Growth of the rabbitfish Siganus randalli Woodland - University of ...

INTRODUCTIONRabbitfishes belong to the genus Siganus of the family Siganidae (Woodland, 1990).Siganids are herbivorous marine and brackishwater fishes that are found throughout the Indo­West Pacific (Woodland, 1983), and the more common species are the objects of traditionalsubsistence and commercial fisheries throughout this region. There has been interest in theculture of these fishes in ponds or cages in several areas (Duray, 1990; Tacon et aI., 1990;Tawada, 1991) including Guam and Micronesia (Nelson, 1988), and siganids are one of thegroups identified by the Pacific Aquaculture Association as being of interest for aquaculturedevelopment within Micronesia. The work described here was undertaken to provide usefulinformation about rates of growth, production, and the efficiency of feed conversion forevaluating the potential of siganid production in ponds in this region. It was also hoped thatthis study would provide information to be used to identify areas where additional research isneeded.Our work has focused on Siganus randalli (Fig. I), a species described in the revisionof the family by Woodland (1990). This siganid was only recently discovered on Guam butis common in Sasa Bay and the inner portions of Apra Harbor. We chose this species forseveral reasons: it is one of the larger siganids; it is tolerant of a wide range of salinities;and, most importantly, because we have been successful in spawning this species and rearingthe larvae to adults.The work described here is presented in five sections: I) production of juveniles foruse in growth trials, 2) controlled growth experiments, 3) growth trials in commercialaquaculture ponds, 4) an interview with a commercial farmer experienced at raising siganidsin Taiwan, and 5) a summary. The work is a technical report and intended for use byresearchers, extension agents, and those involved in aquaculture planning and development atGuam and at other Pacific islands. The work also serves as the final report for a projectfunded by the Pacific Aquaculture Association.