Impact of endosulfan on the profiles of phospholipids at sublethal concentration in the male Heteropneustes fossilis (Bloch)

Male Heteropneustes fossilis were exposed for 30 days at sublethal concentration (0.002 ppm) during different phases of its annual reproductive cycle. Its impact on total phospholipids (TP), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatdylinositol (PI) and phosphatidylethanolamine (PE) were measured in liver, plasma and testes. During preparatory phase, in general, the levels for TP, PC, PS, PI and PE decreased after endosulfan exposure in the above tissues. During prespawning and spawning phases, the phospholipids also showed decreasing trend. The postspawning phase, exhibited decline in hepatic levels of PS and PI only and remained unaffected in the other two tissues. During the resting phase too, the hepatic levels of TP, PS and PI declined and remained unaltered in others. The present results indicate that endosulfan have very selective effects on phospholipids classes during different phases of the annual reproductive cycle interfering with the production of lipid deprived energy i.e. vitellogenin. In general, endosulfan has inhibitory role during reproductive growth affecting phospholipid biosynthesis via hepatic enzyme systems as well as by hormonal imbalance.     

Endosulfan induced changes in phospholipids in the freshwater female catfish, Heteropneustes fossilis (Bloch)

The catfish, H. fossilis were exposed to endosulfan for 30 days at sub-lethal concentration (0.002 ppm) during different phases of its annual reproductive cycle. Its impact on total (TP) and different phospholipids- phosphatidylcholine (PC), phosphatidylserine (PS), phosphatdylinositol (Pl) and phosphatidylethanolamine (PE) were measured in liver plasma and ovary. On pesticide exposure, during preparatory phase, the hepatic TP PC and PE were declined. The plasma levels of TP, PC and PS were declined with the elevation of PE whereas in ovary only PC was lowered after endosulfan exposure. During pre-spawning phase, the hepatic TP, PC and PE declined in liver plasma and ovary after endosulfan exposure. During spawning phase, only plasma and ovarian phospholipids showed decrease in their levels following endosulfan exposure. In the post-spawning phase, endosulfan elevated the levels of TP, PC and PS in ovary but had no effect on their levels in liver and plasma. During resting phase, the TP, PC and Pl were found to be decreasing its levels. Thus it appears that this pesticide interfere with phospholipids metabolism during annual reproductive cycle of this species.     

Changes in tissue cholesterol and serum cortisol level during four reproductive phases of the male freshwater fish, Notopterus notopterus

The tissue cholesterol and serum cortisol changes during four reproductive phases has been studied in the freshwater fish Notopterus notopterus of male sex during four phases, preparatory (January - March), prespawning (April - May), spawning (August - September) and post spawning (November - December). The cholesterol content of the testis and liver increased during preparatory phase and maximum content of cholesterol was during spawning phase. The serum cortisol estimated by radioimmunoassay (RIA) technique which indicated that the level of the hormone was high during pre-spawning and spawning phases compared to other two phases. The increase in cholesterol during preparatory and spawning phases may be because of increase in cortisol synthesis needed for testicular growth and spermetogenesis during these phases. The gonadosomatic index (GSI) also increased during these phases.     

Role of cortisol on condition factor in the female freshwater fish, Notopterus notopterus during four reproductive phases

The condition of the female fish, Notopterus notopterus was studied during four phases of the reproductive cycle in control and after cortisol hormone treatment. The condition of the fish including condition factor (K) and somatic condition factor (Ks) was determined based on weight of the body, length of the fish and gonad weight. In control fish the condition of the fish improve during prespawning phase compared to other phases. The hormone cortisol level estimated by radioimmunoassay (RIA) technique was found to be increased in preparatory and decreased during prespawning phase, may be because of the hormone involvement in metabolic activity, vitellogenesis. In cortisol treatment, the condition of the fish decrease during prespawning phase, compared to other phase may be because of extra expenditure of energy for progressing reproductive activity such as vitellogenesis.     

Seasonal ovarian cycle in freshwater teleost, Labeo rohita (Ham.) in Tarai region of Uttaranchal

Seasonal ovarian cycle, based on histophysiological changes, and correlative variations in liver were studied in an Indian major carp, Labeo rohita reared in captivity under ambient environmental conditions in Tarai region of Uttaranchal. The oocyte features used for marking ovarian cycle included nuclear-ooplasmic ratio, yolk vesicle incorporation into ooplasm, number and size of nucleolus and differentiation of follicular layer. Based on these features the ovarian cycle in L. rohita was divided into five phases i.e. resting, preparatory, pre-spawning, spawning and post-spawning/regression. The resting and preparatory phases were characterized by the dominating presence of chromatin-nucleolar and yolk-vesicle stage oocytes. The pre-spawning phase ovary was marked by the prevalence of yolk globule stage oocytes having cortical alveoli and differentiating follicular wall. The oocytes containing densely packed yolk-granules and large masses of yolk vesicles and also exhibiting germinal vesicle movement (GVM) signified the ovary of spawning phase. The ovary in regression phase contained pre-ovulatory atretic oocytes and significant number of oogonia. The histophysiological changes in liver showing augmented biosynthetic activity during preparatory and pre-spawning phases seemed well correlated with the gonadal development. The increasing water temperature and day-length apparently was favourable for the gonadal development in L. rohita.     

Tissue cholesterol and serum cortisol level during different reproductive phases of the female freshwater fish Notopterus notopterus (Pallas)

In the present study tissue cholesterol and serum cortisol changes during two reproductive phases have been correlated in the freshwater fish Notopterus notopterus. The reproductive cycle of N. notopterus has two phases such as breeding phase (April - August) and non breading phase (October - December). The cholesterol content of the ovary and liver increased during breeding phase. The serum cortisol estimated by radio immuno assay (RIA) technique indicates that the level of the hormone was high during breeding phase compared to non breading phase. The increase in cholesterol during breeding phase may be because of increase in cortisol synthesis needed for ovarian growth and vitellogenesis. The gonadosomatic index (GSI) also increases during breeding phase.     

Sorption of the natural endocrine disruptors,oestrone and 17 beta-oestradiol in the aquatic environment

Adsorption of hydrophobic contaminants at the particle/water interface is one of the key processes controlling their fate in the aquatic environment. The sorption of the natural female hormones oestrone and 17-oestradiol has been studied under simulated riverine conditions. Both the kinetics and the effects of varying fundamental environmental parameters (e.g. sediment properties) on the thermodynamic equilibrium partition coefficient (K _p) have been studied in continuous and batch sorption experiments, respectively. Results showed that the sorption of oestrone and 17-oestradiol by sediment was relatively slow, reaching equilibrium in 50 days. In addition, relatively small adsorption of both oestrone and 17-oestradiol onto the sediment was observed, with K _p values between 200 and 250 mL g^–1. The comparable K _p values of the two compounds reflect their structural similarity. It can be concluded that the two endocrine disruptors, oestrone and 17-oestradiol remain primarily in association with the aqueous phase.     

Histopathological changes in liver of Heteropneustes fossilis exposed to cypermethrin

Cypermethrin was administered to Heteropneustes fossilis in chronic concentration to determine lesion of liver as indicators of tissue damage. The cypermethrin dose used was 1/4 of 96 hr LC50. Histopathological changes in liver ranged from vacuolization, necrosis, fibrosis of perivascular region and disposition of yellow brown grains at different time of exposure viz; 20th, 30th, 40th and 60th days.     

Ovary structure and oogenesis in Cirratulus cirratus (Polychaeta: Cirratulidae)

Oogenesis in polychaetes has, in most species, two main phases: a coelomic phase during which vitellogenesis occurs, and an ovarian phase. Details of the latter are known in very few species. Efficient reproduction requires coordination between these two phases of oocyte differentiation. The ovaries of Cirratulus cirratus (O. F. Müller) occur 2/segment throughout the fertile region of the body; 5 main stages of oocyte differentiation can be recognised on them: stem cells, oogonia, premeiotic oocytes, early oocytes and terminal oocytes. A quantitative study of the composition of the ovary throughout the reproductive cycle shows that the ovary size is approximately constant, but that the percentage of cells in the terminal oocyte stage is reduced to zero prior to spawning. This stage in oocyte differentiation is therefore a critical one, at which oogenesis may be arrested. The ovary alternates between a proliferative phase when the terminal oocytes are present, and a non-proliferative phase when they are absent. The overall rate of germ cell production for each ovary is low, less than 1 cell/ovary/day, and the, ovary tissue turnover time is greater than 2 years. A qualitative model describing the production of oocytes is presented, and the implications of the low rate of germ cell production are discussed. A low rate of germ cell proliferation, as in Cirratulus cirratus, implies that the rate of oocyte output into the coelom will be controlled by factors influencing the later stages of ovarian oocyte differentiation.     

Changes in phospholipase A2 activity and lipid content during early development of Atlantic halibut (Hippoglossus hippoglossus)

During early development in fish, phospholipase A₂ (EC 3.1.1.4) regulates membrane lipid modifications, which relates to changes in environmental conditions and provision of fatty acids required for metabolic energy substrates and prostaglandin biosynthesis. A method to analyze phospholipase A₂ in rat tissues has been modified to measure its activity in embryonic Atlantic halibut (Hippoglossus hippoglossus L.). Egg and embryo samples were collected during the 1994 spawning season. Enzyme activity was undetectable at fertilization but in 10-d embryos was 230 pmol mg⁻¹ h⁻¹ (at 20 °C) and increased by ∼120% at hatch (17-d). Significant alterations in the fatty acid composition of important phospholipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), were also observed. The content of some critical polyunsaturated fatty acids, and the ratio of unsaturated/saturated fatty acids, declined significantly over development. Acyl-chain restructuring mediated through the activity of phospholipase A₂, coupled with other observed lipid changes (significant increases in the PC/PE ratio and cholesterol content), would produce a decreased fluidity of membranes during embryonic development, coinciding with the predicted upward movement of larvae in the water column. Arachidonic acid (20:4n-6) removed from PE could serve as a precursor for biosynthesis of 2-series prostaglandins, and eicosapentaenoic acid (20:5n-3) from PC is a likely source for other prostaglandin types. Despite removal of polyunsaturated fatty acids, there was an overall increase in lipid and fatty acid concentration, which can be attributed to amino acid catabolism during early developmental stages. Received: 9 September 1996 / Accepted: 8 September 1997     

Changes in dopamine,norepinephrine and serotonin levels in the pituitary,telencephalon and hypothalamus during gonadal development of male <Emphasis Type="Italic">Lutjanus argentiventris</Emphasis> (Teleostei)

Biogenic amines are important in the regulation of certain aspects of teleost reproduction, but relatively little is known about variations in their levels in the nervous system during the reproductive cycle. The aim of this study was to investigate changes in the levels of dopamine (DA), norepinephrine (NE), serotonin (5-HT), the DA metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) and the 5-HT metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the pituitary and brain (hypothalamus and telencephalon) of the adult male of the tropical marine yellow snapper Lutjanus argentiventris during the reproductive cycle (quiescent, prespawning and spawning periods). Gonad weight, gonad/body weight ratio and plasma-testosterone levels increased steadily throughout gonadal development, but 17#-estradiol levels did not vary significantly. Pituitary DA and DOPAC levels and the DOPAC/DA ratio declined with gonadal development, whereas hypothalamic DOPAC level and DOPAC/DA ratio increased. In the telencephalon, DA and DOPAC levels and DOPAC/DA ratio all peaked in the prespawning period; however, DA level was lowest in the spawning period, whereas DOPAC level and DOPAC/DA ratio were both lowest in the quiescent period. Telencephalic NE, 5-HT and 5-HIAA levels likewise all peaked in the prespawning period, and were lowest in the spawning period. Telencephalic 5-HIAA/5-HT ratio peaked in the quiescent period and was lowest in the spawning period. No significant variation was observed either in pituitary NE level or in hypothalamic NE, 5-HT and 5-HIAA levels. The present results indicate that males of L. argentiventris show a decline in pituitary DA activity during gonadal development. We discuss the possible involvement of biogenic amines in the regulation of GTH II secretion, through direct action on the pituitary or indirect modulation of gonadotrophin-releasing hormone neuron activity.     

Action of eyestalks on the ovary in Rhithropanopeus harrisii and Crangon crangon (Crustacea: Decapoda)

The annual cycle of ovarian activity and eyestalk effects on the ovary in different phases of its activity were examined in the crab Rhithropanopeus harrisii Gould ssp. tridentatus Maitland, and the sand shrimp Crangon crangon L. In both species, the annual ovarian cycle consists of two phases of vitellogenesis and the resting phase. In R. harrisii, the eyestalks exert an inhibitory effect on vitellogenesis during the phase of vitellogenesis outside the breeding season, and are necessary for the process of oviposition during the breeding season. In C. crangon, ovary-inhibiting hormone is present in the eyestalks outside the breeding season, and has not been detected during this season. The resting phase of the ovary after the breeding season is caused by the ovary-inhibitiing hormone. Females of C. crangon are a suitable material for testing ovary-inhibiting hormone activity, while female R. harrisii are not.     

Toxicity of cypermethrin on total lipids and free fatty acids in liver,muscle, kidney and ovary of Clarias batrachus (L) and recovery response

Alterations in the levels of lipid metabolites, total lipids and free fatty acids, were studied in physiologically important tissues viz; liver, muscle, kidney and ovary of a freshwater edible fish Clarias batrachus. The fish was exposed to sublethal concentration (1/3 of LC50 value for 96?h) of a synthetic pyrethroid insecticide, cypermethrin for 1, 5 and 10 days. After 10 days of exposure, fish were released into fresh water and total lipids and free fatty acids were determined at intervals of 1, 5 and 10 days to assess fish recovery response after cessation of cypermethrin exposure. Fish showed an increased rate of lipogenesis in liver, muscle, kidney and ovary during the exposure period followed by a decrease after transfer of fish into fresh water. There was also an elevation in liver and kidney free fatty acids contents, while the muscle and ovary free fatty acid contents were reduced during exposure period. The alterations in free fatty acids were restored to near normal values after 10 days of cessation of exposure.     

Changes in lipid class and fatty acid contents in the ovary and midgut gland of the female fiddler crab Uca tangeri (Decapoda,Ocypodiadae) during maturation

Changes in biochemical composition, lipid class and fatty acid contents were studied in the ovaries and midgut glands of the fiddler crabs Uca tangeri Eydoux during maturation. Wild females were caught during spring and early summer of 1992 in the Bay of Cádiz (southwest Spain), near the mouth of the San Pedro river. Protein and total lipid contents in the ovaries increased significantly from Stages III to IV, at the expense of total carbohydrate, which showed a large decrease during the same period. In the midgut gland, the protein content did not present any significant variation, whereas total lipids and total carbohydrates presented opposite up and down trends during maturation. In the ovary, total polar lipids increased significantly during the final phase of maturation (Stages III to IV), mainly due to the significant contribution of the phosphatidylcholine and phosphatidylethanolamine fractions. In contrast, total neutral lipids showed an upward trend throughout the whole maturation period, mainly due to significant increases of the triacylglycerol fraction. In the midgut gland, total polar lipids (mainly phosphatidylcholine) and total neutral lipids (mainly triacylglycerol) presented significant decreases from Stages II to III, the phase which preceded major increases in both polar and neutral lipids in the ovaries. Cholesterol content did not vary during maturation in either organ, in the ovary or midgut gland. Major fatty acids in the ovaries [16:0, 16:1 (n-7), 18:1 (n-9), 18:1 (n-7), 18:2 (n-6), 18:3 (n-3), 20:4 (n-6), 20:5 (n-3) and 22:6 (n-3)] did, however, accumulate significantly at later stages of maturation. It is noteworthy that arachidonic acid [20:4 (n-6)] content remained constant during all stages of maturation but decreased significantly in total polar lipids in the later phases of maturation. In contrast, eicosapentaenoic acid [20:5 (n-3)] increased significantly in all lipid fractions in the later stages, and docosahexaenoic acid [22:6 (n-3)] remained constant in the polar lipids and increased during later stages in the triacylglycerol fraction. Major fatty acids in the midgut gland lipids showed significant decreases from Stages II to III, just before the final period of maturation.     

Manipulation of the seasonal reproductive cycle in winter flounder,Pleuronectes americanus,using a gonadotropic hormone releasing hormone

A gonadotropic hormone-releasing hormone analogue ([D-Ala⁶, Pro⁹-NHEt]LHRH, GnRH-A) was administered to the winter flounder, Pleuronectes americanus (Walbaum) at different stages of the reproductive cycle from September 1988 to July 1989. Both males and females responded to releasing hormone treatment throughout the year except for a brief summer period in post-spawned fish when the gonads were regressed. In females, GnRH-A markedly increased plasma estradiol-17 and testosterone levels and accelerated growth of the ovaries during the period of early gonadal recrudescence beginning in August. In prespawning females, GnRH-A treatment increased plasma testosterone levels in association with a stimulation of germinal vesicle migration and ultimately ovulation. During the fall, GnRH-A treatment of males increased plasma androgen levels (testosterone and 11-ketotestosterone) and stimulated growth of the testes. In February, a time when spermiation is initiated in only half of the males, the proportion of spermiating males was increased by treatment with releasing hormone, indicating that spermiation can be advanced in some males by ca. 2 mo.A portion of this work was given as a poster presentation at the XIth International Symposium on Comparative Endocrinology, Malaga, Spain, May 14–20, 1989     

A correlative study on liver glycogen and endosulfan toxicity in Heteropneustes fossilis (Bloch.)

The biochemical tests were conducted to find out the relationship between liver glycogen and endosulfan toxicity on a catfish, Heteropneustes fossilis (Bloch.) using 0.00075, 0.00050 and 0.000375 ppm concentrations for 15, 30, 45 and 60 days of exposure periods. The quantity of liver glycogen showed decreasing trend as concentration of toxicant increased. The depletion in glycogen contents is greatly affiliated to cellular damage in hepatic cells.     

内分泌干扰物莠去津对鲫鱼血清激素的影响

为了研究低剂量条件下,内分泌干扰物莠去津对鲫鱼血清激素的影响,探讨其作用机理和剂量-效应关系,同时筛选出敏感的生物标志物,实验以除草剂莠去津对鲫鱼进行低剂量染毒(染毒浓度0～3mg·L-1),采用放射免疫法测定莠去津长期暴露下(60d)幼年雄性鲫鱼血清中性激素(17β-雌二醇(E2)、睾酮(T))及甲状腺激素(促甲状腺激素(TSH)、三碘甲状腺原氨酸(T3))的浓度,并将测定结果与空白对照及溶剂对照进行比较.结果发现:1)莠去津长期暴露下,各处理组鲫鱼血清E2浓度普遍升高,0.023、0.094、1.500、3.000mg·L-1组与空白对照相比,升高显著(p<0.05);2)各处理组鲫鱼血清T浓度与空白对照相比均无显著性差异(p>0.05);3)莠去津长期暴露下,低浓度莠去津组(0.006、0.023mg·L-1组)鲫鱼血清TSH浓度与空白对照相比差异不显著(p>0.05),而高浓度莠去津组(0.094、1.500、3.000mg·L-1组)则显著降低(p<0.05);4)类似地,莠去津长期暴露下,低浓度莠去津组(0.006、0.023、0.094、0.375、1.500mg·L-1组)鲫鱼血清T3浓度与空白对照相比差异不显著(p>0.05),只有高浓度莠去津组(3.000mg·L-1组)显著升高(p<0.05).实验结果表明,低剂量长期暴露下,莠去津对鲫鱼体内性激素及甲状腺激素具有一定的干扰作用,尤其是对17β-雌二醇影响更为显著,因此,17β-雌二醇可作为评价农药内分泌干扰效应的生物标志物.     

Effect of cortisol on female freshwater fish Notopterus notopterus

In the present study, effect of cortisol on the ovary of the freshwater fish Notopterus notopterus was studied during four phases of the reproductive cycle. The hormone was injected 60microg/fish for ten days. Cortisol in fish is known to increase the metabolic activity. After the hormone treatment the ovarian somatic index and the hepatosomatic index increases during non breeding phase. The young oocytes transferred into vitellogenic oocytes in all the phases after cortisol treatment. The cortisol induced increased ovarian activity may be due to increase in the metabolic activity through the involvement of hepatic cells specially during non-breeding period providing support for energy production for reproductive activity in the freshwater fish N. notopterus.     

Scent-marking behavior in wild groups of common marmosets (Callithrix jacchus)

Scent-marking in mammals has been frequently related to within-group social and reproductive dominance and to defense of territory and resources. We studied the scent-marking behavior of five wild groups of common marmosets, Callithrix jacchus, during 5 months of the fruiting season in northeastern Brazil. Circumgenital marking was the most common type of marking. Marks were distributed throughout the home range and were deposited mainly during travel and intergroup encounters. Although marks were commonly deposited at gum trees, there was no evidence that the animals used scent marks to label fruiting trees or sleeping sites. Contrary to expectations, reproductively dominant females did not mark more than reproductively subordinate females. Moreover, during intergroup encounters, reproductively subordinate females displayed higher frequencies of scent-marking than the reproductively dominant females of their group. Our results suggest that scent-marking is not strictly tied to reproductive dominance or territorial (or resource) defense in common marmosets. Because marks provide information about individual identity and reproductive condition, scent marks could serve different functions when used by different individuals. The high frequency of marking by reproductively subordinate females during intergroup encounters suggests that scent-marking might be used to signal to individuals of neighboring groups. Our data highlight the importance of social and ecological variables in scent-marking behavior. Received: 26 October 1998 / Received in revised form: 20 May 1999 / Accepted: 30 May 1999     

Growth and elemental composition (C,N, H) in Inachus dorsettensis (Decapoda: Majidae) larvae reared in the laboratory

Larvae of the spider crab Inachus dorsettensis were reared in the laboratory at constant 12 °C. Development lasted 8 to 10 d in the Zoea I, 10 to 12 d in the Zoea II and 14 to 20 d in the megalopa stage. During this time, larval growth was measured in samples taken every 2 to 4 d as dry wt (W), carbon (C), nitrogen (N), and hydrogen (H); energy content (E) was calculated from C. Biomass and energy (per individual) increased in each larval stage as a parabola-shaped function of age, which could be fitted by a power equation. C, H, and E show a higher percentage gain (relative to the initial values at hatching) than W or N, suggesting that proportionally more lipid than protein is accumulated during larval development. There are cyclical changes in the relative (per unit of W) biomass and energy figures, corresponding to the larval moult cycles: immediately after each ecdysis all these values decrease, presumably due to rapid uptake of water and minerals, then they increase again due to tissue growth and remain high until the next moulting occurs. Cyclical changes in the C/N ratio suggest that proportionally more lipid than protein is accumulated during the initial (postmoult) phase of the moult cycle, followed by a period of balanced or protein-dominated gain during the intermoult and premoult phases. These patterns of growth and elemental composition observed during the complete larval development and in single moult cycles of I. dorsettensis are compared with those described in the literature for other decapod species. This comparison suggests a high degree of similarity in biochemical composition and growth characteristics of larval decapod crustaceans.