Studies on distribution and sex ratio of Notopterus notopterus in the aquatic bodies in and around Gulbarga.

S. V. Sathish; R. S. Kulkarni

Volume : III, Issue : XII, December - 2014

Studies on distribution and sex ratio of Notopterus notopterus in the aquatic bodies in and around Gulbarga.

S. V. Sathish, R. S. Kulkarni

Abstract :

Distribution, frequency of various maturity stages and sex ratio were studied in freshwater fish Notopterus notopterus in the three selected aquatic bodies near Gulbarga. The percentage of fish catch and the frequency of fishes in different stages in the aquatic bodies (1 & 2) is slightly variable, no fishes were noticed in aquatic body 3, which is productive. The study reveals that male to female ratio was almost 1:1.1 in both aquatic bodies (aquatic body-1 and 2) indicating a slight domination of females. The analysis of chi-square values obtained for each month in both aquatic bodies revealed �no significant� departure from ratio 1:1. However some variation was noticed during the months of April and October in both aquatic bodies. Five maturity stages were identified on the basis of gonad condition. N. notopterus is supposed to be the fractional spawner, which is suggested by the relative availability of all the five stages during April and August. GSI values are drastically increased from January and reaching maximum during Feuary-July. The gradual depletion was noticed from August. The OSI data indicates that vitellogenic oocytes are produced between January- Feuary and June-July. The matured eggs are spawned in March and August respectively in both the aquatic bodies. No fishes were found in aquatic body-3.