Asian-Pacific Aquaculture 2019

June 19 - 21, 2019

Chennai Tamil Nadu - India

EVALUATION OF SEASONAL REPRODUCTIVE MATURITY OF GOLDEN MAHSEER Tor putitora IN RELATION TO CHANGING TEMPERATURE AND THYROID STATUS

Debajit Sarma*, Annu Sharma and Prakash Sharma
ICAR-Directorate of Coldwater Fisheries Research, Bhimtal
Email: dsarma_sh@yahoo.co.in
 

Sexually matured male and female golden mahseer (Tor putitora) were taken for studying the seasonal dynamicity of gonadosomatic (GSI), viscerosomatic (VSI) indices, gonadal status, nutritional status at liver and renal thyroid follicles. At least five numbers of mature male and female fishes were sampled in summer, monsoon, pre-winter and winter. Values of GSI and VSI calculated for individual fishes, and gonad, liver and kidney were processed for histology. The values of VSI in females were found in the range from 4.3 to 5.4, lowest in pre winter and highest in winter; and in males, it was found in the range of 3.4 (summer) to 8.1 (winter). The trends of GSI values in both male and female were found to be similar, increase from summer to monsoon and then decrease in pre-winter, followed by one more rise in winter. In female gonads, the compositions of oocytes, especially cortical alveoli and vitellogenic were found to be associated with GSI values. In males as well, GSI values were found to be linked with gonadal status; regression in pre-winter, initiation of spermatogenesis in winter and full of spermatozoa in following seasons. In the case of hepatocytes density, highest value in female was recorded in pre-winter. However in male, highest was recorded in summer and lowest in winter. Seasonal dynamics of renal thyroid follicle densities were found to be different in male and female; in pre-winter, highest value in male and lowest value in female were recorded. In male, the highest number of renal thyroid follicles in pre winter is perhaps due to their role in male gonadal recruitment. The present work on seasonality of male and female reproductive status, renal thyroid follicle and liver nutritional status is the first report on golden mahseer, and this information is valuable for future research in reproductive biology of this and other related species.