Induced spawning techniques practised at Batu Berendam, Melaka, Malaysia

Abstract

Techniques of induced spawning as practised at Batu Berendam, Melaka, were developed from 1974 to 1986. Early attempts using salmon gonadotropin SG-G100 were found to be effective but very expensive. Alternatively, the technique of hypophysation, that is, injection of either homoplastic or heteroplastic pituitary gland extract, was adopted. Freshly prepared or acetone-pre-served pituitary extracts from mature bighead and silver carp were administered to bighead and silver carp spawners; the extracts were found to be effective and 30 times cheaper than SG-G100. In addition, the use of acetone-dried common carp pituitary extract produced more consistent results. Using this technique, we were able to induce spawning in local as well as exotic carps. More refined human chorionic gonadotropin administered with homoplastic or heteroplastic pituitary extract proved to be equally effective on local as well as exotic carps and catfish. Some of the dosages have been standardized, in particular for bighead carp, Aristichthys nobilis, silver carp, Hypophthalmichthys molitrix, local carp, Leptobarbus hoevenii, and striped catfish, Pangasius sutchi. The most recent development is the effective administration of luteinizing hormone-releasing hormone analog to P. sutchi, either singly or in combination with homoplastic pituitary extract.