Academic literature on the topic 'Gonad condition'
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Journal articles on the topic "Gonad condition"
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Sulistiono, Suzana Refiani, Fadly Y. Tantu, and Muslihuddin. "Gonad Maturity of Coconut Crab (Birgus latro) in Pasoso Island, Central Sulawesi." Jurnal Akuakultur Indonesia 8, no. 2 (July 1, 2009): 175. http://dx.doi.org/10.19027/jai.8.175-184.
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<p>Study on gonad maturity of coconut crab (<em>Birgus latro</em>) was carried out from June 2004 to January 2005. Crabs were collected by some gears such as trap, net and by hand. Observation was done to know sex ratio, gonad maturity and eggs diameter, while analysis was employed to estimate condition factor, gonado somatic index and fecundity. Observation result showed that condition factor, gonad maturity and gonado somatic index varied depending on sampling month. Gonado somatic index showed a high value around November/December. A similar result was also showed by condition factor and gonado somatic index that was high around November /December. Fecundity varied from 58.717 to 197.400. Oocyte diameter varied from 0,015 to 0,035 mm, had one mode that is clasified to be a total spawner.</p> <p>Keywords : Gonad maturity, coconut crab (<em>Birgus latro</em>), total spawner.</p> <p> </p> <p>ABSTRAK</p> <p>Penelitian tentang kematangan gonad kepiting kelapa (<em>Birgus latro</em>) dilakukan sejak Juni 2004 sampai Februari 2005. Sampel kepiting ditangkap dengan menggunakan beberapa peralatan, yaitu perangkap, jaring dan secara langsung dengan tangan. Pengamatan dilakukan terhadap jenis kelamin, kematangan gonad dan diameter telur, sedangkan analisis dilakukan untuk menentukan faktor kondisi, indeks kematangan gonad, dan fekunditas. Hasil pengamatan menunjukkan bahwa faktor kondisi, kematangan gonad dan indeks kematangan gonad bervariasi tergantung dari bulan pengambilan contoh. Pengamatan kematangan gonad menunjukkan bahwa nilai tertinggi terdapat pada November/Desember. Keadaan yang sama juga ditunjukkan dengan nilai faktor kondisi dan indeks kematangan gonad yang cukup tinggi pada bulan November /Desember. Fekunditas berkisar antara 58.717-197.400 butir telur. Diameter telur berkisar antara 0,015-0,035 mm, memiliki 1 puncak sehingga dapat diklasifikasikan sebagai total spawner.</p> <p>Kata kunci : Kematangan gonad, kepiting kelapa (<em>Birgus latro</em>), total spawner.</p>
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Varkentin, Alexander I. "Seasonal dynamics of gonads maturity and indices of body condition for walleye pollock Theragra chalcogramma in the northern part of the Okhotsk Sea." Izvestiya TINRO 180, no. 1 (March 30, 2015): 77–92. http://dx.doi.org/10.26428/1606-9919-2015-180-77-92.
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Seasonal dynamics of gonad maturity and body condition indices (liver weight, hepato-somatic index, weight-size ratio) is analyzed for walleye pollock in the northern Okhotsk Sea. Its spawning season is rather long both for the whole population and any spawning ground, e.g. at West Kamchatka the fish with melting gonads is observed from December to September and probably later, but the mass spawning continues about one month - in March-April, on average. After the spawning, a new annual biological cycle begins from the period of gonad recuperation (stages of gonad maturity VI and VI-II) that continues 2-3 months followed by the period of gonad maturation from the stage III to the next spawning. The portion of the pollock females and males with the stage III is the highest in August-September, and with the stage IV - in March, before the mass spawning. In the northern Okhotsk Sea, the dynamics of maturing is similar, with the lag of 2-3 weeks. However, the gonad maturing depends on thermal conditions: they develop faster in «warm» years than in «cold» ones. Besides, big fish begin to spawn earlier than small ones spawning in the first time. Males usually stay on the spawning grounds longer than females. Body condition of walleye pollock is influenced by the process of gonad maturation. Energy potential of its individuals forms until August-September, and begins to decrease when gonads transform from the stage III to the stage IV. Later the indices of body condition continue to decrease till spawning in March-April, and melting individuals and postspawners have the lowest values. After the spawning, the indices begin to grow again because of active feeding.
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Young, P. C., G. J. West, R. J. McLoughlin, and R. B. Martin. "Reproduction of the commercial scallop, Pecten fumatus, Reeve, 1852 in Bass Strait, Australia." Marine and Freshwater Research 50, no. 5 (1999): 417. http://dx.doi.org/10.1071/mf98149.
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To examine the reproduction of Pecten fumatus Reeve, 1852, samples were taken monthly from beds off King Island and in Banks Strait, from July 1986 to July 1987. For each sample the mean gonad-free tissue weight and standardized gonad weight were calculated. The percentage of the sample with each of five macroscopically determined reproductive stages was also measured. Changes in the proportion of cell types within the ovarian part of the gonad were determined by histological and stereological methods. A seasonal cycle of gonadal development occurred at each site, commencing at the time of lowest water temperatures and highest nutrient concentrations. This development progressively increased as the nutrient concentrations declined. No correlation was seen between chlorophyll a and gonad condition. A synchrony in gonad condition was present among individuals in samples; this was greatest at Banks Strait where gonads were larger, and phosphate, nitrate and silicate concentrations were significantly greater. There was no reduction in somatic tissue weight with increase in gonad tissue weight. Maximum gonad development preceded spatfall at each site by about one month.
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Joll, LM, and N. Caputi. "Geographic variation in the reproductive cycle of the saucer scallop, Amusium balloti, (Bernardi, 1861) (Mollusca:Pectinidae), along the Western Australian coast." Marine and Freshwater Research 46, no. 4 (1995): 779. http://dx.doi.org/10.1071/mf9950779.
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The reproductive cycle of the saucer scallop Amusium balloti was examined at three sites spanning a large part of the north-south range of the species on the western coast of Western Australia. Variations in gonad dry weight were highly cyclical, with minimum gonad weights in Shark Bay (25�S) occurring between January and March and maximum gonad weights occurring around July or August. The pattern of variation in gonad weight at the Abrolhos Islands (29�S) and Fremantle (32�S) was similarly cyclical, but the times of high and low gonad weights occurred at similar times at both sites and approximately two months later than in Shark Bay. The variations in gonad weight were associated with large variations in meat weight and condition, which would need to be considered in any yield analyses of fisheries for this species. Gonad dry weight increased rapidly following the end of the resting period, and histological examination showed that gonads contained mature gametes within one to two months of the end of the resting period. Although gonad weights continued generally to increase over a period of three to four months following the end of the resting period, variations in gonad weight during this period indicated that partial spawning may be occurring before the time of peak gonad weight. Residual gametes were observed in the ciliated ducts of scallop gonads within one to two months of the start of the rapid increase in gonad weight until the onset of the resting period, indicating that partial spawning was occurring throughout this time. Estimation of the settlement dates of recruits supported the conclusion that spawning commenced shortly after gonads began their rapid weight increase and suggested that spawning may follow a lunar cycle. Partial spawning provides multiple opportunities for larvae to develop in environments conducive to high larval survival and may be an important factor in determining recruitment success.
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Ramofafia, Christain, Maria Byrne, and Stephen Battaglene. "Reproductive biology of the intertidal sea cucumber Actinopyga mauritiana in the Solomon Islands." Journal of the Marine Biological Association of the United Kingdom 81, no. 3 (June 2001): 523–31. http://dx.doi.org/10.1017/s0025315401004179.
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Over a four year period, gonad index, examination of gonad tubules, and histology were used to study the reproduction in the sea cucumber Actinopyga mauritiana. This species reproduced annually during the warmer months of the year in Solomon Islands. This annual reproductive cycle progressed through five maturity stages: recovery, growing, mature, partly-spawned and spent. The recovery stage (March–May) was marked by initiation of gametogenesis and coincided with decreasing day length. The growing stage (June–September) was characterized by development of gametes through to the mature stage (October–December). Spawning occurred October through December and coincided with increased water temperature and day length. Spent gonads (January–March) contained a few unspawned gametes or completely lacked gametes. Although A. mauritiana had annual reproduction, individuals lacking or having indeterminate gonads were present year-round. Macroscopic examination of gonad tubules after biopsy provides a practical tool for assessing maturity condition of broodstock in the field during the reproductive season.
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Pawson, M. G., and G. D. Pickett. "The Annual Pattern of Condition and Maturity in Bass, Dicentrarchus Labrax, in Waters Around England and Wales." Journal of the Marine Biological Association of the United Kingdom 76, no. 1 (February 1996): 107–25. http://dx.doi.org/10.1017/s0025315400029040.
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Morphometric data on bass, Dicentrarchus labrax L. (Pisces: Percoidei), sampled around the coasts of England and Wales between 1982 and 1990, have been analysed to elucidate seasonal patterns of feeding, body condition and gonad maturity. The somatic condition and fat reserves of bass in the Irish Sea and southern North Sea improved more rapidly during the spring and summer than in bass further to the south. In winter, however, fat reserves were higher and there was more food in the stomachs of bass caught in the western English Channel. The onset of maturity was related to fish length. Male bass became mature for the first time at 32–36 cm total length, but though many females showed signs of gonad growth at this size, no female <42 cm was found with mature (ripe or spent) gonads. Gonad development in adult bass of both sexes began in October and, from January until June, most males >36 cm had ripe testes. The period during which ripe eggs could be expressed from the ovaries of female bass was briefer, with spawning apparently peaking in April. It is concluded that the migration of adult bass to the north in spring and southwards and westwards in autumn has both growth and reproductive benefits related to sea temperature, and that the more limited movements of bass <42 cm, which remain in relatively cold, inshore waters in winter, results in an inhibition of gonad maturity in females.
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Bernet, Daniel, Thomas Wahli, Christoph Küng, and Helmut Segner. "Zooplankton Feeding Induces Macroscopical Gonad Malformations in Whitefish (Coregonus ssp.) from Lake Thun, Switzerland." Fishes 5, no. 3 (August 20, 2020): 26. http://dx.doi.org/10.3390/fishes5030026.
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Alterations in gonad morphology are widespread in wild fish populations. Whitefish (Coregonus spp.) from Lake Thun, Switzerland, display a high prevalence of macroscopical gonad malformations including fusions to the musculature, segmented gonads and intersex condition. The aim of the present study was to evaluate whether the gonad morphological changes in Lake Thun whitefish are caused by genetic factors, environmental factors (water, diet) or “gene × environment” interaction. We performed two independent experiments of a three-year duration in which we reared whitefish from fertilization until adulthood and tested the possible causative factors using a matrix design: (i) genetics—comparing the prevalence of gonad malformations in whitefish of different genetic origin reared under identical environmental conditions (same diet, same water, same experimental facility); (ii) environment—comparing the prevalence of gonad malformations in whitefish of the same genetic origin reared in different water sources and/or fed with different diets; and (iii) gene-environment interaction—comparing the prevalence of gonad morphological alterations in relation to the combinations of genetics and environmental factors. Two diets were used for the rearing experiments: either zooplankton collected in Lake Thun which represents the natural diet of whitefish, or an artificial dry food which was used as control. The key finding of this study is that the inducing factor of the gonad malformations is contained in the zooplankton of Lake Thun. Fish fed with this diet developed a significantly higher prevalence of malformations than fish from any other treatment, irrespective of the genetic origin and/or the water source. This result could be repeated in the two independent experiments. Importantly, the prevalence values observed in the experimental fish fed with Lake Thun zooplankton were similar to the prevalence values recorded in free-ranging whitefish in the lake. The findings of this study advance the understanding of the causes of gonad morphological alterations in wild fish populations.
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Oktaviyani, Selvia, and Wanwan Kurniawan. "Aspek reproduksi ikan kakap Lutjanus vitta (Quoy & Gainmard, 1824) di Teluk Jakarta dan sekitarnya." Jurnal Iktiologi Indonesia 17, no. 2 (June 24, 2018): 215. http://dx.doi.org/10.32491/jii.v17i2.360.
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Study on reproductive aspects of brownstripe red snapper Lutjanus vitta (Quoy & Gainmard, 1824) in Jakarta Bay and its surroundings can obtain important information for fish resources management. The objective of this research is to analyze length frequency distribution, sex ratio, gonadal maturation, gonado somatic index, the length at first maturity (Lm) and the average length of captured (Lc) for this fish. This research was conducted from April 2014 to January 2015 with sampling location in Tanjung Pasir Fishing Port, Tangerang. Fish sampling and of fish that were. The observed aspects included fork length, weight, sex, gonad maturity and gonad weight was done monthly. The result showed that the fork length of this fish ranged between 132-265 mm with the equal sex ratio. The capture fish are dominated by fish with immature stage. The highest of gonado somatic index was on September 2014 (2%). The fork length at first maturity (Lm) were 252 mm (male) and 187 mm (female) while the average fork length of captured (Lc) was 178 mm. This condition can cause a growth overfishing. AbstrakKajian beberapa aspek reproduksi ikan kakap Lutjanus vitta (Quoy & Gainmard, 1824) di Teluk Jakarta dan sekitarnya dapat menghasilkan informasi yang sangat penting dalam rangka pengelolaan sumber daya ikan tersebut. Tujuan pene-litian ini adalah untuk menganalisis sebaran frekuensi panjang, nisbah kelamin, kematangan gonad, indeks kematangan gonad, ukuran kali pertama matang gonad, dan rata-rata panjang tertangkap ikan kakap. Penelitian dilaksanakan pada bulan April 2014 hingga Januari 2015 di Tempat Pelelangan Ikan (TPI) Tanjung Pasir, Tangerang. Aspek yang diamati meliputi panjang cagak dan bobot tubuh ikan, jenis kelamin, kematangan gonad, dan bobot gonad. Hasil penelitian me-nunjukkan bahwa ukuran panjang cagak ikan kakap berkisar antara 132-265 mm dengan nisbah kelamin dalam keadaan seimbang. Ikan kakap yang tertangkap didominasi oleh ikan yang belum matang gonad. Indeks kematangan gonad tertinggi terjadi pada bulan September 2014 yaitu 2%. Ukuran panjang cagak kali pertama ikan matang gonad (Lm) adalah 252 mm (jantan) dan 187 mm (betina), serta panjang cagak rata-rata tertangkap (Lc) adalah 178 mm. Kondisi ini dapat menyebabkan lebih-tangkap yang mengganggu tingkat pertumbuhan ikan kakap.
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Salgado-Ugarte, Isaías Hazarmabeth. "Reproduction and Condition Indices-Body Structures Adjusted Means Comparison of Silver Perch (Bairdiella chrysoura) from Tampamachoco Lagoon, Northeastern Mexico." International Journal of Zoology and Animal Biology 5, no. 3 (2022): 1–13. http://dx.doi.org/10.23880/izab-16000384.
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Background: The study of reproduction and condition are fundamental topics in fisheries science. To this aim, there are several methods including Gonadosomatic index, Condition factors (Fulton, Ricker, relative) and hepatosomatic index. These traditional methods present several drawbacks (ratio indices with variability and distribution problems; assumption of linear relationships and of independence from length, focus on the intercept of linear models, etc.). In this study, we present an application of the multivariate analysis of covariance (MANCOVA) to analyze reproduction and condition of Bairdiella chrysoura from Tampamachoco Lagoon compared with some traditional indexes. Methods: This comparison takes into account the biological data (lengths and weights) collection of 9,505 individuals of B. chrysoura registered during an annual period (May 1990- June 1991) at five localities in the Western side of the Tampamachoco Lagoon, Mexico. We compared Gonadosomatic index, Relative Condition Factor and Hepatosomatic index values to lengthadjusted means of gonad, eviscerated and liver weights from the multivariate analysis of covariance (MANCOVA) of females, males and indeterminate sex individuals. Results: High gonad, low hepatic and condition mean values (adjusted by MANCOVA) indicated the spawning period (February to March). The opposite trend among gonad weight with both, liver and somatic weights appears to indicate the metabolism focusing on gonad development for the onset of the spawning season. The patterns described by the adjusted means from MANCOVA were highly correlated and synchronic to the traditional index values. Conclusions: Therefore, the length-adjusted mean values of gonad, eviscerated body, and liver weights represent a useful alternative to the common ratio based estimators.
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Bradford, Rodney G. "Role of spawning condition in the determination of the reproductive traits of spring- and autumn-spawning Atlantic herring from the southern Gulf of St. Lawrence." Canadian Journal of Zoology 71, no. 2 (February 1, 1993): 309–17. http://dx.doi.org/10.1139/z93-043.
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Mature spring-spawning (May–June) and autumn-spawning (August–September) herring differ in total weight. Autumn herring have both heavier gonads and higher somatic weights at length. Both the residual levels of storage lipids and somatic weight at length, corrected for storage lipid, are higher in autumn than in spring. Within spawning seasons, males and females deplete the same amount of storage energy. Percent somatic lipid content is positively correlated with body size during spring but shows no relationship to body size in autumn. These patterns indicate that the relative allocation of storage energy to reproduction differs with spawning season. Spring spawners (lengthy gonad maturation period) allocate proportionally more storage energy to routine and active metabolism than autumn spawners (brief gonad maturation period). The low intercept and steep slope of the gonad weight – length relationship for spring spawners reflect the interaction between decreasing metabolic rate with body size and increasing storage energy capacity with body size. Egg weight is unrelated to the parent's somatic lipid content for either spawning group. Spawning history (recruit versus repeat spawning) has only a minor influence on egg weight.
Dissertations / Theses on the topic "Gonad condition"
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Oates, Mark. "Observations of Gonad Structure and Gametogenic Timing in a Recovering Population of Ostrea lurida (Carpenter 1864)." Thesis, University of Oregon, 2013. http://hdl.handle.net/1794/13329.
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From January 2012 to December 2012 I collected adult oysters from two intertidal populations on a monthly basis in the Coos Bay estuary, Oregon for histological analysis of their gonads. Gametogenesis and spawning occur seasonally from May through September, when water temperatures exceed 14.5° C, with brooding oysters found from July through September. Oocyte diameters increased significantly from May to June, and from June to July within oyster populations at Haynes Inlet and Coalbank Slough, respectively. Male gametogenesis initiated in May at Haynes Inlet and in June at Coalbank Slough. Dry meat condition values increased significantly during periods of reproduction and decreased following the reproductive season's end. Condition index values for Coalbank Slough were consistently lower than those at Haynes Inlet, suggesting poor nutrition or physiological stress. Salinities below recorded physiological thresholds are believed to be the primary environmental factor influencing the discrepancy in reproductive activity at Coalbank Slough.
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Livore, Juan Pablo. "Strength of sea urchin herbivory and condition from biogeographic to organismal scales." Thesis, 2012. http://hdl.handle.net/2440/75506.
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Amongst the many ecological processes that can have an influence on community structure within marine ecosystems, herbivory is recognised as having an important role. Algae are not only living components of the community, they often provide a physical structure, food and protection indispensable for many other species. Therefore, understanding herbivore behaviour and their effects on the surrounding habitat is vital to further comprehend benthic marine ecosystem dynamics. Strength of herbivory is often determined by simple numbers of individual herbivores. There are however, other factors that may influence herbivore feeding behaviour such as food quantity and quality. Changes in food availability can have a strong influence on the dynamics of consumers that rely on allochthonous sources as their main supply of energy. I tested the hypothesis that a decrease in per capita food supply to a sedentary herbivore has a negative effect on herbivore condition and also affects the surrounding habitat through changes herbivore feeding behaviour. The reduction in food supply had a negative influence on herbivore gonad condition, whilst concomitant increases in consumer density caused greater foraging of the surrounding habitat. Poor consumer condition can be the result of food limitation and in some cases can lead to stronger herbivory. This process could help explain barrens creation across many subtidal rocky coasts. Ecological traits may have a stronger influence on population and community dynamics than currently acknowledged; particularly sedentary herbivores that may be incapable of migrating to alternate environments. I assessed the effects of origin of food and its frequency of delivery on sea urchin behaviour and condition. Higher consumption rates and poorer condition were associated with food originating from sheltered coasts; coinciding with observations of urchin over-grazing in this type of Environment. Whilst algae derived from exposed coasts caused lower consumption rates and better condition; coinciding with no urchin over-grazing on exposed reefs. Understanding such trait-mediated responses to allochthonous food may assist the development of more comprehensive models that account for variation in strength of
herbivory. Many studies have focussed on foraging of canopy-forming algae by sea urchins associated with barrens, however, foraging effects of urchins not associated with barrens is less clear. I tested the hypothesis that the sedentary (largely site attached) sea urchin Heliocidaris erythrogramma has detectable effects on the canopy-forming and understory algae. In a location where densities were at the upper limits of their range of a region that lacks sea urchin barrens, algal cover was estimated beneath and immediately around sea urchins. The area under the urchins was consistently bare rock. Sea urchin removal experiments showed that canopy-forming algae were able to develop in greater covers after 16 months and approached those in areas that naturally lacked urchins. In the area immediately surrounding the sea urchins, turf-forming algae dominated the first 5-6 cm, whilst at 8 cm canopy-forming algal cover matched areas without urchins. Cover of canopy-forming algal can be reduced in the presence of non-barren forming urchins, albeit only within a few centimetres of individual urchins. This suggests that such organismal-scale effects may have an influence on the ecology of rocky coasts with dense populations of these urchins (e.g. sheltered coasts). In conclusion, strength of herbivory can depend on many factors that vary across a broad range of scales. In this thesis, I provide knowledge on some of the factors associated with herbivory by the purple sea urchin, Heliocidaris erythrogramma. I show that herbivore abundance and condition which can directly affect strength of herbivory vary at regional (i.e. Eastern Australian Current v. Leeuwin Current) and local scales (ie. sheltered v. exposed coasts). I also demonstrate that drift-algal quantity and origin can have a strong influence on sea urchin condition and feeding behaviour. Finally, the organismal scale effect (i.e. centimetres) may not only be detectable but also influential at some places and scales. Together, these results suggest that populations of herbivores, their condition and impact, may have predictable effects from local through regional scales. The integration of such dependencies to general models may contribute to a more comprehensive understanding of rocky subtidal ecosystems.Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2012
Books on the topic "Gonad condition"
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V. N. V. K. Sastry. Between Gond rebellions. [Hyderabad?, India]: V.N.V.K. Sastry, 1989.
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Chauhan, Abha. Tribal women and social change in India. Etawah: A.C. Bros., 1990.
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N, Sharma K. K., ed. Genetic demography: A case study of Raj Gond tribe. Delhi: Academic Excellence, 2005.
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The Maria Gonds of Bastar. Delhi: Oxford University Press, 1991.
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The scheduled tribes in transition: A sociological study of Gonds. New Delhi: Classical Pub. Co., 2008.
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Banerjee, B. G. Tribal demography of Gonds. Delhi: Gian Pub. House, 1988.
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Yadav, Smita. Precarious Labour and Informal Economy: Work, Anarchy, and Society in an Indian Village. Palgrave Macmillan, 2018.
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Yadav, Smita. Precarious Labour and Informal Economy: Work, Anarchy, and Society in an Indian Village. Palgrave Macmillan, 2018.
Find full textBook chapters on the topic "Gonad condition"
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Gooren, Louis J. G. "Transsexualism." In Oxford Textbook of Endocrinology and Diabetes, 1463–68. Oxford University Press, 2011. http://dx.doi.org/10.1093/med/9780199235292.003.9134.
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Transsexualism is the condition in which a person with apparently normal somatic sexual differentiation is convinced that he/she is actually a member of the opposite sex. It is associated with an irresistible urge to be hormonally and surgically adapted to that sex. Traditionally transsexualism has been conceptualized as a purely psychological phenomenon, but research on the brains of male-to-female transsexuals has found that the sexual differentiation of the brain—the bed nucleus of the stria terminalis (BSTC) and the hypothalamic uncinate nucleus—had followed a female pattern (1). This finding may lead to a concept of transsexualism as a form of intersex, where the sexual differentiation of the brain (which in mammals also undergoes sexual differentiation) is not consistent with the other variables of sex, such as chromosomal pattern, nature of the gonad and nature of internal/external genitalia. Thus it can be argued that transsexualism is a sexual differentiation disorder.
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"Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques." In Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques, edited by Edie Marsh-Matthews and William J. Matthews. American Fisheries Society, 2010. http://dx.doi.org/10.47886/9781934874141.ch23.
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<em>Abstract</em>.—Using artificial stream mesocosms, we conducted two experiments in consecutive summers to examine proximate and residual effects of simulated drought on survivorship, body size, condition, and reproduction of fishes common in southern Oklahoma streams. In summer 2000, we examined proximate effects on central stonerollers <em>Campostoma anomalum</em>, bigeye shiners <em>Notropis boops</em>, black-stripe topminnow <em>Fundulus notatus</em>, longear sunfish <em>Lepomis megalotis</em>, and orange-throat darters <em>Etheostoma spectabile </em>exposed to either continuous flow or to simulated drought for 40 d. Survivorship did not differ between treatments for central stonerollers, bigeye shiners, or orangethroat darters, but was lower in the drought treatment for both blackstripe topminnow and longear sunfish. Body size of survivors in the drought treatment tended to be smaller for central stonerollers. Condition of bigeye shiner and central stoneroller individuals was lower in the drought treatment, and bigeye shiner females exposed to drought were less likely to have mature eggs. In summer 2001, we simulated drought for 35 d and examined residual effects on central stonerollers, bigeye shiners, and orangethroat darters approximately 6 months later. Survivorship assayed in spring 2002 was marginally lower for orangethroat darters. Body size of central stonerollers in the drought treatment was smaller, consistent with proximate effects of drought on body size. Bigeye shiners did not differ between treatments in either body size or condition, indicating no residual effect of drought on fat stores despite much lower condition immediately following drought in summer 2000. For orangethroat darters, individuals exposed to drought tended to be larger and in better condition and to have more mature gonads than individuals in the flow treatment after the recovery period. The results of our two experiments demonstrate that drought affects survival, growth, body condition, and reproduction in different ways for different species, and proximate effects do not necessarily predict residual effects on fishes that survive drought.
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Allchin, Douglas. "Male, Female, and/ or — ?" In Sacred Bovines. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190490362.003.0024.
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Intersex individuals are coming out of the closet. Witness, for example, the 2003 Pulitzer Prize in Fiction for Jeffrey Eugenides’s Middlesex. The story follows someone with 5-alpha-reductase deficiency, or late-onset virilization. Imagine yourself raised as a girl, discovering at puberty (through cryptic, piecemeal clues) that you are male instead. Or male also? Or male only now? Or “just” newly virile? The condition confounds the conventionally strict dichotomy between male and female, masculine and feminine. It teases a culture preoccupied with gender. What are male and female, biologically? How does nature define the sexes, and sex itself? The questions seem simple enough. Seeking answers, however, may yield unexpected lessons—about the role of biological definitions; about assumptions concerning universals, rarities, and “normality”; and about the power of mistaken conceptions of nature to shape culture. Conceptualizing sex as male and female seems straightforward. In the standard version (familiar even to those unschooled in biology), females have two X chromosomes, while males have an X and a Y. They have different gametes: one moves, one stays stationary. These differences seem foundational. They seem to explain why male and female organisms have contrasting gonads, contrasting hormone-mediated physiologies, and contrasting secondary sex characteristics. Once-homologous organs follow divergent developmental trajectories. Perhaps even contrasting behaviors express the purported evolutionary imperative of each gamete: the “promiscuous,” uncaring male of cheap sperm, and the cunning, protective female of big-investment eggs. The apparent alignment of the two sexes through all levels of biological organization seems to validate this categorization as scientifically sound. Good biologists know better. First, sex may be determined in many ways. Birds use a “reversed,” WZ system, where females have the distinctive chromosome. Many insects have a haplodiploid system, where sex is determined by having a single or double set of all the chromosomes. Crocodiles and turtles develop their sex in response to temperature cues, not genes alone. The spoonworm Bonellia responds instead to whether females are absent or already present in the area.
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"Invasive Asian Carps in North America." In Invasive Asian Carps in North America, edited by Diana M. Papoulias, James Candrl, Jill A. Jenkins, and Donald E. Tillitt. American Fisheries Society, 2011. http://dx.doi.org/10.47886/9781934874233.ch18.
Full textAbstract:
<em>Abstract</em>.—The Asian black carp <em>Mylopharyngodon piceus </em>is of interest to the aquaculture industry in the United States as a biological control for snails and mollusks. However, past experience in North America with other Asian carps has raised concern that black carp will establish wild populations and negatively affect native populations of fish and invertebrates, especially mollusks. The demand for black carp has led biologists to seek ways to allow their use while at the same time maintaining control over their distribution and reproduction. Physical containment and restrictions on importation, release, and stocking have mostly failed. Control of reproduction holds more promise. The induction of triploidy (having three sets of chromosomes), which can render an individual biologically sterile, is of particular interest. The main purpose of this study was to evaluate the efficiency of proposed testing procedures used to assure genetic triploidy in black carp prior to distribution by the state of Missouri, using black carp and grass carp <em>Ctenopharyngodon idella</em>. Our objectives were to (1) verify if the ploidy determination methodology (nuclear size) employed was 100% accurate, (2) determine growth and survival of juvenile black carp over extended periods of time under laboratory and pond conditions, and (3) histologically examine development and gametogenesis in gonads collected from triploid and diploid black and grass carps of different ages and stages of maturation. Comparison of erythrocyte nuclear size using the Coulter counter method versus the more accurate method of flow cytometry that measures DNA content indicated an error rate of 0.25% by the former method. Black carp grew and survived well in mid-Missouri ponds. Triploid grass carp males appeared to produce functional gametes, and some triploid black carp male testes had apparently normal spermatocytes within cysts. A few normally developing oocytes at previtellogenic and vitellogenic stages were observed in triploid grass carp females, and a few normal perinuclear oocytes could be identified in triploid black carp females. Currently, the standards of the U.S. Fish and Wildlife Service’s triploid grass carp voluntary inspection program are being followed by some states to manage triploid black carp. Our results indicate that although the percentage of diploid black carp that could pass through the currently proposed screening program is small, overall numbers of diploid black carp distributed in a state could be substantial depending on the number of triploids distributed. Furthermore, despite indications that triploid male black carp can be expected to be functionally sterile, reproductive studies may be warranted given the large wild populations of diploid grass carp, bighead carp <em>Hypophthalmichthys nobilis</em>, and silver carp <em>H. molitrix </em>in the Mississippi River basin system.
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"Invasive Asian Carps in North America." In Invasive Asian Carps in North America, edited by Diana M. Papoulias, James Candrl, Jill A. Jenkins, and Donald E. Tillitt. American Fisheries Society, 2011. http://dx.doi.org/10.47886/9781934874233.ch18.
Full textAbstract:
<em>Abstract</em>.—The Asian black carp <em>Mylopharyngodon piceus </em>is of interest to the aquaculture industry in the United States as a biological control for snails and mollusks. However, past experience in North America with other Asian carps has raised concern that black carp will establish wild populations and negatively affect native populations of fish and invertebrates, especially mollusks. The demand for black carp has led biologists to seek ways to allow their use while at the same time maintaining control over their distribution and reproduction. Physical containment and restrictions on importation, release, and stocking have mostly failed. Control of reproduction holds more promise. The induction of triploidy (having three sets of chromosomes), which can render an individual biologically sterile, is of particular interest. The main purpose of this study was to evaluate the efficiency of proposed testing procedures used to assure genetic triploidy in black carp prior to distribution by the state of Missouri, using black carp and grass carp <em>Ctenopharyngodon idella</em>. Our objectives were to (1) verify if the ploidy determination methodology (nuclear size) employed was 100% accurate, (2) determine growth and survival of juvenile black carp over extended periods of time under laboratory and pond conditions, and (3) histologically examine development and gametogenesis in gonads collected from triploid and diploid black and grass carps of different ages and stages of maturation. Comparison of erythrocyte nuclear size using the Coulter counter method versus the more accurate method of flow cytometry that measures DNA content indicated an error rate of 0.25% by the former method. Black carp grew and survived well in mid-Missouri ponds. Triploid grass carp males appeared to produce functional gametes, and some triploid black carp male testes had apparently normal spermatocytes within cysts. A few normally developing oocytes at previtellogenic and vitellogenic stages were observed in triploid grass carp females, and a few normal perinuclear oocytes could be identified in triploid black carp females. Currently, the standards of the U.S. Fish and Wildlife Service’s triploid grass carp voluntary inspection program are being followed by some states to manage triploid black carp. Our results indicate that although the percentage of diploid black carp that could pass through the currently proposed screening program is small, overall numbers of diploid black carp distributed in a state could be substantial depending on the number of triploids distributed. Furthermore, despite indications that triploid male black carp can be expected to be functionally sterile, reproductive studies may be warranted given the large wild populations of diploid grass carp, bighead carp <em>Hypophthalmichthys nobilis</em>, and silver carp <em>H. molitrix </em>in the Mississippi River basin system.
Conference papers on the topic "Gonad condition"
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Soni, Abhishek, Nupur Bansal, A. K. Dhull, Vivek Kaushal, and A. K. Chauhan. "Pure primary non gestational choriocarcinoma ovary – diagnostic dilemma and treatment intricacy." In 16th Annual International Conference RGCON. Thieme Medical and Scientific Publishers Private Ltd., 2016. http://dx.doi.org/10.1055/s-0039-1685331.
Full textAbstract:
Introduction: Germ cell tumors of the ovary include all neoplasm derived from primordial germ cells of the embryonal gonad. Five percent of germ cell tumors are malignant, representing three to five per cent of all ovarian carcinomas of which pure primary non-gestational ovarian choriocarcinoma accounts for less than one per cent of ovarian tumors. Primary choriocarcinoma of ovary could be gestational or nongestational in origin. They pose diagnostic challenges in reproductive age group patients because of elevated human chorionic gonadotrophin (hCG). Non-gestational choriocarcinoma (NGCO) is resistant to single agent chemotherapy, requiring more aggressive combination chemotherapy post surgery. Due to the rarity of the disease, this article reviews the treatment protocol for NGCO. Methods: All the articles related to choriocarcinoma of ovary at Pubmed, Google scholarly article and Scopus were assessed and reviewed and their references were also reviewed and included in this article. Discussion: Clinical diagnosis of NGCO is often challenging because the clinical symptoms are often nonspecific and can mimic other, more common conditions that occur in young women, such as a hemorrhagic ovarian cyst, tuboovarian abscess, ovarian torsion, and ectopic pregnancy. The symptoms of vaginal bleeding, elevated hCG level, pelvic pain, and an adnexal mass often lead to incorrect diagnosis of ectopic pregnancy, threatened or incomplete abortion, cervical polyp, or other types of malignancy. Non-gestational choriocarcinomas have been found to be resistant to single agent chemotherapy, have a worse prognosis, and therefore require aggressive combination chemotherapy. Adjuvant chemotherapy with the EMA (etoposide 100mg/m2, methotrexate 100mg/m2, actinomycin-D 0.5mg) regimen may be given, for six to nine courses at seven days interval. Studies suggest that the disease responds well to the combination of surgery and postoperative adjuvant chemotherapy. However, long term effects of such therapy should be further studied with more cases. Conclusion: Because of the small number of patients with pure ovarian choriocarcinoma, a consensus on the treatment regimen including surgery and chemotherapy is lacking. Surgery with adjuvant combination chemotherapy is the standard treatment of choice.