地理ジャーナルと自然災害
オープンアクセス

概要

Length-Weight Relationship, Condition Factor and Gut Content of Chrysichthys Furcatus Gunther, 1864 (Bagridae) from Cross River at Ahaha

Irom Okey*, Offem BO and Keremah RI

The study aimed to estimate the length weight relationship, condition factor and gut content of Chrysichthys furcatus a commercial important food fish in Obubra, central Cross River State. Monthly samples were collected for six month between May to October 2014. During the period a total of 187 specimens comprising of 125 females and 62 males were collected. The length - weight frequency distribution shows a total length ranged of 16 cm-60 cm and weight 50 g-549 g. The female fish have the highest length and weight frequency distribution except at weight ranged of 50 g-99 g where the males were more. Both sexes exhibited negative allometric growth pattern with an increased in length resulting to increase in weight of the fish. The condition factor (k) decreased with increased in the size of fish, why July and August recorded the least monthly condition factor. About 102 (54.55%) stomachs had some degree of food items in their guts with medium size specimens having the highest number of stomachs with some degree of food than small and large respectively. A total of 7 major categories with 27 food items comprising of animals, plants and detritus materials were identified. The sum total of 3,486 prey item with Cyclops (531) 15.24% constituting the most encountered while coleopteran (10) 0.29% was the least encountered prey. The most occurred prey item was detritus (100%) and Cyclops (98.12%) while the least coleopterans 3.67% with sand grains (11.44%) constituting the bulks of the gut content. The index of relative importance (IRI) reveals that Cyclops (1736.72), keretela (1394.82), tublex (1251.06), crustacean (1238.33) and crustacean eggs (1238.33) were the important and preferred prey item in the guts of C. furcatus. The ability of fish to capitalize on any available food items in the environment (euryphagous) is an important characteristic of culturable fish species. This implies that C. furcatus have brighter prospects for culture in ponds and proper species management and sustainability.