No abstract

No abstract

The communication, dealing with the prevalence of protozoan parasites of the ornamental fish of West Bengal. During the study more than five hundred fish have been examined from five districts namely, Nadia, Hooghly, Howrah, North 24-pargana and South 24-pargana of West Bengal during pre-monsoon, monsoon and post-monsoon season. The study reveals that the intensity of infection is more in case of ciliate parasites. The highest ectoparasitic infection has been recorded during post-monsoon season, i.e. from November to February, followed by the pre-monsoon period while the lowest infection was recorded during monsoon i.e. from July to October which may lead to the conclusion that environmental factors are responsible for spreading infection.

A study was undertaken to evaluate the effect of stocking density on brood stock development of mud crab (Scylla serrate) in brackishwater earthen ponds. Four stocking densities such as 6000/ha (T 1); 8000/ha (T 2); 10000/ha (T 3) and 12000/ha (T 4) were tested and the crabs were allowed to fed with 50% slaughterhouse+25 percent tilapia (Oriochromis niloticus)+25% soft shrimp head. In terms of survival rate (both male and female) the stocking density having 6000/ha showed the best performance. For female crab significant lower survival (p<0.05) was observed for T 3 and T 4 compare to T 1 and T 2. But for final growth and carapace width, an insignificant variation was noted among the treatments. However, in case of T 1 and T 2 , 2.5-3.0 percent of females were found to became berried showing significant variation with other two treatments proved that high stocking has inverse effect on brood development.

No abstract