Pabdah catfish, Ompokpabdawas collected from the Old Brahmaputra river and successfully induced to breed by injecting pituitary gland extract to evaluate spawning performances and developmental stages under a photo microscope from February 2018 to August 2018. In this study, absolute fecundity of the O. pabdafemales varied from 6,676 to 20,410 eggs per fish. The GSI value of male and female was lower during September and gradually attained its maximum level in June with the highest average value 6.75±0.2 and 1.053±0.2 in female and male, respectively. The average fertilization and hatching rate of eggs were found 78.67±1.33% and 70.21±0.73%, respectively at 24.5±1.0°C. Fertilized eggs were brownish in color, very transparent and adhesive in nature with 1.0 to 1.2 mm in diameter. Cleavage stages were completed at 1.50 h of post fertilization and it eventually took 23.00 h for hatching. Larva was appeared with prominent three pairs of barbells after 12.00 h of hatching. It took 3 d post hatching to absorb their yolk sac and feeding exogenously. The present work supplemented to the deficient information on detailed spawning and developmental biology of O. pabdain order to save this species from extinction. Asian J. Med. Biol. Res. September 2020, 6(3): 449-459

Fish meal (FM) has excellent protein and lipid profile. However, FM is losing its acceptability and substituted with plant protein due to FM has high price, high demand, and sustainability issues in global aquaculture production. In this study, experimental diets were prepared by substituting FM with fermented soybean meal (FSM) or normal and untreated soybean meal (SM) to assess the effects on growth, hematology, innate immunity, gut physiology, and digestive enzyme activities in juvenile silver barb, Barbonymus gonionotus. Five diets, that is, 40% FM (FM 40), 20% FM + 20% FSM (FM 20 + FSM 20), 20% FM + 20% SM (FM 20 + SM 20), 40% FSM (FSM 40), and 40% SM (SM 40) were fed to the fish two times daily for 90 days. After 90 days of feeding trial, FM 40, FM 20 + FSM 20, and FM 20 + SM 20 diet groups showed significantly higher weight gain (WG) and specific growth rate (SGR) compared to the FSM 40 and SM 40 diets. Hepatosomatic index (HSI) and viscerosomatic index (VSI) were significantly higher in fish fed with the FSM 40 and SM 40 diets than those of fish fed with the FM 40 diet. Hematocrit, hemoglobin, and erythrocyte count were significantly lower in fish fed with the SM 40 diet compared to fish fed with the FM 40 and FM 20 + FSM 20 diets. Superoxide dismutase and catalase activities in the liver were significantly higher in fish fed with the SM 40 diet compared to fish fed with the FM 40 diet. However, serum thiobarbituric acid reactive substances in fish fed with the experimental diets were unaltered. Fish showed significant reduction of villus height (Vh) in the anterior and posterior intestine of fish fed with the FSM 40 and SM 40 diets, whereas muscular thickness was opposite to the findings of Vh. Digestive enzyme activities in intestine were significantly higher in fish fed with the FM 40 diet compared to those in the SM 40 diet. The results of the present study revealed that the 50% of FM can be replaced by FSM or SM as a source of protein without affecting the growth of juvenile silver barb.

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The present study was conducted to assess the harvesting procedures, nutritional value of stingray in the coastal district Cox’s Bazar, Bangladesh and its utilization as value-added product. Data were collected through direct observation, focus group discussion, questionnaire interview and cross check interview. It was found that stingray was mainly caught by artisanal fishery using gill net, set bag net and long line within 5-40 m depth ranges about 100-200 km at west direction, 10-60 km at south direction and 50-100 m depth ranges about 60-100 km at southwest direction from Fishery ghat, Cox’s Bazar. In the west direction, stingray harvesting grounds were Sonar char, Rupar char, Char Gongmoti and Dublar char in Patuakhali district, and Cox’s Bazar coast, Teknaf coast, St. Martin’s island coast and the south patches at south direction and middle ground at southwest direction. Generally stingrays was harvested throughout the year but were abundant during December and January. At fish landing center, the supply chain of stingray from fishermen to consumers passed through a number of intermediaries e.g., dealer, wholesaler, retailer and supplier. The market value of stingray varied where fishermen sold at 90-140 Tk/kg that passed through these channels and at last consumers got it at 140-250 Tk/kg. Six species of stingray were found in Fishery ghat, Cox’s Bazar namely Himantura gerrardi, Dasyatis bennetti, Himantura uarnak, Himantura undulata, Himantura bleekeri and Neotrygon kuhlii. Among them H. gerrardi and H. bleekeri were available and very popular in the market. The average moisture, protein, lipid, carbohydrate and ash content of H. bleekeri were determined as 78.08%, 14.80%, 4.31%, 0.95% and 1.87%, respectively and total energy content 103.78 Kcal. Three utilization processes were investigated in this study namely fish ball of stingray, stingray recipe with sour of tomato and stingray recipe with sour of tamarind. Fish ball was preferred as an excellent product and others were as very good products. Dried stingray products were only utilized by tribal peoples. Dried meat, skin and spine were exported abroad namely to China, Thailand, Myanmar and Singapore. J. Bangladesh Agril. Univ. 16(3): 539–544, December 2018