Written Paper

Aspects of the reproductive biology of Heterobranchus longifilis (Valenciennes, 1840) in the Idodo River Basin, Southeastern Nigeria  [1997]

Inyang, N.M. Anibeze, C.I.P. Mgbenka, B.O. (University of Nigeria, Nsukka (Nigeria). Dept. of Zoology)

استعراض النص الكامل

The maturation stages of the gonads, size at maturity, sex ratio and fecundity of Heterobranchus longifilis (Valenciennes, 1840) were examined on 320 specimens collected from the Idodo River, southeastern Nigeria from April 1991 to September 1992. Individuals with all stages of gonad maturation were collected throughout the year. The main spawning period based on gonad maturation occurred from May to September while a second period was in January and February. These periods coincided with the main rainy season and the short rainy season of the year, respectively. There was no significant difference (p more than 0.05) in the male:female ratio of the pooled sample. Fecundity ranged between 6001 to 51216 eggs per female (mean 24816 more or less 14676; weight of female, 374 more or less 297 g). Fecundity was highly and positively correlated with total length (r = 0.955), standard length (r = 0.937), body weight (r = 0.941) and ovary weight (r = 0.981) of the fish.


Journal of African Zoology (Belgium)

الرقم التسلسلي المعياري الدولي (ردمد) : 0776-7943