No abstract

An investigation was conducted on fungal disease of freshwater fishes in Natore district of Bangladesh from September 2005 to February 2006. A total of 2097 fish specimens where about 300 fishes under 15 fish species (8 culturable and 7 non culturable) were infected with fungal disease. Among culturable species most fungal infected fishes was C. mrigala (24.71%) where the total length, total weight and group of this infected fish was 10.8 to 40 cm, 10 to 995 g and 10.1 to 15 cm respectively followed by C. idellus (16.28%) and L. rohita (13.43%). Among non culturable species the most fungal infected fish was C. punctatus (22.42%) where the total length, total weight and group of this infected fish was 11 to 23 cm, 15 to 20 g and 20.1 to 25 cm respectively followed by C. striatus (16.88%) and P. ticto (15.31%). Disease in culturable fish species was less (13.40%) than non-culturable species (15.19%). Three genera of fungi were identified where Branchiomyces sp. was associated with gill rot disease and Saprolegnia sp. and Aphanomyces sp. were associated with ulcer types of disease. The incidence (%) of disease was highest in the month of December (22.49%) followed by November (20.25%) and January (18.00%). Keywords: Fungal disease; Infected fish; Incidence DOI: 10.3329/jbau.v7i1.4979 J. Bangladesh Agril. Univ. 7(1): 157-162, 2009

An experiment was conducted from December 2003 to April 2004 to observe the over‐wintering growth of freshwater prawn, Macrobrachium rosenbergii, with catla, Catla catla and rohu, Labeo rohita in polyculture using formulated diets. The study was conducted in eight experimental ponds, each 80 m2. Three experimental diets containing 30% protein were prepared using fish meal, meat and bone meal, mustard oilcake, rice bran, wheat bran and molasses (binder), and assigned to treatments T1, T2 and T3 respectively. A commercial diet from Saudi‐Bangla Fish Feed was assigned to T4 (reference diet). Each treatment had two replicate ponds. Juvenile prawns and catla and rohu fingerlings (initial weight 1.60±0.10, 30.0±1.2 and 25.0±1.1 g respectively) were stocked at a ratio of 2:1:1 (prawn:catla:rohu). A total of 160 prawn and fish (20 000 ha−1) were stocked in each pond. Fish were fed twice daily at 3% body weight (b.w.) for the first 3 months and 5% b.w. for the last 2 months. Prawns in T1 fed diet 1 had significantly higher (P<0.05) weight gain compared with that of T3. The reference group and T2 had intermediate values not significantly different from either. Weight gains of catla and rohu were significantly higher in T1. The feed conversion ratio values of different diets ranged between 1.89 and 2.13. Survival (%) ranged from 90.0% to 95.0% for catla, 87.5% to 92.5% for rohu and 70.0% to 76.3% for M. rosenbergii, and there were no significant differences (P>0.05) among different treatments. Total production ranged between 2196 and 2679 kg ha−1, with T1 showing significantly higher production and net profit (taka 56 531.9 ha−1). The results of the study demonstrated that it is possible to culture M. rosenbergii with carp in polyculture during the winter utilizing the late‐produced PLs. Further study is needed to determine the optimum stocking density of M. rosenbergii in carp polyculture.

An investigation was conducted to have a clear idea on current aquaculture practicesof 67 fish farmers in Birganjupazila, Dinajpur district for a period of six months fromOctober 2016- March 2017. Fish farmers were selected randomly from three villagesof Moricha Union of Birganjupazila through questionnaire interview, FGD and crosscheck interview and secondary information were used to assess the performances inaquaculture activities. Most of the farmers (52.24%) had pond having the size rangefrom 5 to10 decimal with the mean depth 4.44 ft. It was found that 79% of pondscontained water throughout the year and 21% pond had water for a period of 6 to 8months. The major culture species was Indian major carps along with SmallIndigenous Species. About 76% farmer used feed in culture pond and none of thefarmers were found to take any measures for maintaining proper water quality. Thetotal fish production was found as 1204 kg where Tilapia ranked highest with 22% inthe study area. About 92.5 % farmers use the fish only for family consumptionwhereas the remaining farmers (7.5%) used for both family consumption and sales.The major problems identified during the culture period were high price of quality fishseeds and feeds, less protein in feed, poor technical knowledge etc. It is therefore,necessary to provide necessary training to the farmers, institutional and policysupports and proper credit facilities for sustainable fish production as well assustainable livelihood of the poor farmers. Res. Agric., Livest. Fish.7(2): 341-349,  August 2020