Effects of environmental enrichments on ovarian development of Buitta Catfish (Sperata sp.: Family Bagridae) in captivity

Abstract

Environmental enrichment (EE) is an important factor that helps improve both the physical and psychological behavior of farmed animals. This factor also controls social interactions and provides more stimulants to influence the reproductive performance of animals in captivity. As EE plays an important role in animal reproduction, the present study was designed to investigate the effects of different types of tank bottom enrichments on the ovarian development of Buitta (Sperata sp.) catfish in captivity. Barren (T_A), muddy (T_B), and sandy (T_C) enrichments were utilized for four months to observe the physical and psychological changes of the catfish. The results showed significant differences (p < 0.05) in the weight gain, gonadosomatic index (GSI), and hepatosomatic index (HSI) of the fish, however, no significant difference was found in the fish fecundity. The most prominent changes include weight, ripeness, the biochemical composition of body tissues, and the frequency distribution of the migratory nucleus in the oocytes. Moreover, the diameter of oocytes that occurred in the enrichment T_C (p < 0.05) was significantly higher than the enrichments T_A and T_B. Histological observation found at least two stages of the ovarian oocytes development process in each ovary indicating the asynchronous self-reproduction of the fish. Additionally, biological macromolecules analysis found higher protein content in the muscle (86.04%), liver (52.97%), and oocyte (64.71%) and a higher deposition of lipid within the oocytes (32.33%) and liver (27.06%) for enrichment T_C, while these values were lower for the other two treatments. Finally, the study suggests that a sandy environment should be used to obtain an acceptable level of oocyte development in the female Buitta fish in captivity.