Annual Ovarian cycle of Mastacembelus armatus (Lacepede) from the Dimna Lake, Jharkhand (India)

Sushant Kumar Verma^a*, Abdul Alim^b & Thakur Das Murmu^c
aResearch fellow, Dept. of Zoology, Co-operative College, Jamshedpur
^b Dept. of Zoology, Co-operative College, Jamshedpur, Ranchi University, Ranchi
^cResearch fellow, BRNS project on Biodiversity, Co-operative College, Jamshedpur

Received 17th May, 2009: Revised 3rd August, 2009

Abstract : Gono somatic index (GSI), gonadal histology, and ova diameter were analyzed for one year to determine the reproductive cycle of female Mastacembelus armatus (L.) Monthly observations of these parameters indicate its marked seasonal cycle with a single breeding peak in a year which extends from late july to September. Average GSI value of female Mastacembelus armatus was found to range from 2.113 ± 0.88 to ± 1.86. The highest GS1 value was obtained in August. On the basis changes in gonosomatic index, ova diameter and development stages of oocytes the ovarian cycle of  Mastacembelus armatus can be divided into resting phase(December, January and february), early maturation phase(march and april), advance maturation phase(may), prespawning phase(june and early july), spawning phase(late july, august and September)and postspawning phase(october and November)