No abstract

Histoarchitecture effect of cypermethrin was investigated in the gills and liver of freshwater catfish, Pangasianodon hypophthalmus (weight 60-70g) over an exposure period of 96 h as an endpoint of toxicity. The fish were exposed to five acute concentrations (0.00ml/L, 0.025ml/L, 0.050ml/L, 0.075ml/L and 0.10ml/L) and the 96 h LC 50 was 0.075 ml/L. The physical reactions observed in the treated fish were erratic swimming, discolorations of the skin, loss of reflex, hyperactivities, surfacing, increasing opercula ventilation and these effects increased with increasing concentration of the toxicants and duration of exposure. The most common changes in gills histoarchitecture at all doses of cypermethrin were curl shape gill lamellae, bulged with the fusion of secondary gill lamellae, severe epithelial necrosis in gill lamellae and hypertrophy. The changes observed in the liver tissues were cloudy swelling, focal necrosis and hypertrophy of hepatocytes, degeneration of hepatocytes and cytoplasmic, extensive vacuolation of hepatocytes and pyknotic nuclei. The results of this histoarchitecture analysis of gills and liver tissues indicate a direct correlation between cypermethrin exposure and the histoarchitecture disorders.

The study was conducted to evaluate the effect of antibiotic on shelf life in rohu fish, Labeo rohita (Hamilton) under ice storage condition. Oxytetracycline (OTC), the most widely used antibiotic, was fed to rohu (average body weight 16.0 g) at the rate of 2 g/kg through fish diet for 5 days and their shelf life was determined in iced condition. Organoleptically, fish were found to be acceptable up to 16 days before becoming inedible compared to 15 days for control fish which received pelleted diet with no antibiotic under the same condition. Initial moisture, ash, protein, lipid, NPN and TVB-N values were 70.42±1.91%, 2.80±0.10%, 17.90±0.50%, 3.12±0.04%, 0.0086±0.01% and 17.43±0.60 mg/100g respectively in the control which reached at values of 78.45±1.50%, 3.84±0.10%, 13.47±1.00%, 2.80±0.08%, 0.0053±0.001%, 26.17±0.76 mg/100g, respectively after 16 days of ice storage. There was no significant difference for these values compared to control group. In case of total bacterial load, values of aerobic plate count (APC) was 2.0±0.1×103 during the start of ice storage condition which increased significantly to 5.6±0.38×10 7 , exceeding the acceptable limit for ice stored fish. The APC values also did not show any significant variation compared to control fish, suggesting that the use of antibiotic in fish diet had little or no effect on shelf life of rohu fish during ice storage condition.

This datasheet on Pen aquaculture in Bangladesh covers Identity, Overview, Case Study, Environmental Requirements, Growout Systems, Related Content, Further Information.

A total of 50 sub-adults of Pangasianodon  hypophthalmus averaging 3.0 kg were stocked in a pond having an area of 0.2 ha.  During winter months, fishes were fed with commercially available pelleted feed containing about 28% protein at the rate of 1.5% body weight daily while feeding rate was 3% during summer months. For augmentation of gonadal maturation, water shower was provided in the pond during winter months. Females were found with bulging belly and male with running milt during spawning season. Milt sample was expelled from mature and healthy brood by gentle abdominal pressure and collected into a clean and dry tube of 5 ml capacity.  The milt samples were primarily placed in sealed ice box for 2-3 minutes then it was stored in a normal freezer for 20 minutes at 0 to 40C and then milt was stored in a deep freezer at -150C.  Dimethyl-sulphoxide (DMSO) was used as cryo-protectant and phosphate buffered saline was used as extender.  Cryo-tubes were leveled as A, B and C for storing 4, 8 and 12 hours, respectively.  Leveled cry-tubes ware placed in the refrigerator for 15 min to reduce temperature to 4°C before fast freezing in the freezer. Then the tubes were stored in a deep freezer at -15°C.  Sperm motility of fresh milt was recorded as 95%. In the thawing process, these cryo tubes were first transferred into refrigerator for 20 min to allow the milt to thaw from -20°C to 4°C inside the refrigerator.  Thereafter, cryo tubes were transferred at room temperature and allowed to stand 5 min before mixing with female eggs. Thawed milt was added to the fresh eggs of Pangasius hypophthalmus and thoroughly mixed. After approximately 3 minutes, water was added to water-harden the eggs.  Motility of cryo-preserved milt was nil.  It is probably due to improper method applied to preserve the milt.  For short-term preservation, milt was stored in ice box for 2, 4 and 8 hours.  Motility rate of Pangasius hypophthalmus ranged between 5 and 50% and fertilisation rate varied between 1 and 40%, respectively.  Asian Australas. J. Biosci. Biotechnol. 2016, 1 (2), 398-401