CRC REEF RESEARCH CENTRE TECHNICAL REPORT No. 31

Defining the reproductive biology of a large serranid Plectropomus leopardus.

M.A. Samoilys, CRC Reef Research Centre Ltd
A. Roelofs, CRC Reef Research Centre Ltd

EXECUTIVE SUMMARY

There are three main objectives to this manual. First, to provide a brief description of the ontogenetic and sexual development of gonadal tissue in the common coral trout, Plectropomus leopardus, as an introduction to the reproductive biology of a tropical protogynous hermaphrodite (section 2). Second, to provide details of the laboratory methods that we used to measure the reproductive stages and batch fecundity of P. leopardus (section 3). These were histology of gonad sections using haematoxylin and eosin stains, and counts of whole oocyctes, both standard procedures in reproductive studies. Third, to define the reproductive developmental stages in females and males, illustrated with colour plates, using detailed criteria to establish a standard for staging P. leopardus (section 4). We also discuss problems that we encountered in staging the gonads of P. leopardus, in section 5, to highlight some typical errors in histological interpretations, and provide some guidance in minimising these errors. Finally, in section 6, we provide brief concluding remarks. Much of this work is not new. We have relied heavily on previous reproductive work on P. leopardus by Ferreira (1995) and Adams (1996). Our aim is to synthesise information available from a variety of sources and provide a focussed laboratory guide for assessing the reproductive biology of a large exploited serranid on the Great Barrier Reef. Laboratory protocols developed for the CRC Reef's Effects of Line Fishing Project (Davies et al. 1998, Mapstone et al. 1998) have built on the work described in this manual.

We have structured the report to reflect the objectives described above. We have also included a glossary to assist with terminology. In section 2 we have referred to a number of developmental stages with which the reader may not be familiar. These terms are fully described in section 4 where we define the developmental stages in detail.

THIS PUBLICATION IS CITED AS:
Samoilys, M.A., Roelofs, A. (2000)
Defining the reproductive biology of a large serranid Plectropomus leopardus
CRC Reef Research Centre Ltd
Technical Report No. 31
Townsville; CRC Reef Research Centre Ltd, 36 pp.

ISBN 1 876054 46 8

A full copy of this report may be obtained from the author(s), and through the following libraries: