Breeding performance of Malaysian mahseer, Tor tambroides and T. douronensis broodfish in captivity

Abstract

Tor tambroides and T. douronensis are highly valued freshwater cyprinids. Owing to their cultural and economic importance, and concerns over their conservation status, a captive artificial propagation programme was established in Sarawak, Malaysia, to produce seedstock for conservation and aquaculture purposes. This paper describes work that followed the initial breakthrough in artificial propagation of captive, pond-reared broodfish of the two Tor species, primarily on the overall breeding performance of broodfish over a 3-year period. Breeding performance generally increased through the study period, indicating an overall improvement in husbandry and breeding techniques since commencing breeding trials. Spawning was induced in most months of the year. Seasonal patterns in spawning performance were not clear, but nevertheless the influence of monsoonal climate patterns was evident as higher breeding performance indicators were observed during the northeast monsoon. Some individual broodfish were injected and stripped up to 11 times during the study, and there were as little as 30 days between successful strippings. Considerable variability was observed in each of the breeding performance indicators with successive hypophysation, although in T. tambroides, there were signs of an increase in some of these indicators with successive hypophysation attempts. Multiple injection of Ovaprim, and repeated stripping of eggs, does not appear to reduce breeding performance, at least for T. tambroides. © 2007 The Authors.