Owolabi Olufemi D
Department of Zoology, University of Ilorin, P.M.B. 1515, Ilorin 240003, Nigeria.
Pak J Biol Sci. 2007 Oct 15;10(20):3644-9. doi: 10.3923/pjbs.2007.3644.3649.
The influence of size, sex and season on the feeding regime of S. membranaceus were examined over a period of 24 months in Jebba Lake, Nigeria using frequency of occurrence, numerical, gravimetric and index of Relative Importance (RI) methods. Dietary composition and feeding intensity were sex dependent. RI established that there was a progression from a detritivorous diet in fish below 20 cm Standard Length (SL), through a transitional planktivorous phase (20-27 cm, SL), to a predominantly molluscivorous/insectivorous diet in fish above 27 cm SL; thus indicating a switch from a relatively passive filter-feeding habit when young to an active predatory habit at adult stage. Food preference also varied with season hence intraspecific competitions were low. Abundant food and ability to evolve trophic strategies that ensure optimum foraging in spite of seasonal changes enable S. membranaceus to maintain its overwhelming prominence and wide distribution in Jebba Lake.
在尼日利亚杰巴湖，通过出现频率、数量、重量和相对重要性指数（RI）方法，在24个月的时间里研究了体型、性别和季节对膜质丽脂鲤摄食方式的影响。饮食组成和摄食强度取决于性别。RI确定，标准长度（SL）低于20厘米的鱼的饮食从碎屑食性开始，经过一个过渡性的浮游生物食性阶段（SL为20 - 27厘米），到SL超过27厘米的鱼以软体动物/昆虫为主要食物；因此表明从幼鱼期相对被动的滤食习性转变为成年期主动的捕食习性。食物偏好也随季节变化，因此种内竞争较低。丰富的食物以及尽管有季节变化仍能进化出确保最佳觅食的营养策略的能力，使膜质丽脂鲤在杰巴湖保持其压倒性的优势和广泛分布。
