The effects of diet and temperature on enzymes, hormones, and fecundity of the African Catfish Clarias gariepinus (Burchell 1822)

Abstract

The aim of this study was to check the effect of multiple temperatures and various protein diet formulas on liver enzymes, gonadotropins, and growth hormone (GH) using African catfish Clarias gariepinus. C. gariepinus was exposed to multiple temperatures (T 24°C , T 28°C , and T 32°C ) and various protein diet formulas: D 1 (fishmeal-based diet), D 2 (soymeal-based diet), and D 3 (pea-meal based diet). Tilapia commercial feed (D 4 ) was used as reference diet. A total of 720 individuals with an average weight (101-104 g) were stocked at a density of 20 individual fish per tank in 12 tanks of three replicates. Liver enzymes, gonadotropins, GH, and fish fecundity were measured after 16 weeks. The results revealed that liver enzyme like glutamate-oxaloacetate transaminase was significantly (P < 0.05) lowered at T 28°C : D 2 diet, while glutamic pyruvic acid transaminase was lowered by T 28°C : D 4 diet. However, no effect was observed on creatinine (P > 0.05) at any experimental condition. Follicle-stimulating hormone and luteinizing hormone were significantly (P < 0.05) increased at T 28°C : D 1 diet and T 32°C : D 1 diet, respectively. GH was significantly (P < 0.05) increased by T 28°C : D 1 . The relative weight of the ovary of C. gariepinus was significantly (P < 0.05) increase at T 32°C : D 1 , while the testis relative weight was increased with T 24°C : D 3 . The result from this study revealed that there is a direct relationship of temperature on fish fecundity, enzymes, and reproductive hormones in C. gariepinus. The temperature of 28°C along with fishmeal or soy-meal positively improved the fecundity and health of fish.

A Comparison of the Physiological Responses to Heat Stress of Two Sizes of Juvenile Spotted Seabass (Lateolabrax maculatus)

“…ALT and AST are secreted and expressed by the liver and are usually released into the blood in small amounts [16]. Previous studies on puffer fish Takifugu obscurus and Wuchang bream Megalobrama amblycephala Yih showed that the activities of ALT and AST were increased sharply after heat stress, and the liver was damaged [39,40].…”

“…Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are mainly found in the liver, and damage to the liver causes them to be released into the blood in large amounts [15]. Therefore, the levels of ALT and AST are important indicators to check whether liver function is normal [15][16][17].…”