Intestinal absorption by Sarotherodon galilaeus (syn Tilapia galilaea ) of Lake Kainji, Nigeria

Carbohydrates, protein, lipid and crude fibre were found to reduce in amount from the anterior to posterior regions along the gut of Sarotherodon galilaeus collected from Lake Kainji. Different regions of the gut exhibited different absorptive powers and all the compounds were differently absorbed in amount. Different sizes of fish showed different absorptive capacity

Absorption of food in the black-jaw tilapia, Sarotherodon melanotheron (Ruppell) from a small tropical man-made lake in Ibadan, Nigeria

The carbohydrate, protein and lipid contents of the food ingested and their absorption in the intestine of Sarotherodon melanotheron inhabiting Awba lake in Ibadan, Nigeria, were investigated. Total carbohydrates of the ingested food ranged from 39.33 to 55.38% (mean = 48.70% while total protein and total lipid ranged from 10.10 to 17.13% (mean = 12.91%) and 7.79 to 8.96% (mean = 8.28%) dry weight, respectively. Calculated total percentages absorbed were 54.86-62.01 (mean 58.07) carbohydrates 47.33-54.06 (mean = 50.43) protein and 43.27-52.23% (mean 46.56) lipid. Absorption of protein and carbohydrate occurred mostly in the fore-gut (the first one-third of the intestine), while lipid was mostly absorbed in the mid-gut (the second one-third of the intestine). Dietary carbohydrate, protein and lipid contents of the food as well as the absorptive capacity of the intestine for these components of the food varied with size of fish

On the results of preliminary fishing trials with shark long lines in Veraval waters

Experimental fishing operations with shark long lines were conducted in the sea off Veraval with a view to studying their efficiency and gathering information on the available resources of sharks to be used for planning the future gear investigations. The trials were undertaken in 1967, employing departmental fishing vessel "Fishtech No. IV" (10.9 m O.L. and 48 H.P. engine). A total of 5525 hooks were employed and 242 sharks weighing 8629 kg were landed. Data on composition of catch, weight of fishes landed, effectiveness of various baits in capture of different species of sharks and effectiveness of gear including its catch efficiency in this area were compiled. Bait preference was also observed in certain species of sharks caught. Chirocentrus dorab proved to be the cheapest and most effective bait in capture of all the three varieties of sharks landed.

On the results of bottom-drift-long-lines operated off Veraval with particular reference to selective action of baits and hooks used

Hither to comprehensive data on the various types of baits used for capture of predatory fish and selective action of different hooks for bottom-drift-long lines is conspicuous by its absence. In the present studies attempts were made to evaluate the effectiveness of three types of baits and four sizes of hooks. Significant results obtained during the course of these investigations are presented in this communication.