Fish Breeding

The objective of this present study is to determine the optimum concentration for glutathione in the cryopreservation of seurukan fish (Osteochilus vittatus) spermatozoa. A completely randomized design (CRD) was used with 6 treatments and 3 replications. The Seurukan fish sperm was diluted in extender with a ratio of 1:20 (sperm: extender), then glutathione was added at a concentration of 0, 10, 20, 30, 40 and 50 mg L À1. Next, the sperm thawed at 39e40 C for 3 min and mixed with 100 eggs which were randomly selected. The success of the fertilized egg was observed 6 h after fertilization, while the hatching rate was examined 60 h after fertilization. The ANOVA test showed that the addition of glutathione significant affected the sperms motility, fertility and hatching rate of seurukan fish Osteo-chilus vittatus eggs (P < 0.05). By segregation the fresh sperm, a higher sperm motility rate was recorded with an addition of 30 mgL À1 of glutathione (63.00 ± 5.89), however, this value was not significantly different from using concentration of 10 and 20 mg L À1. A higher fertilization rate was produced using glutathione concentration of 50 mg L À1 (51.33 ± 17.01); however, it was also not significantly different from the concentration of 20, 30 and 40 mgL À1. In addition, a higher hatching rate was also recorded using glutathione concentration of 50 mg L À1 (40.33 ± 12.89), this value was not significantly different from using 40 mgL À1 glutathione. Hence, a conclusion was drawn that the optimum concentration of glutathione is 40 mg L À1 of diluent.

The objective of the present study was to determine the most suitable extender and their respective dilution ratios for African catfish sperm for artificial induced breeding and cryopreservation purposes. Three natural extenders were tested i.e. coconut water, sugarcane water and soybean solutions, at three different levels of sperm to extender dilutions of 1:20, 1:30 and 1:40. While Ringer solution was used as a control Diluted sperm were fertilized with ready isolated eggs to assess the fertility and hatching rate at 0, 6 and 12 hour intervals. The results showed that the eggs hatched approximately 19 to 27 hours after fertilization. In general, the fertilization and hatching rates decreased with increasing dilution ratio. With respect to natural extenders, the coconut water showed the highest fertility and hatching rates at 1:20 dilution ratio. Therefore, coconut water at 1:20 dilution ratio was the optimal condition for African catfish spermatozoa among the natural extenders inv...

The study was conducted to know the induced breeding technique of common carp verities. Scale carp (C. carpio var. communis), mirror carp (C. carpio var. specularis) and leather carp (C. carpio var. nudus) are chosen for the experiment at Ma-Fatema Fish Hatchery in Jessore from January to March, 2016. For induced breeding practice of common carps generally 1 st dose of PG hormone only injected to the female brood fishes only. After 6 hours of the 1 st dose, female brood fishes were injected with the 2 nd dose of hormone at 4 mg PG/kg body weight and male brood fishes were injected at 2 mg PG /kg body weight for scale carp and mirror carp; 4 mg PG/kg body weight for leather carp. After 6-7 hours of injection of 2 nd dose brood fishes became ready to spawn. The fertilized eggs were hatched after 42-48 hours. The mean ovulation rates were 90.01±2.55, 85.75±4.3 and 78.98±5.85 for scale carp, mirror carp and leather carp, respectively. The mean fertilization rates were 83.06±3.04, 81.54±3.61 and 79.88±5.35 for scale carp, mirror carp and leather carp, respectively. The mean hatching rates were 77.6±3.93, 76.16±2.91 and 74.59±4.65 for scale carp, mirror carp and leather carp, respectively. The mean survival rates were 73.44±4.94, 71.92±1.94 and 69.58±3.79 for scale carp, mirror carp and leather carp, respectively. This is first research work on comparative study of common carps induced breeding in Bangladesh.

Materi yang ditulis dalam setiap bab dalam buku referensi ini diperuntukkan sebagai buku bacaan untuk mata kuliah Pemuliaan Ikan (Semester V) dan Teknologi Pembenihan Ikan (Semester VI), yang dapat membantu pemahaman mahasiswa mengikuti mata kuliah tersebut.
Pemilihan strain ikan yang memiliki karakter unggul dan dapat bersifat stabil di setiap generasi merupakan kunci penting dalam mempertahankan pertumbuhan ikan dan produksi hasil budidaya ikan. Perbanyakan atau produksi ikan secara berkelanjutan memerlukan kualitas genetik induk yang prima dan dicerminkan dalam performa pertumbuhan dan reproduksi induk yang tinggi. Pemahaman tentang genetika induk penting untuk memilih stok induk betina dan jantan unggulan yang memiliki garis keturunan berasal dari tetua unggul sebagai plasma nutfah genetik unggulan spesies ikan tertentu. Hal ini bermanfaat untuk mencetak galur keturunan ikan unggul di setiap generasi dalam upaya menjaga kemurnian strain ikan unggulan tersebut.
Teknik produksi galur murni spesies ikan budidaya telah banyak diterapkan di balai-balai riset perikanan di Indonesia maupun yang dilakukan oleh peneliti genetika ikan melalui program pemuliaan ikan. Aplikasi pemuliaan secara konvensional (selective breeding, hibridisasi) dan modern (teknologi transgenesis) pada ikan budidaya telah membuahkan hasil dengan dilepas sebagai ikan unggulan dan digunakan sebagai komoditas budidaya ikan di masyarakat.
Perbedaan mendasar antara pemuliaan konvensional dan modern disajikan dalam buku ini, untuk menggambarkan setiap proses pemuliaan hingga terbentuk ikan unggulan guna mempermudah menerapkan teknik pemuliaan tersebut dengan sumberdaya yang dimiliki pembenih skala mini dan skala besar. Pemilihan induk unggul yang memenuhi kriteria aspek genetis dan reproduksi akan memberikan jaminan terhadap ketersediaan produksi benih berkualitas yang dihasilkan. Prinsip utama dalam pemuliaan ikan difokuskan terhadap karakter-karakter genetis penting yang menguntungkan dalam budidaya seperti pertumbuhan cepat, akivitas reproduksi tinggi dan tahan terhadap penyakit tertentu perlu diindentifikasikan secara detail yang dapat diwariskan kepada keturunannya melalui program pemuliaan ikan yang dipilih. Sebagai bahan kuliah, buku referensi ini mengugunakan lingkup teori genetika ikan, biologi reproduksi ikan dan bioteknologi ikan untuk menjelaskan materi pada sub bab yang berkaitan dengan lingkup keilmuan tersebut.
Akhirul kalam, semoga buku ini dapat memberikan manfaat bagi para pembaca dan sebagai sumbangsih yang dituangkan dari berbagai riset penelitian yang berhubungan dengan pemuliaan ikan.

This study was conducted to determine the efficacy of preserved and fresh pituitary extract of Clarias gariepinus (Burchell, 1822) to induced spawning in the same species. Growth performance of fry was also monitored for 15 days to determine the possible effect of natural hormone treatment on the fry. Pituitary glands (PG) were obtained from 12 male broodstocks, six extracted PG were preserved in 96% ethanol 24 h before injection, while the other were extracted and used in their fresh state. The PG solutions (1 g ml −1 of saline water) were injected at 1 ml kg −1 of the female broodstock. Ovaprim R (a synthetic hormone) was used as the control and administered at a rate of 0.5 ml kg −1 of fish. After a uniform latency period of 9 h 30 min, fish were striped, fertilized, incubated and the performance evaluated. Results obtained revealed better hatching performance using Ovaprim R synthetic hormone (64.52%), however, preserved PG gave better hatchability (59.74%) than fresh PG extract (51.39%). After 15 days of feeding ad libitum with shell-free Artemia cysts, the growth of fry spawn with preserved PG was comparable with that of the control, while least performance was observed using the fresh PG. It was concluded that preservation of PG in ethanol 24 h before injection had a positive effect on breeding performance and could be exploited in the commercial production of C. gariepinus fingerlings.

Starved was one effort that can reduce the feed consumption and feed residues
without decreasing growth of cultured fish. The purpose of this research was to determine the effect of starved periodically to the specific growth rate and feed efficiency of tilapia reared in the pond. The research had been conducted in Laboratorium Budidaya Perairan, Faculty of Agriculture, Sriwijaya Unversity on April – Juni 2016. This research method used Completely Randomized Design with four treatments and three replications that was every day feed without starvation (P0), one day feed one day starvation (P1), two days feed one day starvation (P2) and three days feed one day starvation (P3). Parameters of this research are specific growth rate, feed efficiency, survival rate and water quality (temperature, pH, DO, ammonia). The result showed that starved periodically significantly effect to the growth rate and feed efficiency of cultured tilapia in the pond. Treatment P1 (one day feed one day starvation) gave highest specific weight growth rate and specific length growth rate which were 2.32%.day-1 and 1.27%.day-1 then feed efficiency was 84.46%. The highest survival rate occurred in treatment P1 (one day feed one day starvation) 82%. Water quality of this research were temperature 27.0-31.5 oC, pH 6.8-7.9, dissolved oxygen 4.53-7.23 mg.L-1, and ammonia 0.01-0.30 mg.L-1.

Present study was conducted on induced breeding of commercially important Clarias batrachus due to the
non-availability of its quality seeds from the natural resources for environmental degradation, shrinkage of natural
breeding ground and illegal killing of juveniles and brood fishes. The aim of the study was to achieve success in
fertilization and hatching using various doses of different inducing agents at different temperatures and latency
periods followed by stripping method. In this study the developmental stages of fish (fertilized egg to 45th day old fish)
were characterized chronologically. A trial was also made to optimize the survival rate of young developing fish upto
45th day by manipulating their feeding schedule and environmental conditions. The breeding experiments were done
with pituitary gland extracts (40 and 120 mg/kg. body weight for female and 25 and 50 mg/kg. body weight for male)
and Ovaprim (0.8 and 2.0 ml/kg body weight for female and 0.4 and 1.0 ml/kg body weight for male) at 26º, 28º and
30ºC. The highest rates of fertilization (80%) and hatching (71%) of eggs were recorded in Clarias batrachus injected
with carp pituitary gland extracts @ 50 mg/kg body weight of male and 120 mg/kg body weight of female at 28ºC
with a latency period of 15 hours. The fertilization and hatching rates were 77% and 65% respectively at 28°C at the
higher doses of Ovaprim. The highest survival rate (82.5%) of developing fish was achieved supplying zooplankton
as live feed upto 12th day followed by alternate supply of zooplankton, boiled egg with vitamin C and chopped tubifex
from 13th to 45th day of rearing in indoor polyvinyl chloride tray with minimum fluctuation in temperature and dissolved
oxygen.

An experiment was performed to appraise the biological performances and ingestive behavior of Nile tilapia (Oreochromis niloticus). In this respect, we examined three tilapia stocking densities; low density (LD, 100 fish m-3), medium density (MD, 200 fish m-3) and high density (HD, 400 fish m-3). Lately, Aeromonas hydrophila defied fish evaluated through calculating the cumulative mortality (%). Stocking density had no influence on survival rate while, the final weight markedly reduced with increased density. The ingestive behavior was higher in MD- reared fish than the LD-reared group, however, fish at HD had a higher feed intake (%) and feed conversion ratio. Fish at LD showed marked higher levels of total protein, albumin and globulin compared with those reared at HD. The plasma glucose and cortisol levels elevated in HD-raised fish contrast to LD and MD groups. LD-raised fish had more elevated RBCs and WBCs parallel to MD and HD. Similarly, lymphocytes, neutrophils, and monocytes (%) decreased with increasing density. Also, Serum antioxidant and lysozyme enzymes were considerably (P<0.05) higher in LD compared with MD and HD groups. Meanwhile, the Phagocytic index expressively increased in MD-raised fish compared with LD and HD groups. Finally, the HD -raised fish showed a markedly higher cumulative mortality (%) (χ2= 6.257**) than the MD and LD-raised fish. In light of these results, a high-density culture evolved chronic stress in Oreochromis niloticus and consequently altered the biological performances, ingestive behavior with a subsequent immune depressive effect as displayed by the cumulative mortality (%).

Induced breeding of African catfish Clarias gariepinus was conducted to investigate the effect of different male-female broodstock ratio on the breeding performance. The broodstock for the experiment were collected from the National Institute for Freshwater Fisheries Research, New Bussa and the experiment was carried out at the hatchery section of Happy Island Garden, Sokoto. The experiment was set up in a completely randomized design (CRD) with treatment combinations as; 1:1 male:female broodstock ratio (Treatment A), 1:2 male:female broodstock ratio (Treatment B) and 1:3 male:female broodstock ratio (Treatment C). The broodstocks were injected with ovulin hormone at the recommended dosage of 0.5ml/kg body weight for the females and half dosage was administered to the males. The result showed that Treatment A had the highest fertilization rate (71.66%) and hatching rate (88.70%) as well as survival rate (73.17%) followed by Treatment B with 68.69% fertilization but had the least va...

This study aim to study the spawning performance of African catfish induced with ovaprim serially diluted with 9% saline and coconut water at ratios of 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 and 1:9 with 1:0 serving as the control, latency period was standardized using recommended time by the manufacturer. For saline water, egg hosed out with ease only for dilution of 1:1 and with harder press striping was possible till 1:7 beyond which stripping was not possible, however using coconut water, eggs hosed out with ease up to 1:4 while harder press made striping possible till the last dilution (1:9). Fertilization decreased significantly (P > 0.05) as the dilution increases with both diluents. Hatching was presumed complete at about 28 hours after fertilization. Result obtained show that hatchability decreased with increasing dilution with saline while there was no statistical change in values obtain with coconut water up to 1:3 however value decreased thereafter, the study shows that hatchery operation for African catfish can use coconut water and saline water as diluents up to 1:4 and 1:1 dilution respectively at normal latency period without significant effect on spawning performance.

Aquaculture is being the fastest food production sector in the world with an estimated production of about 179 million tonnes. The fish production from capture fisheries (96 million tonnes) is almost stagnant for many decades but the demand is rising significantly due to the awareness about the health benefits of fish consumption. The additional demand for fish
consumption must be achieved only through aquaculture. The current fish production from aquaculture has increased from 44 million tonnes (2005) to 82 million tonnes (2018) and it is sharing almost 45% of total global fish production but this production level is not sufficient to fulfil the demand (FAO, 2020). This article will focus on the present status and future scope of freshwater aquaculture in India to achieve blue revolution in India.

The need for pro-fertility agents in fish with possible minimal side effects, availability, acceptability and affordability informed the evaluation of powder of Tetracarpidium conophorum seeds in male Clarias gariepinus brood stock because of its medicinal properties. Fifteen outdoor concrete tanks consisting of triplicates for each treatment group were used. Triplicate groups of male C. gariepinus (303.22±1.89 g body weight) were fed with four diets supplemented T. conophorum seed powder respectively, a control diet without T. conophorum seed powder 2 times a day at 3% of body weight for 70 days. Male C. gariepinus broodstocks (average individual weight, 303.22 ± 1.89 g) were randomly distributed with density of 10 fish into 15 outdoor concrete tanks. At the end of the 70-day experiment, gonado-somatic index and reproductive indices were determined. Fish fed experimental diets showed significantly improved gonado-somatic index and reproductive indices over the control treatment. Higher gonado-somatic index and reproductive indices were recorded for the fish fed diet of 200 mg kg _1 T. conophorum seed powder compared to other experimental diets. The results indicated that supplement diets with medicinal plant (T. conophorum) enhanced growth and improved gonado-somatic index, and reproductive indices of male C. gariepinus broodstocks. T. conophorum have a potential pro-fertility property which can be exploited in fish seed production by hatchery operators.

ABSTRACT
The Mekong River Basin is one of the most biologically diverse inland water systems in the world, and is the home of some 1,200 fish species. The seven-line barb is one of the most important indigenous fish of the Mekong Basin and is considered as a flagship species in the content of conservation. It has been classified as endangered on the IUCN Redlist since 1996. In Thailand, the fish is found in Mae Klong River in the central part and in the Mekong River in the northeastern part of the country. However, natural populations have been extirpated from the Mae Klong River and can be expected to disappear as more impoundments are constructed in the Mekong. At present, it is not known whether the fish that occur in various parts of the Mekong River are genetically the same or not. Therefore, it is urgently important to develop the breeding technique and examine the genetic diversity of seven-line barb in order to develop a management plan to improve the situation of the species.
Studies on induced spawning of the Thai carp, Barbonymous gonionotus, indicated that the gonadotropin (GtH) secretion and spawning induction in tropical cyprinids is regulated by a dual control of gonadotropin releasing hormone and dopamine. The use of Gonadotropin releasing hormone analog (GnRHA) in combination with a dopamine antagonist such as domperidone (DOM) has proven to be very effective in spawning induction in the Thai carp. This technique was used to develop breeding technique in seven-line barb. The result showed that using Buserelin (BUS), a mammalian GnRHA, in combination with DOM alone was not as effective as using pituitary gland (PG) or using two injections of BUS+DOM and PG. Additional of gonadoplex (GDP), a mammalian GtH, could not increase the effectiveness if PG was sufficiently given. The most effective method for induced ovulation of the seven-line barb was to use two injections of 10 µg/kg BUS+10 mg/kg DOM for the first injection and 6 hrs after, 1.5-2.5 dosages of PG. Furthermore, multiple injections of the mature female with 500 IU/kg hCG to increase its oocyte diameter to >1.7 mm follow by two injections of BUS in combination with DOM was found to be the most potent technique for inducing spawning of captive seven-line barb.
Microsatellite DNA markers for seven-line barb were developed from the wild caught samples using (GT)15 probe. The number of alleles per locus ranged from 7 to 16. The expected heterozygosities ranged from 0.47 to 0.91. Also, these primers were successfully amplified in the two closely related species, P. labeamajor and P. labeaminor. These markers have proven to be very useful for the population genetic structure study in this species and other related cyprinids.
Genetic diversity of seven-line barb was investigated using 6 msDNA markers and sequencing analysis of mitochondrial DNA control region (mtDNA). Both msDNA and mtDNA showed concordant results in demonstrating similar genetic diversities and population structuring of seven-line barb. Furthermore, genetic diversity of seven-line barb was quite high compared with other endangered fish species reported to date. Population sub-structuring of seven-line barb was also observed which was no evidence for isolation by distance and no apparent physical barriers. The results suggested that the number of populations of seven-line barb may be determined by the number of geographic setting within which their life cycle can be completed. For management point of view, it is proposed that all populations should be directed toward preserving the genetic integrity of each group.
Genetic diversity within and between hatchery populations of seven-line barb was compared with those of wild populations using 5 microsatellite DNA markers (msDNA) and sequencing analysis of the mitochondrial DNA control region (mtDNA). Both msDNA and mtDNA markers showed comparable results in demonstrating similar genetic diversities of seven-line barb. Marked reductions of genetic variability in the hatchery populations compared with the wild populations were observed in term of both msDNA number of alleles and mtDNA haplotypes. FST and ST also suggested that the magnitude of the genetics divergence within and among wild and hatchery populations of seven-line barb was significant. The lower genetic variability observed in the hatchery populations may cause by bottleneck effect due to the limited number of effective parents when each population was founded. Enhancing genetic variability and eliminating the accumulated effect of inbreeding of hatchery populations by means of increasing effective population size, preventing inbreeding and using selective breeding based on the principle of minimal kinship broodstock management is recommended to minimize genetic impacts of restocking program.
The effectiveness of the minimal kinship (MK) selective breeding and random breeding on preservation of genetic diversity of the hatchery populations of seven-line barb was compared. The results indicated that the minimal kinship, calculated by Psa values (MKp) based on 5 msDNA markers yielded a better result in retaining the loss of HE and AE than the random selection. For HE, the differences of both approaches were prominent when the number of parent used in each generation was more than 10 pairs. Further, the loss of HE significantly decreased when the number of parent increased (Kruskal Wallis test, p<0.05). The MKp approach could increase about 6.4% of HE within 30 generations when at least 100 parents were used and 500 offspring were kept in each generation. On the other hand, the MKp selective breeding showed a better result in retaining the loss of AE only when the number of parent was at 100 pairs. MKp selective breeding approach could conserve about 80% of AE for 30 generations when at least 500 offspring was kept (O=500) and 100 parents (P=100) were used as breeders in each generation. Furthermore, if the number of parent was set at 100 individuals, inbreeding will not occur in the MKp selective breeding approach. For preserving genetic diversity of seven-line barb, it is recommended to use minimal kinship selective breeding approach which uses 100 parents and keep 500 offspring in each generation.
From the results, the conclusion and recommendation on broodstock management of seven-line barb are as follow:
1. Because the seven-line barb in the Mekong River exhibits the genetics divergence according to their spawning grounds, each population could be considered as “Management Units”. All population should be directed towards preserving the genetic integrity of each group.
2. Since the genetic diversity of hatchery populations was different from the wild population, it should not be used for restocking. Captive broodstock used for restocking program should be founded by collecting fish from the wild populations, and the offspring should be released back into natural habitat from which the founders were derived. However, these broodstock could still be used for seed fish production of genetically improved by selective breeding on important traits being important for efficiency on growing, survival, and palatability for aquaculture purpose.
3. Breeding of the seven-line barb should be done by using minimal kinship selective breeding approach in order to retain genetic diversity of the captive stock.
4. Induced spawning of seven-line barb should be done using multiple injections with hCG to increase the oocyte diameter to > 1.7 mm follow by 2 injections of BUS and DOM. Genetic variability of seed fish should be examined before restocking and/or aquaculture used.
5. Genetic diversity of both wild and hatchery populations should be monitored regularly in order to assess the success of its management plan.

Three strains of African catfish (Clarias gariepinus) from the Netherlands (Dutch), Indonesia and Kenya (Lake Victoria) were studied in hatchery conditions to compare their fecundity, growth performance and survival rates. The results indicated that fecundity was significantly higher (P < 0.05) in the Kenyan strain (145715.17 eggs Kg-1) and lower in the Indonesian strain (86354.55 eggs Kg-1). The Indonesian strain had significantly (P< 0.05) higher final mean body weight, specific growth rate and food conversion ratio. Survival rate was significantly different among the strains (P <0.05); with the Indonesian strain having the highest survival rate (68.13 ±4.50%) and the Kenyan strain the lowest survival of 23.28 ±0.40%. It was concluded that significant variations existed in the three strains of C. gariepinus available in Kenya and development of a population involving the three strains is ideal, but should be accompanied by further studies over a wide range of culture systems and conditions. Meanwhile, the Indonesian strain is recommended for aquaculture in Kenya.

The present study was carried out to develop captive brood-stock, induce natural spawning and rear fry of Ompok bimaculatus, with an aim to conserve and propagate its stocks. Adult fish collected from an irrigation tank in Karnataka State were reared to maturity with chopped trash fish. The sex of brooders was identified based on morphological features. The brooders were induced to spawn with a single dose of ovaprim at 0.8-0.9 ml/kg female and 0.4 ml/kg male or ovatide at 0.9-1.0 ml/kg female and 0.3-0.4 ml/ kg male. About 8-12 h after hormone injection, the brooders spawned naturally in spawning tank. The fertilization rates were 82.4-86.5 and 70-84% for ovaprim and ovatide, respectively. The corresponding hatching rates were 71.6-83.5 and 75-85%, with hatching periods varying between 18 and 24 hours. The fully swollen fertilized eggs were round and brownish with a average diameter of 1.05 mm. The egg, embryonic and early larval stages were similar to those reported for other species of butter catfish. The yolk-sac absorption period was 3-4 days. The average length of the newly hatched larva was 2.40 mm. When the fry were fed on Artemia nauplii, egg yolk, Tubifex worms and chicken liver, the maximum growth and survival were obtained with Artemia nauplii although the best SGR was observed when fed with Tubifex worms, followed by chicken liver.

This study aim to study the spawning performance of African catfish induced with ovaprim serially diluted with 9% saline and coconut water at ratios of 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 and 1:9 with 1:0 serving as the control, latency period was standardized using recommended time by the manufacturer. For saline water, egg hosed out with ease only for dilution of 1:1 and with harder press striping was possible till 1:7 beyond which stripping was not possible, however using coconut water, eggs hosed out with ease up to 1:4 while harder press made striping possible till the last dilution (1:9). Fertilization decreased significantly (P &gt; 0.05) as the dilution increases with both diluents. Hatching was presumed complete at about 28 hours after fertilization. Result obtained show that hatchability decreased with increasing dilution with saline while there was no statistical change in values obtain with coconut water up to 1:3 however value decreased thereafter, the study shows th...

Indonesian leaffish, Pristolepis grootii (Bleeker, 1852), is an undomesticated freshwater fish species native to the rivers, flooded swamps, and tributaries of Indonesia. The fish is mainly captured for consumption. In order to prevent its extinction and supply its growing demands, the artificial breeding of the fish should be developed. The purpose of this study was to determine the optimum dose of luteinizing hormone-releasing hormone analog (LHRHa) for stimulating the female P. grootii gonadal development at a dosage of 0, 1, 10, and 50 µg kg-1 of fish. Female fish (20.0 ± 0.6 g) were adapted for 30 days in the rearing environment and then separated into 12 aquariums with six fish per aquarium. Fish were then reared for another 21 days and fed with Tubifex sp. The LHRHa injection was conducted twice on day-7 and 14. Fish bodyweight, gonadosomatic index, gonad histology, blood estradiol-17β, and FSH-β and LH-β gene expression were evaluated at day 0, 7, 14, and 21. The results showed that the injection of the LHRHa hormone stimulated the development of fish gonads and was better achieved with a higher concentration of LHRHa. The best treatment was observed by the administration of 50 µg kg-1 of LHRHa that produced the fastest development among all treatments. This study demonstrated that the LHRHa induction could potentially stimulate the gonadal development of the newly domesticated fish. To our knowledge, this is the first study that reported the success of the induction of female gonad development in the Indonesian leaffish P. grooti.

Induced breeding of African catfish Clarias gariepinus was conducted to investigate the effect of different male-female broodstock ratio on the breeding performance. The broodstock for the experiment were collected from the National Institute for Freshwater Fisheries Research, New Bussa and the experiment was carried out at the hatchery section of Happy Island Garden, Sokoto. The experiment was set up in a completely randomized design (CRD) with treatment combinations as; 1:1 male:female broodstock ratio (Treatment A), 1:2 male:female broodstock ratio (Treatment B) and 1:3 male:female broodstock ratio (Treatment C). The broodstocks were injected with ovulin hormone at the recommended dosage of 0.5ml/kg body weight for the females and half dosage was administered to the males. The result showed that Treatment A had the highest fertilization rate (71.66%) and hatching rate (88.70%) as well as survival rate (73.17%) followed by Treatment B with 68.69% fertilization but had the least va...

Induced breeding of African catfish Clarias gariepinus was conducted to investigate the effect of different male-female broodstock ratio on the breeding performance. The broodstock for the experiment were collected from the National Institute for Freshwater Fisheries Research, New Bussa and the experiment was carried out at the hatchery section of Happy Island Garden, Sokoto. The experiment was set up in a completely randomized design (CRD) with treatment combinations as; 1:1 male:female broodstock ratio (Treatment A), 1:2 male:female broodstock ratio (Treatment B) and 1:3 male:female broodstock ratio (Treatment C). The broodstocks were injected with ovulin hormone at the recommended dosage of 0.5ml/kg body weight for the females and half dosage was administered to the males. The result showed that Treatment A had the highest fertilization rate (71.66%) and hatching rate (88.70%) as well as survival rate (73.17%) followed by Treatment B with 68.69% fertilization but had the least va...

Induced breeding, embryogenic chronology and larva development of Heteropneustes fossilis were studied in this work. One sexually matured female was injected intramuscularly with dry carp pituitary gland suspension at 4 mg/ kg-of body weight. After a latency period of eight hours, the female was stripped while the male was sacrificed to remove the testes which were macerated to fertilize the eggs. Incubation was carried out at 27℃ and the different stages of embryo were photographed using a Nikon SMZ 800 binocular microscope. Hatching started 23.53 hrs after fertilization and the percentage hatchability was 97.5%. Hatchlings had a mean length of 2.5 mm and mean yolk diameter of 0.1 mm. The yolk was completely absorbed between the third and fourth day of hatching and exogenous feeding started on the fourth day of hatching. The mean percentage survival was 75% .

Genetic information is essential for conservation and future aquaculture development of the endangered catfish Rita rita (Hamilton, 1822). Two hundred catfish, R. rita, 50 from four rivers, the Old Brahmaputra, Jamuna, Meghna and Kangsa were collected and analysed to evaluate the genetic diversity and population structure using five microsatellite primers (Cba06-KUL, Cba08-KUL, Cba09-KUL, Phy03-KUL and Phy07-KUL). Four of the five amplified loci were found polymorphic (P95) in all the populations and 46 alleles were recorded with 9 to 14 alleles per locus. Differences were observed in the total number of alleles ranging from 41 to 44, effective number of alleles from 29.96 to 37.46, observed heterozygosity from 0.57 to 0.76, Shannon’s information index from 2.09 to 2.30 and polymorphic information content from 0.84 to 0.88 among the four populations. Results exposed the highest levels of genetic diversity in the Meghna population while the lowest in the Kangsa population of R. rita. All the populations were significantly deviated (P < 0.001) from the Hardy-Weinberg equilibrium for all the loci. Nei’s genetic distance between populations ranged 0.007 to 0.017 with low overall genetic difference FST = 0.011 and high gene flow Nm = 24.333, indicating that R. rita populations were not subdivided. This study revealed a high level of gene diversity with deficiency in genetic heterogeneity in all the populations of R. rita, emphasising natural management, conservation and rehabilitation measures of this species.

Three strains of African catfish (Clarias gariepinus) from the Netherlands (Dutch), Indonesia and Kenya (Lake Victoria) were studied in hatchery conditions to compare their fecundity, growth performance and survival rates. The results indicated that fecundity was significantly higher (P < 0.05) in the Kenyan strain (145715.17 eggs Kg-1) and lower in the Indonesian strain (86354.55 eggs Kg-1). The Indonesian strain had significantly (P< 0.05) higher final mean body weight, specific growth rate and food conversion ratio. Survival rate was significantly different among the strains (P <0.05); with the Indonesian strain having the highest survival rate (68.13 ±4.50%) and the Kenyan strain the lowest survival of 23.28 ±0.40%. It was concluded that significant variations existed in the three strains of C. gariepinus available in Kenya and development of a population involving the three strains is ideal, but should be accompanied by further studies over a wide range of culture systems and conditions. Meanwhile, the Indonesian strain is recommended for aquaculture in Kenya.

Natural round batfish broodstocks were maintained in cage in earthen pond. On August, 12 females with total length 29.4±2.5 cm and bodyweight 1.1±0.3 kg and 3 males with total length 28.8±1.5 cm and weight 1.0±0.2 kg were moved to spawning pond (2.6x3.1x1.2 m cement pond). Floating eggs with 1.31±0.05 mm in diameter form natural spawning were occurred. Preliminary study on larvae development showed that mouth open at 30 hrs and rotifers were observed in stomach at 48 hrs after hatching. The experiment on nursing of 1-10 day round batfish larvae with difference stocking density (1, 2 and 3 fish/liter) and fed rotifer (density 5-10 pcs/ml) was studies. The results showed that survival rate was 44.8±7.6, 38.3±11.2 and 45.6±7.0 % and total length was 5.08±0.11, 5.40±0.18 and 5.20±0.31 mm respectively. There are no difference in survival rate (p=0.570) and total length (p=0.263) among treatment. The experiment on nursing of 10-20 day with stocking density (0.5, 1.0, 2.0 and 3.0 fish/liter) and fed artemia was studies. The results showed that survival rate was 99.4±1.0, 100.00±0.0, 100±0.0 and 99.8±0.2 % total length was 24.8±1.9, 24.0±2.2, 24.0±2.2 and 21.7±2.6 mm and fin complete was 57.50±4.33, 30.83±8.87, 19.17±6.29 and 7.50±0.00 % respectively. There are no difference in survival rate (p=0.499) among treatment, but there is difference in total length (p=0.001) and fin complete (p=0.000).

Study on the effect of cryoprotectants on abnormality and motility of baung, Mystus nemurus spermatozoa were evaluated using transmission and scanning electron microscopy. Four cryoprotectants, dmso, ethanol, methanol and glycerol at concentration of 10% were tested in triplicates. Three ml of fresh sperm which was diluted with 60 ml of ringer solution was added to each of twelve 5-ml vials containing of 0.50-ml of the cryoprotectants. The vials were placed in an icebox containing dry ice 5 min and then storage into container containing liquid nitrogen for 13 months. The effect of cryoprotectants on the spermatozoa abnormality and motility were significant (P < 0.05). The spermatozoa abnormality was significantly lower in methanol (62.65%) compared with the other cryoprotectants. The spermatozoa motility was higher in methanol, but not significantly different with ethanol (P > 0.05). It is a negative correlation between sperm motility and abnormality. Generally, higher abnormalities of spermatozoa resulted low motility.

Study on the effect of cryoprotectants on abnormality and motility of baung, Mystus nemurus spermatozoa were evaluated using transmission and scanning electron microscopy. Four cryoprotectants, dmso, ethanol, methanol and glycerol at concentration of 10% were tested in triplicates. Three ml of fresh sperm which was diluted with 60 ml of ringer solution was added to each of twelve 5-ml vials containing of 0.50-ml of the cryoprotectants. The vials were placed in an icebox containing dry ice 5 min and then storage into container containing liquid nitrogen for 13 months. The effect of cryoprotectants on the spermatozoa abnormality and motility were significant (P < 0.05). The spermatozoa abnormality was significantly lower in methanol (62.65%) compared with the other cryoprotectants. The spermatozoa motility was higher in methanol, but not significantly different with ethanol (P > 0.05). It is a negative correlation between sperm motility and abnormality. Generally, higher abnormalities of spermatozoa resulted low motility.

The objective of the present study was to determine the most suitable extender and their respective dilution ratios for African catfish sperm for artificial induced breeding and cryopreservation purposes. Three natural extenders were tested i.e. coconut water, sugarcane water and soybean solutions, at three different levels of sperm to extender dilutions of 1:20, 1:30 and 1:40. While Ringer solution was used as a control Diluted sperm were fertilized with ready isolated eggs to assess the fertility and hatching rate at 0, 6 and 12 hour intervals. The results showed that the eggs hatched approximately 19 to 27 hours after fertilization. In general, the fertilization and hatching rates decreased with increasing dilution ratio. With respect to natural extenders, the coconut water showed the highest fertility and hatching rates at 1:20 dilution ratio. Therefore, coconut water at 1:20 dilution ratio was the optimal condition for African catfish spermatozoa among the natural extenders investigated.

The aims of this study were to determine the influence of the factors affecting fin damage under different rainbow trout production systems and to compare the findings with the known experimental reports. The study was based on a questionnaire that included information about the main factors i.e. oxygen level in exit water, water temperature, stocking density, daily feed ration, number of meals and grading frequency on seven rainbow trout farms. Standard multiple regression analysis, based on a previously published fin damage dataset, was used to assess the relationship between the level of fin damage per fin and the factors. Daily feed ration received the strongest weight in the model for the caudal, anal and both pectoral fins, whereas number of meals received the strongest weight in the model for both pelvic fins. Grading frequency received the strongest weight only in the dorsal fin model. Lower levels of daily feed ration and number of meals combined with higher water temperatu...

; Tel: +2348036320095. SUMMARY A total of 120 Clarias gariepinus, 120 of Heterotis niloticus and 150 Oreochromis niloticus were collected from integrated fish cum chicken reservoir for Aeromonas hydrophila screening. Samples were collected twice monthly for one calendar year. The physico-chemical parameters of the reservoir water were taken each sampling day. Bacterial culture involved pre-enrichment in alkaline peptone water and incubation in nutrient o agar at 37 C for 24hrs. Standard biochemical assays such as Gram-staining, catalase, oxidase, hydrogen sulphide, indole, methyl red and Voges-Proskauer tests were performed to confirm the bacterium. Prevalence rates of A. hydrophila in O. niloticus, C. gariepinus and H. niloticus was 34%, 31.7% and 27.5% respectively. The study shows that O. niloticus is more prone to thebacterium followed by C. gariepinus and least H. niloticus. Although the organism was isolated all the months of the year, it was observed that there was higher prevalence of the organism during the warmer months.

A focused review on the use of LHRHa in induced breeding of fishes in India was made. Use of LHRHa is mainly restricted to high value brackish water and marine fish species whose market value generally exceeds INR 300-400/kg (USD 4.5-6/kg). Published information on use of LHRHa in induced breeding of fishes in India could document only twelve species out of which nine were brackishwater or marine fish. Besides length and weight, the egg diameter of female fishes (&gt;0.45–0.7 mm) is an important criterion for treating the fishes with LHRHa. LHRHa is either used alone or in combination with HCG (most popular), PGE, 17α-MT and Pimozide. Dosage of 20-70 µg/kg body weight for females and 10-40 µg/kg body weight for males with a latency period of 24-36 hours is most common in India. Experiments with LHRHa are being carried out mainly by ICAR-CIBA, Chennai (dominant) and ICAR-CMFRI, Kochi. Standardization and optimization of LHRHa dosage has been attained in Asian Seabass (Lates calcarife...

The aims of this study were to determine the prevalence of fin damage in farmed rainbow trout and to see whether the level of damage differed between different fish categories and farms. The study was field based and included the fin damage analysis and clinical description of the damaged fins. Fins were analyzed in two categories of fish (weight below 30g (min. 5g) and over 100g (max. 250g)). Thirty fish per category were randomly selected, netted and each rayed fin was assessed and photographed (total of 5880 fins were analyzed in 840 fish from seven rainbow trout farms). The prevalence of fin damage was 100% and there was a large range in the level of damage which was mainly characterized by surface abrasions. Worst affected fins in both fish categories were dorsal and pectoral fins. Fin damage was present to a lesser degree in the smaller categories, but there was fin damage in the smallest fish examined. Pattern of damage was Dorsal &gt; Pectoral &gt; Abdominal &gt; Anal &gt; T...

The objective of this present study is to determine the optimum concentration for glutathione in the cryopreservation of seurukan fish (Osteochilus vittatus) spermatozoa. A completely randomized design (CRD) was used with 6 treatments and 3 replications. The Seurukan fish sperm was diluted in extender with a ratio of 1:20 (sperm: extender), then glutathione was added at a concentration of 0, 10, 20, 30, 40 and 50 mg L À1. Next, the sperm thawed at 39e40 C for 3 min and mixed with 100 eggs which were randomly selected. The success of the fertilized egg was observed 6 h after fertilization, while the hatching rate was examined 60 h after fertilization. The ANOVA test showed that the addition of glutathione significant affected the sperms motility, fertility and hatching rate of seurukan fish Osteo-chilus vittatus eggs (P &lt; 0.05). By segregation the fresh sperm, a higher sperm motility rate was recorded with an addition of 30 mgL À1 of glutathione (63.00 ± 5.89), however, this value...

The aims of this study were to determine the prevalence of fin damage in farmed rainbow trout and to see whether the level of damage differed between different fish categories and farms. The study was field based and included the fin damage analysis and clinical description of the damaged fins. Fins were analyzed in two categories of fish (weight below 30g (min. 5g) and over 100g (max. 250g)). Thirty fish per category were randomly selected, netted and each rayed fin was assessed and photographed (total of 5880 fins were analyzed in 840 fish from seven rainbow trout farms). The prevalence of fin damage was 100% and there was a large range in the level of damage which was mainly characterized by surface abrasions. Worst affected fins in both fish categories were dorsal and pectoral fins. Fin damage was present to a lesser degree in the smaller categories, but there was fin damage in the smallest fish examined. Pattern of damage was Dorsal &gt; Pectoral &gt; Abdominal &gt; Anal &gt; T...

Study on the effect of cryoprotectants on abnormality and motility of baung, Mystus nemurus spermatozoa were evaluated using transmission and scanning electron microscopy. Four cryoprotectants, dmso, ethanol, methanol and glycerol at concentration of 10% were tested in triplicates. Three ml of fresh sperm which was diluted with 60 ml of ringer solution was added to each of twelve 5-ml vials containing of 0.50-ml of the cryoprotectants. The vials were placed in an icebox containing dry ice 5 min and then storage into container containing liquid nitrogen for 13 months. The effect of cryoprotectants on the spermatozoa abnormality and motility were significant (P < 0.05). The spermatozoa abnormality was significantly lower in methanol (62.65%) compared with the other cryoprotectants. The spermatozoa motility was higher in methanol, but not significantly different with ethanol (P > 0.05). It is a negative correlation between sperm motility and abnormality. Generally, higher abnormalities of spermatozoa resulted low motility.