Diet and feeding ecology of black-barred halfbeak Hemiramphus far(Forsskal, 1775) (Hemiramphidae) from Karachi coast of Pakistan

Objective:To describe the diet and feeding ecology ofHemiramphus far (H. far) through investigating the stomach contents. <br> Methods: Sampling of total 430 individuals ofH. far was carried out from commercial catches landed at West Wharf fish harbor of Karachi coast, Pakistan during January–December 2010. The total length and weight of each individual were recorded. Samples were parted into Group 1 (15–20 cm,n = 240) and Group 2 (21–26 cm,n = 190), to estimate changes in diet with fish size. To remove alimentary canal, fishes were dissected and kept into 10% formalin. Then gut contents were examined under a light microscope for each intestine. Stomach fullness as well as dietary composition was ascertained from gut contents. Examination and analyses were conducted using frequency of occurrence and numerical method. <br> Results:The examination confirmed 47.67% stomach as empty. Furthermore, our study revealed that the diet ofH. far consists of fishes, isopods, ostracods,Daphnia, shells, algae, unidentified plants and animal materials. This study proved thatH. far is an omnivorous fish feeding on fishes, isopods, shells, algae and plant and animal originated different food items. According to the Schoener overlap index, there was no significant difference in feeding of the two length groups ofH. far (C = 0.833). In addition, the Shannon-Wiener index presented that in Group 1, the prey diversity of the halfbeak was lower (H = 0.90) than that of Group 2 (H = 1.02). <br> Conclusions: The findings of the present study would be very effective for sustainable management of black-barred halfbeak fishery in the Karachi coast of Pakistan and the surrounding ecosystems.

Morphological characters of Botia lohachata

Objective:To provide complete and informative description on morphometric characters i.e.,relationships between length-weight(LWRs)and length-length and meristic characters of Botia lohachata from the Ganges River,Northwestern Bangladesh.Methods:Samples were collected occasionally using different fishing gears from July 2015 to June 2016.For each individual,total 15 lengths were taken using digital slide calipers and body weight was measured using an electronic balance with 0.01 cm and 0.01 g accuracy,respectively.The LWRs was estimated using the formula:W=a×L^(b),where W was the body weight(g);L was the length(cm)and,a and b were LWRs parameter.The meristic data were counted using magnifying glass.Results:A sum of 110 individuals of Botia lohachata were hardly collected.Total length was varied from 3.70-6.80 cm and body weight was ranged from 0.55 to 2.80 g.The LWRs were highly correlated(P<0.001)with r^(2)values greater than 0.961.The calculated overall allometric coefficient(b)indicated negative allometric growth pattern(b<3.00,P<0.001).In addition,all length-length relationships were highly significant(P<0.001)and most of the r^(2)values were greater than 0.950.The fin formula was-dorsal,D.10-11(2-3/8);pectoral,P_(c).8-10(4-6/4);pelvic,P_(v).8(2-3/5-6);anal,A_(n).6-7(2/4-5);and caudal,C_(a).20-22(6-8/14-16).Conclusions:The findings of the present study will keep a crucial contribution to fisheries scientist in favor of identification of this fish,stock assessment and sustainable conservation in the Ganges River of Bangladesh and adjoining countries.Also,these results will impart valuable information for the FishBase,as well as provide an important baseline for further studies.