Evaluation of some feeding indices of Pomadasys kaakan in the Northern Persian Gulf

  In this paper the Vacuity Index (VI), Fullness Index (FI) and Food Preference Index (FPI) for the stomach contents of Pomadasys kaakan were evaluated to assess the quantity and kind of food which this fish consumes in the Persian Gulf. A total of ۲۲۷ specimens were collected from fishing trawlers or landings from November ۲۰۰۵ to September ۲۰۰۶. ۲۴.۷% of stomachs were full, ۱۱.۹% were semi-full and ۶۳.۴% were empty. The seasonal average of VI was ۷۷.۴, ۴۴.۶, ۸۰.۰ and ۵۴.۰ % for autumn, winter, spring and summer, respectively. The overall FI was ۳۶.۶ with seasonal averages of ۲۲.۶, ۵۵.۴, ۲۰.۰ and ۴۶.۰ in autumn, winter, spring and summer, respectively. The main stomach contents were crustaceans (esp. crab & shrimp), fish, mollusks (bivalves, gastropods and cuttlefish), stomatopoda, brittle stars, Lingula sp. and sea weeds. The estimated FPIs for crustaceans were ۷۷.۷, fish ۳۲.۱, mollusks ۲۸.۶ and echinoderms ۱۸.۸ %. Overall, the results show that this fish is a relatively frugal species which consumes crustaceans as main food and has adopted itself with ecological changes of the Persian Gulf.

Keywords:

Pomadasys kaakan , Feeding , Food Preference , Vacuity and Fullness Indices , Persian Gulf