Abstract:The present study deals with the estimation of fecundity and induced breeding of Mystus vittatus by using carp PG hormone. Four different doses were tested, viz. 6, 8, 10 and 12 mg/kg body weight for female and 3, 4, 5 and 6 mg/kg body weight for male. For each dose, three different sex ratios were maintained, viz. 1♂: 1♀, 2♂: 1♀ and 3♂: 2♀. The hormone doses 8 mg/kg for female and 4 mg/kg for male provided the best result in the sex ratio 2♂: 1♀. This treatment combination revealed 80% fertilization and 56% hatching rates. Mean survival percentage of the spawns up to 10 days was 60%.mvi-ms ‡ ¶ct †Usiv gv ‡Qi wW ‡gi cwigvY wbY© q Ges wcwR ni ‡gvb w` ‡q G ‡`i K… wÎg cÖ Rbb NUv ‡bv eZ© gvb M ‡elYv Kv ‡h© i mv ‡_ m¤úwK© Z Pvi ai ‡bi wewfboe gvÎvq ni ‡gvb cÖ ‡qvM Kiv nq †hgb, ¯¿ x gv ‡Qi Rb¨ ˆ`wnK IR ‡bi 6, 8, 10 I 12 wgtMÖ vt/ †KwR Ges cy i"l gv ‡Qi Rb¨ 3, 4, 5 I 5 wgtMÖ vt/ †KwR| cÖ wZ gvÎvi R ‡b¨ wZb ai ‡Yi †hŠbvby cvZ e¨envi Kiv nq †hgb -1♂: 1♀, 2♂: 1♀, 3♂: 2♀| 2♂: 1♀ †hŠbvby cv ‡Z, cy i" ‡li Rb¨ ˆ`wnK IR ‡bi 4 wgtMÖ vt/ †KwR Ges ¯¿ x gv ‡Qi Rb¨ ˆ`wnK IR ‡bi 8 wgtMÖ vt/ †KwR gvÎv me ‡P ‡q fvj djvdj †`q| GB wUª U ‡g›U †_ ‡K 80% dvwU© jvB ‡Rkb Ges 56% n¨vwPs cvIqv hvq| 10 w`b ch© š-gv ‡Qi †cvbv †eu ‡P _vKvi Mo wQj 60%|

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Genetic variation is a key component for improving a stock through selective breeding programs. Randomly amplified polymorphic DNA (RAPD) marker was used to assay genetic variation in two river populations (Halda and Padma) as well as in three hatchery populations of the commercially important Indian major carp, C. catla. Five specimens of each population were collected from each location. Genomic DNA was isolated from the muscle tissue. Five primers were used and in total, 117 bands were obtained of which 51.57% bands were polymorphic. Overall proportions of polymorphism obtained from different populations were found to be 75%, 62%, 50%, 37.5% and 33.33% for BoluharBaor hatchery, Halda and Padma River, Kapotakkha hatchery, and Ma-Fatema hatchery respectively. The highest percentage of intrapopulation genetic similarity was found to be 61.81% in case of Baluhar Baor hatchery and the lowest was found to be 25.63% in case of Kapathakha hatchery. The highest percentage of interpopulation genetic similarity was found to be 85.21% between Kapathakha and Ma-Fatema hatchery population; and the lowest was found to be 46.00% in case of Kapathakha and BaluharBaor hatchery population.  The dendrogram on Average Unweighted Pair Group Method of Arithmatic Mean (UPGMA) showed two clusters, the Halda River and BaluharBaor hatchery population forming one cluster and the other populations the second cluster. Genetic variation obtained in different population of C.catla in the present study is highly satisfactory and indicates that the species can be very easily employed for exploitation for genetic improvement through selection.DOI: http://dx.doi.org/10.3126/10.3126/ijls.v9i1.11924 International Journal of Life Sciences Vol.9(1) 2015 37-42

The paper describes the characterization of water quality of Sundarbans Mangrove Forest of Bangladesh. Water samples of 28 stations, selected from the four major river systems of Sundarbans were collected. The sampling period was from January 2001 to July 2001. The values of ten water quality parameters, such as Temperature, Conductivity, pH, Alkalinity, Free CO2, Salinity, Dissolved Oxygen (DO), Total Suspended Solid (TSS), Hardness and Chemical Oxygen demand (COD) were measured. The values of the parameters obtained indicate that the Sundarbans aquatic habitat is at suitable range for aquatic species.

Bata (Labeo bata), an indigenous, freshwater minor carp, is a great delicacy in Bangladesh. In its natural fishery, bata contributes significantly to the health and nutritional security of a large section of the fisher communities in Bangladesh. However, it is not a popular farmed fish because of its small size and slow growth rate. The induction of triploidy, aimed at providing faster growth and larger body size, could be appropriate for L. bata to enhance its aquaculture potential. In the present study, we induced triploidy in L. bata by applying heat shock on fertilised eggs (that were maintained at the ambient temperature of 26-28 • C), 3 to 5 min post fertilisation and for durations ranging from 1 to 2 min. Four different temperatures, namely, 38, 39, 40 and 41 • C, were tested as heat shock treatments. The optimum treatment combination for triploidy induction in L. bata was found to be 39 • C for the 1 min duration, 3 min after fertilisation, yielding 100% triploidy. Karyotyping revealed 72 chromosomes in the triploid fish (3n), whereas the diploid control (2n) had 48 chromosomes. The growth performance of the triploid hatchlings was compared against the diploid control in experimental ponds.After 12 weeks of rearing, the triploid fish were significantly heavier (p < 0.05) than their diploid counterparts. The survival rate of the triploids was also better (69%) than that of diploids (56%). Overall, results revealed better performance (growth and survival) of triploid bata over diploids, indicating that the farming of triploid bata can be a viable practice in Bangladesh.