University of Khartoum

Investigations into the Growth and Reproduction of Synodontis schall (Bloch - Scbneider, 1801) From The White Nile.

Investigations into the Growth and Reproduction of Synodontis schall (Bloch - Scbneider, 1801) From The White Nile.

Show full item record

Title: Investigations into the Growth and Reproduction of Synodontis schall (Bloch - Scbneider, 1801) From The White Nile.
Author: Abd Elhalim, A. I.
Abstract: In this study, a total of 631 specimens (311 females and 320 males of Synodontis schall were studied. Growth patterns were investigated through Lengt.h-we Lght and length-age relationships. AGeing :celiabili ty through the use of certain bone structures such 2S opercula and vertebrae was c onf i rmed , Grovvth rings wer-e also found to be laid annually on those bones. Back-calculated Leng t hs for the first growth ring were calculated and compared with observed lengths for the same age . .§. schall spawns in July/August, once a year, and se a scn al. charige s in gonad s were studied tllroll.gh inve s t> igation of water and ash content as well as gOl1osomatic indices. Both absolute and relative fecundities vlere investigated and maximum and minimum numbers of eC~3s per inclividual described. Highly correlated predictive equa t i ons wer e described for the relationships between absolute fecundity with length, age, weight and ovary V/eight. Ver.i at.i ons in the egg-diameter during the breeding ae a aori )18r2 f oLl owed; and the morphological changes in the Gon.::ds ( males cnd females) described for all stages of matur. ty and Lrmatu i-Lty ,
URI: http://hdl.handle.net/123456789/599
Date: 1983


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account