Female Catfish Research Articles

From heterosis to outbreeding depression: genotype-by-environment interaction shifts hybrid fitness in opposite directions.

In F1 hybrids, phenotypic values are expected to be near the parental means under additive effects or close to one parent under dominance. However, F1 traits can fall outside the parental range, and outbreeding depression occurs when inferior fitness is observed in hybrids. Another possible outcome is heterosis, a phenomenon that interspecific hybrids or intraspecific crossbred F1s exhibit improved fitness compared to both parental species or strains. As an application of heterosis, hybrids between channel catfish females and blue catfish males are superior in feed conversion efficiency, carcass yield, and harvestability. Over 20 years of hybrid catfish production in experimental settings and farming practices generated abundant phenotypic data, making it an ideal system to investigate heterosis. In this study, we characterized fitness in terms of growth and survival longitudinally, revealing environment-dependent heterosis. In ponds, hybrids outgrow both parents due to an extra rapid growth phase of 2-4 months in year 2. This bimodal growth pattern is unique to F1 hybrids in pond culture environments only. In sharp contrast, the same genetic types cultured in tanks display outbreeding depression, where hybrids perform poorly, while channel catfish demonstrate superiority in growth throughout development. Our findings represent the first example, known to the authors, of opposite fitness shifts in response to environmental changes in interspecific vertebrate hybrids, suggesting a broader fitness landscape for F1 hybrids. Future genomic studies based on this experiment will help understand genome-environment interaction in shaping the F1 progeny fitness in the scenario of environment-dependent heterosis and outbreeding depression.

GnRHr, LHr, and Vg gene expression levels and ovarian development of G5 transgenic mutiara female catfish (Clarias gariepinus) after exposure photoperiod induction

This study aimed to determine the relative expression ratios of the genes gonadotrophin-releasing hormone receptor (GnRHr), luteinizing hormone receptor (LHr), vitellogenin (Vg) and β-actin genes as expression control internal of the G5 fish using real-time PCR in a photoperiod experiment with designed treatments (A: 8L-16D; B: 12L-12D; C: 16L-8D for transgenic fish; and A*: 8L-16D; B*: 12L-12D; C*: 16L-8D for nontransgenic fish) for 60 days of rearing period. Ovary maturation was evaluated in G5 transgenic mutiara catfish during different photoperiod induction. A short photoperiod (8L-16D) induced an high expression of GnRHr, LHr, and Vg genes (mean, 4.42 ± 0.53, 5.63 ± 0.42, and 6.67 ± 0.31, respectively), indicating the role of dark cycle in increasing the gene expressions involved in ovarian maturation of G5 transgenic mutiara catfish. The lowest GnRHr, LHr, and Vg gene expression levels were found in nontransgenic fish (C*) (mean, 1.27 ± 0.13, 1.38 ± 0.24, and 2.42 ± 0.33, respectively). The exposure of transgenic fish (CgGH insert content) to a long photoperiod (16L-8D) resulted in lower expression levels of GnRHr, LHr, and Vg (mean, 2.31 ± 0.27, 2.34 ± 0.25, and 4.49 ± 0.30, respectively) and lower levels of hormones Vg and E2 (mean, 295.16 ± 21.71 μg/mL and 0.25 ± 0.03 ng/mL, respectively) and in non-transgenic fish (mean, 163.54 µg/mL and 0.14 ng/mL, respectively). Short photoperiods (8L-16D and 12l-12D) led to oocyte maturation and higher GSI values (mean, 12.24 ± 0.53 and 10.24 ± 0.38, respectively) compared to long photoperiods (16L-8D). Conversely, a long photoperiod led to decreased GnRHr, LHr, and Vg expression levels, and Vg and E2 hormone levels, leading to the growth of immature oocytes and decreased GSI (mean, 3.93 ± 0.29) in nontransgenic fish. The presence of CgGH in G5 transgenic mutiara female catfish can maintain the growth of primary oocytes to secondary oocytes during the 16L-8D photoperiod induction.

Meiotic deviations and endoreplication lead to diploid oocytes in female hybrids between bighead catfish (Clarias macrocephalus) and North African catfish (Clarias gariepinus).

Reproductive isolation and hybrid sterility are mechanisms that maintain the genetic integrity of species and prevent the introgression of heterospecific genes. However, crosses of closely related species can lead to complex evolution, such as the formation of all-female lineages that reproduce clonally. Bighead catfish (Clarias macrocephalus) and North African catfish (C. gariepinus) diverged 40 million years ago. They are cultivated and hybridized in Thailand for human consumption. Male hybrids are sterile due to genome-wide chromosome asynapsis during meiosis. Although female hybrids are sometimes fertile, their chromosome configuration during meiosis has not yet been studied. We analyzed meiosis in the hybrid female catfish at pachytene (synaptonemal complexes) and diplotene (lampbrush chromosomes), using immunostaining to detect chromosome pairing and double-stranded break formation, and FISH with species-specific satellite DNAs to distinguish the parental chromosomes. More than 95% of oocytes exhibited chromosome asynapsis in female hybrid catfish; however, they were able to progress to the diplotene stage and form mature eggs. The remaining oocytes underwent premeiotic endoreplication, followed by synapsis and crossing over between sister chromosomes, similar to known clonal lineages in fish and reptiles. The occurrence of clonal reproduction in female hybrid catfish suggests a unique model for studying gametogenic alterations caused by hybridization and their potential for asexual reproduction. Our results further support the view that clonal reproduction in certain hybrid animals relies on intrinsic mechanisms of sexually reproducing parental species, given their multiple independent origins with the same mechanism.

Multiple biomarker responses in female Clarias gariepinus exposed to acetaminophen.

Several authors have documented the presences of acetaminophen (APAP) in both surface and groundwater and have received attention from government agencies and basic authorities across the globe. The impacts of such pharmaceutical products on non-target organism like fish are underestimated as a result of selected investigation using few biomarkers. We evaluated the sub-chronic impacts of APAP in female catfish (Clarias gariepinus) using multiple biomarkers. The exposure of female catfish to APAP induced oxidative stress. Markers such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and total antioxidant capacity (TAC) were significantly higher in all exposed groups. Exposure of Clarias gariepinus to APAPA caused histological alterations in the gills (fusion and shortening of some filaments, hyperplasia of the epithelial gill cells, aneurism, congestion, and epithelial rupture of the gills), liver (apoptotic hyperplasia, sinusoidal congestion, and necrosis of the hepatocytes), and gonad (degenerated follicles and ovarian apoptosis). Furthermore, multivariate results indicated that there was a distinct response from the acetaminophen-exposed female catfish, with over 95% of the biomarkers significantly contributing to the discrimination between the acetaminophen-exposed female catfish and the control groups. Our research provides evidence supporting the use of a multiple biomarker approach to evaluate the impacts of drugs on the health status of exposed fish.

Diets with soybean oil and l-carnitine alter lipid metabolism and improve the growth and reproduction of Rhamdia quelen females

This study aimed to evaluate the reproduction, growth, biochemical parameters of blood, hepatic and gonadal redox parameters, hepatic and gonadal histology, and lipid metabolism of silver catfish females (Rhamdia quelen) fed diets containing l-carnitine and different lipid sources. Females were fed for 223 days with eight (08) isoproteic (282 g of digestible protein kg of ration−1) and isoenergetic (13.34 MJ of digestible energy kg of ration−1) diets, containing 0.00, 0.15, 0.45, and 0.75 g l-carnitine kg−1 of feed, and soybean or marine fish oils. Feeding the females diets containing l-carnitine and the different oils resulted in an interactive effect (p < 0.05) that improved the growth and reproduction of the fish. Females fed soybean oil and 0.45 g l-carnitine kg−1 had the highest growth rates, the largest ovaries, and produced the most fertile oocytes, which resulted in the highest hatching rates. These females also showed higher levels of total cholesterol and high-density lipoprotein (HDL) cholesterol, and alterations in the levels of alanine aminotransferase in the blood, in addition to greater activity of hepatic superoxide dismutase and a greater amount of saturated fatty acids in the liver. The ovaries of these females also had the highest amount of docosahexaenoic fatty acid (DHA), highest amount of polyunsaturated fatty acids and fatty acids from the n-3 and n-6 series, and the lowest crude protein content. The interaction between l-carnitine and the lipid source of the diets promoted hepatic protection and regulated lipid metabolism and the fatty acid profile in the liver and ovaries of silver catfish females. The benefits of these interactions improved the growth and reproduction of females fed diets containing soybean oil and 0.45 g l-carnitine kg−1.

Haematological and Innate Immunological Reference Intervals for Farmed Yellow Catfish &lt;i&gt;Horabagrus brachysoma&lt;/i&gt; and Their Seasonal Variations

The reference intervals for haematological and innate immune response variables of healthy adult yellow catfish Horabagrus brachysoma raised in captivity were determined. Reference ranges were established for all parameters and significant (P &lt; 0.05) seasonal variations in most of the haematological and innate immune parameters were observed. Total erythrocyte count, packed cell volume, serum lysozyme and myeloperoxidase activities were found to be higher during winter season whereas most of the red blood cell indices, superoxide production by phagocytes, serum ceruloplasmin and anti-protease activities were marked to be significantly higher during rainy season of the year. Except high total leucocyte count and mean corpuscular haemoglobin, other parameters were found to be significantly lower during summer, possibly indicating a higher disease risk in summer months for this species. However, no significant variations in these variables were obtained between male and female catfish during breeding season. The information generated would be indirectly helpful for determining health status of this endangered species.

Effect of long-term hypoxia on the reproductive systems of female and male yellow catfish (Pelteobagrus fulvidraco).

This study investigated the effects of different levels of hypoxia on the reproductive system of yellow catfish. Yellow catfish (Pelteobagrus fulvidraco) were exposed to three dissolved oxygen concentration levels: normoxia (6.5 ± 0.2 mg/L), moderate hypoxia (MH, 3.8 ± 0.3 mg/L) and severe hypoxia (SH, 1.9 ± 0.2 mg/L) for 30 days. The gonadosomatic index of males, not females, significantly decreased in the SH group. In the SH group, for the females, the ratio of vitellogenic follicles significantly decreased, whereas the number of atretic follicles significantly increased. In male fish, a significantly reduced number of spermatozoa was observed in both the MH and SH groups. Elevated apoptosis levels in the testes and ovaries were observed only in the SH group. Serum 17β-estradiol and vitellogenin levels in females and testosterone levels in males significantly decreased in the SH group. The concentration of 11-ketotestosterone in males significantly decreased in both the MH and SH groups. In female fish, dysregulated expression of the hypothalamic-pituitary-gonadal (HPG) axis, steroidogenesis genes, and hepatic genes related to vitellogenesis were observed only in the SH group. However, in male fish, moderate hypoxia altered the expression of HPG genes, including gnrh1, lhcgr, and amh. Moreover, the MH group significantly altered the expression of steroidogenesis genes like star, 17β-hsd, and cyp17a1. The results of this study suggest that severe hypoxia can cause reproductive defects in female and male yellow catfish. Moreover, the reproductive system of male yellow catfish is more sensitive to moderate hypoxia than that of female catfish. Our findings contribute to our understanding of the response of the teleost reproductive system to long-term hypoxia.

Early Development Of Catfish Larvae Sangkuriang (Clarias gariepinus) From Feed With The Addition Of Curcumin

This study aims to identify the quality of spawning eggs and body length in the early development of catfish larvae from broodstock fed with the addition of curcumin. This research was conducted on October 22 2022 for 2 weeks on Jl. Great Aluminum No. 37, Tj. Mulia Hilir, Kec. Medan Deli, Medan City, North Sumatra 20241. The method used in this research is an experimental method. The sample used is sangkuriang catfish seeds (Clarias gariepinus) obtained from catfish breeding/cultivation. There are 2 pairs in total. Each pair consists of male and female catfish which are placed in the same pond but have been partitioned off. One pair of sangkuriang catfish will be given feed in the form of pellets with the addition of curcumin while the other pair will only be given pellets. The treatment in giving curcumin is 50% of the feed weight once a day the average body length of larvae has a body length and body weight that is higher than curcumin was not given so that the 0% curcumin treatment had the lowest body length. The increase in the diameter of the spawning larvae in the supplemented treatment group curcumin can be caused due to the bioactivity of curcumin as a hepatoprotector, and antioxidants. Curcumin supplementation is 50% of the total feed given to the parent showed more optimal results than the treatment other.

17α-Methyltestosterone enhances growth and reproductive performance of immature male Asian catfish (Clarias macrocephalus)

This study aimed to assess the effects of 17α-methyltestosterone (MT) on the growth and reproductive performance of male Asian catfish (Clarias macrocephalus). A total of 36 immature male Asian catfish (ABW = 125.97 g) were randomly distributed into 12 circular tanks, and fed with either the control diet (with no MT) or diets containing MT at 60 mg·kg-1, 90 mg·kg-1, or 120 mg·kg-1 for 45 days. Results showed that weight gain (WG), specific growth rate (SGR) and feed intake (FI) were significantly higher in the male catfish fed with diets containing 60 and 90 mg·kg-1 MT than in those fed with the control diet. Also, the diet attractability test revealed that the 60 and 90 mg·kg-1 MT groups significantly attracted more catfish than did the control diet; however, increasing MT to 120 mg·kg-1 reduced its attractability to the immature male catfish. MT-treated male catfish exhibited significantly heavier and significantly longer testes than male catfish fed the control diet at the termination of the feeding trial. These male catfish also exhibited significantly higher gonadosomatic indices (GSI) than catfish in the control group. Following induced spawning of nontreated female catfish and artificial fertilization of its eggs using testis preparation from the experimental male catfish at the termination of the feeding trial, results showed that testis preparations from all MT-treated males resulted in significantly higher fertilization (FR) and hatching rates (HR) of the eggs. In conclusion, incorporating MT to the diet improved both the growth and reproductive performance of the male Clarias macrocephalus. Precisely, dosages of optimal dietary MT using a quadratic model for maximal SGR, GSI, FR, and HR values were estimated to be 58.3, 75.0, 90.6, and 78.2 mg·kg-1, respectively.

Benfotiamine in high carbohydrate diet enhances growth and reproductive performance of the Asian native catfish Clarias macrocephalus subadults

Clarias macrocephalus has been extirpated in most regions in the Philippines and as a preliminary study towards its reintroduction, we aimed at enhancing the growth and reproductive performance of the broodstock. Several studies have identified thiamine deficiency as a factor in the extirpation of some important fish species in the wild. The present study aimed to determine the effects of elevated dietary carbohydrates and benfotiamine, a more bioavailable analog of thiamine (vitamin B1). Three diets were used, namely, a commercial diet specific for catfish was used as the control diet (Com), a high carbohydrate (HC) diet, and a benfotiamine-supplemented HC diet (HCB). Results show that survival of the subadult catfish in captivity for 10 weeks was remarkably high, exhibiting an average of 99% for all three treatments (P&gt;0.05). HCB diet resulted in significantly higher final average body weight (FABW), weight gain (WG), specific growth rate (SGR), and significantly best food conversion ratio (FCR) (P&lt;0.05) than the values for both Com and HC groups (P&gt;0.05). For the reproductive performance, female Asian catfish fed the HCB diet exhibited significantly heavier ovary and liver (P&lt;0.05) than those female catfish fed either the Com or HC diet (P&gt;0.05). GSI of the female catfish and fecundity were significantly higher in the HCB group (P&lt;0.05) than in the Com or HC group (P&gt;0.05). In the male catfish, testes were significantly heavier in the HCB group (P&lt;0.05) than in the Com or HC diet (P&gt;0.05). HSI, male LW, and LL were significantly higher in the HC and HCB groups (P&gt;0.05) than in the Com group (P&lt;0.05). GSI values of the male catfish were significantly highest in the HCB (P&lt;0.05), followed by the HC group, and significantly lowest in the Com group (P&lt;0.05). The larval survival rate for one week was significantly higher (P&lt;0.05) in the Asian catfish fed the HCB diet than in those fed the Com or HC diet (P&gt;0.05). In conclusion, elevating dietary carbohydrates in the diet from 7.70% to 22.73% (i.e., Com to HC diet, respectively) did not negatively affect the growth and reproductive performance of the Asian catfish. Further supplementation of benfotiamine at 0.02% to the HC diet enhanced significantly both the growth and reproductive performance of the Asian catfish.

Impact of ovariectomy and estradiol-17β (E2) replacement on the brain steroid levels of the Indian stinging catfish Heteropneustes fossilis

In the present study, effects of ovariectomy (Ovx) and estradiol-17β (E2) replacement on the brain steroid levels were investigated in the resting and prespawning phases of the female catfish Heteropneustes fossilis. The study showed that Ovx resulted in significant decreases in plasma levels of estradiol-17β (E2) and its precursors, and the effect varied with the reproductive stage and duration. Our study showed that E2 supplementation reversed the effect of Ovx in 3-week Ovx fish group, either restored or increased according to the dose. In contrast, E2 levels increased in the brain after Ovx in the resting stage and produced a biphasic effect of significant decreases on week 1 and 2, and significant increases on week 3, 4 and 5 in the pre-spawning stage. The brain E2 levels significantly inhibited in E2 supplementation groups. The testosterone (T) levels showed biphasic effects, an initial decrease (up to 3 weeks Ovx) and an increase later (week 4, 5) in the resting stage. In the pre-spawning stage, the T levels increased significantly after Ovx. The E2 supplementation significantly inhibited the T levels, more severely in the low dose group in the resting and pre-spawning stages. Brain 17-hydroxyprogesterone(17-OHP4) levels increased (week 1, 2, 3) but decreased on week 4 and 5 of Ovx in the resting stage and increased throughout Ovx in the pre-spawning stage except in the 5th week (though compared to other steroids, level was very low; almost negligible). The E2 replacement significantly decreased the steroid levels further down compared to the Ovx control group. Brain progesterone (P4) and pregnenolone (P5) levels decreased initially (week 1 and 2 Ovx) and recovered later. The E2 replacement significantly decreased P4 levels in the Ovx fish in the pre-spawning stage and in the lower dose group in the resting stage. The P5 levels remained inhibited after the E2 supplementation in the resting stage but unchanged or increased it in the pre-spawning stage. Brain cortisol (F) levels were inhibited initially (1 and 2 weeks and later increased after OVX in the resting stage. In the pre-spawning stage, the F levels increased in the week 1, 2 and 3 of Ovx and decreased in the 4th and 5th weeks. The E2 supplementation inhibited the cortisol (F) levels in both phases. The results show that ovarian steroids influence neurosteroidogenesis in a reproductive stage-dependent manner.

Seasonal dynamics, kinetics, and effects of 2-hydroxyestradiol-17β on some steroidogenic enzymes in the ovary of the catfish Heteropneustesfossilis

The synthesis of bioactive steroids is catalyzed by an array of enzymes of diverse properties and actions. In the present study, seasonal dynamics and kinetics of key steroidogenic enzymes, 17α-hydroxylase (Cyp17a), 3β-hydroxysteroid dehydrogenase (Hsd3b), 20α-hydroxysteroid dehydrogenase (Hsd20a) and 20β-hydroxysteroid dehydrogenase (Hsd20b) were investigated in the female catfish Heteropneustes fossilis. Further, the effects of the estrogen metabolite 2-hydroxyestradiol-17β (2-OHE2) and human chorionic gonadotropin (hCG) on activities of the above enzymes, cytochrome P450 aromatase (Cyp19a1), and steroid products including testosterone and cortisol were determined. The enzymes under investigation showed significant seasonal variations across the annual ovarian cycle with low activity in the gonad resting phase. The enzymes Hsd3b and Cyp17a showed high activity during early oogenesis but the activities of Hsd20a and Hsd20b were higher towards late oogenesis in the spawning phase. Hsd3b and Cyp17a elicited high apparent Km values (low substrate affinity) and high apparent Vmax in the vitellogenic phase compared to the postvitellogenic phase. Hsd20a did not elicit any significant differences in the kinetic parameters between the two phases. Hsd20b showed high apparent Km values (low substrate affinity) and high Vmax in the postvitellogenic phase. The incubation of ovarian slices with 2-OHE2 for 24 h increased dose-dependently Hsd3b, Cyp17a, Hsd20a and Hsd20b activities, similar to hCG. The levels of the corresponding C21 steroid products, progesterone (P4), 17α-hydroxyprogesterone (17-OHP4), 17, 20α-dihydroxy-4-pregnen-3-one (17,20α-DP) and 17,20β-dihydoxy-4-pregnen-3-one (17,20β-DP), and cortisol were elevated. However, 2-OHE2 decreased significantly the C19 and C18 steroids, testosterone and E2 levels, and Cyp19a activity. The co-incubation with hCG and 2-OHE2 produced a synergistic effect on the enzyme activities except that of CYP19a. The co-incubation reversed the inhibitory effect of 2-OHE2. The data show that 2-OHE2 exerts a dual role on steroidogenesis, stimulating the C21 pathway and inhibiting the C19–C18 pathway, resulting in the steroidogenic shift.

Modulatory Effect of Papaya Extract against Chlorpyrifos-Induced Oxidative Stress, Immune Suppression, Endocrine Disruption, and DNA Damage in Female Clarias gariepinus.

Chlorpyrifos (CPF) is one of the widely used organophosphorus pesticides in agriculture activities and its presence in the aquatic environment has been broadly recorded. In the present study, we investigated the effect of CPF exposure on oxidative stress, innate immunity, sexual hormones, and DNA integrity of female African catfish, Clarias gariepinus, in addition to the potential use of dietary supplementation of papaya, Carica papaya (CP), extract against CPF toxicity. Apparent healthy female catfish (300 ± 10 g) were divided into four groups with three replicates each. The first group served as the negative control (fed on a basal diet) and the other groups exposed to CPF (8.75 µg/L) with or without CP extract (250 mg/kg body weight) for six weeks. The results revealed that CPF exposure exhibited marked elevations in stress markers (glucose and cortisol), serum aspartate aminotransferase, alanine aminotransferase activities, testosterone, and luteinizing hormone level. Moreover, CPF increased the percentage of hepatic DNA damage. In addition, catfish exposed to CPF experienced significant decline in serum total protein, albumin, follicles stimulating hormone, estradiol hormone levels, AChE, immunoglobulin, and lysozyme activity. CPF induced significantly oxidative stress in hepatic and renal tissues. The dietary supplementation with CP extract at a level of 250 mg/kg body weight succeeded to alleviate the negative effects of CPF on the physiological, immunological, and antioxidant status of female catfish. In addition, CP extract alleviated the endocrine disruption and hepatic DNA damage and counteracted the subchronic CPF toxicity in female African catfish. Finally, the CP extract may be used as a feed additive in the aquatic diet.

Comparison of growth performance among channel-blue hybrid catfish, ccGH transgenic channel catfish, and channel catfish in a tank culture system

Fish is an essential source of high-quality protein for people worldwide. The present study was designed to compare the growth performance among the channel-blue hybrid catfish, channel catfish transgenic for the channel catfish growth hormone (ccGH) cDNA driven by the antifreeze protein promoter from an ocean pout Zoarces americanus (opAFP-ccGH), and non-transgenic channel catfish control. Mean body weight of channel-blue hybrid catfish was 15.80 and 24.06% larger than non-transgenic channel catfish control at 4 and 18 months of age, respectively. However, transgenic opAFP-ccGH channel catfish were 5.52 and 43.41% larger than channel-blue hybrid catfish and 22.19 and 77.91% larger than their controls at 4 and 18 months of age, respectively. Significant differences in mean body weight between the sexes within all genetic types were found. Males were larger than females (P < 0.001). However, mean body weight of non-transgenic males was not larger than transgenic opAFP-ccGH females or male and female hybrid catfish. Condition factor of transgenic opAFP-ccGH channel catfish was higher (P < 0.05) than that of full-sibling, non-transgenic channel catfish and hybrid catfish. The mean percentage body weight gain of GH transgenic channel catfish was 559%, the channel-blue hybrid catfish was 384.9% and their non-transgenic controls channel catfish was 352.6%.

Intraperitoneal injection of genistein affects the distribution and metabolism of cholesterol in female yellow catfish Tachysurus fulvidraco.

Genistein is an abundant phytoestrogen in soybean. This study aimed to determine the effects of genistein on cholesterol distribution and metabolism in female yellow catfish. Three hundred fish (49.2 ± 1.4g) were randomly divided into five treatments and received intraperitoneal injections as follows: (1) blank, no injection; (2) control, vehicle only; (3) E2, 17β-estradiol at 10μg·g-1 body weight; (4) low genistein doses, genistein at 10μg·g-1 body weight; (5) high genistein doses, genistein at 100μg·g-1 body weight. Both high and low genistein doses significantly reduced (p < 0.05) serum TC and LDL-C 24h after injection. Moreover, the high genistein doses significantly reduced (p < 0.05) serum HDL-C. Both high and low doses of genistein significantly increased (p < 0.05) hepatic TC. Only high genistein doses significantly increased (p < 0.05) ovary TC. In the liver, both high and low genistein doses significantly increased (p < 0.05) protein and mRNA expression of ldlr. Meanwhile, high genistein doses significantly decreased (p < 0.05) mRNA expression of hmgcr. In ovary tissue, high genistein doses significantly decreased (p < 0.05) mRNA expression of cyp11a1. These results suggested that genistein affected the cholesterol distribution in female yellow catfish. Both high and low doses of genistein reduced cholesterol content in blood and increased its content in the liver by increasing the uptake of blood cholesterol. Meanwhile, high genistein doses may inhibit hepatic cholesterol synthesis. Additionally, high genistein doses could increase cholesterol transfer from serum into the ovary and disturb cholesterol conversion to pregnenolone.

MATURASI IKAN LELE MUTIARA Clarias gariepinus BETINA DENGAN ESTRADIOL-17? MELALUI PAKAN

Some problems in catfish culture are the spawning circle, female catfish begin to mature gonad at 10 months, and after 1,5 months can spawn again. The purpose of this study was to evaluate the process of accelerating maturation female mutiara catfish with the addition Estradiol-17? by oral treatments. The study was design used 3 treatments : 0 ml/kg feed, 0,4 ml/kg feed, 0,6 ml/kg feed with three individual replications. The result showed that the addition of Estradiol-17? significantly affected on reproductive performance : Gonado Somatic Index (GSI) 102,3% and eggs diameter 16,4% in female mutiara catfish compared with 0 ml/kg feed. Key words : Clarias gariepinus, Eggs Diameter, Estradiol-17ß, Gonadosomatic Index (GSI), Reproductive Performance.

Chitosan nanoparticles alleviated endocrine disruption, oxidative damage, and genotoxicity of Bisphenol-A- intoxicated female African catfish

Bisphenol-A (BPA) is widely used in production of plastic products. It can reach the ecosystems affecting aquatic organisms most likely fishes. The purpose of this study was to study the toxic effects of BPA on the biochemical variables and oxidative stress in female African catfish, Clarias gariepinus and to estimate the protective role of chitosan nanoparticles (CSNPs) against BPA toxicity. Five groups in triplicates of fish were divided as follows: group I was control, group II was treated with CSNPs (0.66 ml/L), group III was exposed to BPA (1.43 μg/L), group IV was treated with BPA (1.43 μg/L) plus CSNPs (0.33 ml/L), and group V was treated with BPA (1.43 μg/L) plus CSNPs (0.66 ml/L) for 30 days. Blood and liver tissue samples were collected at the end of experiment for the biochemical and oxidative stress biomarkers analyses. Results exhibited that serum Follicle Stimulating Hormone (FSH) and 17-β Estradiol (E2) were significantly decreased in female catfish. While, serum Testosterone (T.) and Luteinizing Hormone (LH) were increased after exposure to BPA. Marked increment in superoxide dismutase (SOD) and malondialdehyde (MDA) levels of hepatic tissue of catfish exposed to BPA. Furthermore, significant reduction in hepatic catalase (CAT), glutathione peroxidase (GSH-px), total antioxidant capacity (TAC), reduced glutathione (GSH), and glutathione S-transferase (GST) levels were decreased significantly in BPA-exposed catfish compared to the control group. However, administration of female C. gariepinus with the low and high doses (0.33 ml/L and 0.66 ml/L) of CNPs restored the biochemical parameters to be close to the normal values of the control group and also, reduced oxidative stress induced by BPA toxicity. This improvement was evident in fish administrated with the high CSNPs dose (0.66 ml/L) compared to catfish exposed to BPA in group (III). Furthermore, the percentage of hepatic DNA damage was detected in group III exposed to BPA alone. However, it was declined after co- administration with both the low and high doses of CSNPs. The study has revealed that treatment with CSNPs has antagonistic functions against the toxicity of BPA in female African catfish.

STUDY OF PITUITARY GLAND EXTRACT UTILIZATION FROM STRIPED CATFISH WASTE FOR REPRODUCTION PERFORMANCE IMPROVEMENT OF NORTH AFRICAN CATFISH (Clarias gariepinus)

One of the problems in North African Catfish (Clarias gariepinus) breeding is the inability to spawn spontaneously due to a specific spawning season. This happens due to reproductive dysfunction resulting in a slow development of gonads in catfish broodstock. This research aimed to study the effect of injection of pituitary gland extract from Striped Catfish head waste on the spawning performance of North Africans Catfish. This study used a completely randomized design (CRD) with 4 treatments and 3 replications. The treatments were A (pituitary gland 0 mg/kg broodstock), B (pituitary gland 200 mg/kg broodstock), C (pituitary gland 300 mg/kg broodstock), and D (pituitary gland 400 mg/kg broodstock). The spawning process was performed with a ratio of 1:1 between male and female broodstock. The pituitary gland was injected into the head of female catfish at 07:30 pm and at 04:00 am. The research parameters observed were relative fecundity, fertilization rate (FR), hatching rate (HR), and survival rate (SR). The results showed that injection of the pituitary gland from Striped Catfish head waste could increase spawning performance with relative fecundity reaching of 31,357±12,265 eggs/ kg of female broodstock, FR 65±4%, HR 74±14%, and SR 81±10%. Therefore, hypophysation by utilizing Striped Catfish head waste is effectively increases the spawning performance of North African Catfish (Clarias gariepinus) seen from the high values of relative fecundity, FR, HR, and SR of larvae in treatment B (200 mg/kg broodstock).

Female fish farmers: How technically efficient are they? Evidence from Delta State Nigeria

The study investigated the technical efficiency of female catfish growers in Delta State, Nigeria. Data have been obtained using questionnaires from 112 female catfish farmers who have been randomly selected. Descriptive statistics, cost and return analysis as well as the stochastic model have been used in the analysis of data. The results showed that the mean age, farming experience and household size of the female fish farmers were 42 years old, 8 years and 6 persons respectively. Most of the participants are married and educated. The gross margin and net farm income were N490,378.46 and N416,242.82k respectively. With a rate of return on investment and a BCR (Benefit Cost Ratio) of 0.64 and 1.64, fish farming was found to be profitable. The Stochastic frontier outcome showed that the size of the pond, fingerlings, feed and water supply had a significant and positive effect on fish production, while the cost of medication had an inverse relationship with fish production. Age, education and household size have been found to increase technical performance, while technical inefficiency is increased by distance from farm location and credit access. The finding further revealed that a female fish farmer had a technical efficiency of 53.5% in the area of study. This is a signal that by implementing the technologies practiced by the best farmers, fish productivity can be improved by about 46.5% by the farmers. The coefficient of elasticity was 0.567, which indicated that the female catfish farmers were in Phase II. The failure of farmers to reach the production frontier may however be due to certain factors, including insufficient funding, high feed costs, water supply and fingerlings shortages. On the basis of the results, female fish farmers should be supported by means of professional training in fish production practices to ensure that their resources are optimally utilized.

Reproductive Aging of African Catfish in Aquaculture

The work is devoted to the study of reproductive aging of African catfish in the conditions of industrial aquaculture. The problem is urgent, because industrial aquaculture changes the biology of African catfish so much that it loses its ability to reproduce naturally. The offspring of African catfish can be obtained only with the use of hormonal inducers of gametogenesis. Questions of age selection of producers and age composition of breeding stock in this type of fish are still open. In practice, we have to face the facts of poor quality of sexual products in primary spawning or old females and males. The aim of the study was a comparative assessment of age-related variability of reproductive properties of female and male African catfish in the conditions of industrial aquaculture. The results of our study showed the presence of age-related dynamics in the quality of sexual products in African catfish. Age-dependent differences in the quality and fertilization of eggs, the viability of embryos and larvae, their size, and the quality of offspring were established. When studying the properties of sexual products in fish of different ages, differences in morphometric and physiological parameters were found for a complex of indicators such as the size and diameter of eggs, sperm concentration, and the number of viable spermatozoa. Evaluation of the influence of parents age on the viability of offspring in the embryonic and postembryonic periods revealed that this indicator is the lowest in first – spawning fish, and the highest in middle-aged fish. The Russian Foundation for Basic Research has supported our study with the grant No. 18-416-730005.