An experience of obtaining mature eggs of the Siberian sturgeon (Acipenser baerii (Brandt, 1869)) in non-traditional period

Purpose. To investigate the peculiarities of obtaining ovulated eggs of the Siberian sturgeon in hatchery conditions in non-traditional (winter) period and determine major features of brood fish used for the experiments. Methodology. The material for the study were age-10+ Siberian sturgeon females with body weights of 6.20-8.24 kg grown in conditions of floating cages in a water body with natural temperature regime of the forest-steppe zone of Ukraine. The experiments were conducted with a regulated water temperature regime in the third decade of January with the use of natural gonadotropic drugs for the stimulation of egg maturation in fish. Brood fish were prepared for the experiment in the recirculating aquaculture system. Measurement of fisheries parameters and study of physicochemical factors of the aquatic medium were performed according to generally accepted methods. Experiment results were assessed statistically using standard software. Findings. With water temperature of 14-15оС, depending on the dosage of the gonadotropic drug, different efficiencies of gonad maturation in experimental groups of fish were detected. More than 85% of females matured after dosing of gonadotropic drugs 3.5 and 4.5 mg / kg. In the version with a minimum dose of gonadotropic substance 2.5 mg / kg responded positively to hormonal stimulation 57% of females. The average weight of eggs obtained in some groups of brood fish was 819.5-1079.0 g. Average working fecundity and relative working fecundity in experimental groups of the Siberian sturgeon females varied within 47.95-52.64 thousand eggs and 6.93-7.17 thousand eggs/kg of fish body weight, respectively. The duration of maturation after the second (resolving) administration of the gonadotropic drug until the moment of the occurrence of the ovulation process varied mainly within 15-20 hours. Originality. The peculiarities of obtaining mature eggs of the Siberian sturgeon with the use of methods of industrial reproduction of sturgeons, which are new for the aquaculture of Ukraine, were studied. Practical value. The study results are of interest for the development of modern methods of sturgeon aquaculture in conditions of fish farms of industrial type. Key words: brood Siberian sturgeon, industrial aquaculture, non-traditional technologies, eggs, ovulation, fisheries parameters.

Induced Breeding of Fresh Water Menoda Catfish (Hemibagrus Menoda) Using Ovupin Hormone

An experiment on induced breeding of menoda catfish, Hemibagrus menoda was conducted during the period from May 2017 to July 2018 by using commercial Ovupin hormone (GnRHa, Gonadotropin Releasing Hormone Analogues) to attain its optimum dose. The study consists of three treatments, each with three replications. The objective of the experiment was to find out the effective dose for induced breeding. The breeding parameters were determined in terms of ovulation, fertilization, hatching, and survival rate. A total of 36 males and 18 females lived brood fish were kept in the ratio of 2♂:1♀ for breeding purpose. The commercial Ovupin hormone were injected at the doses of 4 (T1), 6 (T2), 7 (T3) mL Ovupin·kg-1body weight for female and 1.5(T1), 2 (T2), 3(T3) mL Ovupin·kg-1 body weight for male in a triplicate replication. In this study, it was found that treatment T2 demonstrated the best spawning performance for both male and female and were statistically significant (p<0.05). The investigation indicated that the dose of Ovupin hormone 6mL Ovupin·kg-1body weight for female and 2 mL Ovupin·kg-1 body weight for male determines the highest spawning performance of menoda catfish which should be recommended for high quality eggs and larvae. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(2): 11-18

TEKNIS PRODUKSI PEMBENIHAN DAN PENDEDERAN IKAN LEMON ALGAE EATER Gyrinocheilus aymoneiri DI ADE’S FISH FARM, KABUPATEN BOGOR, JAWA BARAT

ABSTRACTLemon fish Algae Eater is one of the aquarium fish which is well-known as Algae Eater. The Lemon Algae Eater is placed in a pond measuring 2 m x 3 m x 0.8 m, with a water height of 50 cm. For optimum health, feed the Algae Eater with Feng Li pellets by having a restricted feeding method or this can also be limited to 5% from the brood fish weight. The semi-natural hatchery of Lemon fish Algae Eater is needed. An aquarium (100cm x 60 cm x 50 cm) with a water height of 30 cm is needed for the hatchery of Lemon fish Algae Eater eggs. The average fecundity of Lemon fish Algae Eater eggs produced in 1 spawning can reache up to 84 742 eggs with the average of Fertilization Rate is 79%, the Hatching Rate is 83%, and the Survival Rate is 74%. The Lemon Algae Eater eggs will hatch in 10-12 hours. Fish nursery of lemon fish algae eater is used pond measures 3 m x 2 m x 1.5 m. The freshly hatched larvae are harvested at the age of 30 days and 45 days with a size of 1.2-1.5 cm/fish and 2.5-3 cm/fish. ABSTRAKLemon algae eater merupakan salah satu ikan aquarium yang dikenal sebagai pemakan alga. Pemeliharaan ikan lemon algae eater dilakukan pada bak beton yang berukuran 2 m x 3 m x 0.8 m, dengan tinggi air 50 cm. Pakan yang diberikan berupa pelet feng li dengan metode pemberian pakan restricted atau metode dibatasi dengan 5% dari bobot induk. Pemijahaan induk ikan lemon algae eater dilakukan secara semi alami. Wadah penetasan telur ikan lemon algae eater menggunakan akuarium ukuran 100 cm x 60 cm x 50 cm dengan tinggi air 30 cm. Rata-rata fekunditas telur ikan lemon algae eater yang dihasilkan dalam 1 kali pemijahan mencapai 84 742 butir telur dengan memiliki nilai rata-rata Fertilization Rate sebesar 79%, Hatching Rate sebesar 83%, dan Survival Rate sebesar 74%. Telor ikan lemon algae eater akan menetas dalam waktu 10-12 jam. Kegiatan pendederan ikan lemon algae eater menggunakan wadah bak beton yang berukuran 3 m x 2 m x 1.5 m. Benih yang dipanen berumur 30 hari dan 45 hari dengan ukuran 1.2 -1.5 cm/ekor dan 2.5 - 3 cm/ekor.

According to the issue of the giant freshwater prawn ((Macrobrachium rosenbergii)

Purpose: study the biotechnical features of rearing juvenile giant freshwater prawn (Macrobrachium rosenbergii) using recirculating aquaculture systems (RAS).Materials and methods. Two fish-farming modules RAS and aquarian complex were used for the work. One of them has a total volume of 6.5 m3, the second - 14.5 m3. Larvae were reared in gasite cages of 0.021 m3 in an aquarian complex of two 200-liter aquariums. Larvae of one female prawn were used in an amount of 8500 units. At each stage of prawns' development we used different versions of feed of both animal and plant origin: artemia, minced fish, boiled chicken eggs (protein + yolk), beef liver and oat flakes.Results. Brood fish were kept at an average planting density of 6.2 individuals/m2, with a sex ratio of 1:4.5 (males: females). The planting density of larvae in cages was 2,125 units/cage or 101.2 units/liter. The average weight of juveniles during rearing of postlarvae at 130 days was 3.19 g. Juvenile yield was 49.9%. Specific growth rate of biomass varied from 4.87 to 3.68 %. Planting density of juveniles varied from 1775,6 units/m2 to 660,9 units/m2. As a result, the feeding coefficient was 5.24 units. Growing productivity was 362.7 pcs/m2 or 1156.8 g/m2 in the RAS module.Conclusion. There were established biotechnical peculiarities and production possibilities of growing young giant freshwater prawn (Macrobrachium rosenbergii) using fish-breeding RAS and aquarian complex. Modernization of fish-feeding RAS and use of some recommendations on feeding suggest the possibility of their use for breeding and rearing of juvenile giant freshwater prawns in already existing warm-water enterprises, initially aimed at other objects of aquaculture.

Sakhalin Sturgeon Аcipenser mikadoi (Hilgendorf, 1892): Searching for Technology of Artificial Propagation in Aquaculture

It shows searching for a solution to the issue of the stock rebuilding of the Red List species — the Sakhalin sturgeon. It describes the results of the expedition to the Tumnin river aimed at brood fish procurement and optimization of the technology for its reproduction together with the brood fish grown in aquaculture. It lists the morphological characteristics and fish-cultural and bio-data of the spawner caught in the Tumnin river and the milters grown at the Anyuy Sturgeon Fish Hatchery. A method for the obtainment of reproductive products, hatching and juvenile fish growning is described. As a result of sampling for biopsy, it has been found that the coefficient of oocytesʼ nucleus polarization was 7.4 on the average. The hormonal preparation surfagon was used for sex products stimulation at males and a female. The female ovulated in 12 hours after permitting injection. It was managed to get 2,378 g eggs on the average 87.6 per cent of fertilization. The average ejaculate volume was 455 ml. The spermatozoon mobility at mean 14 °C temperature made up 208 sec. A double fertilization method was used at fertilization of an eggs part, moreover the eggs received were of a high piscicultural quality (99%). The average diameter of swollen eggs was maximum 6.8 mm and minimum 6.6 mm after fertilization. The larvae production made up to 30%, i.e. 27,850 of incubated eggs. 1000 ongrown fry were stocked into the Tumnin river, the last juveniles were directed to fish cultural farms of Russia with a view to form there recruitment-and-brood stocks. According to results of experimental works, done in the Anyuy Fish Hatchery, the first provisional technology of work was recommended on fertilized eggs production from the Sakhalin sturgeon spawners after the schema “a wild female + farmed males” by a method of a double fertilization with the increased exposition time.

INDUCED SPAWNING AND LARVAL DEVELOPMENT OF VIETNAMESE KOI, Anabas testudineus (Bloch, 1792), USING SALMON GONADOTROPIN RELEASING HORMONE ANALOGUE (S-GnRHA)

The present research work has been carried out to obtain evidence on breeding and embryonic growth of A. testudineus by using S-GnRHa. Fish were injected with three different doses (0.25, 0.5, and 1.0 mL/kg body weight) of synthetic hormone S-GnRHa each with three replications, where male brood fish received half of the doses of female. The fecundity of A. testudineus was ranged from 47,227 to 77,561 during the study period and except control group all the hormone received group ovulated within 12 hours of hormone injection. Among all groups, the highest fertilization rate (89.33%), highest hatching rate (79.5%) as well as highest survival rate (67.0%) was obtained at 0.5 mL/kg body weight hormone dose recipient group. The fertilized egg’s diameter was recorded as 77.59 ± 3.50 µm. The first cleavage had appeared within 18-25 min of fertilization and eventually the morula, blastula, and gastrula stages were observed at 3:10 h, 4 h, and 5:30 h, respectively after fertilization. Larvae with distinguished head, body form and tail appendage spotted between 17-22 h and the larvae started hatching at 19 h after fertilization. The average length of larvae accounted as 105.41 ± 3.73 µm. The findings of present study revealed that 0.5 mL/kg S-GnRHa could be efficient dose for successful induced breeding of A. testudineus.

Dose Optimization of Ovatide Hormone for Induced Breeding of Freshwater Gang Magur, Hemibagrus Menoda (Hamilton, 1822)

An experiment on induced breeding of gang magur, Hemibagrus menoda (Hamilton, 1822) using Ovatide hormone was carried out at in the Field Laboratory Complex of Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh. This study consists of three treatments each with three replications. The objective of the experiment was to find out the effective dose of Ovatide hormone for induced breeding. A total number of 54 brood fish were used for the experiment among which 36 were male and 18 were female. Brood fish were kept in the ratio of 2♂:1♀ for breeding purpose. Female brood fish were injected at the rate of 7, 5, 3 ml Ovatide/kg body weight while the males were injected with 3, 2.5 and 1.5 ml Ovatide/kg body weight respectively in T1, T2, and T3 at the same time. The brood fish were injected with single dose of Ovatide in all treatments. Ovulation rates were 0%, 100%, 63%; fertilization rates were 0%, 97%, and 90%, and hatching rates were 0%, 95% and 76% in treatments T1, T2, and T3 respectively. Fertilized eggs were incubated for 21-22 h in all the treatments. Higher ovulation rate (100 %), fertilization rate (97%), hatching rate (95%) and survival rate (85%) were found in treatment T2. Therefore, the optimum dose of Ovatide hormone for induced breeding of H. menoda is 2.5 and 5 ml Ovatide/kg body weight of male and female brood fish, respectively. Res. Agric., Livest. Fish.8(1): 171-179, April 2021

Polyculture of Largemouth Bass (Micropterus salmoides) with Blue Tilapia (Oreochromis aureus): Using Tilapia Progeny as Forage

In this study, five, 0.04-ha ponds were stocked with advanced size largemouth bass fingerlings at densities of 124, 247, 494, 988, and 1136/ha. Tilapia brood fish were stocked at densities of 590/ha (male: female ratio was 1:3). Pond trials were conducted for a 6-month period, June to December 1985. Bass survival ranged from 40 to 89%. Bass stocked at densities 494/ha (low density) grew significantly larger than those at 988/ha (high density). Mean bass weights and percent weight gains at harvest in low versus high density ponds were 593 g and 3,318% and 120 g and 329%, respectively. High density bass ponds produced larger tilapia broodfish at harvest. The number of juvenile tilapia surviving in low density bass ponds was substantially greater (20,000 juveniles/ha) than in high density bass ponds (99 and 420 juveniles/ha). The higher survival of tilapia juveniles in low density bass ponds was the apparent cause of significantly higher turbidity (determined from secchi disc measurements) in these ponds. The results of this study suggest that forage/predator ratios, based on densities of female tilapia broodfish to bass, of 0.7 and 1.4 are suitable for controlling spawn and producing large tilapia or for producing large bass, respectively.

Reproduction of Indian Mackerel Rastreliger kanagurta (Cuvier, 1816) in Morodemak Coast Demak Regency

Indian mackerel is a group of small pelagic fish that has high economic value and is ecologically important. The catch of Indian mackerel in the Morodemak Coastal Fishing Port of Central Java has decreased within 2016-2018, which is suspected by overexploitation. This study aims to observe the reproduction of Indian mackerel. Fish samples were collected from the catches of the mini purse seine operated by fishermen in April-June 2019. The fish samples were measured their length and weight individually, then the abdomen dissected to collect gonad, and counted in sub-sample of the egg number. Data were analyzed to determine the length-weight relationship of fish, sex ratio, gonad maturity level (GML), gonad maturity index (GMI), the size of the first gonad matured, and the egg number in each gonad brood fish. The results showed a negative allometric length relationship, and the length-weight relation equation in female fish was W = 0.038 L 2.59 and in male was W = 0.178 L 2.03. The value of fish condition factors in males, and females obtained values ranging from 1-2. The proportion of fish in GML III ranges from 27.2 to 82.5%, while GML IV ranges from 3.6 to 33.8%. Fish GMI ranged from 0.17 to 4.75%. The eggs number ranged from 11.235 to 40.878 grain. The female Indian mackerel get the first gonad matured at the size of 15.2 cm.