Effect of catfish supplementation on the fatty acid status and growth of undernourished rural preschool children under 6 years of age: An intervention trial in Lebowa, South Africa.

A group of 102 preschool children aged 13-69 months from a rural area of Lebowa were selected from a cross-sectional study of 659 children for an intervention trial (12 months) to study the effect of catfish (Clarias gariepinus) supplementation on their plasma phospholipid fatty acid status and growth. They were classified into undernourished and control groups according to their weight-for-age. The undernourished children (n = 52) received 43 g fish and 7.5 g sunflower cooking oil per day, whereas a matched (age and sex) well-nourished control group (n = 50) was not supplemented. At baseline, after 6 months and after 12 months of the study, anthropometry, haematology, blood biochemistry and plasma phospholipid fatty acid analyses were done. In the undernourished group, high baseline oleic acid (18:1 9) levels in plasma phosphatidylcholine (PC) were replaced by docosahexaenoic acid (22:6 3) with supplementation. In plasma PC, this reduction in 18:1 9 and increase in 22:6 3 was associated with significant increases in weight-for-age Z-scores, P = 0.0378 and P = 0.0415, respectively. The fish supplement and cooking oil that supplied additional 7% energy (7% E) and nutrients promoted growth of undernourished children, although this was inadequate for sustained growth during the second 6 months of intervention.

Treatment of Cyprinus carpio L. and Clarias gariepinus (Burchell) embryos with formalin and malachite green: effect of concentration and length of treatment on their survival.

Malachite green and formalin were investigated as prophylactic dip treatments for developing embryos of Cyprinus carpio and Clarias gariepinus. Based on the findings, recommendations are made on the respective concentrations to be used and exposure periods to be followed for both formalin and malachite green for both fish species.

Investigations into the effects of concentration and duration of exposure to formalin and malachite green on the survival of the larvae and juveniles of the common carp Cyprinus carpio L. and the sharptooth catfish Clarias gariepinus (Burchell).

Prophylactic dip treatments using formalin and malachite green were applied to 4-day old larvae and 12- and 20-day old juveniles of the European common carp, Cyprinus carpio and the African sharptooth catfish, Clarias gariepinus. Treatments consisted of 100 mg/l malachite green for exposure periods of 10, 30 or 90 s and 200 mg/l formalin, administered for 30, 60 or 90 min. Larvae and juveniles of C. gariepinus could be treated with 100 mg/l malachite green for 10 s, or with 200 mg/l formalin for 30 min, with minimum mortalities. Both chemicals affected the survival of the C. gariepinus juveniles, especially the 90 min exposure to formalin. Juveniles of both species were extremely sensitive to 100 mg/l malachite green concentrations.