Feeding Habits of Polynemids: Polydactylus Quadrifilis, Galeoides Decadactylus, and Pentanemus Quinquarius of the Continental Shelf of Grand-Lahou, Côte d’Ivoire

Abstract

This paper focuses on the threadfins Polydactylus quadrifilis, Galeoides decadactylus, and Pentanemus quinquarius captured by the maritime traditional fishing of Grand-Lahou in Côte d'Ivoire. It aims to determine their feeding habits based on weighing, measuring of body, and intestine height and identification of prey. The specimens of Polydactylus quadrifilis with height lower than 55 cm have an average of 12±1 intestinal filaments, whereas those of height higher than 100 cm have an average of 20±2 of them. This average is constant concerning Galeoides decadactylus (12±2) and Pentanemus quinquarius (11±2), for all height. The specimens of Polydactylus quadrifilis consume mainly fish (74.45%), followed by shrimps (10.06%). The juvenile ones of less than one year prefer shrimps (80.28%), whereas fish are preferred (87.07) by the older individuals. Whatever their age, Galeoides decadactylus and Pentanemus quinquarius mainly consume shrimps in the ratio of 83.11% and 68.75% respectively. The relative yearly food consumption reveals for Polydactylus quadrifilis a quantity of 0.124 T/Km2 /year, whereas that of Galeoides decadactylus is 0.02 T/Km2 /year. As for the specimens of Pentanemus quinquarius, they consume 0.013 T/Km2 /year. Threadfins have very short intestine (IC < 1) relatively to the intestinal coefficient. Their food habit is relating to stomach and intestine capabilities.