Mohammad Rafiqur Rahman

Bio: Mohammad Rafiqur Rahman is an academic researcher from Bangladesh Agricultural University. The author has contributed to research in topics: Population & Stocking. The author has an hindex of 2, co-authored 5 publications receiving 13 citations.

Evaluation of growth, survival and production of stinging catfish shing (Heteropneustes fossilis) at different stocking densities in primary nursing

Abstract: An experiment was carried out in six nursery ponds of 5.0 decimal each with 4 days old stinging catfish shing (Heteropneustes fossilis) spawn at three stocking densities viz. 2, 3 and 4 million ha for the period of 4 weeks from 01 June to 28 June 2017. MEGA pre-nursery and nursery feeds were provided three times daily at the rate of 15% for the first one week and were decreased by 1% every week thereafter. Growth of fry was inversely related to stocking densities. Similar inverse relation was also observed in case of survivals, which were 55.74, 50.20 and 34.41% at 2, 3 and 4 million spawn ha stocking densities, respectively. The final length, final weight and survival rate of H. fossilis fry were significantly (P<0.05) higher in T1 than those obtained from T2 and T3, respectively. Considering the highest gross and net production the stocking density applied in 3 million spawn ha found best in primary nursing which a better production to fish farmers but more research still needed to further optimize stocking density of H. fossils.

Comparison of growth performance of gynogenetic female, gynogenetic neo-male and normal mixed-sex silver barb (Barbonymus gonionotus) in earthen ponds

Abstract: The experiment was conducted to compare the growth performance of gynogenetic females and gynogenetic neo-males with mixed-sex silver barb (Barbonymus gonionotus) in six earthen ponds for a period of 120 days. Three treatments i.e. T1 (Gynogenetic female), T2 (Gynogenetic neo-male) and T3 (mixed-sex, control) each having two replicates were stocked with 60 fish/decimal. During stocking the mean length and weight of fishes were 5.83±0.12 cm and 2.72±0.10 g, 5.85±0.12 cm and 2.77±0.12 g and 5.79±0.16 cm and 2.66±0.16 g, in T1, T2 and T3, respectively. The fishes were reared with a commercial fish feed (Mega Feed) of different types such as pre-starter (36% crude protein) for the first 42 days, starter (32% protein) for the second 42 days and grower (32% protein) for the last 36 days. Water quality parameters were measured and found in optimal levels for fish culture. A significantly highest (p 0.05) different. Similar trend was also observed in other growth parameters such as final length, final weight, % weight gain, average daily gain and specific growth rate among the treatments. However, no significant difference (p>0.05) was observed for survival among the treatments. The significantly highest (p>0.05) gross and net production was observed in T1 (1219.62±23.29 and 1178.83±22.33 kg/ha/120 days) and lowest in T3 (1029.38±22.44 and 989.54±21.30 kg/ha/120 days) and no significantly different (p> 0.05) was observed for the production between T1 and T2. Considering the growth performance of silver barb, it can be concluded that the gynogenetic females and neo-males possess higher production potentiality and thus generation of all-female population using neo-males would be an effective approach for accelerating fish production.

Induction of meiotic and mitotic gynogenesis in silver barb (Barbonymus gonionotus) through cold shock treatment

Abstract: This study was dealt with induction of diploid meiotic and mitotic gynogenesis in Barbonymus gonionotus through cold shock treatment for production of monosex all-female population. For inhibition of paternal inheritance, sperm DNA was denatured by exposing cell suspension containing 8×108 ml-1 to UV at 196 μWcm-2 for 1.5 min. After fertilization of eggs using uv-treated sperm, meiotic diploidization was done by cold shock treatment at 2 °C for 1 min applied 1.5 min of post-fertilization that produced 44.23±0.62% meiotic gynogens. Mitotic diploidization was done by the same cold shock treatment applied after 27.5 min of fertilization that produced 36.70±0.63% mitotic gynogens. Ploidy status of all the progenies was evaluated by karyotyping. The karyotype analysis revealed 23 (N) chromosomes in haploids, and 46 (2N) chromosomes in meiotic and mitotic gynogens and controls. Sexing of fish showed nearly all-female, ranging from 98.28 to 100% and 96.43 to 100% female in the meiotic and mitotic gynogens respectively. The sex ratio in the control group was nearly 1:1. DNA microsatellite analysis revealed that the meiotic gynogenetic offspring possessed two alleles the same as their mother and the mitotic gynogenetic offspring possessed any of the two alleles of their mother and became homozygous. No meiotic and mitotic gynogens have inheritance of paternal alleles. The control offspring shared alleles from both male and female parents. Thus, the study confirmed the production of meiotic and mitotic gynogens of silver barb through cold shock treatment and they could be converted into sex-reversed males (XX) by masculinizing hormone treatment for production of monosex all-female population.

Effects of stocking density on the growth, survival and production of endangered bata, Labeo bata (Hamilton, 1822) in primary nursing

Abstract: Effect of stocking densities on the growth, survival and production of bata, Labeo bata fry and fingerlings were tested in a primary nursery rearing system. The experiment was conducted for a period of 4 weeks in six earthen nursery ponds having an area of 0.032 ha each. Four-day-old fry stocked at 1.0 million/ha was designated as treatment-1 (T1), 1.5 million/ha as treatment-2 (T2) and 2.0 million/ ha as treatment-3 (T3). At stocking, all fry were of same age with a mean length and weight of 1.03±0.03 cm and 0.12±0.01 g, respectively. Fry in all the treatments were fed with Mega commercial fish feed. Physico-chemical parameters such as water temperature, transparency, dissolve oxygen, pH and total alkalinity in all the treatments were suitable ranges for fry and fingerling rearing. Plankton population (both phytoplankton and zooplankton) were found to be at optimum level for fish culture. Highest weight gain was observed in T1 (3.46±0.08) and lowest in T3 (1.98±0.03). Final length, final weight and survival of fingerlings also followed the same trends as weight gain. Fingerlings in T1 produced significantly higher specific growth rate (12.15±0.08) than T2 (11.31±0.03) and T2 (10.22±0.05). Feed conversion ratio was significantly lower in T1 (0.26±0.01) than T2 (0.42±0.02) and T3 (0.65±0.01). Significantly higher number of fingerlings was produced in T3 (1177700±4700) than T2 (963300±9900) and T1 (717850±7350), respectively. Despite of this, consistently higher net benefits were found from T1 than T2 and T3. Overall, highest growth (3.60±0.16 g), survival (71.79 ± 1.04%) and net benefits (TK. 127,087.00) of fingerlings were obtained at a density of 1.0 million hatchlings/ha. Therefore, out of three stocking densities, 1.0 million fry/ha appears to be most suitable stocking density for nursing and rearing of L. bata fry and fingerlings in primary nursing.

Induction of gynogenesis in red crucian carp using Spermatozoa of blunt snout bream

Abstract: Gynogenetic diploid was induced in red crucian carp (RCC) (Carassius auratus Red Variety) eggs using UV-irradiated spermatozoa from blunt snout bream (B) (Megalabrama amblycephala) or from mirror carp (C) (Cyprinus carpio. L). Spermatozoa were genetically inactivated by an appropriate UV dosage, and then the maternal DNA was duplicated with cold shock at 0–4°C. When using the spermatozoa of B, the fertilization rate, hatching rate and survival at first feeding were 52.6 ± 3.0 %, 23.6 ± 4.1 % and 15.7 ± 3.4 % respectively, and the survival at first feeding was significantly higher than that (11.3 ± 2.2%) when using the spermatozoa of C(Cypripnus carpio. L). According to the morphological characteristics, the chromosome number and the degree of gonadal development, gynogenetic RCC could be distinguished from the control hybrids of RCC ♀ × B♂. The individuals with red body color, 100 chromosomes and normal gonadal development were syccessful gyogenetic RCC, while the individuals with 124 or 148 chro...