Food habits of catfish Plicofollis tenuispinis (Pay, 1877) in coastal waters of western Qeshm in the Persian Gulf

Feeding habits and feeding indices of catfish Plicofollis tenuispinis (Pay, 1877) in coastal waters of Qeshm island around Gouran region were studied during May 2016 to April 2017 by sampling 15 fish per month throughout one year. Mean value of fish fork length was 24.43 ± 2.52 cm. Relationship between fork length and total weight was determined as W=0.012 FL3.066, which considering the amount of b, indicates the isometric growth of P. tenuispinis. The highest amount of gastrosomatic index was in spring and the lowest was in winter revealing that the highest feeding intensity was in spring for this species in coastal waters of western Qeshm island. Mean value of vacuity index was calculated 35.01 ± 15.91 for this species that ranks this species as a relatively edacious species. Season based analysis of VI data indicated that the lowest amount of VI or the highest number of full stomachs was in spring. Evaluation of food preference index showed that fish, shrimp, bivalves, crabs, mollusks and algae constituted 52.45, 21.31, 5.73, 4.91, 3.27 and 0.81 percent of stomach contents, respectively. Therefore, fish were the main and shrimps were the second prey priority. Crabs, bivalves, mollusks and algae were the accidental preys consumed by this species. Index of relative length of gut was 2.08± 0.26 indicating that P. tenuispinis is omnivorous in coastal waters of western Qeshm island.