Aspects of the biology of the characid Anoldichthys spilopterus Boulenger (Osteichthyes: Characidae) in the River Jamieson, Delta State, Nigeria

  • R. B. Ikomi Department of Zoology, Delta State University, Abraka, Nigeria

Abstract

Data on the abundance, distribution, growth, dietary patterns and reproduction of the characid Anoldichthys spilopterus in the River Jamieson, Nigeria, are presented. A spilopterus constituted 13.8% of the characid catch and was captured throughout the year with peak abundance during the dry season. It attained a maximum standard length of 9.0 cm and weighed of 18.5g. The growth in length relative to weight was allometric. The condition factor ranged from 2.01 - 2.76 and was generally inversely related to increase in fish length. The condition factors were higher during the wet season than in the dry season. A. spilopterus was a mesopredator feeding essentially on a variety of allochtonous insects, with fish, plant seeds and detritus supplementary to the diet. It was primarily a day feeder with no clear qualitative variation in feeding habit with size. A. spilopterus is a one-time spawner, breeding between June and September. Fecundity estimates ranged from 100 to 380. Average GSI value was 1.83%.

KEY WORDS: Anoldichthys spilopterus, characid, abundance, distribution, food, feeding habit, growth pattern, breeding, Nigeria.

Tropical Freshwater Biology 10 (2001) 57 – 74
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Articles

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eISSN: 0795-0101