Masculinization of African Catfish (Clarias gariepinus) Treated with Gokshura (Tribulus terrestris)

The present paper describes the effects of Tribulus terrestris, a masculinization agent, on the sex reversal of African catfish, Clarias gariepinus. One-day-old hatchlings were immersed in water containing an extract of T. terrestris at a rate of 0, 3, 6, or 9 g/30 l water for 30 days. The 9 g treatment resulted in 80.42% male populations. Morphological and histological examinations of the gonads in all groups revealed no intersex fish. Histological examination of fish treated with T. terrestris revealed no damage to the testes or ovaries. Despite differences in sex ratio, growth rate, ovaries, and testes, fish treated with T. terrestris were histologically similar to fish from the control groups. Survival ranged from 72% in the 3 g group to 80% in the 9 g during treatment and did not significantly differ from the control (p>0.05). The best growth was obtained in the 9 g treatment. Introduction Tribulus terrestris L. (Zygophyllaceae), also called gokshura, is a medicinal herb used in Bulgaria, eastern Europe, the Far East, China, and India to treat sexual deficiencies (Bucci, 2000). Tribulus terrestris has been reported to enhance libido sexualis, increase testosterone and LH levels, improve athletic performance, and increase the number and motility of spermatozoa (Adimolja, 2000; Bucci, 2000; Gauthaman et al., 2002). Tribulus terrestris contains a number of substances known as steroidal saponins. The saponin in T. terrestris thought to be responsible for its effect on testosterone levels is known as protodioscin (Adimolja and Adaikan, 1997; Ganzera et al., 2001). It is believed that T. terrestris affects androgen metabolism, significantly increasing testosterone or testosterone precursor levels (Neychev and Mitev, 2005). Oral administration of T. terrestris increased sexual behavior in male rats (Gauthaman et al., 2003) and had a proerectile effect on rabbits (Adaikan et al., 2000). * Corresponding author. Tel.: +90-326-2455816, fax: +90-326-2455817, e-mail: [email protected]