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

Aluminium in Fisch und Fischereierzeugnissen

Recent reports associating aluminium with several skeletal (osteomalacia) and neurological disorders (encephalopathy and Alzheimer’s disease) in humans suggest that exposure to aluminium may pose a hazard to health. This requires the examination of aluminiumcontent in different foodstuffs. Therefore, an analytical method for the determination of aluminium in fish and fishery products, especially in fishery products packaged in aluminium cans, was developed using graphite furnace atomic absorption spectrometry. Fillets of lean and fatty fish showed aluminium levels lower than 1mg/kg wet weight, muscle of crustacean, molluscan and shellfish had apparently higher aluminium levels (up to 20 mg/kg wet weight). The aluminium content in some aluminum-canned herring was much higher than the content found in herring caught in the North Sea. These results indicate that aluminium is taken up by the herring fillets in aluminium cans, presumably through the slight and slow dissolution of aluminium from the can wall, due to some defects in the protective lacquer layer. A comparison of the aluminium levels measured in canned herring with the average aluminium-intake (normally between 3 and 5 mg/day) or with the provisional tolerable daily intake of 1mg/kg body weight per day (WHO 1989) indicated, that the aluminium content of the edible part of aquatic food does not play a significant role. High consumption of fish fillets does not pose any health risk.