Brood Stock Research Articles

Influence of Dietary Fatty Acids on Fish Sperm Tolerance to Cryopreservation

ABSTRACTTo meet growing fish demand, aquaculture must develop sustainable, cost‐effective, and high‐performance fish feed formulations for industry advancement. Plant‐based lipids are a viable alternative to forage fish ingredients in finfish diets. However, most plant‐derived lipids lack long‐chain polyunsaturated fatty acids (LC‐PUFA) like EPA and DHA, which are nutritionally essential for fish. This review summarizes recent findings on the nutritional aspects of fish brood stock and sperm quality, emphasizing the effects of fatty acids on reproductive outcomes. Studies indicate that substituting fish oil with plant oils alters the fatty acid profiles in fish tissues and gametes, potentially compromising sperm quality, cryopreservation success, and progeny viability. Sperm membrane lipids, including EPA, DHA, and ARA, are vital for motility and fertilization rates post‐thaw. Additionally, cryopreservation has been linked to molecular and epigenetic alterations in sperm, which may negatively affect offspring quality. The role of mRNA and noncoding RNA in regulating sperm function and embryonic development is well known, and thus any damage to these molecules as a consequence of cryopreservation might induce long‐term effects on offspring. Proteomic analyses reveal that cryopreservation can lead to significant protein loss in sperm, diminishing their functional and fertilization capabilities. Optimizing cryoprotectant protocols and freezing techniques is crucial to reduce damage, while dietary fatty acids play a key role in preserving sperm quality during cryopreservation stress. Further research with omic technologies is crucial to fully understand sperm tolerance to cryopreservation, which will improve reproductive outcomes and enhance sustainability and quality in aquaculture.

Managing Complexities in Giant Freshwater Prawn Breeding Facilities in Perak, Malaysia: A Case Study

Malaysia's aquaculture industry has seen significant growth in recent years, with the giant freshwater prawn (Macrobrachium rosenbergii) emerging as a key species of economic importance. This study examines the intricate challenges faced by hatchery owners’ breeding facilities in Manjung, Perak, Malaysia as they strive to maintain and improve the brood stock production of this valuable crustacean. The research focuses on multifaceted, operational aspects of managing giant freshwater prawn hatcheries. Through a combination of field studies guided by qualitative methodology, the identification of primary obstacles encountered at Manjung breeding facilities was evaluated via current management practices. The findings revealed that hatchery owners lack adequate managerial skills in handling operational matters such as budgeting, labor utilization, utilities, marketing, and networking. The most critical factor was cost-effective sourcing of healthy, brood stock supply from local fishermen. Furthermore, the research underscores the importance of genetic diversity in broodstock populations as hatcheries struggle with inbreeding depression, necessitating the development of more robust breeding programs. From the socio-economic standpoint, a holistic approach to addressing these issues, emphasizes the need for increased collaboration between research institutions, government agencies, and private sector stakeholders. The study provided a comprehensive overview of the complexities inherent in managing giant freshwater prawn breeding facilities in Malaysia. By identifying key challenges and potential solutions, it aims to contribute to the sustainable development of this vital sector of Malaysia's aquaculture industry. The findings have implications for policy-making, industry practices, and future research directions in the field of freshwater prawn aquaculture and food security agenda.????????????????

Monitoring egg fertility, embryonic morbidity, and mortality in an oviparous elasmobranch using ultrasonography.

Ultrasonography is widely used to monitor pregnancy in viviparous species, but it is underutilized as a tool to characterize embryonic development in oviparous species. Currently, a multi-institutional effort is underway to re-wild the endangered zebra shark (Stegostoma tigrinum) to locations where this species was previously extirpated by leveraging the reproductive efforts of aquarium sharks as a source of brood stock. Zebra sharks are oviparous and fecund, but a large percentage of their yolked eggs do not result in hatchlings. Therefore, ultrasonography represents a potential tool for distinguishing fertile eggs with developing embryos from degrading eggs, and to diagnose changes in early embryonic development predictive of poor outcomes. The objectives of the current study were to use ultrasonography to assess egg fertility, monitor early embryonic development, and identify morphological indicators that may be predictive of early embryonic mortality. Freshly laid eggs from four female zebra sharks were collected and inventoried daily at Aquarium of the Pacific. Eggs were incubated undisturbed for 2 to 4 weeks and subsequently examined weekly via ultrasound to assess fertility and monitor embryo development. Among 120 fertile eggs, embryos were identified as early as 8 days post-oviposition, with average (±SD) time to first observation at 30 ± 7 days. Morphological and behavioral abnormalities were observed for most embryos (n = 84, 70%) as early as 16 days and up to 95 days post-oviposition. Common abnormalities included: bent or curled tails, vesicle(s) at the base of the yolk stalk, and slow or weak movement. Only one embryo survived to hatch during the study and was genetically-confirmed parthenogenetic, suggesting hatching success for parthenotes is low (<1%). Ultrasonography was demonstrated to be an effective and non-invasive method to determine egg fertility, identify embryos with developmental abnormalities, and monitor embryo growth.

Характеристика маточного стада несвицького внутрішньопородного типу українських рамчастої та лускатої порід коропа за комплексом продуктивних та репродуктивних показників

Purpose. To provide an assessment of the complex of productive and reproductive parameters of the brood stock of the Nesvych intrabreed type of Ukrainian framed and scaly breeds of carp grown in pond conditions of the Polissia zone. Methodology. The study was conducted at fish farms of Lviv and Volyn regions of Ukraine during 2004-2024. The material for the study was sexually mature carps of the Nesvych type of different ages. The main fish productive and biological parameters were studied during spring valuation according to generally accepted methods in fish farming. Exterior evaluation was carried out according to weight and the main parameters of body structure. Measurements were made with a centimeter tape with an accuracy of 1 mm. Individual weighing of older age groups was carried out on electronic scales PROK VT-150-R1, juveniles - TS-500. Based on the results of the measurements, the main exterior parameters were analyzed and determined — girth, body length to height ratio, head length. The ejaculate volume was determined using an Eppendorf pipette-dispenser with an accuracy of 0.1 cm3. Sperm movement activity was determined using a Zeiss Axiostar plus microscope with a 20x/0.40 phase-contrast objective. The number of spermatozoa in cm3 was calculated using a Macler camera. Calculation of the absolute working fertility was carried out by the weight method, with the calculation of the number of eggs in 1 g and the subsequent determination of the weight of 1 egg. Relative working fertility was defined as the ratio of working fertility to body weight. Findings. The study showed that carps of the Nesvych intrabreed type had exterior parametetrs typical for Ukrainian carp breeds. At the same time, the working fertility of first-time spawning females was in the range of 328.1 - 522.7 thousand eggs, age 6-8 females - 645.7 - 1178.3 thousand eggs, older age groups - 536.2 – 1014.0 thousand eggs. With the average ejaculate volume of 7.6 – 8.3 cm3 in first-spawning males and re-spawning ones 14.9 – 21.3 cm3, active movement of spermatozoa after their activation was observed: 33.1 – 48.6 s and 56.3 - 59.3 s, respectively. At the same time, the working fertility of males was 90.1 - 443.2 billion spermatozoa. The positive response of female Nesvych carp to pituitary stimulation exceeded 95%. Originality. The results of 20 years of selective-breeding work with a representative of aquaculture in the western region of Ukraine are highlighted. In particular, weight dynamics, main exterior and reproductive parameters of brood fish of different ages of brood carp stock of Nesvych intrabreed type of Ukrainian framed and scaly breeds, which were presented and successfully passed the state approval in 2023, are summarized. Practical value. High fish productive and biological parameters of broodstocks of the Nesvych inbred type allow recommending them for use for the purpose of commercial cultivation. Key words: Nesvych carp, intrabreed type, brood stock, exterior, weight, age groups, condition factor fertility, ejaculate volume.

Natural Spawning Breeding Techniques Analysis of Carp (Cyprinus carpio) in the Fish Seed Center (BBI) Bolangan, Tabanan, Bali

Carp (Cyprinus carpio) is a freshwater fish species with a high tolerance to various environmental conditions. The present study aimed to analyze the seeding process of carp using a natural spawning method at the Fish Seed Center (BBI) Bolangan, Tabanan, Bali. The descriptive analysis had been used to analyze of the data collected through active participation, observation, and interviews. The carp natural spawning techniques at BBI Bolangan were conducted in an earthen pond. The breeding techniques include pond preparation, brood stock selections, fish spawning, larvae or seed maintenance, water quality control, disease control, and fish harvesting. Male and female parents in a 2:1 ratio were required for effective breeding. This natural hatching system produced up to 100806 eggs with a hatching rate of 74.4%, yielding 75000 larvae per female parent. After a week of care, the larvae have a 30% survival rate and are ready for cultivation in the following section (nursery II). We conclude that the Carp (Cyprinus carpio) breeding techniques at the Fish Seed Center (BBI) Bolangan, Tabanan, Bali are technically sound and feasible to apply.

Technological scheme and biotechnical indices of industrial cultivation of Australian redclaw crayfish juveniles in aquaculture

The aim of the work: forming technological scheme and biotechnical indices of industrial cultivation of Australian redclaw crayfish Cherax quadricarinatus juveniles under controlled conditions based on a generalization of available research investigations.Used methods: the study was carried out on the basis of the aquarium room of Invertebrate Aquaculture Department of VNIRO on Australian redclaw crayfish juveniles and adults in the period from 2010 till 2023. Standard methods were used to determine hydrochemical parameters and fish-cultural and biological indicators of individuals. Studies were carried out on the characteristics of the life cycle, early stages of development, physiology and nutrition. The data was processed using statistical methods.Novelty: A technological scheme and biotechnical indicators of industrial rearing under RAS conditions have been formulated for Australian redclaw crayfish juveniles.Results: A technological scheme and biotechnical indicators for cultivation of Australian redclaw crayfish juveniles have been developed for a modular basin complex. The technological scheme includes six stages: “Selection and housing of brood stock” (1); “Mating and obtaining gravid females” (2); “Maintenance of females with eggs and early juveniles” (3); “Ongrowing of juveniles to 0.2–0.8 g” (4); “Ongrowing of juveniles from 0.2–0.8 g to 2–5 g” (5); “Ongrowing of juveniles for broodstock remount” (6). The success of stages 1 and 2 depends on the spawners’ physiological state, which is determined by the housing conditions during the preparation of crayfish for mating. Stages 3–6 require the use of single-type basins, specialization of which is achieved through the installation of sedimentation tanks for holding females with eggs, shelters and volume-structuring substrates of different types.Practical significance: application of the proposed biotechnical methods and approaches to the production and cultivation of juvenile Australian redclaw crayfish will optimize the cultivation of the species, which will be beneficial for the development of its cultivation in fish farms.

Effects of Synthetic Hormones on Fertilization, Fecundity, Hatching and Gonado-Somatic Index of Giant Snakehead (Channa Marulius) in Captivity

The effects of a crude protein (40% CP) diet on the spawning performance of giant Snakehead (Channa marulius) broodstock were assessed in this study through a three-week feeding trial. Mature C. marulius brood stock (N = 36) was taken from the brooders pond and stocked into nine small experimental breeding ponds, each measuring 4mx2mx1.5m (LxWxD). Following acclimatization, all male and female C. marulius broodstock with an average weight of 1.5–2.5 kg BW and a length of 70 cm were removed from the small breeding ponds. The current study's objective was to induce breeding in C. marulius by injecting synthetic hormones intramuscularly and monitoring fertilization, fecundity, hatching, and gonado-somatic index. Using a completely randomized design (CRD), nine fishponds were split into three treatments (T1, T2, and T3) during the study period, each with three replicates. In addition to evaluating the effects of artificially applied hormones, Conceptal® (T1), Suprefact® (T2), and Ovaprim® (T3), this study aimed to comprehend the reproductive biology of C. marulius. The hormones were injected into the test fish at the following proportion (0.3ml, 0.4ml and 0.5ml to male and 0.8ml, 0.9ml and 1.0ml to female’s ml/kg body weight) and then released into the earthen ponds for large scale production of seed. Two-way analysis of variance (ANOVA) was used. The results showed no successful spawning on Conceptal®. The gonado-somatic index (GSI) estimates for the study period showed that Suprefact had the highest average GSI values for both males and females (3.32±1.62% and 1.67±0.18%, respectively), followed by Ovaprim (1.13±0.56 and 1.22±0.68, respectively). Absolute fecundity was also estimated. The result showed that fish stimulated with suprefact (T2) obtained the highest average fecundity (3079.3±100.7%), fertilization rate (96.33±1.20%), hatching rate (94.67±2.40%), and survival rate (95.75±1.51%), then in ovaprim fecundity rate (1669.3±836.5%), fertilization rate (58.00±29.02), hatching rate (61.27±30.65), survival rate (64.67±32.34%), respectively. In conclusion, the use of Suprefact® and Ovaprim® can optimise the results of C. marulius breeding induction in small experimental breeding ponds, ensuring higher-quality eggs and a greater number of normal larvae.

Effects of different stocking densities on growth, nutritional quality, stress and antioxidant response in Labeo rohita; cultured in in-pond raceway system.

A 171-day long experimental trial was undertaken to study intricate physiological response of rohu (Labeo rohita) under stress caused by high stocking density in In-pond raceways system (IPRS). Fingerlings of rohu (initial body weight: 250 ± 1.20 g) were cultured at three different stocking densities; low density (LD) (2.27 kg/m3), medium density (MD) (3.79 kg/m3) and high density (HD) (5.30 kg/m3) in raceways of IPRS production system. Each treatment was in triplicate. Fish growth exhibited a decline in HD treatment statistically as its average weight gain/fish/day was 4.21 g as compared to MD (4.82 g) and LD (4.74 g). Nutritional profile of rohu indicated by the content of crude protein, fatty acids, and profile of amino acids was up to the set dietary benchmarks. Survival rate of fish in all the treatment groups was greater than 99%. The elevated cortisol levels observed in the HD treatment in contrast to the other treatments suggested the presence of stress. The levels of superoxide dismutase, catalase and glutathione peroxidase were also higher in HD as compared to other treatments. However, there were no difference in the level of MDA between the three treatments. Activity of amylase, protease was significantly different in treatment whereas the difference in lipase activity was found to be insignificant. It can be concluded that medium stocking density i.e. 3.79 kg/m3 outperformed the high density (5.30 kg/m3) in different aspects of this study. Nevertheless, additional research is imperative to ascertain whether any intermediate stocking density between medium (3.79 kg/m3) and high (5.30 kg/m3) such as 4 kg/m3, 4.5 kg/m3, or 5 kg/m3, could potentially serve as suitable options for rohu. It is also suggested that brood stock of rohu should be genetically improved to obtain stress resilient fingerlings which will perform better at high stocking density at large scale production level.

Antibiotic susceptibility and resistance genes profiles of Vagococcus salmoninarum in a rainbow trout (Oncorhyncus mykiss, Walbaum) farm.

Disease outbreaks negatively affect fish production. Antimicrobial agents used in the treatment of diseases become ineffective over time because of antibiotic resistance developed by bacteria distributed in the aquaculture environment. This study was conducted for 4 months (cold period) in a fish farm to detect the fish disease, cold water streptococcosis. In the study, four brood stock showing disease signs were detected. Bacteria isolates were obtained and identified as Vagococcus salmoninarum. Antimicrobial susceptibility of V. salmoninarum was tested and antibiotic resistance gene profiles of V. salmoninarum isolates were screened. The phylogenetic relation of the isolates with the previously reported strains was evaluated. Antibiotic resistance developed by pathogenic bacteria is distributed in the aquaculture environment. The transfer of resistance genes from one bacterium to another is very common. This situation causes the antimicrobial agents used in the treatment of diseases to become ineffective over time. The disc diffusion test showed that all four isolates developed resistance to 13 (FFC30, AX25, C30, E15, CF30, L2, OX1, S10, T30, CRO30, CC2, PT15 and TY15) of the evaluated antibiotics and were about to develop resistance to six others (AM 10, FM 300, CFP75, SXT25, APR15 and TE30). Furthermore, antibiotic resistance genes tetA, sul1, sul2, sul3, dhfr1, ereB and floR were detected in the isolated strain. Moreover, the phylogenetic analysis showed that isolated V. salmoninarum strain (ESN1) was closely related to the bacterial strains isolated from USA and Jura.

Present status of brood stock management and breeding operations at Carp Hatcheries in Jashore, Bangladesh

Sustainable aquaculture production depends on the proper management of brood stock. In this regard, multiple survey studies were reviewed to assess the present status of management of carp brood stock at Jashore region in Bangladesh from March 2023 to August 2023. A total of 38 hatcheries were selected in Jashore. The areas of ponds were ranged from 33.33 to 400 decimal and shape with maximum rectangular. The green color water of pond was 79% and 75% practice pond drying. Most of the farmers applied liming doses were ranged from 500- 1200 gm dec-1. Most of the farmers used rotenone (39%) to control predators in the brood stock pond. Different sorts of fertilizers both organic and inorganic were applied. Most of the brood stocks (39%) were collected from the hatcheries and the rest of them were collected from other pond, World fish, BFRI and the natural sources (Halda and Padma River). Moreover, 4 carp species (rui, catla, mrigala and kalbashu) among 13 endemic and 4 exotic carp species (silver carp, grass carp, bighead and common carp) out of 6 exotic carp’s species were used for seed production. Negative selection of brood stock was performed in few hatcheries in order to reduce the cost for collecting or purchasing good quality broods. The formulated feed which contained 20-30% protein for carp brood stock were prepared using the indigenous ingredients including mainly rice bran, mustard oil cake, vitamin and mineral premix, wheat flour, fish meal and soya bean flour and maize flour. The main problem of hatchling production is Argulosis (fish lice) diseases which causes 95% of hatchlings mortality. Finally, these survey findings indicate that proper brood stock management could be a good approach to attain the main purpose of aquaculture.

Investigation into the Impacts of Varied Batches of Stripped Eggs on the Reproductive Success of Clarias gariepinus

This study was conducted at the hatchery complex of Akwa Ibom State University to investigate the effects of different batches of stripped egg on reproductive performances of Clarias gariepinus. Nine brood stocks of Clarias gariepinus (six males and 3 females) with average body weight of 2.3kg and 64.2 cm where carefully selected for the study. Six matured males were euthanized for the removal of testis without hormonal inducements. The milt collected from the six males were pooled together and divided into 12 portions each diluted with 2mL of normal saline solution. Three female brood stocks where separately induced with hormone at single dosage of 0.5ml/kg body weight and allowed for a period of 10 hours before stripping. Stripping of eggs from each brood stock where in four batches, each batch measured 50g and labeled A, B, C and D. 3g of eggs containing approximately 2000 oocytes (eggs) where measured out from each batch and mixed with the diluted milt and incubated in a 2 x 1 x 10cm3 of water in a concrete pond at temperature of 26oC in three replicates. The result revealed that the reproductive performances considered in this study decreased as the batches of stripped eggs increased from 1 ̶ 4 batches. The first batch of stripped eggs produced 87.69 ± 0.42, 97.06 ± 0.84, 84.29 ± 1.05 percentage fertilization, hatchability and survival rate respectively, while the least batch of stripped eggs (batch 4) produced the least value of fertilization 50.33 ± 1.67, 31.93 ± 4.94 hatchability and survival rate value of 42.69 ± 0.61. Therefore, from the above result, the least batch of stripped eggs should not be used for fertilization because the unhatched or dead eggs has a negative effect on the fertilized eggs including fry at the hatchery level.

Prevalence of Lernaea cyprinacea Infections in Indian Major Carp at Fish Farms of Bihar, India

Lernaea cyprinacea, commonly known as anchor worms, represents a significant parasitic threat to Indian Major Carp (IMC) species in the aquaculture system. Lernaea parasitizing is widely reported, affecting brood stock, fingerlings, and marketable-sized freshwater fish species globally. This study aims to comprehensively investigate Lernaea infections in ten fish farms across Bihar, India, focusing on the prevalence, intensity, water quality parameters, fish weight, and associated factors affecting the occurrence of this parasite. The research combines field surveys, laboratory analysis, and epidemiological assessments to provide a holistic understanding of the impact of Lernaea on the health and productivity of Indian major carp populations. The analysis revealed a positive correlation between host body weight and the intensity of Lernaea cyprinacea infestation. Larger fish were more susceptible to parasitic infections, highlighting a potential vulnerability associated with the size of the host. In conclusion, this study contributes valuable insights into the dynamics of Lernaea cyprinacea infections in IMC stocks, emphasizing the species-specific susceptibility and the influence of host body weight on parasitic infestations. The findings provide a foundation for informed aquaculture practices aimed at minimizing the prevalence and impact of Lernaea, thereby enhancing the overall health and productivity of fish farms in the region. In conclusion, current research confirms that Labeo catla and larger fish are very susceptible to Lernaea cyprinacea infection.

Comparative Study of Inducing Broodstock with Natural and Artificial Hormones on Reproductive Performances of Clarias gariepinus

This study was conducted to investigate the effects of artificial and natural hormones (ovaprim and pituitary extract) on the reproductive performances of Clarias gariepinus (African catfish). A total of twenty brood stock, 12 males and 8 females with mean weight of 2.0 kg each were selected for breeding following the external morphological characteristics and standard breeding procedure. The water parameters for indoor culture tanks during the study were optimal for breeding: pH 7.31; temperature, 27.6˚C. Dissolved oxygen, 5.18 mg L-1. The result revealed no significant (P &gt; 0.05) differences in water quality parameters between the culture tanks for artificial and natural hormonal applications during the study. The percentage fertilization, hatchability, survival and fry production success were: 89.23%, 93.31%, 87.16% and 69.41%; and 79.02%, 72.56%, 67.32% and 34.67% respectively, for pituitary extract and Ovaprim®. Pituitary extract recorded higher values and significantly performed better (P &lt; 0.05) between the two treatments. This indicates that natural hormone (pituitary extract) is equally effective and therefore recommended for the artificial propagation of Clarias gariepinus.

Effects of Multiple Batches of Stripped Eggs on the Reproductive Performances of Heterobranchus longifilis

Studying the effects of multiple batches of stripped eggs contributes to the sustainability and viability of aquaculture practices by improving our understanding of reproductive performance and informing best practices in breeding programs, hence, the need to investigate on the effects of multiple batches of stripped egg on reproductive performances of Heterobranchus logifilis became necessary. The aim was to provide valuable information for decision-making processes in aquaculture operations. Nine brood stocks of H. longifilis (6 male &amp; 3 female) with average body weight of 2.3 kg and average length of 64.2 cm where carefully selected for the study. Six matured males were sacrificed for the removal of testis without hormonal inducements. The milt collected from the six males were pulled together and divided into twelve portions each diluted with 2ml of normal saline solution. Three female brood stocks where separately induced at single dosage of 0.5ml/kg body weight and allowed for a period of 10 hours before stripping. Stripping of eggs from each brood stock where in four batches, each batch measured 50g and labeled A, B, C &amp; D. 3g of eggs containing approximately 2000 oocytes (eggs) where measured out from each batch and mixed with the diluted milt and incubated in a 2 x 1 x 10cm3 of water in a concrete pond at temperature of 26oC in three replicates. The result revealed that the reproductive performances considered in this study decreased as the batches of stripped eggs increased from 1- 4 batches. The first batch of stripped eggs produced 90.17 ± 0.44%, 97.78±0.86%, 89.48 ±1.08% fertilization, hatchability and survival respectively, while the least batch of stripped eggs (batch 4) produced the least value of fertilization (5.83 ± 1.69%); 45.00±4.90% hatchability and survival value of 5.59 ± 0.61%. Sequel to the findings of the present study, the least batch of stripped eggs should be avoided for use in fertilization since the unhatched or dead eggs has some detrimental effects on the fertilized eggs including fry at the hatchery level.

Gonadotropic Activity of Pituitary Extract of African Catfish, Clarias gariepinus, in Mammals using Immature Wistar Rats as Models.

The pituitary glands normally produce and stores gonadotropic hormones (GnH) that are responsible for ovulation and spermiation in animals. However, whether fish pituitary extracts can elicit same effects in treated animals need elucidation as a prelude to their practical usage in animals. The aim of this study was to investigate the oestrus-inducing potential of the pituitary gland extract of the Africa Catfish (Clarias gariepinus) in immature Wistar rats. The experiment involved the use of 18 immature female Wistar rats and 10 male catfish brood stocks with the use of six Wistar rats per groups as follows: Group A had human chorionic gonadotropin (hCG) treatment. Group B had only normal saline treatment as the control whereas Group C had the C. gariepinus pituitary extract administration to induce oestrus with treatments occurring twice six hours apart in each group. There was an obvious expression of visible signs of heat and the presence of uterine horn oedema with significant (p < 0.05) increase in reproductive tract weight and uterine width and length. However, only progesterone levels increased significantly (p < 0.05) in the hCG and the C. gariepinus pituitary extract treated groups compared to other assayed hormones. These results showed that C. gariepinus pituitary extract has the capacity to induce oestrus in Wistar rats because of its gonadotropic effects, which needs further investigations at higher doses and for longer exposure periods for possible oestrus induction and synchronization in higher mammals. Further favourable results could herald the possible patent of the catfish pituitary extract for either experimental or commercial use in mammals.

Effects of broodstock sex pairing ratios and rest periods of the nile tilapia &lt;i&gt;Oreochromis&lt;/i&gt; &lt;i&gt;niloticus&lt;/i&gt; on fry production

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.&#x0D;

Effect of pituitary gland from spent and unspent female brood fish on the spawning performance of African catfish (&lt;i&gt;Clarias gariepinus&lt;/i&gt;)

Pitutary gland produces, accumulates and stores gonadotropic hormone which plays active role in ovulation as intermediary between central nervous system and gonads. However, information on the efficacy of pituitary gland from newly spent Clarias gariepinus for inducing ovulation is yet established. The effect of pituitary gland from spent and unspent female fish on the induced breeding performance of Clarias gariepinus was tested. The experiment was set up in a completely randomized design (CRD). Nine (9) brood stock distributed into three treatments were used for the experiment (Treatment 1 was injected with 0.5ml synthetic hormone (Ovulin), Treatment 2 was injected with pituitary from already spent female fish and Treatment 3 was injected with pituitary from unspent fish) and each treatment was replicated three times. The result showed that Treatment 2 had the highest mean values for fecundity rate (122.92%) and was not significantly different from the other treatments. It also has higher value for fertilization rate (60.67%) and high stripping percentage but lower (P &lt; 0.05) hatching rate (13.619) when compared with Treatment 1 which had the highest value for hatching rate (22.79%) followed by Treatment 2 (19.739%) with statistical similarity (P &gt; 0.05). The present research demonstrated that C. gariepinus can successfully be induced to ovulate with pituitary from spent female fish, ensuring maximum use of brood fish and production of high-quality eggs and normal hatchlings.

Evaluation of Growth Parameters in Post Larvae Catfish in Relation to Feed Types

The aim of this research is to evaluate growth parameters in post larvae catfish in relation to feed types. This study will analyze the trend for length of Claria gariepinus fed on commercial feed, maggot and zooplankton; analyze the trend of weight of Claria gariepinus fed on commercial feed, maggot and zooplankton; analyze the relationship between length and weight and; make forecasts for the length and weight of the fish fed on the specified feed types. Artificial reproduction of African Catfish (C geriepinus) was carried out using the hypophysation technique. Brood stocks were selected from centrally located parent stock holding ponds. Males and females were conditioned in separate ponds. The brood stocks were fed with 20% crude protein formulated feed, acclimatized for three weeks, then transferred into the hatchery holding tanks between 240 Celsius and 270 Celsius to stimulate ovulation after injecting the females with 0.5ml of ovalin. Fertilized eggs were incubated in continuous flow of water until hatching was completed. A commercial starter feed consisting of 8% ash, 6% fiber, 12% NFE, 1.5% calcium, 1.6% sodium, 1.5% phosphorous and sufficient amount of essential vitamins was administered to the larvae. Larvae were randomly distributed into 45 plastic tanks in a flow-through system at a density of 500 fish per tank. Fifteen fries were randomly selected from each holding tank and measurements on weight and length collected daily. Time series analysis and regression analysis were applied in the study. It was found that the length and weight of post larvae fed on mixed zooplankton was consistently lower than the other treatments. The length and weight of the fish fed on the three feed types were successfully modeled and forecasts made for future five periods while the relationship between length and weight was found to be significant on a linear regression model. This certainly adds value as the weight of post larvae catfish is measure with less difficulty and without causing injury or stress to the fish than measurement of length.

Brood Stock Development, Reproductive Performance and Breeding of African Catfish (Clarias gariepinus) in Pakistan

Brood Stock Development, Reproductive Performance and Breeding of African Catfish (Clarias gariepinus) in Pakistan

Polymorphism analysis of the Insulin-like Growth Factor-1 (IGF-1) gene encoding growth in F5 Golden Kamper chicken (Gallus gallus domesticus)

Golden Kamper Chicken is a chicken cross between pelung and layer chickens with good meat and egg productivity. Insulin-like growth factor-1 (IGF-1) gene is one factor affecting the speed of chicken growth. This research aims to study the character of F5 Golden Kamper chickens and analyze the IGF-1 gene to determine its effect on chicken growth. The research will be done by hybridizing the F4 Golden Kamper hen and rooster, raising brood stock and DOC, egg collection, growth data collection, blood collection, DNA isolation, DNA amplification, electrophoresis, and sequencing. The observed parameters are DOC weight for the first seven weeks and polymorphism of the IGF-1 gene. Data was analyzed using Microsoft Excel, Genestudio, MEGA11, and IBM SPSS 25 software. Sequencing data were processed using the Genestudio application, alignment with MEGA11, and genotype-haplotype associations using Pearson correlation and Linear Regression F test. The results showed that the molecular marker polymorphism of the IGF-1 gene was found at 12 mutation points. IGF-1 gene polymorphism did not correlate with the weight of F5 Golden Kamper chickens.