Journal of Fisheries (University of Rajshahi)
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Lengths, length-length relationships and condition factor of Indian catfish Gagata cenia (Hamilton, 1822) in the Padma River, Bangladesh
This study described some biological parameters including lengths, length-length relationships and Fulton’s condition factors of Gagata cenia in the Padma River of Bangladesh, based on 1120 specimens collected from May to November, 2012. Maximum 39.78% female fishes were belonging to the length category of 55-60 mm whereas 51.06% male were belonging to 50-55 mm.The highest mean total lengths were found 66.51±10.28 mm (combined sex), 70.12±09.49 mm (female) and 61.08±09.45 mm (male) in the month of June. Similar findings are also presented for standard length, fork length, body depth, dorsal length, pectoral length, pelvic length and anal length. Linear relationships were also studied among mentioned lengths. Strong positive correlations were observed in all cases. Speraman’s Rank test indicated that there was a strong, positive correlation between total length and condition factor in female, which was statistically significant (rs=0.210, P=0.044). In male, there was no significant correlation between these two (rs=0.167, P=0.262). The Mann-Whitney U-test showed that the female individuals had the highest condition factor (Mean rank of 79.76). There was a statistically significant differences in the Fulton’s condition factor between males and females (two tailed, Mann-Whitney U = 1324)
Gonad development and size at maturity of the male mud crab Scylla paramamosain (Forsskål, 1755) in a tropical mangrove swamp
The reproductive traits and size at sexual maturity of the male mud crab Scylla paramamosain were investigated in Pak Phanang mangrove swamps, Thailand. Samples were taken seven times from the local middlemen mud crab traders during June 2006 to January 2008. Gonad development was determined based on histological appearance that was classified into three stages: 1) Immature (Spermatogonia), 2) Maturing (Spermatocytes) and 3) Mature (Spermatids and Spermatozoa). Among the sample population, the highest 72% was under gonad development stage I, whereas mature stage III was only 12%. The size at first maturity was estimated by the external allometric growth and histological observation of gonad. The size at which 50% of individuals attain sexual maturity was estimated by the two mathematical models such as probit analysis and logistic curve. The mean size at first sexual maturity and 50% maturation of male S. paramamosain were 96 mm and 109 mm internal carapace width (ICW) which revealed that 88% individuals were immature. The present result suggested that the minimum legal size of male S. paramamosain capture should be >110 mm ICW
Genetic variation among three wild populations of stinging catfish (Heteropneustes fossilis) by allozyme electrophoresis
Stinging catfish (Heteropneustes fossilis) is one of the most popular indigenous catfish having considerable potential for aquaculture and commercial importance in Bangladesh. With a view to assessing the genetic status of H. fossilis, three samples Chalan Beel (Pabna), Burungi Beel (Jamalpur) and Bagapura Beel (Mymensingh) were analyzed. For genetic variation study, five enzymes (LDH, EST, MDH, PGM and GPI) were used encoded by eight loci of which three were polymorphic (Mdh-1*, Est-1* and Gpi-1*). The highest mean proportion of polymorphic loci, mean number of allele and the mean proportion of heterozygous loci per individual of the Chalan Beel population were observed (25.00%, 1.250 and 6.250%, respectively). The highest gene flow (33.5) and lowest population differentiation (0.0074) found in Burungi Beel-Bagapura Beel indicated the close relationship among them. In the Nei’s UPGMA dendrogram, the Chalan Beel population formed one cluster by the genetic distance of 0.0371 and the other cluster was formed by Burungi Beel and Bagapura Beel populations (D=0.003). The results suggested that a considerable genetic variation is maintained among the natural H. fossilis populations
Behaviour of fourteen exotic ornamental fishes of Bangladesh under starved condition in aquaria
The behaviour of fourteen exotic ornamental fishes of Bangladesh under starved condition in aquaria was experimented from January to December, 2011. Fishes were belonging to 13 genera, 09 families and 4 orders. Two treatments each with three replications were used. Four different behavioural phases of fish were monitored through constant observation. Almost all the behavioural phases were seen earlier in the fishes of treatment T1. Marble angel survived more (1022±4.02 hrs; T2) than others. The lowest survival period (116±2.44 hrs; T1) was seen for albino suckermouth. Fishes were died earlier in T1 than T2, due to presence or absence of aeration facilities. Water temperature, dissolved oxygen, free CO2, pH, total alkalinity, ammonia-nitrogen and chlorine level were found to be varied from 25.66±0.17 to 28.66±0.35°C, 3.80±0.06 to 4.73±0.07 mg/l, 9.21±0.05 to 11.75±0.03 mg/l, 7.13±0.05 to 7.47±0.07, 76.66±1.64 to 108.92±3.20 mg/l, 0.0010±0.0006 to 0.0133±0.002 mg/l and 0.0045±0.001 to 0.012±0.0014 mg/l, respectively. The research findings would be helpful in gathering basic knowledge on different behavioural phases through which aquarists can maintain primitive behavioural phase in their aquaria. Further research work is suggested in the aforesaid theme massively
Livelihood of the fishermen in Monirampur Upazila of Jessore district, Bangladesh
The study was conducted to assess the livelihood of fishermen in Monirampur Upazila of Jessore district from July to December, 2012. The mean age and fishing experience of fishermen were 35.22±9.67 and 17.9±7.12 years, respectively. Primary occupation for majority fishermen (90%) was fishing. The mean monthly income of the household (HH) was BDT 9470±4806.89. Only 2% fishermen were landless. 4% fishermen had training on fishing/fish culture. 46% fishermen involved in NGOs for loan and savings. 52% fishermen cultivated paddy during boro (summer) season whereas only 18% cultivated paddy during aman (rainy) season. Major protein sources to the HHs (monthly) were- small indigenous species (SIS) (4.60±2.64 kg), non-SIS (6.31±4.18 kg), meat (3.54±1.67 kg), eggs (18.73±22.20 pieces), and milk (11.10±15.54 liter). The major HH expenditures were- food, education, health, furniture, cloths and others. All fishermen were vulnerable to vabadaha, a situation when water logging takes place during monsoon due to lack of sufficient water drainage system
Production and quality assessment of fish burger from the grass carp, Ctenopharyngodon idella (Cuvier and Valenciennes, 1844)
Fish burger was produced from grass carp (Ctenophygodon idella) to assess the feasibility of value addition to this low priced fish in Bangladesh. Different food additives (25% mashed potato, 2% NaCl, 2% soybean oil, 2% spices and 0.6% sugar) were used to enhance the consumer’s acceptance of the fishery product. Consumers' acceptance of the fish burger was determined by sensory evaluation based on its color, flavor, softness or firmness (S/F), chewy/rubbery (C/R) using 10 point scoring system by a group of 10 untrained judges (20-50 years old). The results were found as follows: color (7.25±1.15), flavor (6.67±1.17), S/F (8.47±1.20) and C/R (7.83±1.23). Evaluation of proximate composition showed that the moisture and protein contents in grass carp mince were 79.15±1.16 % and 18.01±0.44 % respectively which were higher than that of fish burger, 69.46±0.89 % and 16.42±0.57 %, respectively. Lipid (6.64±0.15 %) and ash (2.98±0.09 %) contents in fish burger were also higher than fish mince. The pH of fish mince and fish burger was 6.8±0.11 and 6.6±0.05 respectively. Therefore, from simple cost-profit analysis, it can be assumed that business of fish burger in Bangladesh has a very good prospect and it would be profitable
Management and socio-economic conditions of fishermen of the Baluhar Baor, Jhenaidah, Bangladesh
This study was conducted on the management of the Baluhar Baor and fishermen’s socio-economic conditions of the baor in Jhenaidah district, Bangladesh. Data were collected by interviews, FGDs and CIs with key informants. This baor was managed under Oxbow Lake Project-1 of Department of Fisheries of Bangladesh government. Hypophthalmichthys molitrix, Labeo rohita, Catla catla, Cirrhina cirrhosus, Cyprinus carpio and Ctenopharyngodon idella were commonly stocked at the composition of 34%, 13%, 12%, 12%, 15% and 14%, respectively. Kochal, komor and chack fishing were used for harvesting and yearly production was 750 kg/ha. While studying the socio-economics, 58% fishermen were lived in joint families. 78% fishermen used kancha sanitary latrine which reflects their poor hygienic condition but they used tubewell for drinking water. 58% fishermen were with 0.041 hectare lands and 74% lived in kancha house. The annual income varied from BDT 15,000 to 60,000. Education level was found very low and only 18% completed their primary education. Majority fishermen (82%) visited village doctor for health services due to low income and lack of knowledge. All fishermen were fully dependent on baor fishery for their livelihood. It is possible to uplift their socio-economic by managing the baor with improved technology