A Comparative Study of Feeding of Three Fish Species in the Southern Part of Al-Chibayish Marsh, Iraq

Abstract

Three species of fish Tigris asp (Leuciscus vorax) locally named " Shilluk "and Abu mullet (Planiliza abu) locally named "Khushani" and Blue tilapia (Oreochromis aureus) were collected from the Southern part of the Al-Chibayish marsh to study the composition of its natural food during the period from February 2014 to January 2015. Each species was divided into two-length group (1 and 2). Fishes consisted high percentage of Tigris asp food for both length groups, which reached 50% and 68% respectively. In contrast, sand and mud were of great importance in the food of Abu mullet that comprise 41% and 40% for the two length groups, respectively. The aquatic plant were most important in the food of blue tilapia at percentage of 56% and 50% for the two length groups, respectively. The highest feeding intensity (point/fish) reached by Tigris asp (11.30 and 13.50) during spring, for Abu mullet (10.52 and 8.08) during summer and autumn, whereas for Blue tilapia blue reached (14.82 and 12.66) in the spring and winter for the two length groups, respectively. However, feeding activity values differed according to month. The three species of fish showed a different specialization in the selection of their food components. The small individuals of the Tigris asp were narrowly specialized in food (0.27) while the large individuals were highly specialized (0.25), whereas Abu mullet and Blue tilapia showed narrow specialization (0.42 and 0.37) and (0.32 and 0.32) for the two length groups respectively.

Keywords

• Leuciscus vorax
• Planiliza abu
• Oreochromis aureus
• Natural food
• IRI