ISSN:
1573-5117
Keywords:
Sudan
;
abundance
;
breeding
;
sex-ration
;
Tilapia
;
Labeo
;
White Nile
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Seasonal abundance, maturation and sex-structure were studied in populations of T. nilotica and L. niloticus in the Jebel Aulia reservoir and in the White Nile below the dam. L. niloticus showed a single annual breeding cycle from mid-July to December and was most abundant in October in the lake, and in early November in the river. T. nilotica showed two distinct annual seasons of abundance: summer (April to June) and autumn (November to October). Spawning activity was highest in summer (April to June) and autumn (late July to September). The sex-ratio varied inversely with age (size); males were predominant in populations of older fish, perhaps because of their greater endurance to adverse conditions as evidenced by their better survival in hypoxic water.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00025800
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