Articles de revues : « Lampros »

1

HALL, JASON P. W. « Two new genera in the Nymphidiina (Lepidoptera : Riodinidae : Nymphidiini) ». Zootaxa 1415, n^o 1 (5 mars 2007) : 35–42. http://dx.doi.org/10.11646/zootaxa.1415.1.4.

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Two new riodinid genera in the subtribe Nymphidiina (tribe Nymphidiini) are described from the lowlands of the Amazon basin. Livendula Hall, n. gen., is described with huebneri Butler as its type species, and the following eleven species are transferred to Livendula (n. combs.) from Adelotypa Warren: amasis Hewitson, aminias Hewitson, aristus Stoll, balista Hewitson, epixanthe Stichel, huebneri Butler, jasonhalli Brévignon & Gallard, leucocyana Geyer, leucophaea Hübner, pauxilla Stichel, and violacea Butler. Minotauros Hall, n. gen., is described with lampros Bates as its type species, and the following two species are transferred to Minotauros (n. combs.) from Adelotypa: lampros Bates, and charessa Stichel.

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Fortin, Christian, Martin Ouellet, Isabelle Cartier, Daniel Banville et Claude B. Renaud. « Biologie et situation de la Lamproie du Nord, Ichthyomyzon fossor, au Québec ». Canadian Field-Naturalist 121, n^o 4 (1 octobre 2007) : 402. http://dx.doi.org/10.22621/cfn.v121i4.512.

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La Lamproie du Nord est une espèce propre à l’Amérique du Nord et elle ne se rencontre, au Québec, que dans l’extrême sud de la province. Cette lamproie a été observée dans le fleuve Saint-Laurent ainsi que dans 11 de ses tributaires. Elle aurait disparu de la rivière Yamaska où elle avait été recensée entre 1946 et 1959. Poisson non parasite, sa taille au stade adulte ne dépasse habituellement pas 160 mm. Les larves, appelées ammocètes, et les adultes ne se retrouvent qu’en eau douce. Les cours d’eau utilisés sont généralement des ruisseaux et des rivières à fond graveleux ou sablonneux. La Lamproie du Nord requiert deux habitats distincts, soit un pour les adultes reproducteurs et un autre, le long du même cours d’eau, pour le développement des ammocètes. La détérioration de l’habitat et la pollution des eaux représentent les principales menaces à la survie des lamproies. La faible fécondité et la mobilité réduite de la Lamproie du Nord font en sorte que cette espèce est peu adaptable aux modifications de son environnement.The Northern Brook Lamprey is endemic to North America. In Quebec, it is restricted to the southernmost part of the province. This lamprey is known from the St. Lawrence River as well as in 11 of its tributaries. It appears to have been extirpated from the Yamaska River where it was collected between 1946 and 1959. It is a nonparasitic fish and its adult size does not usually exceed 160 mm. Larvae, called ammocoetes, and adults are found only in fresh water. Watercourses where it occurs are generally streams and rivers with gravel or sandy bottoms. The Northern Brook Lamprey requires two types of habitats during its life cycle, one for spawning adults and one, along the same watercourse, for the developing ammocoete. Habitat degradation and water pollution are the major threats to the survival of lampreys. The low fecundity and low dispersal abilities of the Northern Brook Lamprey make this species poorly adapted to withstand changes in its environment.

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Petersen, Mette K. « Fecundity and juvenile survival of Bembidion lampros and Tachyporus hypnorum ». Entomologia Experimentalis et Applicata 87, n^o 3 (juin 1998) : 301–9. http://dx.doi.org/10.1046/j.1570-7458.1998.00335.x.

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Petersen, M. K., B. Ekbom et H. P. Ravn. « Temperature dependent winter survival of Bembidion lampros and Tachyporus hypnorum ». Journal of Insect Physiology 42, n^o 11-12 (novembre 1996) : 997–1005. http://dx.doi.org/10.1016/s0022-1910(96)00072-8.

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Merivee, Enno, Angela Ploomi, Märt Rahi, Anne Luik et Väino Sammelselg. « Antennal sensilla of the ground beetle Bembidion lampros Hbst (Coleoptera, Carabidae) ». Acta Zoologica 81, n^o 4 (24 décembre 2001) : 339–50. http://dx.doi.org/10.1046/j.1463-6395.2000.00068.x.

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McBurney, Kim M., et Glenda M. Wright. « Chondrogenesis of a non-collagen-based cartilage in the sea lamprey, Petromyzon marinus ». Canadian Journal of Zoology 74, n^o 12 (1 décembre 1996) : 2118–30. http://dx.doi.org/10.1139/z96-241.

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Chondrogenesis of the trabeculae, non-collagen-based cartilages in prolarval stages of the sea lamprey, Petromyzon marinus, was examined by light and electron microscopy. Chondrogenesis of the trabecular cartilages in prolarval lampreys commenced with the formation of mesenchymal condensations. Two peaks in mesenchymal cell density occurred, one prior to condensation formation and a second immediately before cartilage differentiation. The possibility of inductive influences by epithelio-mesenchymal interactions on the initiation of chondrogenesis is discussed. Bilateral condensations first appeared by day 17 post fertilization ventromedial to the eyes in a band of tightly packed yolk-laden mesenchymal cells that represent neural crest derived tissue. Cartilage differentiation occurred by day 19 post fertilization and was indicated by the presence of matrix-synthesizing organelles and the first ultrastructural appearance in the extracellular matrix of lamprin, a structural protein unique to lamprey cartilage. Lamprin was initially deposited as discrete 15- to 40-nm globules. Subsequently, lamprin appeared as fibrils aggregated into branching and parallel arrays arranged in pericellular, territorial, and interterritorial zones. Lengthening of the trabecular cartilages was primarily by appositional growth at the rostral end. The timing of the appearance of trabecular cartilages in prolarval stages likely reflects the functional importance of these structures for supporting the brain as the lamprey initiates burrowing behaviour.

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Brenøe, Jane. « Wet extraction-a method for estimating populations ofBembidion lampros(Herbst) (Col., Carabidae) ». Journal of Applied Entomology 103, n^o 1-5 (12 janvier 1987) : 124–27. http://dx.doi.org/10.1111/j.1439-0418.1987.tb00968.x.

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Çilgi, Tamer, Steve D. Wratten, Jacqueline L. Robertson, David E. Turner, John M. Holland et Geoff K. Frampton. « RESIDUAL TOXICITIES OF THREE INSECTICIDES TO FOUR SPECIES (COLEOPTERA : CARABIDAE) OF ARTHROPOD PREDATOR ». Canadian Entomologist 128, n^o 6 (décembre 1996) : 1115–24. http://dx.doi.org/10.4039/ent1281115-6.

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AbstractIn laboratory bioassays, four carabid species [Agonum dorsale (Pontoppidan), Bembidion lampros (Herbst), B. obtusum Serville, and Demetrias atricapillus (L.)] that are important predators of aphids in cereals in the United Kingdom were exposed to deposits of deltamethrin, dimethoate, or pirimicarb on glass for up to 72 h. We detected differences between compounds and species that are discussed in the context of exposure of these predators to insecticides in the field. We also describe problems involved in obtaining comparative toxicity data when dilutions of field application rates for target species are used in bioassays with nontarget species. Such problems add another dimension to risk assessment based on laboratory data.

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Guseva, Olga G., et Alexander G. Koval. « Distribution of ground beetles of the genus Bembidion (Coleoptera, Carabidae) in the agricultural landscape in Northwestern Russia ». Acta Biologica Sibirica 7 (6 septembre 2021) : 227–36. http://dx.doi.org/10.3897/abs.7.e70229.

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We have observed seven species of predator beetles of the genus Bembidion in the agricultural landscape of the Leningrad Region (Northwestern Russia) between the years 2008 and 2018. These species reach their highest abundance in sun-exposed areas, especially mesophilic B. quadrimaculatum Linnaeus, 1761, B. properans (Stephens, 1828), B. lampros (Herbst, 1784), and B. femoratum Sturm, 1825. A few mesohygrophilic B. guttula (Fabricius, 1792) and B. gilvipes (Sturm, 1825) live primarily in areas of dense vegetation. Finally, the hygrophilic B. bruxellense (Wesmael, 1835) was only observed on the most humid soils. Assemblages of Bembidion ground beetles were separated in the fields, field boundaries, and adjacent habitats.

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10

Jensen, L. Boye. « Effect of temperature on the development of the immature stages ofBembidion lampros [Coleoptera : Carabidae] ». Entomophaga 35, n^o 2 (juin 1990) : 277–81. http://dx.doi.org/10.1007/bf02374803.

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Petersen, Mette K. « Capacity of Bembidion lampros and Tachyporus hypnorum to survive periods of starvation in early spring ». Entomologia Experimentalis et Applicata 90, n^o 2 (février 1999) : 207–14. http://dx.doi.org/10.1046/j.1570-7458.1999.00440.x.

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Knapp, M., et P. Saska. « The effects of habitat, density, gender and duration on overwintering success in Bembidion lampros (Coleoptera : Carabidae) ». Journal of Applied Entomology 136, n^o 3 (27 mai 2011) : 225–33. http://dx.doi.org/10.1111/j.1439-0418.2011.01643.x.

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13

Rozek, Maria. « C-bands and NORs on Chromosomes of Bembidion lampros (Herbst) and Bembidion properans (Steph.) (Coleoptera, Carabidae). » CYTOLOGIA 63, n^o 3 (1998) : 317–21. http://dx.doi.org/10.1508/cytologia.63.317.

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Davy, Christina M., Juliana Skuza et Amelia K. Whitear. « Spiny Softshell (Apalone spinifera) turtles exhibit scarring consistent with attempted lamprey bites ». Canadian Field-Naturalist 132, n^o 2 (1 janvier 2019) : 120–21. http://dx.doi.org/10.22621/cfn.v132i2.2039.

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We captured 46 Spiny Softshells (Apalone spinifera) during a mark–recapture study on Lake Erie (2012–2015). Six (13%) exhibited circular scars consistent with the bites of small parasitic lampreys. Two species of parasitic lampreys occur in Lake Erie: the invasive Sea Lamprey (Petromyzon marinus) and the native Silver Lamprey (Ichthyostomyzon unicuspis). The scars showed only the marks of the putative teeth surrounding the suctorial mouth, preventing identification based on the position of the supraoral teeth and suggesting that lampreys are rapidly dislodged from the turtles. To our knowledge, this is the first evidence of lampreys biting freshwater turtles.

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Whyte, John N. C., Richard J. Beamish, Norma G. Ginther et Chrys-Ellen Neville. « Nutritional Condition of the Pacific Lamprey (Lampetra tridentata) Deprived of Food for Periods of Up to Two Years ». Canadian Journal of Fisheries and Aquatic Sciences 50, n^o 3 (1 mars 1993) : 591–99. http://dx.doi.org/10.1139/f93-068.

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The anadromous parasitic Pacific lamprey (Lampetra tridentata) does not feed during metamorphosis or its spawning migration. To assess the utilization of body reserves, we compared the compositions of an adult lamprey held for 2 yr without food, recently metamorphosed lampreys, and lampreys starved for 6 mo. Moisture was higher and soluble ash and lipid levels were lower in tissue of the 2-yr-starved than in metamorphosed lampreys (2.67 and 3.39 kj∙g−1, respectively). Fatty acid profiles of 2-yr-starved and metamorphosed lampreys were qualitatively similar except for the presence of 15:0 in the latter. Substantially lower levels of 14:0 and 16:1 n7 and higher levels of polyunsaturated fatty acids occurred in starved lampreys. Changes in composition of lampreys starved for 6 mo were similar to changes between the 2-yr-starved and metamorphosed lampreys. Maintenance energy in a normalized 1-g lamprey starved for 6 mo was derived from catabolism of 71% lipid and 29% protein; total loss was 2.56 kJ or 49% of the original energy. The ability to survive extended periods on endogenous reserves, which may have allowed L. tridentata to survive past environmental catastrophes, allows it to migrate considerable distances to spawning areas in the headwaters of rivers.

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Baker, Cindy F., Don J. Jellyman, Kathryn Reeve, Shannan Crow, Michael Stewart, Tyler Buchinger et Weiming Li. « First observations of spawning nests in the pouched lamprey (Geotria australis) ». Canadian Journal of Fisheries and Aquatic Sciences 74, n^o 10 (octobre 2017) : 1603–11. http://dx.doi.org/10.1139/cjfas-2016-0292.

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The pouched lamprey (Geotria australis), one of four Southern Hemisphere lamprey species, is New Zealand’s only freshwater representative of the agnathans. In contrast to that of Northern Hemisphere lampreys, the reproductive ecology of Southern Hemisphere lampreys is poorly understood, with no documented nesting sites or spawning behaviours. In the present study, we utilized passive integrated transponder tags to track migratory adult G. australis to locate spawning sites. Across 2 years, six cryptic nesting sites were discovered, each containing eggs and a single male and female lamprey. The postspawning pairs were all located underneath large boulders, with the eggs forming a coagulated cluster that adhered to the underside of the boulder. Both the male and female lamprey survived spawning for over 105 days. The observed spawning nests highlight a substantial divergence in the reproductive behaviour between Northern and Southern Hemisphere lampreys, as the present observations of G. australis are the first that support clustered cryptic egg deposition and an extended time to mortality postspawning. This study offers the first insights to the long-standing mystery of Southern Hemisphere lamprey reproduction.

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Archangelsky, Miguel. « Immature Stages of Neotropical Enochrus (Coleoptera : Hydrophilidae) : E. (Methydrus) lampros Knisch, 1924 and E. (Hugoscottia) tremolerasi Knisch, 1922 ». Aquatic Insects 24, n^o 1 (janvier 2002) : 41–52. http://dx.doi.org/10.1076/aqin.24.1.41.4912.

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Renaud, Claude B., Henry K. T. Wong et Janice L. Metcalfe-Smith. « Trace Metal Levels in Benthic Biota from Four Tributaries to the St. Lawrence River, Quebec ». Water Quality Research Journal 33, n^o 4 (1 novembre 1998) : 595–610. http://dx.doi.org/10.2166/wqrj.1998.034.

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Abstract Lamprey ammocoetes (Agnatha: Petromyzontidae) and freshwater mussels (Bivalvia: Unionidae), two groups of organisms that are closely associated with sediments, were collected from the Châteauguay, Bécancour, Sainte-Anne and Saint-Maurice rivers in July 1992 and analyzed for residues of 13 metals in their tissues. The hypothesis that lamprey larvae and mussels would bioaccumulate comparable levels of metals due to similarities in their ecology was rejected. Lampreys (Ichthyomyzon fossor and Lampetra appendix) from the Châteauguay River (the only site where both lampreys and mussels were collected) accumulated significantly lower concentrations of Ag, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Tl, V and Zn than mussels (Elliptio complanata), suggesting that lampreys may be capable of regulating these metals. Conversely, lampreys accumulated much higher concentrations of Hg than mussels (1748 to 6793 versus 579 to 982 ng/g dry weight, respectively), indicating that they may be suitable biomonitors for Hg. Organisms that are capable of regulating metals are not normally recommended for biomonitoring purposes. Nevertheless, significant differences among rivers were observed for many metals based on the lamprey data. As metals in the gut contents of three specimens of Sea lamprey (Petromyzon mar-inus) from the Saint-Maurice River accounted for a substantial portion of the whole body burden of metals, a gut content correction factor is recommended for these organisms. Further studies are required to properly evaluate lamprey ammocoetes as biomonitors for trace metals in freshwater systems.

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Cochran, Philip A., et James F. Kitchell. « A Model of Feeding by Parasitic Lampreys ». Canadian Journal of Fisheries and Aquatic Sciences 46, n^o 11 (1 novembre 1989) : 1845–52. http://dx.doi.org/10.1139/f89-232.

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We derived a quantitative feeding model to estimate energy intake by parasitic sea lampreys (Petromyzon marinus) as a function of lamprey mass, host mass, and attachment time. Comparison of model predictions with observed growth by lampreys with known feeding histories suggests that the feeding model, used in conjunction with a previous model of lamprey energetics, generates unbiased predictions of energy intake and subsequent growth. On the basis of the relationship between energy intake and attachment time, and in accordance with previous theory on partial prey consumption, we hypothesized that duration of attachment by lampreys to individual hosts should vary inversely with host density. No significant difference in attachment time or latency to attack at two host densities could be detected, although the first attachment by a lamprey tended to be longer than its second, regardless of host density.

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Shi, Hongyang, Christopher M. Holbrook, Yunqi Cao, Nelson Sepúlveda et Xiaobo Tan. « Measurement of suction pressure dynamics of sea lampreys, Petromyzon marinus ». PLOS ONE 16, n^o 4 (27 avril 2021) : e0247884. http://dx.doi.org/10.1371/journal.pone.0247884.

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Species-specific monitoring activities represent fundamental tools for natural resource management and conservation but require techniques that target species-specific traits or markers. Sea lamprey, a destructive invasive species in the Laurentian Great Lakes and conservation target in North America and Europe, is among very few fishes that possess and use oral suction, yet suction has not been exploited for sea lamprey control or conservation. Knowledge of specific characteristics of sea lamprey suction (e.g., amplitude, duration, and pattern of suction events; hereafter ‘suction dynamics’) may be useful to develop devices that detect, record, and respond to the presence of sea lamprey at a given place and time. Previous observations were limited to adult sea lampreys in static water. In this study, pressure sensing panels were constructed and used to measure oral suction pressures and describe suction dynamics of juvenile and adult sea lampreys at multiple locations within the mouth and in static and flowing water. Suction dynamics were largely consistent with previous descriptions, but more variation was observed. For adult sea lampreys, suction pressures ranged from –0.6 kPa to –26 kPa with 20 s to 200 s between pumps at rest, and increased to –8 kPa to –70 kPa when lampreys were manually disengaged. An array of sensors indicated that suction pressure distribution was largely uniform across the mouths of both juvenile and adult lampreys; but some apparent variation was attributed to obstruction of sensing portal holes by teeth. Suction pressure did not differ between static and flowing water when water velocity was lower than 0.45 m/s. Such information may inform design of new systems to monitor behavior, distribution and abundance of lampreys.

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Jolley, Jeffrey C., et Kenneth M. Lujan. « Pathogens of Pacific Lamprey Detected Through Routine Fish Health Screenings ». Journal of Fish and Wildlife Management 10, n^o 2 (1 mai 2019) : 517–24. http://dx.doi.org/10.3996/122018-jfwm-119.

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Abstract Interest in conservation, management, and captive rearing of Pacific Lamprey Entosphenus tridentatus in the Pacific Northwest has risen in recent years. General and specific information regarding the occurrence of fish pathogens and the risk of Pacific Lamprey as a vector for pathogens to other species is not well understood. Specific efforts to captively rear or artificially propagate Pacific Lamprey at facilities that are used for Pacific salmon Oncorhynchus spp. have increased. We performed fish health surveys on wild-caught larval and adult Pacific Lamprey from locations that were used as lamprey sources for captive research to determine the occurrence of bacteria, viruses, and parasites that may be pathogens. A variety of potential pathogens was detected, most notably Aeromonas hydrophila and Vibrio vulnificus from larval Pacific Lamprey and A. salmonicida from adult lampreys. There was a general lack of pathogenic activity and absence of viral detections from all lampreys. The diversity of bacteria encountered from the larvae in our study could be indicative of the wide diversity of bacteria that is known to be associated with larval lamprey in general. Further efforts to understand pathogenic risk from Pacific Lamprey to salmonid propagation programs are warranted.

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Holbrook, Christopher M., Nicholas S. Johnson, Juan P. Steibel, Michael B. Twohey, Thomas R. Binder, Charles C. Krueger et Michael L. Jones. « Estimating reach-specific fish movement probabilities in rivers with a Bayesian state-space model : application to sea lamprey passage and capture at dams ». Canadian Journal of Fisheries and Aquatic Sciences 71, n^o 11 (novembre 2014) : 1713–29. http://dx.doi.org/10.1139/cjfas-2013-0581.

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Improved methods are needed to evaluate barriers and traps for control and assessment of invasive sea lamprey (Petromyzon marinus) in the Great Lakes. A Bayesian state-space model provided reach-specific probabilities of movement, including trap capture and dam passage, for 148 acoustic tagged invasive sea lamprey in the lower Cheboygan River, Michigan, a tributary to Lake Huron. Reach-specific movement probabilities were combined to obtain estimates of spatial distribution and abundance needed to evaluate a barrier and trap complex for sea lamprey control and assessment. Of an estimated 21 828 – 29 300 adult sea lampreys in the river, 0%–2%, or 0–514 untagged lampreys, could have passed upstream of the dam, and 46%–61% were caught in the trap. Although no tagged lampreys passed above the dam (0/148), our sample size was not sufficient to consider the lock and dam a complete barrier to sea lamprey. Results also showed that existing traps are in good locations because 83%–96% of the population was vulnerable to existing traps. However, only 52%–69% of lampreys vulnerable to traps were caught, suggesting that traps can be improved. The approach used in this study was a novel use of Bayesian state-space models that may have broader applications, including evaluation of barriers for other invasive species (e.g., Asian carp (Hypophthalmichthys spp.)) and fish passage structures for other diadromous fishes.

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Elliott, SAM, N. Deleys, E. Rivot, A. Acou, E. Réveillac et L. Beaulaton. « Shedding light on the river and sea lamprey in western European marine waters ». Endangered Species Research 44 (22 avril 2021) : 409–19. http://dx.doi.org/10.3354/esr01113.

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Lampreys are ancestral jawless vertebrates with particularly complex life histories. Population declines resulting from increased anthropogenic pressure have been observed. For semelparous diadromous lampreys, the marine phase remains largely a black box, making targeted management and conservation measures difficult to implement. Here, we collated a database of 168904 hauls from both fisheries-dependent and fisheries-independent surveys between 1965 and 2019. Lampreys were observed in only 254 hauls (<1% lamprey presence); 421 sea lamprey Petromyzon marinus and 300 European river lamprey Lampetra fluviatilis were identified. Sizes ranged from 13 to 92 cm and from 14 to 42 cm, respectively. The majority of lampreys (61%) were caught by mobile demersal gear types. The highest presence of both species was recorded within the Greater North Sea, followed by the Bay of Biscay. L. fluviatilis was observed closer to the coast than P. marinus. For both lampreys, there was an increase in size with distance from the coast. P. marinus were predominantly <60 cm and observed from August to February, indicating that these were sexually immature juveniles migrating out to sea. For L. fluviatilis, the majority were thought to be adults (>20 cm) and occurred in autumn, indicating inshore migration. Our observations provide insight into the ecology of lampreys at sea and highlight study locations and gear types, which may be more pertinent for future research. Greater awareness is needed during surveys to collate catch information on lampreys and improve understanding of their ecology and phenology at sea.

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Petersen, Mette K. « The timing of dispersal of the predatory beetles Bembidion lampros and Tachyporus hypnorum from hibernating sites into arable fields ». Entomologia Experimentalis et Applicata 90, n^o 2 (février 1999) : 221–24. http://dx.doi.org/10.1046/j.1570-7458.1999.00442.x.

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Chiverton, Philip A. « Searching behaviour and cereal aphid consumption by Bembidion lampros and Pterostichus cupreus, in relation to temperature and prey density ». Entomologia Experimentalis et Applicata 47, n^o 2 (mai 1988) : 173–82. http://dx.doi.org/10.1111/j.1570-7458.1988.tb01133.x.

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Wagner, C. Michael, Eric M. Stroud et Trevor D. Meckley. « A deathly odor suggests a new sustainable tool for controlling a costly invasive species ». Canadian Journal of Fisheries and Aquatic Sciences 68, n^o 7 (juillet 2011) : 1157–60. http://dx.doi.org/10.1139/f2011-072.

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Here we confirm a long-standing anecdotal observation; the sea lamprey ( Petromyzon marinus ) actively avoids the odor emitted by decaying conspecifics. We extracted the semiochemical mixture produced by the putrefying carcasses of sea lampreys via Soxhlet extraction in ethanol and exposed groups of 10 migratory-phase lampreys to either the putrefaction extract (N = 8) or an ethanol control (N = 8) in a laboratory raceway. Sea lampreys rapidly avoided the putrefaction odor while exhibiting no response to the ethanol control. This response was elicited with a diluted mixture (1:373 000) and was maintained for 40 min (the duration of exposure), after which the lampreys quickly returned to their nominal distribution. The ease with which this odor is obtained, and the rapid and consistent behavioral response, suggests the substance will prove useful as a repellent in the sea lamprey control program carried out in the Laurentian Great Lakes.

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Perrault, K., I. Imre et G. E. Brown. « Behavioural response of larval sea lamprey (Petromyzon marinus) in a laboratory environment to potential damage-released chemical alarm cues ». Canadian Journal of Zoology 92, n^o 5 (mai 2014) : 443–47. http://dx.doi.org/10.1139/cjz-2013-0095.

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Sea lampreys (Petromyzon marinus L., 1758) invaded the Great Lakes early in the 20th century and have caused economic and ecological damage to native fish species. The integrated sea lamprey control program involves low-head barrier dams, lampricides, and trapping. The search for low cost and less toxic alternatives to lampricides could involve the use of repellents in the form of chemical alarm cues. The objective of this study was to determine whether larval sea lamprey showed a behavioural response when exposed to damage-released chemical alarm cues by increasing their swimming time, rate of direction changes, or rate of escape attempts in an artificial stream channel experiment. Larval sea lampreys were exposed to conspecific larval sea lamprey extract, heterospecific swordtail (Xiphophorus hellerii Heckel, 1848) extract, or a distilled water control. The larvae increased their rate of escape attempts after exposure to both swordtail and larval lamprey extracts and their rate of direction changes after exposure to sea lamprey extract. However, larvae did not increase their swimming time in response to any experimental stimuli. This is the first study to suggest that larval sea lamprey respond to potential chemosensory risk assessment cues.

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Johnson, Nicholas S., Michael J. Siefkes, C. Michael Wagner, Heather Dawson, Huiyong Wang, Todd Steeves, Michael Twohey et Weiming Li. « A synthesized mating pheromone component increases adult sea lamprey (Petromyzon marinus) trap capture in management scenarios ». Canadian Journal of Fisheries and Aquatic Sciences 70, n^o 7 (juillet 2013) : 1101–8. http://dx.doi.org/10.1139/cjfas-2013-0080.

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Application of chemical cues to manipulate adult sea lamprey (Petromyzon marinus) behavior is among the options considered for new sea lamprey control techniques in the Laurentian Great Lakes. A male mating pheromone component, 7α,12α,24-trihydroxy-3-one-5α-cholan-24-sulfate (3kPZS), lures ovulated female sea lamprey upstream into baited traps in experimental contexts with no odorant competition. A critical knowledge gap is whether this single pheromone component influences adult sea lamprey behavior in management contexts containing free-ranging sea lampreys. A solution of 3kPZS to reach a final in-stream concentration of 10−12 mol·L−1 was applied to eight Michigan streams at existing sea lamprey traps over 3 years, and catch rates were compared between paired 3kPZS-baited and unbaited traps. 3kPZS-baited traps captured significantly more sexually immature and mature sea lampreys, and overall yearly trapping efficiency within a stream averaged 10% higher during years when 3kPZS was applied. Video analysis of a trap funnel showed that the likelihood of sea lamprey trap entry after trap encounter was higher when the trap was 3kPZS baited. Our approach serves as a model for the development of similar control tools for sea lamprey and other aquatic invaders.

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Langille, Robert M., et Brian K. Hall. « Artificial fertilization, rearing, and timing of stages of embryonic development of the anadromous sea lamprey, Petromyzon marinus L. » Canadian Journal of Zoology 66, n^o 2 (1 février 1988) : 549–54. http://dx.doi.org/10.1139/z88-081.

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For experimental analysis of agnathan (lampreys and hagfishes) development, the only choice at present is the lamprey, yet these animals present severe restrictions to their use. The average duration of the breeding period of mature anadromous sea lamprey, Petromyzon marinus, caught off the coast of Nova Scotia, is approximately 3 weeks, after which the animals die. At present no hormonal treatment or other method exists either to initiate precocious sexual development or to effectively increase the natural, limited fertilization period of this species. The present study demonstrates that by (i) anaesthetizing lampreys in a buffered medium and housing animals in darkness or reduced light to reduce stress, (ii) raising embryos from each fertilization at three different temperatures, 15, 18, and 21 °C, and (iii) staggering fertilizations, the period over which lamprey embryos are available can be maximized even with a limited supply of breeding stock. In addition, a detailed account of lamprey handling and housing are included for those considering using this animal for the first time.

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Taylor, Eric B., Les N. Harris, Erin K. Spice et Margaret F. Docker. « Microsatellite DNA analysis of parapatric lamprey (Entosphenus spp.) populations : implications for evolution, taxonomy, and conservation of a Canadian endemic ». Canadian Journal of Zoology 90, n^o 3 (mars 2012) : 291–303. http://dx.doi.org/10.1139/z11-135.

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Parapatric freshwater and anadromous parasitic lampreys (Petromyzontiformes) from southwestern Vancouver Island, British Columbia, have been described as distinct taxa (Vancouver lamprey ( Entosphenus macrostomus (Beamish, 1982)) and Pacific lamprey ( Entosphenus tridentatus (Richardson, 1836)), respectively), using morphology, life history, and physiology. We tested for genetic differentiation at microsatellite DNA loci between these taxa and similar freshwater parasitic lampreys from two other lakes. The number of alleles and expected heterozygosity averaged 3.8 and 0.50, respectively, across loci and populations, and anadromous populations were more variable than freshwater populations. Population subdivision was moderate (FST = 0.096, P < 0.001) and 3% of the total variation was found between taxa and 1.7% was found among populations within taxa (both P < 0.001). Parapatric freshwater and anadromous parasitic lampreys separated by a maximum of 40 km were more distinct (mean FST = 0.042) than were anadromous populations located 800 km from one another (mean FST = 0.012). Localities within lakes with parasitic freshwater lampreys, however, showed little differentiation (FST = 0.0–0.08). Our data support recognizing E. macrostomus and E. tridentatus as distinct species, but similar levels of differentiation between these taxa and other freshwater parasitic lampreys suggest a species complex where the taxonomy remains unclear.

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Hansen, Gretchen J. A., et Michael L. Jones. « A rapid assessment approach to prioritizing streams for control of Great Lakes sea lampreys (Petromyzon marinus) : a case study in adaptive management ». Canadian Journal of Fisheries and Aquatic Sciences 65, n^o 11 (novembre 2008) : 2471–84. http://dx.doi.org/10.1139/f08-153.

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We developed and evaluated an alternative method (rapid assessment or RA) for assessment of larval sea lampreys, Petromyzon marinus . We determined that using RA would result in at least as many, if not more, sea lampreys being killed than would using the current assessment method (quantitative assessment sampling or QAS) to select streams for lampricide treatment. Both assessment methods were carried out simultaneously throughout the entire Great Lakes basin from 2005 to 2007. RA required fewer resources than the current method and thus allowed for the chemical treatment of additional streams with lampricides, given a fixed overall budget for control. Population estimates generated from the QAS surveys showed that using RA would result in approximately equal numbers of metamorphosing lamprey and greater numbers of larval lamprey killed than by using QAS. Mark–recapture results indicated that prioritizing streams for treatment using RA may result in higher numbers of metamorphosing and larval lampreys killed than by using QAS. RA is currently being adopted throughout the Great Lakes as the method for assessing larval sea lamprey populations. Other fishery management programs may benefit from examining the value of their assessment programs relative to other uses of resources.

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Wallin, Henrik. « Habitat selection, reproduction and survival of two small carabid species on arable land : a comparison between Trechus secalis and Bembidion lampros ». Ecography 12, n^o 3 (octobre 1989) : 193–200. http://dx.doi.org/10.1111/j.1600-0587.1989.tb00838.x.

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Jorgensen, Jeffrey C., et James F. Kitchell. « Growth potential and host mortality of the parasitic phase of the sea lamprey (Petromyzon marinus) in Lake Superior ». Canadian Journal of Fisheries and Aquatic Sciences 62, n^o 10 (1 octobre 2005) : 2343–53. http://dx.doi.org/10.1139/f05-144.

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Landlocked Lake Superior sea lampreys (Petromyzon marinus) cause a significant but uncertain amount of mortality on host species. We used a sea lamprey bioenergetics model to examine the scope of host sizes vulnerable to death as a consequence of sea lamprey feeding and incorporated the bimodal lake-ward migration of parasitic sea lampreys. At their peak feeding rate and maximum size (P = 1.0, proportion of maximum consumption), spring migrants were capable of killing lean lake trout (Salvelinus namaycush) hosts ≤ 2.0 kg, which was larger than fall migrants (1.8 kg). Spring migrants feeding on Pacific salmon (coho (Oncorhynchus kisutch), Chinook (Oncorhynchus tshawytscha), and steelhead (Oncorhynchus mykiss)) killed hosts ≤ 2.0 kg, but fall migrants killed hosts as large as 2.8 kg. Although there is no direct empirical evidence, bioenergetics modeling suggests that it is plausible that some of the largest sea lampreys in Lake Superior spent more than one summer as parasites. Two-summer parasites readily attained sizes of sea-run adult anadromous sea lampreys and killed hosts from 3 to >5.5 kg in size. The maximum upper limit number of 2-kg hosts killed by two-summer parasites was nearly twice that of one-summer parasites.

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Mallatt, Jon, R. Dale McCall, J. Franklin Bailey et James Seelye. « Effects of lampricides on the gill ultrastructure of larval sea lampreys and rainbow trout fry ». Canadian Journal of Zoology 72, n^o 9 (1 septembre 1994) : 1653–64. http://dx.doi.org/10.1139/z94-221.

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Larval lampreys (Petromyzon marinus) and rainbow trout fry (Oncorhynchus mykiss) were exposed to toxic solutions of the lampricidal chemicals TFM (3-trifluormethyl-4-nitrophenol) and Bayer 73 (5,2′-dichloro-4′-nitrosalicylanilide). Both species were exposed to their 9-h LC100 for 9 h or until they were near death. The respiratory lamellae of the gills were then studied with transmission electron microscopy. In lampreys, damage was confined to presumed ion-uptake cells. Both lampricides produced similar changes in these cells: cell rounding, enlargement of mitochondrial profiles, vacuolization of the cytoplasm, and widening of the intercellular spaces. Bayer 73 caused a greater incidence of necrosis of ion-uptake cells than did TFM. Exposure to lethal TFM/Bayer-73 mixtures (containing 0.4–1.6% Bayer 73) affected lamprey gill lamellae in the same way as did Bayer 73. Unlike lamprey gills, trout gills were entirely unaltered by levels of the lampricides lethal to trout. These findings suggest that (i) disruption of ion-regulating cells contributes to the mortality of lampreys exposed to lampricides and to the high susceptibility of lampreys to TFM; (ii) the mechanisms of cytotoxicity of TFM and Bayer 73 are similar.

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Wong, Marty K. S., et Yoshio Takei. « Characterization of a native angiotensin from an anciently diverged serine protease inhibitor in lamprey ». Journal of Endocrinology 209, n^o 1 (10 janvier 2011) : 127–37. http://dx.doi.org/10.1530/joe-10-0422.

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Angiotensinogen belongs to family A serine protease inhibitors (SERPIN family) and we have cloned and characterized SERPIN genes in two lamprey species, which possess all the properties of angiotensinogen. The putative angiotensinogens in lampreys can be considered as an evolutionary link between SERPIN and other angiotensinogen according to the phylogenetic analyses. The inferred sea lamprey angiotensinogen gene was expressed abundantly in liver and to a lesser extent in other tissues. The predicted lamprey angiotensin I (Ang I) sequence was unique and different from the teleost-type Ang I identified previously by the incubation of lamprey plasma with its kidney extract. Therefore, we characterized and compared the biochemical and physiological properties of this native lamprey Ang II (LpAng II) (EEDYDERPYMQPF) with teleost-type Ang II (NRVYVHPF). Using a newly developed RIA for LpAng II, plasma levels in Japanese lamprey were measured (157.4±35.2 fmol/ml, n=6), but teleost-type Ang II was undetectable. In conscious cannulated lamprey, LpAng II at 100 pmol/kg elicited a transient vasodepressor effect. At doses higher than 300 pmol/kg, a biphasic cardiovascular response with an initial vasodepressor effect followed by a transient rebound vasopressor effect was observed in a dose-dependent manner. However, teleost-type Ang II was not vasoactive up to 1 nmol/kg. In Japanese eel, LpAng II injection up to 3 nmol/kg did not alter the cardiovascular parameters. Our results suggested that the renin–angiotensin system first appeared in cyclostomes, and LpAng II could be important for the regulation of cardiovascular dynamics in lampreys because of its potent and acute vasoactive effect.

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Brown, J. A., et J. C. Rankin. « Lack of glomerular intermittency in the river lamprey lampetra fluviatilis acclimated to sea water and following acute transfer to iso-osmotic brackish water ». Journal of Experimental Biology 202, n^o 8 (15 avril 1999) : 939–46. http://dx.doi.org/10.1242/jeb.202.8.939.

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Previous studies have suggested that in the lamprey Lampetra fluviatilis, in contrast to teleost fish, all glomeruli are actively filtering. In the present study, we have applied the ferrocyanide technique to obtain more definitive values for the population of filtering nephrons in the lamprey under conditions of high (in fresh water) and low (in sea water) glomerular filtration rate (GFR) and when the branchial osmotic gradient was eliminated by acute transfer of freshwater lampreys to iso-osmotic brackish water. These studies demonstrated that the renal antidiuresis in lampreys acclimated to full-strength sea water does not involve any reduction in the filtering population of glomeruli. Transfer to brackish water significantly reduced GFR and thereby urine flow rate (287+/−23 ml kg-1 24 h-1 in fresh water; 6.9+/−2.5 ml kg-1 24 h-1 in brackish water). In four of the eight fish examined, 100 % of glomeruli remained filtering; in the other four fish, non-filtering glomeruli occurred in patches along the kidney, always associated with an absence of vascular perfusion, which implies possible endocrine/neural control of vascular tone. The numbers of non-filtering glomeruli were always small, and these glomeruli do not appear to make a major contribution to the overall decline in urine output. The results provide firm evidence that although lampreys, like teleosts, show considerable variations in urine output, the renal mechanisms by which lampreys and the teleosts achieve this differ fundamentally, with glomerular intermittency playing little or no part in the lamprey.

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Bartels, Helmut, Margaret F. Docker, Ursula Fazekas et Ian C. Potter. « Functional and evolutionary implications of the cellular composition of the gill epithelium of feeding adults of a freshwater parasitic species of lamprey, Ichthyomyzon unicuspis ». Canadian Journal of Zoology 90, n^o 10 (octobre 2012) : 1278–83. http://dx.doi.org/10.1139/z2012-089.

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This paper provides the first description of the cellular composition of the gill epithelium of feeding adults of Ichthyomyzon unicuspis Hubbs and Trautman, 1937 (silver lamprey), a parasitic species of lamprey that is confined to fresh water. The surface layer of this epithelium consists solely of pavement cells and intercalated mitochondria-rich cells, which are the only cell types found in all freshwater stages of lampreys and thus considered responsible for the uptake of Na+ and Cl– in hypotonic environments. This epithelium does not contain, however, the chloride cells present during the marine parasitic phase of anadromous lamprey species, such as Petromyzon marinus L., 1758 (sea lamprey), and which are responsible for secreting excess Na+ and Cl–. The absence of this cell type in parasitic adults of I. unicuspis also differs from its presence in parasitic adults of landlocked P. marinus and metamorphosing individuals of the exclusively freshwater nonparasitic species Lethenteron appendix (DeKay, 1842) (American brook lamprey), and which thus reflects the retention of a cell type that was crucial for osmoregulation during the marine phase of their respective anadromous parasitic ancestors. The absence of chloride cells in I. unicuspis is consistent with the hypothesis that Ichthyomyzon, which is at or close to the base of the phylogenetic tree for Northern Hemisphere lampreys (Petromyzontidae), evolved in fresh water or has been confined to fresh water for a very long period.

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Holland, J. M., J. N. Perry et L. Winder. « The within-field spatial and temporal distribution of arthropods in winter wheat ». Bulletin of Entomological Research 89, n^o 6 (décembre 1999) : 499–513. http://dx.doi.org/10.1017/s0007485399000656.

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AbstractThe within-field spatial distribution of some common farmland arthropods from the Carabidae, Araneae and Collembola was assessed using two-dimensional grids of pitfall traps distributed across whole winter wheat fields. In the first year, the extent to which arthropod capture was influenced by location within the field and sampling intensity was examined using a nested grid design (1.5 m, 7.5 m and 30 m spacings). In the second year, distributions within two different-sized winter wheat fields were compared. Spatial pattern and association between arthropods and weed cover were analysed using SADIE and trend surfaces were used to visualize distributions. Many of these arthropod groups exhibited aggregated distributions within the fields in clusters larger than 30 m across, demonstrating that the numbers captured will vary depending on the location of sampling within a field. Amara species, Bembidion lampros Herbst, Carabidae and Lycosidae were predominantly found within 60 m of the field edge. Nebria brevicollis Fabricius and Pterostichus madidus Illiger were found within the field in patches of one and two hectares, respectively. Linyphiidae were relatively homogeneously distributed across the fields. There was some evidence of clustering by Collembola. The spermophagous Carabidae and Lycosidae were positively associated with the degree of weed cover. SADIE analytical techniques were useful for identifying the importance and location of patches with greater and less than average numbers, although a minimum of 36 sample points is recommended.

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Sobrido-Cameán, Daniel, Luis Yáñez-Guerra, Alexandre Deber, María Rodicio et Antón Barreiro-Iglesias. « Expression of Kisspeptin 1 in the Brain of the Adult Sea Lamprey Petromyzon marinus ». Life 11, n^o 11 (3 novembre 2021) : 1174. http://dx.doi.org/10.3390/life11111174.

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Kisspeptin peptides play major roles in the regulation of reproduction and puberty onset in mammals. While most mammals only have one kisspeptin gene, other jawed vertebrates present two or three genes. Recent data also revealed the presence of two genes in lampreys (jawless vertebrates). However, apart from gene sequence data, there is almost no information on the kisspeptinergic system of lampreys. Here, we report phylogenetic and cluster-based analyses showing that the duplication of the ancestral kisspeptin gene occurred before the separation of jawless and jawed vertebrates. We also studied the expression of the kisspeptin transcripts in the brain of post-metamorphic juveniles and upstream migrating adult sea lampreys. Our in situ hybridization results revealed expression of kisspeptin 1 in hypothalamic neurons, which indicates that the hypothalamic expression of kisspeptins is an ancestral character in vertebrates. We also observed the presence of kisspeptin 1 expressing neurons in the paratubercular (posterior tubercle) nucleus of the diencephalon. This is the first description of the presence of kisspeptin 1 expressing neurons in this brain region in any vertebrate. We did not detect expression of kisspeptin 2 in the juvenile or adult sea lamprey brain with in situ hybridization. Our data provides an anatomical basis to study the role of kisspeptin 1 in the hypothalamic-pituitary system of lampreys and the contribution of diencephalic kisspeptinergic neurons to different circuits of the lamprey brain.

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Reinhardt, U. G., L. Eidietis, S. E. Friedl et M. L. Moser. « Pacific lamprey climbing behavior ». Canadian Journal of Zoology 86, n^o 11 (novembre 2008) : 1264–72. http://dx.doi.org/10.1139/z08-112.

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New lamprey-friendly fishways feature inclined ramps that facilitate passage of Pacific lampreys ( Lampetra tridentata (Richardson, 1836)) over Bonneville Dam on the Columbia River, USA. We observed the lampreys moving against water at two flow volumes and on two ramps of 45° and 18° angles relative to horizontal. We documented climbing movements using high-speed video (125 frames/s). Lampreys advanced on the ramps by repeated cycles of attaching to the ramps by their sucker mouths (resting phase), bending their bodies into a W shape (stage II), and then, rapidly straightening the body to propel themselves up the ramp, with simultaneous brief (20–140 ms) release of suction (stage III). We inferred that lampreys were using burst swimming to propel themselves up the ramp, because we observed inflection points in the body curvature traveling toward the posterior of the body and the center of mass moving up, during stage III. This climbing behavior is not described for any other fish species. Vertical motion, relative to the ground, during each cycle of movement was greatest in the 45° ramp – low water flow volume treatment (mean of 0.07 L/cycle), but the movement upstream along the ramp plane was greatest on the 18° ramp, regardless of flow volume. These findings can be used to develop ramp designs that maximize lamprey climbing performance.

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Talabishka, E. M., N. G. Bogutskaya et A. M. Naseka. « Local migration and feeding habits of Carpathian lamprey Eudontomyzon Danfordi (Petromyzontes : Petromyzontidae) in Tisza River System (Danube drainage, Ukraine) ». Proceedings of the Zoological Institute RAS 316, n^o 4 (25 décembre 2012) : 361–68. http://dx.doi.org/10.31610/trudyzin/2012.316.4.361.

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The paper presents data on the feeding habits and migratory activity of Carpathian lamprey Eudontomyzon danfordi Regan, 1911, one of the few predatory lampreys resident in rivers. Observations made in winter revealed some feeding activity though it was commonly supposed that the lampreys cease feeding by the end of autumn. The most intensive feeding occurs from May till August; during the same period, the lampreys actively migrate upstream. Observations made at the rapids revealed that E. danfordi actively preys and feeds during day time when and where the concentration of its prey is high, not only in the evening or at night as was believed earlier.

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Sobrido-Cameán, Daniel, Ramón Anadón et Antón Barreiro-Iglesias. « Expression of Urocortin 3 mRNA in the Central Nervous System of the Sea Lamprey Petromyzon marinus ». Biology 10, n^o 10 (28 septembre 2021) : 978. http://dx.doi.org/10.3390/biology10100978.

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In this study, we analyzed the organization of urocortin 3 (Ucn3)-expressing neuronal populations in the brain of the adult sea lamprey by means of in situ hybridization. We also studied the brain of larval sea lampreys to establish whether this prosocial neuropeptide is expressed differentially in two widely different phases of the sea lamprey life cycle. In adult sea lampreys, Ucn3 transcript expression was observed in neurons of the striatum, prethalamus, nucleus of the medial longitudinal fascicle, torus semicircularis, isthmic reticular formation, interpeduncular nucleus, posterior rhombencephalic reticular formation and nucleus of the solitary tract. Interestingly, in larval sea lampreys, only three regions showed Ucn3 expression, namely the prethalamus, the nucleus of the medial longitudinal fascicle and the posterior rhombencephalic reticular formation. A comparison with distributions of Ucn3 in other vertebrates revealed poor conservation of Ucn3 expression during vertebrate evolution. The large qualitative differences in Ucn3 expression observed between larval and adult phases suggest that the maturation of neuroregulatory circuits in the striatum, torus semicircularis and hindbrain chemosensory systems is closely related to profound life-style changes occurring after the transformation from larval to adult life.

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Rous, Andrew M., Adrienne R. McLean, Jessica Barber, Gale Bravener, Theodore Castro-Santos, Christopher M. Holbrook, Istvan Imre, Thomas C. Pratt et Robert L. McLaughlin. « Spatial mismatch between sea lamprey behaviour and trap location explains low success at trapping for control ». Canadian Journal of Fisheries and Aquatic Sciences 74, n^o 12 (décembre 2017) : 2085–97. http://dx.doi.org/10.1139/cjfas-2016-0445.

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Crucial to the management of invasive species is understanding space use and the environmental features affecting space use. Improved understanding of space use by invasive sea lamprey (Petromyzon marinus) could help researchers discern why trap success in large rivers is lower than needed for effective control. We tested whether manipulating discharge nightly could increase trap success at a hydroelectric generating station on the St. Marys River. We quantified numbers of acoustically tagged sea lampreys migrating up to, and their space use at, the hydroelectric generating station. In 2011 and 2012, 78% and 68%, respectively, of tagged sea lampreys reached the generating station. Sea lampreys were active along the face, but more likely to occur at the bottom and away from the traps near the surface, especially when discharge was high. Our findings suggest that a low probability of encountering traps was due to spatial (vertical) mismatch between space use by sea lamprey and trap locations and that increasing discharge did not alter space use in ways that increased trap encounter. Understanding space use by invasive species can help managers assess the efficacy of trapping and ways of improving trapping success.

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Mickle, Megan F., Scott M. Miehls, Nicholas S. Johnson et Dennis M. Higgs. « Hearing capabilities and behavioural response of sea lamprey (Petromyzon marinus) to low-frequency sounds ». Canadian Journal of Fisheries and Aquatic Sciences 76, n^o 9 (septembre 2019) : 1541–48. http://dx.doi.org/10.1139/cjfas-2018-0359.

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Hearing ability is well studied across teleost fishes in general, and vertebrates more broadly, but little is known about sound detection abilities of lampreys (Petromyzontiformes), a basal extant vertebrate group. The sea lamprey (Petromyzon marinus) is a destructive invader of the Laurentian Great Lakes, while numerous lamprey species (including the sea lamprey) are imperiled in their native ranges. In both management scenarios, behavioral manipulation tactics to control movement and distribution are desired. Therefore, we describe the hearing ability and behavioral responses of adult and juvenile sea lamprey to sound to reveal how hearing may have evolved in vertebrates and determine possible management applications. Based on auditory evoked potentials, sea lamprey detected tones of 50–300 Hz with equal sensitivity, but did not detect sounds above 300 Hz. In a laboratory bioassay, sea lamprey behaviorally responded to sound range of 50–200 Hz, with a general increase in swimming and a decrease in resting behaviours at both juvenile and adult stages relative to no-sound controls. To our knowledge, this is the first test of lamprey hearing, and the results support that sound may be a means to modify lamprey behaviour for management purposes.

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Hardisty, M. W., I. C. Potter et R. W. Hilliard. « Physiological adaptations of the living agnathans ». Earth and Environmental Science Transactions of the Royal Society of Edinburgh 80, n^o 3-4 (1989) : 241–54. http://dx.doi.org/10.1017/s0263593300028686.

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ABSTRACTThe modes of life and environments of the extant agnathans (cyclostomes) are discussed in relation to their adaptations to temperature, light, oxygen and salinity. As their antitropical distribution indicates, both hagfishes and lampreys are cold water groups. Since hagfishes live in deeper waters than lampreys, they are not exposed to the marked seasonal changes in temperature and light which influence major events in the lamprey life cycle. Both groups tend to be nocturnally active, either burrowing during daylight as in the case of larval lampreys (ammocoetes) and most hagfishes, or showing cryptic behaviour as in the case of adult lampreys. Olfaction plays a major part in the location of prey, presumably aided in adult lampreys by their eyes and sensitive electrosensory system. Rates of standard oxygen consumption, ventilatory frequency and heart rate of adult lampreys increase at night. Standard oxygen consumption is relatively low in ammocoetes (as it also is in hagfishes) but increases markedly during metamorphosis into the adult lamprey. Ammocoetes and hagfishes, and to a lesser extent adult lampreys, are resistant to reduced environmental oxygen tensions. Differences in the oxygen dissociation curves of ammocoetes, adult lampreys and hagfishes can be related to differences in the characteristics of their monomeric haemoglobins and their environments and modes of life. The extraordinary tolerance of the hagfish heart to hypoxia is a reflection of a robust capacity for glycolysis, an LDH isozyme geared towards anaerobic functioning and a low work output. The hagfishes, which are restricted to marine waters, are osmoconformers. The osmolality of their blood, which is almost wholly attributable to inorganic ions, is virtually identical to that of full strength sea water (c. 1000 mOsmkg−1). By contrast, the osmolality of the blood of larval and adult lampreys when in fresh water is only 205-260 mOsm kg−1, i.e. about one quarter to one fifth of those of hagfish, and these rise only to 240-270 mOsm kg−1 in the adults of anadromous lampreys in sea water. The regulation of ions by adult lampreys is achieved by mechanisms similar to those adopted by teleosts. The implications of the contrasting ionic and osmotic physiology of the two living groups of agnathans are discussed in relation to their possible environmental history and against the background of their Carboniferous fossil representatives.

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Smith, Jeramiah J., Nataliya Timoshevskaya, Chengxi Ye, Carson Holt, Melissa C. Keinath, Hugo J. Parker, Malcolm E. Cook et al. « The sea lamprey germline genome provides insights into programmed genome rearrangement and vertebrate evolution ». Nature Genetics 50, n^o 2 (22 janvier 2018) : 270–77. http://dx.doi.org/10.1038/s41588-017-0036-1.

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AbstractThe sea lamprey (Petromyzon marinus) serves as a comparative model for reconstructing vertebrate evolution. To enable more informed analyses, we developed a new assembly of the lamprey germline genome that integrates several complementary data sets. Analysis of this highly contiguous (chromosome-scale) assembly shows that both chromosomal and whole-genome duplications have played significant roles in the evolution of ancestral vertebrate and lamprey genomes, including chromosomes that carry the six lamprey HOX clusters. The assembly also contains several hundred genes that are reproducibly eliminated from somatic cells during early development in lamprey. Comparative analyses show that gnathostome (mouse) homologs of these genes are frequently marked by polycomb repressive complexes (PRCs) in embryonic stem cells, suggesting overlaps in the regulatory logic of somatic DNA elimination and bivalent states that are regulated by early embryonic PRCs. This new assembly will enhance diverse studies that are informed by lampreys’ unique biology and evolutionary/comparative perspective.

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LeBlanc, P. J., T. E. Gillis, M. F. Gerrits et J. S. Ballantyne. « Metabolic organization of liver and somatic muscle of landlocked sea lamprey,Petromyzon marinus, during the spawning migration ». Canadian Journal of Zoology 73, n^o 5 (1 mai 1995) : 916–23. http://dx.doi.org/10.1139/z95-107.

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The metabolic organization of liver and muscle of the landlocked sea lamprey, Petromyzon marinus, during the spring spawning migration was assessed by measuring activities of key enzymes for several metabolic pathways, the oxidative properties of mitochondria, and plasma concentrations of nonesterified fatty acids (NEFAs) and free amino acids. These determinations indicate that several metabolic sources are used to fuel the energy requirements of muscle. Lamprey muscle has a high capacity to oxidize lipids but the plasma NEFAs are lower than those reported for other species. Of the NEFAs measured in plasma, 18:0 was prominent, accounting for 23% of the total NEFA content of the plasma. High plasma concentrations of ketogenic amino acids and high levels of tissue ketogenic/ketolytic enzyme activities indicate that ketone bodies may also be a major fuel source for migrating sea lampreys. Based on mitochondrial oxidation and enzyme measurements, glutamine catabolism in somatic muscle of lampreys is less important than in other fish red muscle.

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Suzuki, K., RL Gamble et SA Sower. « Multiple transcripts encoding lamprey gonadotropin-releasing hormone-I precursors ». Journal of Molecular Endocrinology 24, n^o 3 (1 juin 2000) : 365–76. http://dx.doi.org/10.1677/jme.0.0240365.

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The cDNA encoding lamprey prepro-gonadotropin releasing hormone-I (lamprey GnRH-I) has been isolated and sequenced in an agnathan, the sea lamprey, Petromyzon marinus. The lamprey GnRH-I precursor is the first identified in an ancient lineage of vertebrates and has the same overall tripartite structure as other vertebrate GnRH precursors. The amino acid sequence of lamprey GnRH-I and the processing site (Gly-Lys-Arg) are highly conserved during 500 million years of evolution with 60-70% identity compared with those of tetrapod and teleost GnRH precursors. In contrast, the GnRH associated peptide regions are markedly divergent, with less than 20% identity compared with all identified vertebrate precursors. Unlike all other known vertebrate GnRH precursors, which typically have one and in a single case two transcripts, three distinct transcripts were isolated and sequenced in lampreys. These lamprey GnRH-I transcripts, termed GAP49, GAP50 and GAP58, differed in the length of the GAP coding sequence and were demonstrated to be the products of a single gene. Analysis of the lamprey GnRH-I gene intron-2 splice junction demonstrated that alternate splicing produces the different lamprey GnRH-I transcripts. Lamprey GnRH-I is the first GnRH gene demonstrated to utilize splice sequence variants to produce multiple transcripts, which may reflect an ancestral gene regulatory mechanism.

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Neave, F. B., N. E. Mandrak, M. F. Docker et D. L. Noakes. « An attempt to differentiate sympatric Ichthyomyzon ammocoetes using meristic, morphological, pigmentation, and gonad analyses ». Canadian Journal of Zoology 85, n^o 4 (avril 2007) : 549–60. http://dx.doi.org/10.1139/z07-032.

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We assessed characters that could be used to differentiate ammocoetes of chestnut lamprey ( Ichthyomyzon castaneus Girard, 1858), northern brook lamprey ( Ichthyomyzon fossor Reighard and Cummins, 1916), and silver lamprey ( Ichthyomyzon unicuspis Hubbs and Trautman, 1937). We sampled ammocoetes of the three species from 25 streams around the Great Lakes. Existing genetic markers were used to identify chestnut lamprey for this study, but the lack of genetic markers for silver and northern brook lampreys forced our preliminary classification of these two species to be based on stream-specific catch records of adults. Comparison of ammocoete gonads was inconclusive as a technique to distinguish between these two species. Other characters examined (including pigmentation patterns, morphometric characters, body shape, and myomere counts) varied significantly among species, but were inadequate for use as diagnostic characters because of high intraspecific variation and overlapping ranges. Chestnut lamprey ammocoetes were sometimes distinguishable by their pigmented lateral line organs, but this character was not always apparent. The lack of distinguishing characteristics makes existing taxonomic keys misleading for identifying Ichthyomyzon lamprey larvae.

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Renaud, Claude B., Klaus L. E. Kaiser, Michael E. Comba et Janice L. Metcalfe-Smith. « Comparison between lamprey ammocoetes and bivalve molluscs as biomonitors of organochlorine contaminants ». Canadian Journal of Fisheries and Aquatic Sciences 52, n^o 2 (1 février 1995) : 276–82. http://dx.doi.org/10.1139/f95-028.

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Lamprey ammocoetes were determined to be as suitable as adult bivalve molluscs for monitoring persistent organochlorine contaminants in the freshwater environment. Ammocoetes of four lamprey species and adults of three bivalve mollusc species, collected from the same seven rivers of the St. Lawrence River basin in Québec, were assayed for 21 organochlorine pesticides and for polychlorinated biphenyl (PCB) congeners. All organochlorine compounds assayed were detected in one or more of the 15 lamprey samples whereas Aldrin, β-BHC, and PCB congeners 1, 3, 12(13), 29, 54, 189, 191, and 199 were not detected in any of the nine bivalve samples. Nine pesticides (Aldrin, Dieldrin, γ-BHC, α-Chlordane, γ-Chlordane, o,p′-DDD, p,p′-DDD, p,p′-DDT, and a-Endosulfan) had higher concentrations in the lampreys. PCB congeners 167(185) and 209 had higher concentrations in bivalves. PCBs accounted for 96.6–99.4% of the organochlorine lipid burden in bivalves, but only 33.4–76.8% in lampreys. On average, ammocoetes had 44 times more lipids per body dry weight than did bivalves. The differences observed in concentrations and types of organochlorine compounds found in the two taxa may be due to differences in the amounts (observed) and types (postulated) of body lipids they each possess.

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