Effect of the Type of Pituitary Extracts and Dose of Synthetic Hormones HCG and Ovaprim on Some Reproductive Characteristics of the Endogenous Catfish of Cameroon Clarias jaensis (Boulanger, 1909) in a Controlled Environment

Aims: Improve the domestication of Clarias jaensis through fry production in a controlled environment.

Place and Duration of the Study: From April to August 2020 in Integrated Aquaculture Common Initiative Group of West in Batie (LN: 5°17'0''-5°18'53'' and LE: 10°17'0''-10°19'31''), Sudano-Guinean altitude zone of West Cameroon.

Study Design: 42 females and 15 males of respective weight and size: 177±40.46g, 347.62±111.72g, 29.02±1.74cm and 39.52±12.27cm were used and divided into 7 batches of comparable weights and sizes. Two randomly selected batches were subjected to the female pituitary extract of Clarias jaensis and Toads, five others to the synthetic hormones HCG (doses 3800 and 4000 IU/kg live weight) and Ovaprim (doses of 0.4, 0.5 and 0.6 ml/kg) respectively.

Methodology: Eggs were enumerated by direct observation after fertilization. At the end of the hatching (D1) and of vitelline resorption (D3), the larvae of each experimental lot were counted and measured.

Results: The mean diameter of the oocytes after induction, the relative and absolute fecundities and the fertility rate were higher in batches treated with the hormone HCG at a dose of 4000 IU/kg (2.12±0.1mm; 29,584±5,19 oocytes/g; 4694±620 oocytes and 80.14±9.78%), the lowest values were obtained with HCG at 3800 IU /kg, Ovaprim at 0.4ml/kg, pituitary toad extract and Ovaprim at 0.5 ml/kg (1.93±0.06mm; 15.29 ± 4.22 oocytes/g; 1410±106 oocytes and 55.34±1.51%). The hatchability rate was higher with Ovaprim at 0.6ml/kg, followed by HCG at 4000 IU/kg, However, no significant differences were observed between treatments (P>0.05)."

Conclusion: In a fish farm of intensive production, the use of the hormone Ovaprim dose 0.6 ml/kg or HCG at 4000IU/kg will lead to high results.