Aspects of the trophic ecology of Liza falcipinnis (Valenciennes 1836) (Pisces: Mugilidae) in the Cross River Estuary (Nigeria)

Abstract

Aspects of the trophic ecology of Liza falcipinnis (Valenciennes) were studied in the Cross River Estuary (CRE) east of the Niger Delta (Nigeria). The trophic spectrum showed that L. falcipinnis fed on a wide variety of food resources. From the index of relative importance (IRI), L. falcipinnis fed primarily on diatoms, FPOM, mud, sand, secondarily on CPOM, prey fish, green algae and blue-green algae while free living nematodes, macrophyte matter, microarthropods and dinoflagellates were incidentally ingested. The spectrum of food dominance ranked on the basis of IRI showed algae > detritus (FPOM + CPOM) > sediments (mud + sand) > prey fish. L. falcipinnis demonstrated monthly/seasonal dynamics in food preferences with greater food richness in the wet season. Monthly plasticity in the indices of stomach fullness showed the presence of food in the stomach every month. L. falcipinnis from CRE may be described as algivore-detritivore feeder. The wide food spectrum shows high trophic flexibility.

Key words: Trophic status, estuary, Liza falcipinnis, seasonal variation.

Journal of Aquatic Sciences Vol.20(1) 2005: 53-62