Female Broodstock Research Articles

Growth, reproduction, fatty acid profiles and offspring performance of broodstock yellow catfish Pelteobagrus fulvidraco fed diets with different lipid levels

Parental nutrition plays important roles in reproductive performance and offspring health of broodstock yellow catfish. However, there is a lack of relevant knowledge concerning the broodstocks of many fish species. This study investigated the influence of dietary lipid levels on growth, spawning performance, tissue fatty acid profiles, sex hormone secretion, and offspring health status of yellow catfish (Pelteobagrus fulvidraco). Five experimental diets were designed containing a 7:3 ratio of fish oil and corn oil blends with graded lipid levels (6.3%, 8.2%, 10.8%, 12.2%, and 14.4% by dry weight) and were fed to female broodstock yellow catfish for 8 weeks. The results showed that weight gain, egg diameter, fertilization ratio, and hatching ratio increased initially and then decreased with increasing dietary lipid levels, reaching optimal peaks in the L10.8 group. Broodstock fed a diet with 10.8% lipid obtained the highest 17-β estradiol concentration. The deposition of highly unsaturated fatty acids in tissues increased initially and then decreased with the increase in dietary lipids, reaching a peak in the 10.8% group. Plasma superoxide dismutase activity and total glutathione content were lowest in fish fed a diet with a 6.3% lipid level, while the contents of malondialdehyde and cortisol in larvae 3 days post-hatching showed an opposite trend, indicating that a low-fat diet reduced the antioxidant capacity of broodstock and induced a stress response that had negative effects on offspring health. Broodstock fed a diet with an appropriate lipid level could increase the expression of antioxidant enzymes by activating the nrf2 signaling pathway. Based on the regression of dietary lipid level and weight gain, reproductive performance, and egg quality of fish, the optimal dietary lipid level was 10.1–11.7% for broodstock yellow catfish.

Teknis Pengelolaan Pembenihan Ikan Mas Mantap Cyprinus carpio untuk Mendapatkan Benih Kualitas Unggul

The development of mirror carp (Cyprinus carpio) farming in Indonesia has progressed very rapidly, as can be seen by the increasing number of varieties of mirror carp produced from various regions with their respective specifications and advantages. Along with the need for carp that are more resistant to environmental changes and disease attacks, the development of the Majalaya carp variety subsequently produces Mantap carp fish that are disease-resistant, and growth in the growth segment is faster. The aim of this study was to disseminate technical information on Mantap fish carp culture to the public so that it can be used as a reference source for the community, especially for cultivators who are interested in developing this fish. In this study, primary and secondary data were collected. Based on the results of a fecundity study, one female broodstock produced 104.496 kg broodstock-1, the average percentage of egg fertilization (FR) was 89,64%, the average hatching rate (HR) was 61,37%, and the average survival rate (SR) until the size of the seed size 2-3 cm reaches 60%.

Effect of Soaking Java barb (Baryoniums gonionotus) Eggs in Jatropha Leaf Solution (Jatropha curcas L.) on Their Hatching and Survival Rate

The biggest problem that often found in barb hatcheries are the poor hatching rate of eggs. One of the causes of low hatchability is infestation of fungi such as Saprolegnia sp. Prevention of the infestation of fungi could be done by adding natural ingredients such as plants leaves that contain antifungal, such as Jatropha leaf. Soaking Jatropha leaf solution aims to protect the chorion from being infestated by fungi so that it can minimize hatching failure of eggs. The purpose of this study was to determine the effect of soaking Jatropha (Jatropha curcas L.) leaf solution on the hatching rate and survival rate of Java barb (Barbonymus gonionotus) eggs. The testing eggs which were used on this study were originated from male and female broodstock aged 1-1.5 years. Experimental method was carried out using a completely randomized design (CRD) consisting of 4 treatments and 5 replications. The treatments were Jatropha leaf solution at dosages of A (0 g/l), B (2 g/l), C (4 g/l), and D (6 g/l). The data observed were embryonic development, hatching rate (HR), survival rate (SR), and water quality. The results showed that treatments C and D demonstrated fastest embryonic development and hatching phase achieved at 475 minutes. Furthermore, treatment C showed the best value with HR (84.00±3.16%), SR (85.24±1.00%). It can be concluded that soaking eggs using Jatropha leaf solution at concentration of 4 g/L significantly improved hatching rate and survival rate of Java barb (Barbonymus gonionotus). Keywords: Jatropha, Java barb eggs, hatchability, fungi

Dietary protein requirement of female climbing perch, Anabas testudineus (Bloch, 1792) broodstock

Nutritional components are multifarious amongst different producers, whereas they are just designed for fish farming but not suitable for improving the reproductive performance of brood fish. Climbing perch, Anabas testudineus is one of the candidate species for freshwater aquaculture in Asia. However, there is little knowledge available about the nutrient requirement of A. testudineus broodstock. Therefore, a feeding trial was conducted for 90-days to optimize the dietary protein requirement for reproductive performances of A. testudineus female broodstock. Six iso-energetic (around 400 Kcal digestible energy/100 g), iso-lipidic (8%) and hetero nitrogenous (25–50% crude protein, CP) semi-purified diets namely, 25% CP (T25), 30% CP (T30), 35% CP (T35), 40% CP (T40), 45% CP (T45) and 50% CP (T50) were prepared for feeding the fish of respective group twice daily. Three hundred and sixty (360) adults A. Testudineus (average body weight 18.67 ± 0.09 g) with female and male ratio of 1:1 were randomly distributed in six treatments in triplicate with the stocking density of 20 fish/ tank (500 L water volume) following a completely randomized design. Results indicated that the gonado-somatic index and viscero-somatic index increased significantly (p < 0.05) up to 40% CP then reduced gradually. But intraperitoneal fat content decreased with increasing dietary protein levels. T40 group showed lowest hepato-somatic index. The absolute fecundity was highest (p < 0.05) in 35% dietary protein fed group but found similar (p > 0.05) between T30 and T45 group. Estradiol was significantly lowest (p < 0.05) but highest 17α, 20β di-hydroxy progesterone level were observed in 35% CP fed group. Cortisol was found highest (p < 0.05) in T40, T45andT50groupand lowest in T35 group. Histological observations revealed that the females with higher proportion of vitellogenic oocytes were from 35% to 40% protein-fed groups. After induced spawning, significantly (p < 0.05) higher fecundity of spawning, rate of fertilization and hatching, and survival of larvae were observed in 40% CP fed group. Second-order polynomial regression analysis of fertilization rate (%) and larval survival (%) estimated 39.07–39.21% dietary protein is optimum for gonadal development, oocyte maturation and reproductive performance of female A. testudineus broodstock.

Positive effects of optimal dietary cholesterol levels on the ovary development and health of female Pacific white shrimp, Litopenaeus vannamei broodstock

Cholesterol is an important precursor necessary for the synthesis of steroid hormones and other functional substances. This study conducted a 28-day feeding experiment to assess the effects of different levels of dietary cholesterol (0.2%, 0.8%, 1.4%, 2.5%, or 3.2%) on the ovarian development and health status of female Litopenaeus vannamei broodstock (initial weight 39.5 ± 4.3 g). The results showed that dietary supplementation with 1.4% cholesterol can significantly increase the GSI and HSI of shrimp. Meanwhile, the 1.4% cholesterol group significantly increased the antioxidant capacity of shrimp, and increased mRNA expression of transcription factors (FoxO, GST) was also coordinated to regulate the antioxidant system. The TG and T-CHO contents were significantly accumulated in the hepatopancreas of shrimp fed a 1.4% cholesterol diet compared to other treatments. In addition, in the 1.4% group, the concentration of estrogen (E2, PROG, MF) was significantly increased compared to that in the other experimental feed groups. This was achieved by upregulating the mRNA expression of Vg, Vgr, StAR3, 3β-HSD, 17β-HSD, and ERR associated with the steroid hormone synthesis pathway. Correlation analysis of serum metabolomics and ovarian transcriptomics found that differential metabolites and differentially expressed genes were commonly significantly enriched in the glutathione metabolism pathway. Increased GST activity further enhances shrimp antioxidant capacity, which may also promote steroid hormone synthesis. In conclusion, dietary supplementation with 1.4% cholesterol can significantly promote ovarian development and strengthen the antioxidant system of female L. vannamei broodstock. To improve reproductive performance and health status, it is suggested that the appropriate dietary cholesterol supplementation content for female broodstock of L. vannamei is 1.606%–1.680%.

Feminization of Maroon Clownfish (&lt;I&gt;Amphiprion biaculeatus&lt;I/&gt;, Bloch 1790) with 17β-Estradiol Hormonal Induction

Highlight Research The 17β-estradiol hormone induction reduces the percentage of R values in skin and fin color by as much as 50-60%. The 17β-estradiol hormone induction increases total length and body weight, estradiol content, GIS and HIS, and also glucose content. The 17β-estradiol hormone induction shows mature development of the gonadal profile from functional male to functional female. Abstract As maroon clownfish (Amphiprion biaculeatus) is a protandrous hermaphroditic fish, feminization process with 17β-estradiol hormone can be applied to accelerate the female broodstock candidate supply for further spawning effort. This study aimed to evaluate the feminization of A. biaculeatus with 17β-estradiol hormonal induction. This study used a completely randomized design with several hormone dosage, namely P0 (without 17β-estradiol hormone induction), P1 (0.5 μg 17β-estradiol/g body), P2 (1.0 μg 17β-estradiol/g body), and P3 (1.5 μg 17β-estradiol/g body). These treatments were applied with three replications. Five fish composed of α-fish, β-fish, and three γ-fish were reared in each aquarium for 90 days with a flowing water system. The α- and β-fish were then removed, while the γ-fish was injected with hormone. Otohime pellet feed was fed three times a day until apparent satiation. The results showed that the 17β-estradiol hormone could induce 100% of the feminization process of male A. biaculeatus. The dosage of P3 obtained the lowest value percentage of red, green, blue (RGB), but showing the highest total of length and body weight (6.67±0.42 cm and 6.40±0.78 g, respectively), estradiol content (149.73±4.24 ρg/mL), GSI and HSI (0.38±0.07% and 3.59±0.49%), and glucose content (4.67±0.64 mg/dL), followed by more mature gonad profile than other treatments. This condition indicates that fish in P3 treatment has been reversed as functional female. The average survival rate for the treatment was as high as 60%. Therefore, the application of 17β-estradiol hormonal induction is effective for the feminization process in A. biaculeatus as a protandrous hermaphroditic fish.

Comparative study of ovarian development in wild and captive-reared long-whiskered Sperata aor (Hamilton, 1822)

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.

Impact of dietary soybean inclusion on the endocrine disruptive effect in female brood stock of Cyprinus carpio

Phytoestrogens, mostly found in legumes, mimic animal estrogens and induce either pro- or anti-estrogenic activity. A feeding trial for matured Cyprinus carpio females was carried out to assess the endocrine disrupting effect of phytoestrogens in SBM and to suggest a dietary inclusion of soybean meal for broodstock of carps. The fish were fed diets containing graded levels of soybean meal (SBM-0, 15, 20, 25, 30, 35, and 40%) for 60 days. To assess the endocrine disruption, sex hormone profiling, gene expression analysis of candidate genes, and histological examinations were conducted. Serum T3, serum vitellogenin, and mRNA levels of cyp19a1, cyp19b, and erβ were found to be higher in fish groups fed with diet containing low levels of SBM (SBM 15, 20, and 25), and significantly lower in high SBM diet (≥30%) fed groups. Serum concentrations of cholesterol, cortisol, and the mRNA level of 20βHSD all decreased as SBM increased. Increased levels of testosterone, estradiol, and the mRNA for the erα gene were observed in the diet when SBM was incorporated into the diet. In the treatment groups with ≥30% inclusion of SBM, the number of vitellogenic oocytes and the gonadosomatic index were significantly lower than the groups with low inclusion levels. Thus, soybean meal can be included in the diet of female carp broodstocks up to 25% without disrupting the reproductive function. However, an inclusion level beyond 25% could harm the endocrine axis, subsequently capable of impacting reproductive performance.

Sex-dependent effects of mechanical delousing on the skin microbiome of broodstock Atlantic salmon (Salmo salar L.)

Delousing strategies, including mechanical delousing, are typically used to treat Atlantic salmon (Salmo salar) sea lice infestations. In this study, we evaluate the impact of mechanical delousing (Hydrolicer) on the skin bacterial microbiome of broodstock female and male Atlantic salmon. 16S rDNA sequencing of salmon skin microbial communities was performed immediately before delousing, right after delousing and 2 and 13 days post-delousing (dpd). The skin bacterial community of female salmon was more diverse than that of males at the start of the experiment. Overall, hydrolycer caused losses in alpha diversity in females and increases in alpha diversity in males. Hydrolicer also caused rapid shifts in the skin microbial community composition immediately after delicing in a sex-specific manner. There was a decrease in abundance of Proteobacteria and Bacteriodetes in both female and male salmon, whereas Firmicutes and Tenericutes abundances increased. Interestingly, the female community recovered faster, while the male community remained dysbiotic 13 dpd due to expansions in Bacteroidetes (Pseudomonadaceae) and Firmicutes. Our data suggest that female broodstock are more resilient to Hydrolicer treatment due to their more diverse skin microbiota community, and that sex influences the skin microbial community and therefore host health outcomes during common farming manipulations.

Impact of water temperature on the shipping of berried female broodstock (Macrobrachium rosenbergii): A study on survival, egg retention, hatching duration, and hatching success rate

This study evaluated the impact of different water temperatures on shipping berried female Macrobrachium rosenbergii broodstocks. The broodstocks, averaging 23±0.07 g in weight and 12±0.1 cm in length, were shipped in styrofoam boxes containing 24L of purified freshwater. Three temperature conditions were tested: 28.5±0.5oC (control), 25.5±0.5oC (T1), and 21.5±0.5oC (T2). Various water quality parameters were measured. Mortality rates were significantly lower in T2 (2.60±0.41%) and T1 (8.96±2.09%) compared to the control (24.89±4.96%) (p&lt;0.05). The percentage of healthy berried females was higher in T2 (64.18±3.77%) and T1 (56.12±0.59%) than in the control (39.43±2.44%) (p&lt;0.05). T2 exhibited the lowest egg weight loss (6.17±0.66 g) and the shortest hatching period (26.33±3.30 hrs) with the highest hatching success rate (90.68±0.34%) (p&lt;0.05). Dissolved oxygen levels decreased more in the control group compared to T1 and T2 (p&lt;0.05). Total nitrite levels increased significantly in the control group compared to T1 and T2 (p&lt;0.05). The study concludes that cooler shipping temperatures, particularly around 21.5oC, benefit the survival, health, and hatching performance of berried female M. rosenbergii broodstocks.

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.

Erratum: Eyestalk Ablation to Increase Ovarian Maturation in Mud Crabs.

Compared to Fishmeal, Dietary Soybean Meal Improves the Reproductive Performance of Female Yellow Catfish (Pelteobagrus fulvidraco) Broodstock.

To investigate the effects of different dietary protein sources on the reproductive performance of female broodstock, yellow catfish (Pelteobagrus fulvidraco) were fed with three experimental diets using fishmeal (FM), soybean meal (SBM), and rapeseed meal (RSM) as main protein sources, respectively. Females (initial weight: 64.56 ± 0.45 g) were distributed into 9 net cages for feeding trial. Results indicated that 30% dietary SBM improved the reproductive performance for higher gonadosomatic index (GSI), relative fecundity, total egg production, egg diameter, and hatching rate. In addition, SBM and RSM diets resulted in higher estradiol (E2), vitellogenin (VTG), luteinizing hormones (LH), and lower follicle-stimulating hormone (FSH) and testosterone (T) in plasma (P < 0.05) of female broodstock. Dietary SBM and RSM also resulted in lower mesenteric fat index (MFI), plasma total cholesterol (TC), plasma total bilirubin (T-Bil) contents, and gonadal cortisol concentrations, while dietary SBM downregulated the transcription levels of steroidogenesis-related proteins by negative feedback (P < 0.05). The results demonstrated that dietary SBM and RSM could promote sex steroid hormone and VTG biosynthesis and showed hypocholesterolemic effects. Besides, 30% dietary SBM inclusion could improve the reproductive performance of female yellow catfish broodstock.

Characterization of maternal immunity following vaccination of broodstock against IHNV or Flavobacterium psychrophilum in rainbow trout (Oncorhynchusmykiss)

Infectious hematopoietic necrosis (IHN) is a significant viral disease affecting salmonids, whereas Flavobacterium psychrophilum (Fp), the causative agent of bacterial coldwater disease (BCWD), remains one of the most significant bacterial pathogens of salmonids. We explored maternal immunity in the context of IHN and BCWD management in rainbow trout (Oncorhynchus mykiss) aquaculture. Two experimental trials were conducted where different groups of female broodstock were immunized prior to spawning with an IHNV DNA vaccine or a live attenuated F. psychrophilum (Fp B.17-ILM) vaccine alone, or in combination. Progeny were challenged with either a low or high dose of IHNV at 13 days post hatch (dph) and 32 dph or challenged with F. psychrophilum at 13 dph. Mortality following a low-dose IHNV challenge at 13 dph was significantly lower in progeny from vaccinated broodstock vs. unvaccinated broodstock, but no significant differences were observed at 32 dph. Mortality due to BCWD was also significantly reduced in 13 dph fry that originated from broodstock immunized with the Fp B.17-ILM vaccine. After vaccination broodstock developed specific or neutralizing antibodies respectively to F. psychrophilum and IHNV; however, antibody titers in eggs and fry were undetectable. In the eggs and fry mRNA transcripts of the complement components C3 and C5 were detected at much higher levels in progeny from vaccinated broodstock and showed a significantly increased and rapid response post-challenge compared with unvaccinated broodstock. After challenges pro-inflammatory cytokine expression was immediately and considerably elevated in the fry from vaccinated broodstock vs. unvaccinated broodstock, whereas adaptive immune genes were elevated to a lesser degree. Results suggest that maternal transfer of innate and adaptive factors at the transcript level occurred because development of lymphomyeloid organs is not complete in such young fry. In addition to documenting maternally derived immunity in teleosts, this study demonstrates that broodstock vaccination can confer some degree of protection to progeny against viral and bacterial pathogens.

Inclusion of live mud polychaete (Marphysa iloiloensis) in the feeding regime improved the hatchery performance of domesticated Indian white shrimp (Penaeus indicus)

A 60-day feeding trial was conducted to evaluate the effect of inclusion frequency of hatchery-bred mud polychaete, Marphysa iloiloensis, as part of a combination diet on the reproductive performance and larval quality of domesticated P. indicus. The two treatments were fed with a combination of formulated diet, mussel, squid, and mud polychaete with once (T1) and twice (T2) a week inclusion in the feeding regime. In contrast, the control group was fed only a diet combination of mussels, squid, and formulated diet. There was no significant difference in the mean survival of male and female broodstock in all treatments upon termination (p>0.05). Shrimp in T1 and T2 performed significantly better than the control in terms of spawning frequency (p=0.037) and fertilization rate (p=0.001), while T1 had significantly high re-maturation (p=0.038). The survival, spawning, hatching rate, egg, and nauplii production did not differ significantly among treatments (p>0.05). Also, no difference in the gonado-somatic index (GSI), hepato-somatic index (HSI), spermatophore weight, and sperm count was found among diet treatments (p>0.05). Post larvae from T1 and T2 performed significantly better than the control after 25 (p=0.008) and 30 (p=0.009) minutes of abrupt exposure to freshwater, respectively. Therefore, even once weekly, mud polychaete inclusion is sufficient to improve the reproductive performance of P. indicus broodstock and produce offspring with boosted resistance in the hatchery.

Evaluation of Growth Performance and Improving Genetic Gain of Blue Tilapia (&lt;I&gt;Oreochromis aureus&lt;/I&gt;) Fourth-generation (F-4) at Brackish Water Pond

Highlight Reseacrh The study showed that the selected F-4 blue tilapia had a better growth pattern than the control (non-selection) F-4 blue tilapia The difference in performance between the two populations of blue tilapia is an illustration of the genetic improvement that is passed on from parents to offspring as a result of the selective breeding The realized heritability value of the weight character of F-4 blue tilapia in the high category There was an increase in growth in the F-4 blue tilapia population with a positive response to selection Abstract Breeding program in order to increase genetic improvement in blue tilapia have not been widely carried out at brackish water ponds. This study aimed to evaluate the increase in growth and genetic gain of F-4 blue tilapia from family selection in ponds with 25-30 gL-1 salinity. The parent used for the formation of F-4 is the selected parent F-3 and as a control using the non-selected parent F-3. Spawning was carried out in a full-sib mating design using the family selection method. The ratio of male and female broodstock is 1: 2. Spawning and nursery activities of F-4 blue tilapia are carried out in freshwater. The enlargement test was carried out in the net cage 5m x2.5m x1 m which was installed in the ponds with a salinity of 25-35 g l-1 for 120 days, at a stocking density of 10 fish m-2. At the end of maintenance, a selection process is carried out on the weight traits. Parameters observed included growth, survival, and genetic values. The results showed that the growth and survival in the F-4 blue tilapia population, male and female selected populations, had a higher value than in the non-selected population. The realized heritability value of the population growth character of the F-4 blue fish is in the high category. The difference in the average weight of the selected blue tilapia and the control was equivalent to an increase in genetic value added by 15.06% (male population) and 17.92% (female population).

Vitellogenin 1 is essential for fish reproduction by transporting DHA-containing phosphatidylcholine from liver to ovary

Vitellogenins (Vtgs) are essential for female reproduction in oviparous animals, yet the exact roles and mechanisms remain unknown. In the present study, we knocked out vtg1, which is the most abundant Vtg in zebrafish, Danio rerio via the CRISPR/Cas 9 technology. We aimed to identify the roles of Vtg1 and related mechanisms in reproduction and development. We found that, the Vtg1-deficient female zebrafish reduced gonadosomatic index, egg production, yolk granules and mature follicles in ovary compared to the wide type (WT). Moreover, the Vtg1-deficient zebrafish diminished hatching rates, cumulative survival rate, swimming capacity and food intake, but increased malformation rate, and delayed swim bladder development during embryo and early-larval phases. The Vtg1-deficiency in female broodstock inhibited docosahexaenoic acid-enriched phosphatidylcholine (DHA-PC) transportation from liver to ovary, which lowered DHA-PC content in ovary and offspring during larval stage. However, the Vtg1-deficient zebrafish increased gradually the total DHA-PC content via exogeneous food intake, and the differences in swimming capacity and food intake returned to normal as they matured. Furthermore, supplementing Vtg1-deficient zebrafish with dietary PC and DHA partly ameliorated the impaired female reproductive capacity and larval development during early phases. This study indicates that, DHA and PC carried by Vtg1 are crucial for female fecundity, and affect embryo and larval development through maternal-nutrition effects. This is the first study elucidating the nutrient and physiological functions of Vtg1 and the underlying biochemical mechanisms in fish reproduction and development.

Priming European Sea Bass Female Broodstock Improves the Antimicrobial Immunity of Their Offspring.

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.

Evaluation of humpback grouper, Cromileptes altivelis reproduction because of mating between males from the wild and females from cultivation

There has been a tendency to decrease the genetic quality of aquaculture commodities, which is a significant problem to be addressed immediately. The study aimed to evaluate the reproduction of humpback grouper broodstock resulting from crossbreeding male broodstock from the wild with female broodstock from captivity. This research used 2 (two) concrete tanks 75 m3 in volume. Each tank was filled with 25 females comprising 15 cultured and 10 broodstock from the wild and conducted from March to November. The broodstock feed consists of fresh fish and squid. The treatment given is the difference in vitamins given. The Tank A was fed an additional vitamin mix, while in Tank B was fed extra vitamins C and E. Recorded parameters such as egg production, egg hatching rate, egg size, spawning frequency, and oil droplet size. The results of humpback grouper reproduction showed that providing fresh trash fish, squid, vitamin C, and vitamin E in the feed yields better results. The spawning frequency was higher in tank B, with 22 times occurrences, compared to tank A, with 17. The highest number of eggs was observed in October, with up to 1,395,000 eggs in Tank B and 1,150,000 in Tank A.

Hormone Application for Artificial Breeding towards Sustainable Aquaculture - A Review

Aquaculture has been the fastest-growing area of worldwide food production and is becoming a vital component of the global economy to feed the rising world population. Hence, directed toward continuing the current level of per head consumption, comprehensive aquaculture production needs to attain eighty million tonnes by 2050. However, some cultured marine fish species, such as salmonids, striped bass, and gilthead seabream, as well as freshwater fish, such as captive Mediterranean amberjack populations (Seriola dumerili) and Mekong River giant catfish (Pangasianodon gigas), exhibit reproductive dysfunction, especially in female brood stock when reared in captivity. Captive females face complications with unsynchronised ovulation, fail to undergo final oocyte maturation (FOM), and no longer spawn due to a lack of luteinising hormone (LH). Thus, artificial breeding has been widely used in aquaculture practices to increase cultured fish production. Farmer has extensively applied commercial hormones such as human chorionic gonadotropin (hCG), Ovaprim, Ovatide, and Ovaplant, through injection and implantation of hormones to stimulate breeding in many farmed fish species. However, artificial breeding is still in its development phase, and some methods are still unable to induce spawning in certain fish species. Different methods, doses, and delivery systems of artificial hormones could improve the efficiency and effectiveness of artificial breeding. This paper discusses the current research on artificial breeding in various fish species as well as new approaches or techniques to be applied in the area to regulate the reproductive process in captive fish for sustainable aquaculture.

Alteration of eggs biochemical composition and progeny survival by maternal high carbohydrate nutrition in a teleost fish

Reproductive performances, and the factors affecting them, are of major importance especially for farmed fish in the context of the development of a sustainable aquaculture. Dietary maternal lipids have been identified as a major factor affecting reproductive performances. Nevertheless, the consequences of carbohydrates have been little studied while plant-derived carbohydrates could be increasingly used in broodstock diets. To explore this issue, 2-year-old female trout were fed either a control diet that contains no carbohydrate and a high protein content (65.7%) or a diet formulated with plant-derived carbohydrates containing 32.5% carbohydrate and 42.9% protein (’HC diet’) for an entire reproductive cycle. The reproductive performances, the quality of the unfertilized eggs and the development of the progeny were carefully monitored. Although the one year HC nutrition had not impaired female growth nor spawns quality, such nutrition had increased the variability of eggs size within spawns (+ 34.0%). Moreover, the eggs produced had a modified fatty acid profile, including a significant reduction in EPA content (− 22.9%) and a significant increase in the AA/EPA ratio (+ 33.3%). The progeny were impacted by such alterations as their survival rates were significantly reduced. A lower plant-derived carbohydrate inclusion (20%) should be considered in aquafeed for female broodstock in trout.