85-88
Diets of Halfbeak Hemiramphus lutkei (Valenciennes, 1847) from Karachi Coast, Pakistan
Authors: SadafTabassum, Farzana Yousuf, Naeema Elahi, Md. Mosaddequr Rahman, Md. Yeamin Hossain
Number of views: 369
Objective: To investigate the diets of the Lutke ’s halfbeak, Hemiramphus lutkei (H. lutkei) to
determine the food and feeding habits.
Methods: Samples of H. lutkei were collected from the landing sites of Karachi Coast, Pakistan.
Total length was measured to the nearest 0.01 cm using digital slide calipers, and total body
weight was measured using an electronic balance with 0.01 g accuracy. The dietary composition
was determined from gut content examination and analysis was done using frequency of
occurrence and numerical methods. To assess the changes in diet with size, H. lutkei were
divided into two size groups, Group 1: 14-20 cm (n=250) and Group 2: 21-25 cm (n=160).
Results: The total length and body weight of the sampled specimens ranged from 14 to 25 cm and
10 to 23.5 g, respectively. Out of the studied specimens, 45.12% fish stomachs were found to be
empty. Dietary composition revealed daphnia, small fish, isopods, unidentified animal materials,
ostracods and unidentified plant materials in the gut contents of Lutke ’s halfbeak. Therefore, H.
lutkei is omnivore fish feeding on algae, zooplankton, small fishes and different food items of both
plant and animal origin. According to the Schoener overlap index (C), there was no significant
difference in feeding of the two length groups of H. lutkei (C=0.833). On the other hand, the
Shannon-Wiener index showed that the prey diversity of the Lutke's halfbeak in Group 1 was
lower (H/=1.545) than that of Group 2 (H/=1.653).
Conclusions: This study reports the first description of diets for H. lutkei, which would be useful
for the sustainable management of this fishery in the coast of Pakistan and also neighboring
countries.