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The dietary lipid level is closely associated with ovarian maturation of broodstock. However, optimal lipid requirements during broodstock gonad development for aquatic animals remain limited. In order to assess the impact of dietary lipid levels (6%, 8%, 10%, 12%, and 14% lipid, denoted as L6%, L8%, L10%, L12%, and L14%) on the ovarian maturation, antioxidant status, and messenger RNA (mRNA) expression of genes involved in the lipid metabolism of Macrobrachium rosenbergii broodstock (initial weight 10.53 ± 1.97 g), this study carried out an 8‐week feeding experiment. The findings showed that while there was no significant difference in the survival rate across the groups (p > 0.05), the weight gain observed in prawns fed the 8% lipid‐level diet was significantly higher than those fed other diets (p < 0.05). The hepatosomatic index and the gonadosomatic index showed a significant increase with the rise in dietary lipid level (p < 0.05). More ovaries from M. rosenbergii broodstock reached stages Ⅲ and Ⅳ after being supplemented with dietary lipid levels between 8% and 14%. Serum glucose content did not show any significant difference among all groups (p > 0.05), but serum triglyceride and total cholesterol content increased followed by a decreasing trend with increasing levels of dietary lipids, both peaking in the prawns fed a 10% lipid‐level diet. Furthermore, the progesterone (PROG) and 17β‐estradiol (E2) content of prawns fed the 10% and 12% lipid‐level diets were significantly higher compared to other groups (p < 0.05). Based on serum E2 and PROG content, the optimal lipid level needed for maximal ovarian maturation was determined to be 11.79% and 10.88%, respectively. Moreover, there were more endogenous vitellogenic oocytes in prawns fed 8% and 10% lipid‐level diets, with a more compact arrangement compared to the less tightly arranged structure of the ovarian tissue in prawns fed other diets. With the increase in dietary lipid levels, there was a significant increase in the activity of superoxide dismutase. The activities of total antioxidant capacity and glutathione peroxidase initially increased and then decreased significantly, peaking at prawns fed 8% and 10% lipid‐level diets, respectively (p < 0.05). The malondialdehyde content reached its lowest point in prawns fed a diet containing 10% lipid. In addition, the mRNA expressions of hepatopancreatic diacylglycerol acyltransferase and acetyl‐CoA carboxylase showed the highest values in prawns fed a 10% lipid diet. Conversely, there was a significant decrease in the mRNA expression of carnitine palmitoyltransferase‐1a in the hepatopancreatic as dietary lipid levels increased. The highest mRNA expression of fatty acid‐binding proteins was observed in prawns fed an 8% lipid diet. In conclusion, dietary lipid levels ranging from 8% to 11.79% are beneficial for ovarian maturation and health of M. rosenbergii broodstock. [ABSTRACT FROM AUTHOR]

Tetraploid oysters are valuable germplasm resources for the production of triploid oysters. However, the broodstock condition and gonadal development of tetraploid oysters are poorly understood. To assess the effects of temperature on gamete quantity and quality, tetraploid and diploid oysters were held at controlled temperatures of 18, 20 and 22 °C for 120 days. The gametogenesis process in tetraploid and diploid oysters showed an accelerated trend in response to increased conditioning temperatures. Nonetheless, the gonadal development of tetraploid oysters was slower than that of diploid oysters. Histomorphometric analysis of gonadal tissues showed variations in observed sex ratio under different conditioning temperatures. The proportions of tetraploid and diploid males increased with elevated temperature. However, survival rates of tetraploid and diploid oysters at 22 °C were significantly lower than those at 18 and 20 °C (P < 0.05). In terms of the number of oocytes and spermatozoa, tetraploid oysters were fewer than diploid oysters. Overall, these results demonstrated the differences in broodstock conditioning and gonadal development between tetraploid and diploid oysters, suggesting the need for specialized broodstock cultivation strategies for tetraploid oysters. [ABSTRACT FROM AUTHOR]

Objective: The need to augment of Walleye Sander vitreus populations may increase as these populations face challenges of changing habitats and climatic conditions. Since little has been published outside of agency reports on wild broodstocks, the intent of this study was to describe sex‐specific Walleye spawning participation from a Great Plains broodstock operation. Specific objectives will assess standardization to collect target number of broodstock effort, catch per unit effort, and length and age participation of female and male broodstock. Methods: Walleye were collected at Sherman Reservoir, Nebraska, during April spawn collection operations from 2015 to 2019. Gill nets were used to collect female Walleye, and boat electrofishing was used to collect male Walleye. Catch per effort was calculated for each sex, fish were measured to nearest 1‐cm length‐group, and a dorsal spine was taken from a subset of fish per length‐group. Mean lengths and ages were calculated for each year of the study. Data were combined for all years of the project to display percent contribution by length and age. Result: The amount of effort to capture 100 female and male Walleye varied by 4× and 2.5×, respectively, over the 5 years of sampling. Mean lengths and ages (±SE) of female (65 ± 1 cm; 10.4 ± 0.1 years) and male (43 ± 1 cm; 6.3 ± 0.1 years) Walleye collected were consistent during this study. The female Walleye collected represented 14 different ages, but ages 9–12 comprised 66% of all captured broodstock. The collected male Walleye also demonstrated age‐compressed spawning tendencies, with ages 4–7 accounting for 74% of collected individuals that represented 13 different ages. Conclusion: These results can define the anticipated variability in catch that can be expected at broodstock collection operations along with connection to specific lengths and ages of Walleye. Additionally, recognition that female and male Walleye broodstock contributions are consistently coming from four specific ages that are not the same year‐classes may allow spawning operation staff to anticipate brood availability and ultimately improve the planning efficiency of these operations. Impact StatementWalleye populations throughout North America have declined, with many populations sustained through stocking efforts. Stockings often rely on a manager's ability to find and manage wild sustainable broodstock. Previous research efforts have focused on the collection of broodstock, egg‐take operations, and stocking products, with little research devoted to the population dynamics of the broodstock themselves. We provide this information for a Great Plains Walleye broodstock to provide a benchmark for managers and provide a template of how awareness of broodstock population characteristics can be integrated into the planning of these operations. [ABSTRACT FROM AUTHOR]

The study examines the impact of integrated biofloc technology (BFT), different salinity levels, and their combined effects over 90 days on various physiological parameters. The investigation includes growth performance and feed utilization, water quality, the chemical composition of biofloc and fish, digestive enzymes, reproductive performance, stress and biochemical indicators, and antioxidant-immune responses in red tilapia (Oreochromis spp.) broodstock. The fish were initially weighed (males: n = 270; 104 ± 0.96 g; females: n = 270; 93.2 ± 0.66 g) and subsequently divided into 12 treatment groups (6 for males and 6 for females) spread across 36 separate tanks (3 tanks per treatment; 45 fish per treatment; 15 fish/tank). The treatments involved three salinity levels (18, 28, and 36 ppt) in both clear water (CW) and BFT systems. The outcomes demonstrated that fish in the 36 ppt salinity with BFT treatment demonstrated significant improvements (P < 0.05) in growth parameters (final body weight, weight gain, and specific growth rate, feed intake, and feed conversion ratio). The condition factor in BFT groups increased in all salinity situations. The survival rates of broodstock were consistently high in all experimental conditions The study found that BFT and salinity significantly impacted (P < 0.05) whole body contents (moisture, protein, lipid, and ash) in both males and females. Water quality parameters showed variations between BFT and CW, with notable impacts (P < 0.05) on dissolved oxygen and pH. The BFT and salinity influenced digestive enzyme activities (protease, amylase, and lipase) and reproductive performance (males) and the 36 ppt salinity with BFT recorded the highest values. The hemato-biochemical and antioxidant-immune responses were also impacted by BFT and salinity exposure. The study highlights the potential benefits of incorporating BFT into red tilapia aquaculture systems, particularly in optimizing growth, health, and reproductive performance under various salinity conditions, which can enhance sustainable intensification, disease control, and environmental stewardship. [ABSTRACT FROM AUTHOR]

A 56-days feeding experiment was conducted to evaluate the effect of dietary protein levels on fish growth, gonad development, and physiological biochemistry of female Pengze crucian carp (Carassius auratus var. Pengze) broodstock. Three isoenergetic diets were formulated, and the crude protein levels were 26.85%, 35.73% and 44.38%, the lipid levels were 7.39%, 7.92% and 7.91%, respectively. The results showed that the weight gain rate (WGR), the specific growth rate (SGR) and the protein efficiency ratio (PER) of the female Pengze crucian carp broodstock increased significantly and the feed conversion ratio (FCR) decreased significantly when the dietary protein level was 35.73% (P < 0.05). The WGR, the SGR and the PER were significantly higher in the 35.73% and 44.38% protein groups than in the 26.85% protein group (P<0.05). Increasing dietary protein levels led to a significant increase in the gonad index and the egg menstrual length of the female Pengze crucian carp broodstock (P<0.05). The higher protein levels resulted in a significant increase in total amino acids, total essential amino acids, and total nonessential amino acids (P<0.05). The varying ovaries of each group of total saturated fatty acids, total highly unsaturated fatty acids, and total polyunsaturated fatty acids all increased significantly with increasing protein levels (P<0.05). Furthermore, the aspartate transaminase (AST), low-density lipoprotein cholesterol (LDLC), and malondialdehyde (MDA) contents in plasma were significantly lower in the 35.73% and 44.38% groups than in the 26.85% group (P < 0.05). The 35.73% group exhibited the highest plasma superoxide dismutase (SOD) activity. The plasma vitellogenin (VTG), estradiol 2 (E2), and progesterone (PROG) in plasma of female Pengze crucian carp broodstock were significantly higher in the 35.73% and 44.38% protein groups than in the 26.85% protein group (P<0.05). The results showed that the addition of an appropriate amount of protein to the feed can significantly improve the growth, gonadal development, and health of female Pengze crucian carp. In this study, the effect of 35.73% protein concentration was better than in the other two groups. [ABSTRACT FROM AUTHOR]

Broodstock nutrition is the most essential constituent of sustainable aquaculture production. Its impact on the reproductive performance and profitability of commercial aquaculture has been the subject of considerable research. The present paper reviews the literature available on the subject, examining the implication of Nile tilapia broodstock nutrition on parameters including maturation, fecundity, fertilization, embryo development, larval quality, and survival rate. The provision of a nutritive diet composed of essential macroand micronutrients including proteins, lipids, carbohydrates, vitamins, minerals, and functional additives, such as prebiotics, enzymes, hormones, and probiotics, in different proportions is discussed. Special emphasis is given to literature dealing with the effects of dietary protein and lipid on vitellogenesis and ovarian maturation, fecundity, egg hatching rate, larval quality, and fry survival number. The impact of the feeding regime on reproductive performance is described. [ABSTRACT FROM AUTHOR]

The commercial viability of walleye (Sander vitreus) as an aquaculture species requires that walleye gametes are available year‐round so that multiple cohorts of walleye can be brought to market throughout the year. This study aimed to apply photothermal manipulations to three groups of walleye broodstock to induce out‐of‐season spawning and obtain a year‐round supply of fertilized walleye eggs. We manipulated photothermal regimes for three groups of broodstock to induce spawning in February (early), April (in‐season), and July (late‐season). In autumn, water temperatures were chilled to 8°C in all treatments. The duration of the chill period varied for each treatment with the early, in‐season, and late treatments remaining chilled for 6, 18, and 30 weeks, respectively, before being warmed to induce spawning. Fecundity was significantly lower for late‐season broodstock. Egg size and gonadosomatic index were significantly smaller in the early‐season treatment. Fertilization success was similar for early and in‐season treatments but was 0% for eggs from the late‐season treatment. Larval survival was significantly lower for walleye from early‐season broodstock. Our results suggest that early out‐of‐season spawning for walleye is possible but comes with tradeoffs of smaller egg size and lower larval survival. [ABSTRACT FROM AUTHOR]

The largescale blackfish, Girella punctata (Gray, 1835), inhabits rocky substrates in the coastal waters of Japan and northeastern Taiwan. Despite its commercial significance, there is limited knowledge regarding its reproductive biology due to the sparse occurrence of broodstocks in its natural environment. This study investigated the reproductive performance and embryonic development of G. punctata, assesses its feeding preferences through controlled feeding trials, and evaluates the impact of various feed types on its growth performance. In total, 124 wild-caught G. punctata were reared for 3–4 years, and their reproductive performance was assessed in 2015 and 2016. Their egg production increased with a sudden water temperature change from 17 ℃ in 2015–22 ℃ and 2016. The total and daily average egg production weights were 3589.22 and 40.79 g, respectively, whereas the total and daily average fertilized egg production weights were 1630.72 and 18.59 g, respectively; moreover, the hatching rate was 42.61 %. During embryonic development, the eggs hatched 45 h post fertilization at 19 ℃. Newly hatched larvae were 2.26 ± 0.04 mm in length with a yolk sac of 1.09 ± 0.02 mm in length. The yolk sac was almost completely absorbed 3 days post hatch (dph), when the larvae grew to a length of 3.42 ± 0.06 mm. We found that fish meal with 40 % protein was the optimal G. punctata fish diet. The weight gain in juveniles fed Cladophora fascicularis ranged from 47 % to 52 %, which was significantly higher than that in those fed Hypnea charoides (p < 0.05). The present study provided a practical guideline on the conditions required for successful fertilization and early development of G. punctata embryos and other larval stages. This information should help ensure greater survival and a higher proportion of healthy G. punctata larvae for mariculture applications.

The blackfin snook, Centropomus medius, is a valuable fish in American and Mexican markets, mainly from catches. Nonetheless, information and studies about the biology of this species still need to be made available; thus, its aquaculture should be developed. This study aimed to describe the seasonal changes of proximate composition during a reproductive cycle of C. medius, analyzing differences between tissues and their changes related to the reproductive process. The snook specimens were collected in Magdalena Bay, Baja California Sur, Mexico, and measured every month from September 2001 to November 2002. Liver, gonads, muscle tissue, and intraperitoneal fat (IPF) were sampled and weighed. The gonadosomatic index (GSI), hepatosomatic index (HSI), IPF ratio, and condition factor index (K) were calculated. The biochemical composition was analyzed in the gonad, liver, and muscle. The reproductive period (RP) of wild C. medius in Baja California Sur, Mexico, was from June to December. The spawning period was recorded at summer temperature (25-30°C) and photoperiod (>13 h daylight) starting in September. High GSI values (gonad development), low HSI values (lipid reserve mobilization), low IPF, and low K ratio were related to elevated temperatures. Moreover, variations were observed in protein, total lipid, triglycerides, and glycogen content in muscle, liver, and gonad according to the reproductive phase. A positive correlation was demonstrated between protein contents in muscle, gonad, and K, with lower concentrations during RP, while liver protein composition showed an opposite pattern. Lipids were mainly present in the liver, and the concentration decreased during RP while muscle increased. The results obtained in this study show differences in the proximate analyses in the liver, muscle, and gonads throughout the year concerning different phases of the reproductive cycle, indicating a great dependence of this process on the mobilization of reserves during C. medius reproduction. Therefore, understanding the feeding requirements to pursue the management of this species in captivity for aquaculture development is greatly important. [ABSTRACT FROM AUTHOR]

The Tbx family is first known through the study of their functions in the body and limbs, and its members Tbx4 and Tbx5 genes are important factors in determining the characteristics of the appendages. Pampus argenteus is one of the important economical marine fishes widely distributed in offshore areas. Therefore, it is necessary to study the role of Tbx family genes in the deletion of pelvic fin in P. argenteus. In this study, we cloned Tbx4 and Tbx5 cDNA sequence of P. argenteus (GenBank: MH709128 and MH712458). The Western blot and real time PCR were used to detect the expressions of Tbx4 and Tbx5 in different developmental stages and tissues of P. argenteus. In addition, whole-mount in-situ hybridization was used to study the localization of Tbx4 and Tbx5 genes in different developmental stages of P. argenteus. Results show that the translation of Tbx4 mRNA was inhibited during the critical period of pelvic fin development. Among different tissues, Tbx4 protein levels were the lowest in the abdominal epithelium, and even lower than that in the pectoral fin, suggesting that the protein expression was also inhibited in the abdominal epithelium of adult P. argenteus. Therefore, the results indicated that upstream genes regulation led to the key stage-specific and low expression of Tbx4 during pelvic fin development and in the abdominal epithelium. [ABSTRACT FROM AUTHOR]

Abstract The commercial viability of walleye (Sander vitreus) as an aquaculture species requires that walleye gametes are available year‐round so that multiple cohorts of walleye can be brought to market throughout the year. This study aimed to apply photothermal manipulations to three groups of walleye broodstock to induce out‐of‐season spawning and obtain a year‐round supply of fertilized walleye eggs. We manipulated photothermal regimes for three groups of broodstock to induce spawning in February (early), April (in‐season), and July (late‐season). In autumn, water temperatures were chilled to 8°C in all treatments. The duration of the chill period varied for each treatment with the early, in‐season, and late treatments remaining chilled for 6, 18, and 30 weeks, respectively, before being warmed to induce spawning. Fecundity was significantly lower for late‐season broodstock. Egg size and gonadosomatic index were significantly smaller in the early‐season treatment. Fertilization success was similar for early and in‐season treatments but was 0% for eggs from the late‐season treatment. Larval survival was significantly lower for walleye from early‐season broodstock. Our results suggest that early out‐of‐season spawning for walleye is possible but comes with tradeoffs of smaller egg size and lower larval survival.

Obtaining viable Argopecten purpuratus seeds faces challenges, especiallyci the unpredictability of the marine environment and high production costs in hatcheries. However, improving the method of "Broodstock Conditioning In Hatcheries" is key to ensure permanent seed supplies by minimizing the dependence on marine conditions and by maximizing economic viability in hatcheries. In an effort to overcome these barriers, broodstock were conditioned into two different environments: (a) Natural Environment: Natural marine conditions located in Bahía Inglesa, Atacama Region, Chile. (b) Hatchery: Laboratory conditions to achieve gonadal maturation, spawning induction, fertilization and larval development. The purpose of this research was to evaluate how the type of reproductive conditioning affects the reproductive potential and nutritional quality of the progeny. Both methods were successful at inducing the necessary maturity for reproduction, obtaining viable gametes and larvae. On the other hand, it was observed that in the natural environment, the oocytes and D larvae reached a greater size and nutritional value, being the most significant differences with (p < 0.05): the size of the D larvae reached figures of 95.8 ± 3.1 μ m and 91.2 ± 2.7 μ m in the environment and hatchery, respectively; the lipid content in dry mass was 25.2 ± 3.1 mg g − 1 and 13.5 ± 1.9 mg g − 1 for the natural environment and hatchery, respectively. Although quality indicators in hatcheries were slightly lower compared to the natural environment, the possibility of conditioning A. purpuratus broodstock independently of environmental variability highlights the importance of further optimizing broodstock conditioning aspects in hatcheries that would allow more predictable and sustainable production. [ABSTRACT FROM AUTHOR]

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Objective: California Yellowtail (CYT) Seriola dorsalis are continuous spawners and rely entirely on their diet to supply nutrients like fatty acids (FAs) to their eggs to support early development. The objective of this study was to determine whether commercial diets could replace a diet consisting of fresh fishery products (FFP‐D) without compromising egg quality and biochemical composition, specifically FAs. Methods: In 2017, one broodstock group (one female and two males) was fed a formulated reference feed (REF‐D; Bio‐Oregon). This pilot experiment showed that it was possible for a minimum of one female and two male broodfish to spawn repeatedly in a tank, a finding that led to a replicated diet experiment during 2018 in which 18 CYT broodfish were divided into six replicate tanks, with one female and two males per tank. Three tanks were fed the FFP‐D as a control, and three tanks were fed a commercial diet (COM‐D; Breed‐M, INVE). For each spawning event, egg quality metrics were collected, along with samples for FA analysis. Result: The 2017 REF‐D treatment produced eggs that met arachidonic acid (ARA) and eicosapentaenoic acid (EPA) requirements and had egg metrics comparable to those obtained from the FFP‐D, with higher viability and average batch fecundity. However, the REF‐D treatment had insufficient docosahexaenoic acid (DHA) and no tank replicates. The 2018 COM‐D treatment produced eggs with large egg and oil diameters and met ARA and EPA requirements but was associated with very poor spawning and hatch success and had insufficient DHA levels. The FFP‐D treatment produced below‐average viability and batch fecundity rates and was unable to meet most essential FA requirements, but it yielded the greatest number of spawning events. Conclusion: None of the experimental treatments, including the control, was able to fully meet the nutritional requirements of CYT broodstock. These results reveal crucial data about current CYT broodstock diets that can facilitate future research for developing nutritionally complete diets, especially in terms of essential FAs. Impact statementThis study investigates three different feed types in California Yellowtail broodstock. We explored if standard fish feeds could replace a standard raw fish diet without compromising egg quality. This is especially relevant to producers because understanding the right feed for broodstock helps ensure a reliable production of high quality eggs. The replacement of a raw fish diet with commercial pellets allows producers to reduce the use of wild‐caught fish as a primary food source for these broodstock, resulting in more sustainable aquaculture practices. [ABSTRACT FROM AUTHOR]

Mixed hybridisation trials involving Clarias gariepinus (CG), Heterobranchus longifilis (HL), and Heterobranchus bidorsalis (HB) were carried out with success using Ovulin as inducing agent. The crossing was followed by an early growth trial using post-yolk sac larvae that lasted ten days. Latency periods in the two catfishes differ, with 11 hours in crosses involving female CG and 12 hours in crosses involving female HL. The fertilisation rates of eggs from the females of the two species indicate that there is no significant discernment in fertilisation (p>0.05), with values ranging from 68.38% (CG×HB) to 80.94% (HL×CG). However, rates <80% indicate egg quality problems. The hatching rate was significantly higher (p<0.05) in both C. gariepinus (62.12%) and Heterobranchus sp. (47.75%) line crosses than the hybrids. There is an additive genetic effect due to the combination of pure-line male and female gametes that elicit better growth as against survival in crosses involving C. gariepinus. The genotype for better survival is in the maternal line of H. longifilis. These culminate into heterosis for growth in hybrid CG×HB and survival in hybrid HL×CG. [ABSTRACT FROM AUTHOR]

The giant freshwater prawn (GFP), Macrobrachium rosenbergii (De Man, 1879) farming industry consistently maintains a high production volume, ranging from 233 to 238 thousand metric tons worldwide annually from 2014 to 2018. Improvements in the quality and quantity of fry are necessary to further boost production. Maturation feed stands as a critical factor in enhancing the quality of broodstock. The nutrient requirements for GFP, (M. rosenbergii) broodstock consist of essential nutrients such as protein (40-45%), lipids (8-10%), and carbohydrates (25-35%). In addition to these major nutrients, minor nutrients like essential fatty acids, cholesterol, phospholipids, vitamins, and minerals play a crucial role in developing a high-quality maturation feed. Research focused on determining optimal levels of essential amino acids and essential fatty acids is essential to enhancing reproductive performance. High-quality maturation diet significantly contributes to the broodstock's reproductive performance and high-quality fry, both of which are paramount in the GFP farming industry. This review paper on maturation diets for GFP serves as a valuable reference for hatchery managers, aiding in the production of high-quality maturation feeds to enhance production efficiency.

Abstract The red snapper (Lutjanus campechanus) has one of the most valued fisheries in the southeastern United States and has been largely studied for its aquaculture potential with varied results that revealed production challenges. This study focused on addressing challenges in larval rearing and juvenile production of this species. Broodstock fish were acclimated in a 60 m3 tank equipped with recirculating aquaculture system (RAS) and temperature control. After 1 year in captivity, fish volitionally spawned and larval rearing trials were conducted in replicated flow‐through seawater tanks ranging from 0.4 to 2.4 m3, at a temperature range of 24–26°C. Enriched s‐strain rotifers, Brachionus rotundiformis (lorica length of 100–210 μm), were used for first feeding. Enriched Artemia sp. were gradually introduced after 18 days post hatch (DPH). The survival rate before metamorphosis (12 DPH) averaged 66.09 ± 0.08%. Survival rate from yolk‐sac larvae to post‐metamorphic early juvenile averaged 4.43 ± 0.01%. At 40 DPH, early red snapper juveniles averaged 0.35 ± 0.02 g in weight and 28.83 ± 0.60 mm in standard length. A total of 31,849 fully weaned juveniles were harvested. This study demonstrates that small strain rotifers can be used exclusively as first feeding prey organism for red snapper larvae, representing a significant advancement for red snapper juvenile production.

Abstract Long-whiskered catfish Sperata aor is a freshwater catfish known for its supreme flesh quality and fast growth, whose captive-reared broodstock denotes a difficult challenge for aquaculture. The reproductive dysfunctions in long-whiskered catfish raised in tank conditions were observed by comparing tissue biochemical composition and ovarian histology of wild female broodstock. Sixty (60) female broodstocks were used in the current study, consisting of 30 reared at sandy-muddy soil tank bottoms in captive conditions and 30 wild individuals collected from the haor basin during the breeding season. The fish reproductive state was investigated using the biometric and reproductive parameters, biochemical composition and levels of amino acids in the different tissues, and histological analysis of ovarian development. Results revealed that the biometrical parameters of wild and captive female broodstocks exhibited no remarkable difference (p > 0.05). Nevertheless, the wild fish had remarkably higher (p 0.05). However, two essential amino acids (EAA), i.e., lysine and phenylalanine, and two non-essential amino acids, i.e., glutamic acid and glycine, were highly significant differences (p

Broodstock nutrition is the most essential constituent of sustainable aquaculture production. Its impact on the reproductive performance and profitability of commercial aquaculture has been the subject of considerable research. The present paper reviews the literature available on the subject, examining the implication of Nile tilapia broodstock nutrition on parameters including maturation, fecundity, fertilization, embryo development, larval quality, and survival rate. The provision of a nutritive diet composed of essential macro- and micronutrients including proteins, lipids, carbohydrates, vitamins, minerals, and functional additives, such as prebiotics, enzymes, hormones, and probiotics, in different proportions is discussed. Special emphasis is given to literature dealing with the effects of dietary protein and lipid on vitellogenesis and ovarian maturation, fecundity, egg hatching rate, larval quality, and fry survival number. The impact of the feeding regime on reproductive performance is described.

The effects of feeding at different densities of Artemia nauplii on the growth and survival of Macrobrachium rude larvae were explored in this study. Two experiments were carried out. In the first trial, larvae were fed three different feeding densities: 1, 3, and 5 nauplii/mL. In the second experiment, feeding densities of 5, 10, and 15 nauplii/mL were used to determine the maximal feeding density of Artemia nauplii for M. rude larvae. There were no significant differences statistically in growth rate or survival between larvae fed 1, 3, or 5 nauplii/mL (P>0.05). Increased feeding density from 5 to 10 nauplii/mL resulted in growth but drastically decreased survival. Feeding above 10 nauplii/mL decreased both growth rate and survival. According to the results of the study, the optimal feeding density of M. rude with Artemia nauplii should be between 5 and 10 nauplii/mL. The study suggests further research into determining ideal feeding density at various phases of larval development in order to better understand the individual feeding requirements at each stage. [ABSTRACT FROM AUTHOR]

The red snapper (Lutjanus campechanus) has one of the most valued fisheries in the southeastern United States and has been largely studied for its aquaculture potential with varied results that revealed production challenges. This study focused on addressing challenges in larval rearing and juvenile production of this species. Broodstock fish were acclimated in a 60 m3 tank equipped with recirculating aquaculture system (RAS) and temperature control. After 1 year in captivity, fish volitionally spawned and larval rearing trials were conducted in replicated flow‐through seawater tanks ranging from 0.4 to 2.4 m3, at a temperature range of 24–26°C. Enriched s‐strain rotifers, Brachionus rotundiformis (lorica length of 100–210 μm), were used for first feeding. Enriched Artemia sp. were gradually introduced after 18 days post hatch (DPH). The survival rate before metamorphosis (12 DPH) averaged 66.09 ± 0.08%. Survival rate from yolk‐sac larvae to post‐metamorphic early juvenile averaged 4.43 ± 0.01%. At 40 DPH, early red snapper juveniles averaged 0.35 ± 0.02 g in weight and 28.83 ± 0.60 mm in standard length. A total of 31,849 fully weaned juveniles were harvested. This study demonstrates that small strain rotifers can be used exclusively as first feeding prey organism for red snapper larvae, representing a significant advancement for red snapper juvenile production. [ABSTRACT FROM AUTHOR]

The giant freshwater prawn (GFP), Macrobrachium rosenbergii (De Man, 1879) farming industry consistently maintains a high production volume, ranging from 233 to 238 thousand metric tons worldwide annually from 2014 to 2018. Improvements in the quality and quantity of fry are necessary to further boost production. Maturation feed stands as a critical factor in enhancing the quality of broodstock. The nutrient requirements for GFP, (M. rosenbergii) broodstock consist of essential nutrients such as protein (40-45%), lipids (8-10%), and carbohydrates (25-35%). In addition to these major nutrients, minor nutrients like essential fatty acids, cholesterol, phospholipids, vitamins, and minerals play a crucial role in developing a high-quality maturation feed. Research focused on determining optimal levels of essential amino acids and essential fatty acids is essential to enhancing reproductive performance. High-quality maturation diet significantly contributes to the broodstock's reproductive performance and high-quality fry, both of which are paramount in the GFP farming industry. This review paper on maturation diets for GFP serves as a valuable reference for hatchery managers, aiding in the production of high-quality maturation feeds to enhance production efficiency. [ABSTRACT FROM AUTHOR]

Background: Mystacoleucus padangensis living in Lake Singkarak, Indonesia, has high potential market demand but is threatened by overfishing and has not been successfully cultured. This study describes the first broodstock development, induced breeding, and larval rearing of M. padangensis. Methods: A total of 1,000 female and 1,000 male broodfish were collected from the wild and reared in two concrete ponds (128 m 2) at the Centre for Biodiversity Conservation, P.T. Semen Padang, Indonesia. The broodfish were fed commercial feed to satiation at 09:00 and 17:00 h. The females (average weight 7.56 ± 0.85 g) and males (4.86 ± 1.20 g) were selected at a ratio of 1:4 (female:male), and gonad maturation was induced with a single dose of GnRH analogue (Ovaprim) of 0.1 ml/fish. At 16 h after hormone injection, eggs were collected individually into a plastic vessel. Spermatozoa were collected with sterile syringes. Eggs were fertilized using the 'dry' method, and 0.5 ml samples (equal to 100 eggs) were taken. The eggs were incubated in a plastic strainer with a water volume of 1.57 litres and placed in a tarpaulin pond with a volume of 150.72 litres. Results: The overall hatching rate was 78.93 ± 4.13%. The newly hatched larvae were 3900.81 µm long, with a yolk sac of 82881.480 µm 2. The mouth opened at 72 days post hatching (DPH) with a gape measuring approximately 61.880 µm. The protocol of larval feeding started with artificial feed, followed by Artemia nauplii up to 30 DPH. Weaning of larvae started at 4 DPH. Larvae started metamorphosis by 15 DPH and ended by 22 DPH when the larvae reached 7430.27 µm. Larval rearing resulted in an average survival rate of 28.4 ± 3.04%. Conclusions: Its successful spawning induction and high larval hatching and survival rates make M. padangensis an excellent aquaculture candidate.

Long-whiskered catfish Sperata aor is a freshwater catfish known for its supreme flesh quality and fast growth, whose captive-reared broodstock denotes a difficult challenge for aquaculture. The reproductive dysfunctions in long-whiskered catfish raised in tank conditions were observed by comparing tissue biochemical composition and ovarian histology of wild female broodstock. Sixty (60) female broodstocks were used in the current study, consisting of 30 reared at sandy-muddy soil tank bottoms in captive conditions and 30 wild individuals collected from the haor basin during the breeding season. The fish reproductive state was investigated using the biometric and reproductive parameters, biochemical composition and levels of amino acids in the different tissues, and histological analysis of ovarian development. Results revealed that the biometrical parameters of wild and captive female broodstocks exhibited no remarkable difference (p > 0.05). Nevertheless, the wild fish had remarkably higher (p < 0.05) GSI (8.73%), oocyte weight (0.45 mg/egg), and ripeness (27.08%) in comparison with captive-reared broodstock. The total length and body weight, body weight and ovary weight, ovipositor diameter and ovary weight, and GSI and HSI displayed a positive relationship with R2 = 1, R2 = 1, R2 = 0.993, and R2 = 0.973, respectively, for wild broodstock, while R2 = 0.994, R2 = 0.806, R2 = 0.804, and R2 = 0.896, respectively, for captive broodstock. Additionally, the proximate composition in oocytes and liver tissues in both broodstocks did not differ significantly (p > 0.05). However, two essential amino acids (EAA), i.e., lysine and phenylalanine, and two non-essential amino acids, i.e., glutamic acid and glycine, were highly significant differences (p < 0.05) in the oocytes and liver of wild broodstock compared to the captive-reared broodstock. On the other hand, the EAA, e.g., isoleucine, threonine, leucine, and arginine, were highly dominated in both wild and captive female brood oocytes and liver. The ovarian histological slides from each fish group showed three oocytes developmental stages that indicated the asynchronous-reproductive ovarian oocytes of this fish. This study may be useful to fully understand the factors affecting the spawning and reproduction of S. aor broodstock, crucial for management in captive conditions as well as conservation and protection for sustainable aquaculture management of S. aor. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of varying male to female brood stock pairing ratios of 1:1, 1:2 and 1:3 with resting intervals of 0, 3 and 7 days on fry production of the Nile tilapia at the Aquaculture Demonstration Centre (ADC), Ashaiman, Ghana. Nine (9) treatments were arranged according to a 3 x 3 factorial design with three replicates giving a total of 27 spawning hapas (1 m3). Male and female brooders of mean body weight (229 ± 5.43 g and 171.6 ± 21.7 g respectively) were paired at the different sex ratios. Water temperature and DO were taken daily whiles pH, salinity and ammonia were measured weekly. All the water quality parameters were within suitable range for Nile tilapia fry production. The total mean fry output for the sex pairing ratios (1:1, 1:2, 1:3) were 716 ± 344, 973 ± 325 and 723 ± 577 respectively. The total fry output for 0, 3 and 7 days of resting were 1503 ± 868, 2030 ± 637 and 3051 ± 1054 respectively with an observed 35% (3 days rest) and 103% (7 days rest) fry production increment over the 0-resting treatment. With respect to the combined effect of varying sex ratios and resting periods, the highest mean fry production (701 ± 405) was attained under the 7 days resting period at a pairing ratio of 1:2. The high reproductive performance of broodstock pairing ratio 1:2 and resting period of 7 days under this study confirms its efficient as a broodstock management technique for an increased Nile tilapia fry production. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent years, Kazakhstan has entered a period of rapid economic development, which will definitely lead to an increase in the anthropogenic pressure on natural resources. Subsequently, adequate measures must be taken to reduce the anthropogenic impact on natural resources, including the ichthyofauna. Therefore, the barbel was included in the Red Book of the Republic of Kazakhstan in 2008. Stocks of commercial fish valuable in the past such as barbels in the Aral–Syrdarya basin are now catastrophically reduced as a result of the anthropogenic impact on the ichthyofauna and natural environment of the Aral Sea region. Currently, the only way to restore the number of barbels is artificial reproduction, in order to preserve biodiversity and restore stocks of this valuable species in the natural environment and aquaculture. The current status of the barbels inhabiting the Kazakhstan section of the Syrdarya River needs special study, as has been noted since the second half of the 20th century. Stocks of commercial fish valuable in the past as barbels in the Aral–Syrdarya basin are now catastrophically reduced as a result of anthropogenic impact on the ichthyofauna and natural environment of the Aral Sea region. The study of the condition; abundance and distribution range is necessary to determine measures for their restoration in natural habitats and their breeding in fish farms. Research on the biotechnology of barbel breeding with subsequent acclimatization and reacclimatization of these fish species will not only improve the composition of the ichthyofauna of the Aral–Syrdarya basin, but also preserve the genetic potential of natural populations. At present, the only way to restore the population of the Aral barbel is stocking hatchery reared juveniles in natural environments. Under the current situation, a way forward is seen in the creation of domesticated replacement-broodstocks of barbels. As a result of the influence of anthropogenic factors, the populations of this species have come to almost complete degradation and depletion and require the development and adoption of urgent measures for their conservation and restoration through reintroduction, which is a priority and urgent task for the fisheries of the republic. [ABSTRACT FROM AUTHOR]

Obtaining viable Argopecten purpuratus seeds faces challenges, especiallyci the unpredictability of the marine environment and high production costs in hatcheries. However, improving the method of "Broodstock Conditioning In Hatcheries" is key to ensure permanent seed supplies by minimizing the dependence on marine conditions and by maximizing economic viability in hatcheries. In an effort to overcome these barriers, broodstock were conditioned into two different environments: (a) Natural Environment: Natural marine conditions located in Bahía Inglesa, Atacama Region, Chile. (b) Hatchery: Laboratory conditions to achieve gonadal maturation, spawning induction, fertilization and larval development. The purpose of this research was to evaluate how the type of reproductive conditioning affects the reproductive potential and nutritional quality of the progeny. Both methods were successful at inducing the necessary maturity for reproduction, obtaining viable gametes and larvae. On the other hand, it was observed that in the natural environment, the oocytes and D larvae reached a greater size and nutritional value, being the most significant differences with (p < 0.05): the size of the D larvae reached figures of 95.8 ± 3.1 μm and 91.2 ± 2.7 μm in the environment and hatchery, respectively; the lipid content in dry mass was 25.2 ± 3.1 mg g−1 and 13.5 ± 1.9 mg g−1 for the natural environment and hatchery, respectively. Although quality indicators in hatcheries were slightly lower compared to the natural environment, the possibility of conditioning A. purpuratus broodstock independently of environmental variability highlights the importance of further optimizing broodstock conditioning aspects in hatcheries that would allow more predictable and sustainable production.

Simple Summary: Immunity is a key factor in the development of fish embryos, as they are exposed to multiple pathogens. In vertebrates, the maternal transfer of immunity influences the acquisition of immunocompetence. In this work, we demonstrate that in fish, broodstock female priming close to the spawning season improves the development of the innate immune system of their progeny. This occurs via the enhancement of several innate activities and the upregulation of the transcriptional levels of different antimicrobial peptides. Moreover, we provide evidence of the existence of the maternal transfer of immune proteins related to antimicrobial responses in European sea bass. This work also demonstrates that the use of a CP-NNV-expressing vector for priming females is safe, as the plasmid was not detected in their progeny. Acquiring immunocompetence is essential in the development of fish embryos, as they are exposed to environmental pathogens even before they are fertilized. Despite the importance of the antimicrobial function as the first line of defense against foreign microorganisms, little knowledge is available about its role in larval development. In vertebrates, transgenerational immune priming influences the acquisition of immunocompetence of specimens, regulating the selective allocation of nongenetic resources to their progeny and modulating their development. In this work, we primed teleost European sea bass broodstock females with a viral protein expression vector in order to evaluate the innate immunity development of their offspring. Several antimicrobial functions, the pattern of expression of gene coding for different antimicrobial peptides (AMPs), and their protein levels, were evaluated in eggs and larvae during development. Our data determined the presence of antimicrobial proteins of maternal origin in eggs, and that female vaccination increases antimicrobial activities and the transcription and synthesis of AMPs during larval development. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

(d) The contacted fish exhibited severely attenuated and flattened epithelium (yellow arrow) and alteration in their pigment layer on the dorsal skin (black arrow, H&E stain) gl Field observations suggested that the sea anemone may be the cause of the acute death of the snubnose pompano and permit. Keywords: broodstock; mortality; permit; red drum; snubnose pompano EN broodstock mortality permit red drum snubnose pompano 1799 1803 5 10/14/22 20221101 NES 221101 In February 2022, unusual acute mortalities were observed in snubnose pompano ( I Trachinotus blochii i ) and permit ( I T. falcatus i ) broodstock held in sea cages in Nha Phu lagoon, Khanh Hoa, Vietnam. Thirty fish ( I n i = 30) were divided evenly among three groups: high density (25 sea anemones per 100 ml), low density (5 sea anemones per 100 ml) and control (no sea anemone). [Extracted from the article]

To assess the lipid requirements of O. macrolepis broodstock, five iso-nitrogenous diets (39 g kg−1) with five lipid levels, 50 (5 L), 70 (7 L), 90 (9 L),110 (11 L), and 130 (13 L; g kg−1), were made. A total of 105 three-year-old individuals (50.11 ± 2.86 g per fish) were divided into five groups (triplicate per group) and were fed with the diets, respectively, for eight weeks. Then, the fish were sampled, and items were determined. The results showed that growth rate and feed efficiency ratio were not significantly affected by diets (p > 0.05). A clear dose–response effect of dietary lipid was observed on somatic indexes of gonad indexes of the O. macrolepis brookstock, with the highest values corresponding to fish fed 9 and 11 g kg−1 lipids, in contrast, gonad indexes were reduced as dietary lipid moved away from this level. The other somatic indexes, such as viscerosomatic index, perivisceral fat index, etc., were not significantly affected by diets (p > 0.05). The content of crude lipid and crude protein in carcass, hepatopancreas, and gonad were not significantly affected by dietary lipid levels (p > 0.05). The gonad fatty acids of 16:0 and 22:6n-3 decreased and 18:2n-6 increased with the increasing lipid level, being significantly altered by diets (p < 0.05). The histological features of the gonad showed no significant difference among the five diets (p > 0.05). The relative expression of sex steroid-synthesizing proteins (fshr, 3β-hsd, 17β-hsd, aro., and star.) in the gonad of fish was most significantly highly expressed in the 9 L and 11 L groups (p < 0.05). The results suggested that a proper dietary lipid level of 90–110 g kg−1 could maintain gonad development of O. macrolepis broodstock without affecting growth performance. [ABSTRACT FROM AUTHOR]

This contribution brings together current knowledge on the use of functional food additives affecting marine fish reproductive performance. This article reviews published studies by several authors who have worked with specialized diets and focused on the dietary needs of brood fish, with the objective of identifying the relevant functional additives with potential to improve reproductive performance. The use of commercial and experimental diets that may have an effect on egg viability, quantity, and quality are discussed, with reference to hatching rates, larval survival, and compositions of fatty acids and amino acids after feed supplementation with various nutritional compounds. The intention of this review is to highlight the benefits of the use of vitamins, carotenes, fatty acids, and proteins of animal origin in broodstock nutrition, all of which have been shown to improve the quality of progeny under captive conditions. Finally, consideration is given to future perspectives on the use of additives in marine fish nutrition. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the most suitable kind of feed for the mud crab, Scylla paramamosain , to grow from juvenile to broodstock size and to monitor their monthly size and growth rate, as well as to (1) record them reaching maturity and (2) their subsequent mating frequency. For this research, a Complete Randomized Design was used with three treatments. Each treatment was carried out with 40 individuals. The crabs are usually grown in 90 m3 concrete tanks. The three feeds tested were: (A) trash fish, Leiognathus equula , (B) a combination of that ice trash fish and oyster meat from Crassostrea iredalei , and, (C) that same oyster meat only. The feed was always given at 3-10% of total body weight/day. Newly adult male crabs were selected for mating with a newly adult female crab. The male crabs fed treatments B and C grew faster than male crabs fed treatment A. While the female crabs fed treatment C grew significantly faster than female crabs fed treatment A (p < 0.05), but not significantly than the female crabs fed treatment B (p > 0.05). A total of 30 female crabs were followed in mating from July 2020 to January 2021, and the highest mating intensity was found from September to October 2020. The present study indicates that mud crabs grow fast when they are fed treatment C, i.e., oyster meat only. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Four isonitrogenous (34.6 g kg-1 of crude protein) and isoenergetic (19.5MJ kg-1 gross energy) were formulated. Each diet was supplemented with 0 (Control), 0.5 g/ 100 g (T1), 1 g/ 100 g (T2) and 1.5 g/ 100 g (T3) dried Cyclotella spp powder. Nile tilapia broodstock were used in the present experiment 32 broodstocks (24 females + 8 males). Broodstock were sexed and transferred to conditioning 8 concrete ponds (3x1x1 m), and kept separately where, males stocked in 4 concrete ponds at stocking of 2 males in each pond also, the same was conducted for females while, stocked at 6 females in each pond in two replicate. No significant differences were found in growth performance and feed utilization for male and female fed diets supplemented with Cyclotella spp for 30 days before mating. The best condition factor and gonadosmoatic index were recorded in T3, which supplemented with 1.5% Cyclotella spp. The higher pH and sperm motility value were detected in male of T3 and T2 with insignificant differences between treatments, while the lowest one was observed in control. The highest value of absolute fecundity, relative fecundity and system productivity were obtained in T3. [ABSTRACT FROM AUTHOR]

Males and females broodstock of Clarias gariepinus (mean weight, 884.00±2.83g) were subjected to dietary supplementation of Cattle Stick (Carpolobia lutea) Leaf (CSL) at different inclusion levels of 0 (control), 0.5, 1.0 and 2.0% to evaluate the efficacy of the plant for growth performance and fertility enhancer. Clarias gariepinus broodstock (96) were allocated into 12 experimental fibre tanks at 8 fish per tank (4 males and 4 females) fed 40% crude protein at 3% body weight twice daily for 56 days. Each treatment was done in triplicate. Biological evaluation and reproductive indices were measured. There was significant difference (P<0.05) in weight gained by fish fed experimental diets. Fish fed experimental diets containing CSL showed significantly higher (P < 0.05) reproductive indices compared to the control diet. 0.5% inclusion level of CSL showed better performance in term of growth performance and reproductive indices and may be considered to be the best tolerance inclusion level for growth performance and fertility enhancer. The results of the study indicate that incorporating Cattle stick leaf diets in fish feed at 0.5% may have the potential for growth performance and fertility-enhancing agent in male and female C. gariepinus broodstock. [ABSTRACT FROM AUTHOR]

Phospholipids have an important antioxidant effect on animals. The effects of different dietary phospholipid sources on the growth, antioxidant activity, immunity, and gut microbiota of female broodstock of Pacific white shrimp Litopenaeus vannamei were investigated. Four isoproteic and isolipid semi-purified diets containing 4% soybean lecithin (SL), egg yolk lecithin (EL), or krill oil (KO) and a control diet without phospholipid supplementation were fed to female broodstock of L. vannamei (34.7 ± 4.2 g) for 28 days. The growth performance, antioxidative capacity, and innate immunity of the female broodstock fed phospholipid supplemented diets were improved regardless of sources compared with the control shrimp. The effects on growth and antioxidant capacity in female shrimp fed the KO diet were highest. The innate immunity of female shrimp fed the EL and KO diets were significantly higher than shrimp fed the SL diet. Dietary phospholipid supplementation increased gut microbiota diversity and richness, and the Chao1 and ACE values in the KO group were significantly higher than in the control group. The richness of Proteobacteria, Photobacterium, and Vibrio decreased, whereas the richness of Firmicutes and Bacteroidetes increased in the shrimp fed the KO diet compared with the shrimp fed the SL and EL diets. The interactions of gut microbiota in shrimp fed the KO diet were the most complex, and the positive interaction was the largest among all the treatments. The functional genes of gut microbiota in shrimp fed the KO diet were significantly enriched in lipid metabolism and terpenoid/polyketide metabolism pathways. Spearman correlation analysis showed that Fusibacter had significantly positive correlations with antioxidant activity (total antioxidant capacity, superoxide dismutase, glutathione peroxidase), immune enzyme activity (phenoloxidase and lysozyme), and immune gene expression (C-type lectin 3, Caspase-1). All findings suggest that dietary phospholipids supplementation can improve the growth and health status of female L. vananmei broodstock. Krill oil is more beneficial in improving the antioxidant capacity and innate immunity than other dietary phospholipid sources. Furthermore, krill oil can help establish the intestinal immune barrier by increasing the richness of Fusibacter and promote the growth of female shrimp. Fusibacter may be involved in iron metabolism to improve the antioxidant capacity of female shrimp. [ABSTRACT FROM AUTHOR]

Existing broodstock research has ascertained that eggs are heavily influenced by broodstock diet, but there is currently sparse information regarding the time it takes for nutrients to transfer into eggs after broodstock feeding. Thus, our study aimed to quantify this duration of broodstock to egg nutrient transfer by feeding two alternating diets. In 2021, nine California yellowtail (Seriola dorsalis) broodstock were fed alternating diets of commercial pellets (Vitalis Prima: Skretting, Norway) and cutbait (70% sardine and 30% squid). These diets were switched every 41 days and then repeated so each diet was provided twice during the study. Biochemical and biometric data from spawns were collected and statistically analyzed by grouping spawns based on diet type and diet duration. Between diet switches, we observed a selective retention of C18:3n-3 (α-linolenic acid) and C18:2n-6 (linoleic acid) from the Vitalis diet, and C20:5n-3 (eicosapentaenoic acid), from the cutbait diet. Our results showed overall fatty acids from both diets were incorporated by the eggs after 10 to 19 days of feeding. Knowing this timing of nutritional incorporation from broodstock diet to eggs will help significantly improve feed efficiency by providing producers with a specific timeframe to maximize egg quality through dietary modifications or supplements. • The lag period of fatty acid incorporation from broodstock diet to egg was within 19 days. • Specific essential fatty acids were selectively retained by eggs from their previous diets. • Vitalis diet is a potential substitute for a standard cut bait diet in California Yellowtail broodstock. [ABSTRACT FROM AUTHOR]

Highlight • Bullet tuna (Auxis rochei Risso 1810) has been identified (measured, weighed) and analyzed. • The resource status of bullet tuna has been estimated based on body shape and age group. • LWR curve is implemented to describe and express the age group of bullet tuna (immature, adult/mature, old) • This study has resulted the composition and ratio of bullet tuna that is suitable to be caught, fit for consumption and worthy of maturation Abstract Bullet tuna (Auxis rochei Risso 1810) or tongkol lisong (Indonesian) is important for human consumption and health as well as an income source for fishers and coastal communities. Its utilization problems are over exploitation, catch domination by immature groups, and the threatened stock security of the bullet tuna (BLT). This research aimed to determine the status of the prospective parent of bullet tuna caught in the Lesser Sunda region, particularly from the Alas Strait to the Indian Ocean, West Nusa Tenggara (WNT). Meanwhile, the data were collected from July to September 2020 (2nd transitional season) at the Tanjung Luar Fishing Port, East Lombok and a dependent survey method was adopted with sampling, interview, observation, and documentation techniques. Fork length and body weight data were used to estimate the length and weight relationship, growth pattern, condition factor, fish age group, and catch worth. The primary and secondary data were processed quantitatively using several equations. The growth pattern of bullet tuna was minor allometric (b = 2.875), worth selling (K > 1.00), and the majority was adult fish or mature group. The LWR model is . This condition indicates the bullet tuna is worth catching and worth spawning, so that it is eligible to be a potential broodstock candidate to support a sustainable management of BLT fisheries. Furthermore, fishers have applied the code of conduct for responsible fisheries (CCRF) in supporting the sustainable development goals.

Krill oil is rich in phospholipids and has been proven to significantly promote ovarian development in shrimp. However, the optimal level and related mechanism are unknown. In this study, four isonitrogenous and isolipidic diets were prepared. These diets included different gradients of krill oil supplementation (3%, 6%, and 9%), with no-krill oil serving as a control. Female Litopenaeus vannamei broodstock with stage I ovarian development were fed these diets for 28 days. The results showed that the inclusion of krill oil in the diet had a positive effect on ovarian development in female shrimp, particularly at the 6% supplementation level. This was evident from the significant improvements in the gonadosomatic index and in the 17β-estradiol, progesterone, and methyl farnesoid levels. Moreover, 6% krill oil supplementation facilitated lipid accumulation in the hepatopancreas, promoted the deposition of yolk granules within the oocyte, and significantly enhanced the mobilization efficiency of triglycerides and total cholesterol from the hepatopancreas to the ovary. The upregulation of the serum metabolites choline and phosphorylcholine promotes the synthesis of phosphatidylcholine and triglycerides. Additionally, prostaglandin E 2 stimulates the production of ovarian steroid hormones. Acamprosate influences the activity of glutamic acid, potentially leading to a reduction in the secretion of gonadal inhibitory hormones. Multiomics analysis revealed joint enrichment of differentially altered metabolites and differentially expressed genes in pathways involved in arachidonic acid metabolism, cholesterol metabolism, and ovarian steroid synthesis. Additionally, there was significant enrichment in glycerophospholipid metabolism. The expression of the cytosolic phospholipase A 2 gene was upregulated in both the lipid metabolism and steroid synthesis pathways. Moreover, the mRNA expression levels of 3β-hydroxysteroid dehydrogenase/delta 5- > 4-isomeras, cytochrome P450 2 L1, and prostaglandin H synthase 2 were also upregulated in the ovarian steroid synthesis pathway. In conclusion, supplementing the diet with 6% krill oil is optimal for promoting lipid metabolism and steroid hormone secretion in female L. vannamei broodstock, thereby enhancing ovarian development and maturation. • Dietary krill oil had a positive regulatory effect on the reproductive activity of L. vannamei. • Dietary krill oil increased lipid metabolism and promoted steroid hormone synthesis. • Dietary 6% krill oil significantly promoted the ovarian development of female L. vannamei. [ABSTRACT FROM AUTHOR]

The demands on aquaculture for high-value products, like the eastern oyster (Crassostrea virginica), continue to rise. To aid commercial production, hatcheries mate diploid females with tetraploid males to produce triploid offspring, which, in many instances, exhibit faster growth than diploid oysters and maintain meat quality during the reproductive season. Many factors limit triploid production by hatcheries, including low gamete quality. While it is known that abiotic factors can influence gamete performance in eastern oyster, the effects of salinity on triploid production are not well understood. To investigate these effects on gametogenesis and gamete quality, adult tetraploids and diploids were held in recirculating aquaculture systems (RAS) at 10, 20, and 30 PSU for 30 days. Each treatment contained six 140 L tanks with 15 oysters per ploidy. All morphometric measurements were recorded and the genotypic sex of the oysters was determined. Sperm density was quantified from tetraploid males. Sperm motility and velocity from tetraploid males was also analyzed by Computer Assisted Sperm Analysis, while their viability was determined using flow cytometry. ATP and lipid peroxidation were quantified for tetraploid sperm via bioluminescence and fluorescence, respectively. Eggs from diploid females were assessed for fecundity and size. For tetraploid males and diploid females, lipids from gonadal tissues were analyzed by gas chromatography. Results showed that survival, shell morphometrics, and sperm density were unaffected by salinity. However, variability in sperm density increased when tetraploids were held at 10 PSU. In general, sperm motion was suppressed for oysters held at 10 PSU, relative to the other salinity treatments. Sperm membrane viability was lowest and variability highest in oysters held at 30 PSU. Salinity did not impact the quantity of ATP in sperm. Lipid peroxidation was higher in oysters held at 30 PSU compared to 10 PSU, while those at 20 PSU demonstrated no significant difference compared to other treatments. Variation in lipid peroxidation was highest at 10 PSU. Oocyte irregularities were more prevalent when diploids were held at 10 and 30 PSU. Developmentally crucial lipids from females, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were highest when oysters were held at 10 PSU, compared to 30 PSU, while the amount of these lipids from either salinity treatment was statistically different from 20 PSU. Fatty acid concentrations within the sperm from tetraploid males did not differ between salinities. In conclusion, gametes collected from both ploidies held at 20 PSU, performed as well or better than those from the other salinities for every hatchery and gamete-quality metric measured. • Identify how salinity (10, 20, 30 PSU) impacts gamete quality in Eastern oyster. • Generally, tetraploid sperm kinematics were suppressed at 10 PSU. • Oxidative stress in males increased at 30 PSU, while sperm viability decreased • Oocyte irregularities were more prevalent when diploids were held at 10 and 30 PSU • Crucial lipids (e.g., EPA, DHA) from females decreased as salinity increased. [ABSTRACT FROM AUTHOR]

A study was carried out to determine the maturation period, quality and quantity of sperms production in Banana shrimp male broodstock, Penaeus merguiensis fed different natural diets. The three different natural diets namely; squid, fish and shrimp flesh used in this study were obtained from known sources and fed to the tested shrimp in triplicate groups. Based on the results obtained, squid seem to be the most effective natural diet as it enhances the sperms maturation within 20 days. Feeding fish and shrimp flesh as diets for the Banana shrimp broodstock resulted in the observation of maturation in 22 and 24 days, respectively. Similarly, squid diet also recorded the highest (p = 0.002; p < 0.05) sperms count (58.6 to 74.5) as compared to fish diet (44.0 to 61.3) or shrimp diet (28.0 to 42.8). Also, feeding squid diet resulted in a higher percentage of live sperms with ranged between 97.75% to 98.80%. On the other hand, broodstocks fed fish and squid flesh was observed with ranges of between 96% to 97.86% and 92.54% to 96.06%, respectively. It was therefore concluded that squid diet was most effective to improve sperm quality, quantity and maturation period in male broodstock of P. merguiensis. Further study should be carried on the reproductive performance of broodstock fed with squid as diets and it effect on the performances of post larvae obtained. [ABSTRACT FROM AUTHOR]

Accidentally entangled and stranded egg masses of Sepia pharaonis in fishing gears were collected from various landing centres of Thoothukudi district. The stranded egg masses were incubated, hatched and larval rearing was carried out at the Molluscan Fish Hatchery of Tuticorin Research Centre of CMFRI. The average hatching rate of S. pharaonis was 95 % for the eggs collected from the fishing nets. The size of day 1 paralarvae of S. pharaonis was 5.46±0.06 mm and reached the average size of 40.10±1.15 mm length and 9.6±0.20 g weight on day 60 with the average survival rate of 70 %. Maximum weight gain (%) was noticed between 20 -- 40 days. The paralarvae of S. pharaonis fed with suitable live feeds until 50 days, after which fed with dead fish and shrimp. The juveniles were transformed as broodstock with an average length of 137.4±8.08 mm and weight of 229.7±21.54 g on 180th day of culture. In the hatchery, the first captive spawning was witnessed on 167th day and the eggs laid by the females ranged from 46 - 118. However, the captive bred egg masses failed to hatch out. Therefore, the hatchery technology needs to be perfected through the development of nutritionally improved broodstock diet to ensure better hatching. During the years 2016 - 2018, altogether 8400 numbers of hatchery reared 60 days old juveniles of S. pharaonis were ranched into the fishing grounds off Tuticorin coast. The biological significance of sea ranching activities to replenish the natural stocks requires further research and evaluation. [ABSTRACT FROM AUTHOR]

The pharmacokinetics and bioavailability of meloxicam were investigated after single intravascular (IV), intramuscular (IM), and oral dose of 1 mg/kg in rainbow trout broodstock at 11 ± 1.2°C. A total of 36 healthy rainbow trout (Oncorhynchus mykiss) broodstock weighing 1.40 ± 0.26 kg was used for the investigation. Plasma concentrations of meloxicam were measured with high‐performance liquid chromatography‐ultraviolet detection, and pharmacokinetic parameters were calculated by non‐compartmental analysis. The elimination half‐life for IV, IM, and oral routes was 3.63, 4.55, and 2.95 h, respectively. The IV route for meloxicam showed the total clearance of 0.05 L/h/kg and volume of distribution at a steady state of 0.20 L/kg. The peak plasma concentration was 2.97 μg/ml for the IM route and 0.84 μg/ml for the oral route. The bioavailability was 78.45% for the IM route and 21.48% for the oral route. Meloxicam following IM and oral administration displayed short t1/2ʎz. The short t1/2ʎz could be an advantage for the short‐term use in acute conditions. The IM route with the good bioavailability can be preferred for the treatment of various conditions. However, developing new oral formulations with the good bioavailability for meloxicam is necessary to minimize stress and trauma through minimal handling in rainbow trout broodstock. [ABSTRACT FROM AUTHOR]

One of the most important stages of domestication in each species is to maintain the animal in a rearing condition up to reaching to maturity and reproduction. Therefore, this study was performed with the aim of reproducing the pikeperch (Sander lucioperca) grown in a captivity condition. For this purpose, two groups of fish including control group (without hormone injection) and hormone induction group (HCG injection at 200 IU/kg) were considered and each group consisted of two replicates and 5 fish in each tank. The results showed that the fish spawned after 74 to 90 hours, but the difference between the two groups in this regard was not significant. The latency time was determined in case of degree-hour in non-injected breeders to 1396.9 ± 157.2 and in injected breeders to 1261.5 ± 34.2 degree-hours (P = 0.356). The response rate of fish in non-injected breeders was 87.5 ± 17.7% and in injected breeders was 75 ± 0.0% (P = 0.423). The quality of nests did not show any significant difference between the two groups. Fertilization rate was 87.3 ± 3.5% in non-injected fish and 82.7 ± 5.4% in injected fish (P = 0.412). According to the obtained results, it can be concluded that due to the complete adaptation of farmed fish to the captive rearing condition, it can be possible to propagate pikeperch without hormonal induction while the desired temperature and suitable spawning ground are available. [ABSTRACT FROM AUTHOR]

Spawning and water temperature are important factors in the reproduction of valuable fishes such as Percids. In the present study, two types of artificial (turf) and natural (willow root) substrates were compared at two different temperatures of 11 and 12.6 °C in pikeperch (Sander lucioperca). The fish were introduced into the concrete tanks after hormone injection and one nest was installed for each breeding pair. After spawning, the nests were transferred to smaller ponds with controlled conditions for incubation. The eggs were hatched without dependence on the substrate, and there was no difference between incubation times. The results showed that the interaction between substrate type and the temperature was not significant. There was no significant difference in reproductive performance of fish by substrate type but at higher temperatures, more fish were spawned. At higher temperatures, most of the broodstock spawned during 3 to 4 days, and at lower temperatures spawned during 4 to 7 days. There was no difference in preference of fish over spawning on the specified substrate during the spawning time. The results of this study showed that spawning in a suitable temperature range and on artificial substrate had higher performance and the use of artificial substrate during semi-artificial reproduction of wild pikeperch is important for the restocking programs.

Abstract The relationship of body weight and length with sperm load and spermatophore weight was evaluated in wild males of Macrobrachium tenellum (Smith, 1871). In addition, the influence of a commercial and natural feed on the load and viability of sperm was determined in wild males. In 28 wild males spermatophore extraction was performed by electrostimulation 24 h after capture to analyze the relationship between body length/weight and sperm load and viability, respectively. Spermatophore weight (SW), total number (TS), dead (DS) and abnormal sperm cells (AS) were used as indicators of sperm viability. The results obtained show that there is a positive correlation between TS per spermatophore compared to body length and weight of the male. To study the effect of different diets on sperm load, three diets were employed: Diet A, commercial shrimp feed; Diet B, natural feed (mixture of squid, sardine and clam); and Diet C, combination of natural and commercial diet. To assess the initial reproductive status of the males at the beginning of the experiment, sperm viability was determined in a subsample of specimens after capture. Broodstock were fed ad libitum once a day during 70 days. TS, DS, AS and SW were evaluated. The results of the bioassay did not show differences between treatments in the parameters analyzed, except DS, which was higher in the initial group. In conclusion, the present work suggests that it is feasible to substitute fresh feed for an artificial diet for the maintenance in captivity of male M. tenellum broodstock shrimp.

The rapid intensification of the aquaculture system has led to several environmental impacts involving water quality deterioration, pollution, and disease outbreaks. Consequently, an eco-friendly technique is inevitable that could ensure better production with less impact on the environment by minimizing the effluent discharge from aquaculture practice. Biofloc technology is such a kind breakthrough that would be easy to perform; operation and establishment procedure is quite simple at a relatively low cost that would be convenient to fish farmers. It can serve as a perfect solution for aquaculture species through improving its all characteristics such as substantial biomass density, survival, and disease resistance ability to the pathogen by an immunostimulatory effect of microbial floc on the immune system that would assure the biosecurity and sustainability of this extraordinary technique. [ABSTRACT FROM AUTHOR]

A comparative analysis of the size–weight and biochemical parameters (total lipid content and their fractional and fatty acid composition) of eggs of wild and cultured producers of the Ob muksun shows significant differences between them. Wild eggs are characterized by their smaller size (by 7%) and lower weight (by 15%), higher fat content (by 13%) and level of diacylglycerols (by 33%), and lower phospholipid content (by 30%) in comparison with cultured eggs. At the same time, cultured eggs differ from wild eggs by a higher level of physiologically significant docosahexaenoic 22:6n-3 (1.8 times) and linoleic 18:2n-6 (7.1 times) acids, but a relatively lower level of eicosapentaenoic 20:5n-3 (in 1.5 times) and arachidonic 20:4n-6 (4.2 times), respectively. Such changes in the fatty acid status lead to a decrease in the cultured eggs of the n‑3/n-6 ratio (by 52%), palmitic 16:0/oleic 18:1n-9 (32%), and α-linolenic 18:3n-3/18:2n-6 (by 45%) and to an increase in 22:6n-3/20:5n-3 (by 63%). In addition, in the eggs of cultured muksun, 68% of the total lipids are 4 acids—16:0, 18:1n-9, 22:6n-3, and 18:2n-6; in wild eggs the share of these acids is 47%. The established differences in the size–weight parameters, the total lipid content, and their fractional and fatty acid composition of wild and cultured eggs of the Ob muksun are most likely associated with the different diet and habitat conditions of the sexually mature fish in captivity and nature. [ABSTRACT FROM AUTHOR]

(Plectropomus leopardus) or grouper coral trout is one kind of commodities that have high economic value. As marine fisheries commodities are much in demand for large-scale farmers or household level will require broodstock who have qualified to produce quality eggs and a good seed. qualified to produce quality eggs and a good seed. The purpose of research is to gain knowledge in maintenance activities of the broodstock grouper coral trout on a concrete tank by comparing theory and application in the field. Maintenance engineering of coral trout grouper broodstock includes the preparation of concrete tanks, broodstock selection, water quality management, feeding, spawning and harvesting of eggs, and disease. Research in Balai Besar Penelitian dan Pengembangan Budidaya Laut (BBPPBL) Gondol. Penyabangan Village, Subdistrict Gerokgak, Buleleng, Bali. On 18th January – 18th February 2016. Methods of work used in this research is descriptive data retrieval methods include primary data and secondary data. Data retrieval is done by means of active participation, observation, interviews and literature study. Results of Field Work Practice is the broodstock of grouper coral trout are maintained as much 217 with an average weight of 512.9 kg and an average length of 56.1 cm. Maintenance of broodstock grouper coral trout performed in container maintenance the round-shaped sized 100 m3 with a depth of 3 m with inlet and outlet Water management is performed by using a system is running water that flowing water as much as 300% -400%, the quality of sea water showing the value of 34.9 ppt salinity, DO 6.0 ppm, pH 8, and the temperature of 29 ËšC. Feed given in the form trash fish as much as 7-10 kg a day. Grouper coral trout spawning is done naturally by the male and female parent ratio of 1: 2, which produce eggs an average 2,252,292 items. During maintenance activities parasites invade have been found. Parasites invade the broodstock of grouper coral trout is Benedenia sp., Cryptocaryon sp., And viral infections Viral Nervous Necrosis (VNN)