Effects of Food and Feeding Habits on Proximate Composition of Silver Catfish, Chrysichthys nigrodigitatus (Lacepede) from the Fresh and Brackish Waters of Akwa Ibom State, Nigeria
Essien, A. I., Joseph, I. I. & Christopher, P. R.
Department of Science Technology,
Akwa Ibom State Polytechnic, Ikot Osurua, P.M.B 1200, Ikot Ekpene, Nigeria
Email: anthonyessien44@gmail.com
Corresponding Author: Essien, A. I.
ABSTRACT
The food, feeding habits and proximate composition of silver catfish, Chrysichthys nigrodigitatus were investigated between February –April, 2017 from artisanal catch landings of the freshwater environment of Itu River and brackish water creeks of Oron in Akwa Ibom State using standard analytical procedures that established the dietary spectrum and nutritive profiles of the fish type. The freshwater catfish samples recorded mean food items of Euglena sp (2.51%) Paramecium sp (10.25%) for Bluegreen algae/cyanophyceae, Spirogyra sp (20.512%) for green algae/chlorophyceae, Asterionella sp (2.564%) for diatoms/Bacillariophyceae while Arthropoda had for Crustacea: Palaemon sp (2.564%); Insecta: Hemiptera (2.564%) and Cladocera: Moina sp (4.025%) and Bosmia sp (10.256%). Rotiferans were totally absent in the dietaries, while sand, mud, detritus and unidentified food items occurred in small proportions. The brackish water samples revealed Euglena sp (7.142%) and Paramecium sp (14.285%) as bluegreen algae/cyanophyta; Spirogyra sp (7.142%) for green algae/chlorophyceae; Keratella sp (7.142%) for Rotifera; Navicular sp (7.142%) as diatoms/bacillariophyceae; while Arthropoda had Moina sp (14.285%) and Bosmia sp (14.205%) in Cladocera; Arstacus sp (7.142%) and Palaemon sp (7.142%) as Crustacea; and Insecta with Orthopera (7.142%). The freshwater samples maintained Moina sp and Spirogyra sp as primary diets; while the brackish water samples had Paramecium sp, Moina sp and Bosmia sp. The proximate compositions derived from the eight dietary materials of freshwater samples revealed a moisture content of (76.63±0.189%), crude protein (63.99±0.270%), crude fat (24.69±0.10%), ash (5.15±0.032%), crude fibre (3.46±0.035%) and carbohydrate (3.05±0.656%), while caloric value was 490.37±2.458kcal. The brackish water samples which fed on ten food items recorded a moisture content of 77.18±0.061%, crude protein (65.16±0.104%), crude fat (23.69±0.056%), ash (5.21±0.010%) and crude fibre (3.55±0.21%). Carbohydrate content and caloric value were 2.39±0.061% and
483.42±0.222kcal respectively. The presence of sand, mud, detritus and unidentified food items in the guts beside other dietary food organisms showed that Chrysichthys nigrodigitatus from both aquatic environments is a benthic omnivore with bentho-pelagic (swimming) ability to gather food materials from the bottom sediment to the water column. Also, the higher proximate values recorded in the study suggest that the brackish water catfish samples of Oron are more intritively richer in food values than the same fish type from the freshwater environment of Itu especially as nutrients richness of the habouring (aquatic) media largely influence proximate contents, growth tendencies, meatiness and marketability of any aquatic outputs used as food.
Keywords: Food, feeding habits, proximate composition, Chrysichthys nigrodigitatus, freshwater, brackish water.
