African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12218

Full Length Research Paper

Cyclical changes in the histology of the gonads (ovary and testes) of African pike, Hepsetus odoe

Idowu, E. O.
  • Idowu, E. O.
  • Department of Zoology and Environmental Biology, Faculty of Science, Ekiti State University, Ado Ekiti, Ekiti State, Nigeria.
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  •  Received: 13 February 2017
  •  Accepted: 20 April 2017
  •  Published: 03 May 2017

Abstract

Morphology, stages of maturation and histology of gonads of African pike, Hepsetus odoe from Ado Ekiti Reservoir were studied from August 2014 to July 2015 in order to establish its reproductive biology. Out of 685 specimens examined 354 were males and 331 were females giving a sex ratio of 1:1.1 (female:male). There was no significant difference (P>0.05) in the sex ratio. The gonads were in pairs. All the gonad maturity stages were encountered in both male and female gonads. These stages were; immature, developing, mature (ripening), ripe and running, and spent.   Histology of female ovary showed that six stages were encountered in the oogenesis, namely, oogonium, primary oocyte, primary vitellogenic oocyte, secondary vitellogenic oocyte, tertiary vitellogenic oocyte and hyaline oocyte while in male spermatogenesis five stages were present which are; spermatogonia, primary  spermatocytes, secondary spermatocytes,  spermatids and spermatozoa   The oocyte diameter of H. odoe is higher when compared to freshwater fishes (the range was from 0.25 to 2.07 mean 1.74 ± 0.16 mm). All the five maturation stages occurred every month throughout the study period except the spent stage (stage V) which occurred only in October and ripe and running stage (Stage IV) which was absent only in December.  This indicates that H. odoe is a multiple spawner in the reservoir.

 

Key words: African pike, gonads, maturity stages, histology, oogenesis, spermatogenesis.