish plague would not be a dominant factor anymore in the interaction between native and invasive species. Since the outcome of those encounters is still unclear, this study explores whether the noble crayfish can stand its ground towards invasive species in such agonistic interactions. Furthermore, the ability of the noble crayfish and invasive crayfish to acquire shelter through agonistic interaction is also assessed. Through pairwise staged interactions, agonistic behaviour and shelter competition between the native A. astacus and the invasive Faxonius limosus and Procambarus acutus were examined. The results showed that A. astacus triumphs over F. limosus and P. acutus in agonistic encounters and in competition for shelter. In turn, P. acutus dominates F. limosus in staged encounters and shelter. In possible future situations were crayfish plague does no longer eradicate noble crayfish populations, our results show that the native noble crayfish might still have a promising future when confronted with invasive species.
45
Ulikowski, Dariusz, and Łucjan Chybowski. "Lake Hańcza – a new site for signal crayfish (Pacifastacus leniusculus Dana) occurrence in Poland." Archives of Polish Fisheries 26, no. 2 (June 1, 2018): 141–47. http://dx.doi.org/10.2478/aopf-2018-0015.
Full textAbstract:
Abstract Crayfish catches were conducted using traps in Lake Hańcza, which is the deepest lake in Poland. Two crayfish populations were found to co-exist in the lake: spiny-cheek crayfish (Orconectes limosus Raf.) and signal crayfish (Pacifastacus leniusculus Dana), which is a new species for this lake. Signal crayfish dominated the samples at 98.5% of the specimens caught. The crayfish occurred at depths of 1-10 m. The mean total body length of the male and female signal crayfish (TL) was 99.5 ± 17.8 mm and 96.5 ± 11.7 mm, respectively, while the average body weight (BW) was 38.7 ± 24.9 g and 26.8 ± 9.5, respectively. Chelae were damaged in 4.5% of the individuals. Fishing efficiency (catch per unit effort – CPUE) was 0.96 crayfish trap−1 night−1. Selected characteristics of the population and of individual signal crayfish from Lake Hańcza were compared with those of the two closest neighboring populations of this species in lakes Mauda and Pobłędzie. The confirmed occurrence of the relatively large signal crayfish population in Lake Hańcza excludes this lake as a possible site for native noble crayfish (Astacus astacus L.) restoration.
46
Hein, Catherine L., Brian M. Roth, Anthony R. Ives, and M. Jake Vander Zanden. "Fish predation and trapping for rusty crayfish (Orconectes rusticus) control: a whole-lake experiment." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 2 (February 1, 2006): 383–93. http://dx.doi.org/10.1139/f05-229.
Full textAbstract:
Improved methods are needed for the prevention and control of invasive species. We investigated the potential to control a rusty crayfish (Orconectes rusticus) population in an isolated lake in northern Wisconsin by trapping adult crayfish and restricting fishing, thereby increasing fish populations and predation on small crayfish. Over a 3 year period, traps and predatory fishes removed substantial portions of the rusty crayfish population. We used an age-structured population model to determine which removal method had the largest effect on crayfish population growth rates. Because more crayfish were vulnerable to and removed by fish predation than by trapping, fish predation caused a larger decline in the population growth rate. However, trapping removed crayfish with the highest reproductive value and caused the largest decline in population growth rate per individual crayfish removed. Consideration of density-dependent responses to removal is necessary to predict long-term effects on rusty crayfish population dynamics. Nonetheless, our results suggest that the combination of trapping and fish predation can control established rusty crayfish populations and deserves further consideration for management.
47
Hollows, John, Thomas Song, and Callum Kyla. "Eight years of freshwater crayfish (Paranephrops zealandicus (White)) harvest from one New Zealand pond: Comments on the resulting population structure." Freshwater Crayfish 25, no. 1 (April 15, 2020): 7–12. http://dx.doi.org/10.5869/fc.2020.v25-1.007.
Full textAbstract:
Abstract A 100 m2 forestry pond was stocked with 65 crayfish (Paranephrops zealandicus (White, 1847)), weighing approximately 35 g, in 2010. Sampling was undertaken at the end of each growing season (March - April) from 2012 to 2019. All crayfish > 45 g were harvested from the population; from 2015 between 1.84 kg and 3.65 kg of crayfish < 45 g were harvested (11 to 24% of the < 45 g population). In 2014, refuge (Cytisus scoparius) for the crayfish was added to the pond. The following year there was a noticeable increase in crayfish biomass, particularly those 45 g or less. In 2018, eight kg of lime was added to the pond. This did not greatly change the pH or calcium in the pond water when measured 10 months later, but there was a corresponding increase in total biomass and biomass of crayfish > 45 g. Crayfish biomass ranged from 2.76 kg (2012) to 17.71 kg (2017). Harvests of crayfish > 45 g ranged from 1.1 kg (2012) to 3.98 kg (2019) and for crayfish < 45 g from 1.84 kg (2018) to 3.65 kg (2016). Our findings suggest that habitat modification and harvesting a range of crayfish size classes can increase total biomass, but not necessarily the biomass of larger crayfish.
48
Kalayda, Marina L., Madina F. Khamitova, and Ilia A. Bogatyrev. "Features of the chemical composition of crayfish." Butlerov Communications 57, no. 1 (January 31, 2019): 72–79. http://dx.doi.org/10.37952/roi-jbc-01/19-57-1-72.
Full textAbstract:
The cultivation of crayfish in the structure of aquaculture in the Middle Volga region can be an important component. Currently, natural crayfish populations in the Republic of Tatarstan include 2 species – narrow-toed crayfish (Pontastacus leptodactylus Esch.) and wide-toed crayfish (A. astacus L.). The development of aquabiological technologies allows the use of natural crayfish populations for the tasks of creating industrial breeding farms. In connection with the global trend of the growing popularity of crayfish in food use, the importance of research on the chemical composition of crayfish as objects of consumption grows. The chemical analysis of narrow-fingered crayfish revealed 13 elements, of which calcium is found in maximum amount in the dry residue. The calcium content in the narrow crayfish was 154.057 g/kg dry weight (fig. 1), the chitinous shell of crayfish contains relatively more calcium – up to 376.282 g/kg of dry weight. The following sequences of the content of chemical elements in crayfish from the Kuibyshev reservoir are noted: in the muscle tissue of edible parts Ca ˃K ˃S ˃P ˃Cu ˃Fe ˃Zn ˃Mn ~ Br ˃Sr; in the shell Ca ˃Si ˃P ˃S ˃K ˃Sr ˃Ti ˃Fe ˃Mn ˃Cu ˃Br ˃Zn ˃As. In crayfish from the Kuibyshev reservoir we studied, the raw muscle mass of the edible parts of the crayfish contained 88.80% of water, 10.28% of organic substances and 0.92% of mineral substances, and in the chitin-containing raw shells of crayfish, respectively, contained 59.2% of water, 36.42% organic matter and 4.38% mineral matter. The particular interest is the study of crayfish shells, since they consist mainly of chitin. It is a bearing polysaccharide for invertebrate, reaching 85% of the weight of the integuments. In the cuticle of arthropods, chitin forms composite complexes with proteins, pigments, calcium salts. In the composition of the shells of crayfish, 376.282 mg/kg dry mass of calcium is noted. In smaller quantities phosphorus, potassium, iron and zinc are noted. Titanium was found in crayfish shells in the amount of 1845 mg/kg dry weight and was not found in their muscle tissue and other aquatic organisms in the region. In the studied crayfish, the content of heavy metals in the wet mass was: Zn – 0.42 mg/kg; Cu 6.5 mg/kg; Fe – 1.39 mg/kg; Sr – 0.23 mg/kg. Residual amounts of zinc and copper in the muscular tissue of the edible parts of crayfish of the Kuibyshev reservoir are within the normal range. The content of hazardous elements (lead, arsenic, cadmium and mercury) in the crayfish from the Kuibyshev reservoir is within the sanitary and epidemiological norms, and in the Volga delta crayfish the lead content is exceeded.
49
Nambiar, Geetika, Leigh Owens, and Jennifer Elliman. "Cherax quadricarinatus Resistant to Chequa iflavirus: A Pilot Study." Microorganisms 11, no. 3 (February 24, 2023): 578. http://dx.doi.org/10.3390/microorganisms11030578.
Full textAbstract:
High mortalities of redclaw crayfish (Cherax quadricarinatus) were reported from northern Queensland farms, mainly attributed to two viruses, Chequa iflavirus and Athtab bunyavirus. From a research population of redclaw crayfish with these pre-existing viral infections, five individuals were found uninfected by Chequa iflavirus but infected with Athtab bunyavirus. A pilot study was designed to examine if progeny crayfish from this cohort were resistant to infections by Chequa iflavirus. Two experiments measured changes in viral load with RT-qPCR. Seven donors, four negative controls and six crayfish injected with a purified virus or saline were used. In Experiment 1, the purified viral inoculum was injected into the crayfish, and they were bled 14 days post-injection (dpi). In Experiment 2, haemolymph containing the viruses was injected into the same crayfish and they were bled at 24 hpi, 48 hpi, 7 dpi and 14 dpi. In Exp. 1, the crayfish cleared Chequa iflavirus infections within 14 dpi, while in Exp. 2, it was within 24 hpi. One mortality was observed, but that crayfish had cleared the virus before dying. The number of copies of Athtab bunyavirus and the weights of the crayfish did not differ significantly (p > 0.05) between the control and injected crayfish. Histology of crayfish all showed that the haemolymph vessels were clear of granulomas, suggesting no bacterial involvement. There was no melanisation in the gill tissue of control crayfish, but it was prominent in virus-injected crayfish. Neither group had haemocytic infiltration of the muscle fibres. Anti-viral immune mechanisms of RNA interference and Cherax quadricarinatus Down Syndrome Cell Adhesion Molecule (DSCAM) are hypothesised to be involved in viral clearance. We conclude that these crayfish were resistant to Chequa iflavirus infections and could be commercially exploited by aquaculturists as a nuclear breeding stock if numbers are increased over time.
50
Zeng, Qinghui, Mingzhong Luo, Lirong Qin, Chao Guo, Jiashou Liu, Tanglin Zhang, Guangpeng Feng, and Wei Li. "Effects of Hypoxia Stress on Survival, Antioxidant and Anaerobic Metabolic Enzymes, and Related Gene Expression of Red Swamp Crayfish Procambarus clarkii." Biology 13, no. 1 (January 6, 2024): 33. http://dx.doi.org/10.3390/biology13010033.
Full textAbstract:
The red swamp crayfish Procambarus clarkii is the most reared shrimp in China, but it is often affected by hypoxia stress in the process of seedling culture and adult crayfish culture. The oxygen consumption rate and asphyxiation point of juvenile crayfish (1.17 ± 0.03 g) and subadult crayfish (11.68 ± 0.11 g) at different temperatures (20, 22, 24, 26, and 28 °C) were studied. The survival, glycolysis, and expression of antioxidant genes were compared under 24 h acute hypoxia stress (1, 2, and 3 mg/L) and normal dissolved oxygen (7.5 mg/L). The results showed that the oxygen consumption rate and asphyxiation point of juvenile and subadult crayfish increased with increasing temperatures (20–28 °C). At the same temperature, the oxygen consumption rate and asphyxiation point of juvenile crayfish were significantly higher than those of subadult crayfish (p < 0.05). Within 24 h, the three hypoxia stress environments did not lead to the death of crayfish, indicating that P. clarkii has a strong ability to adapt to hypoxia. Hypoxia stress significantly affected the activities of antioxidant and anaerobic metabolic enzymes and gene expression in juvenile and subadult crayfish. The activities of the superoxide dismutase (SOD), catalase (CAT), and lactate dehydrogenase (LDH) and the content of lactic acid (LD) in the hepatopancreas of juvenile and subadult crayfish in the hypoxia stress groups increased significantly. The expression levels of SOD mRNA, CAT mRNA, Hsp70 mRNA, and crustin 4 mRNA in the hepatopancreas of juvenile and subadult crayfish in the hypoxia stress groups were significantly higher than those in the control group (p < 0.05), and the higher the degree of hypoxia stress, the higher the expression of each gene. The results showed that the antioxidant system of juvenile crayfish was more sensitive to hypoxia environments, and hypoxia stress resulted in increased stress levels in juvenile crayfish and subadult crayfish.