This series of documents, issued by FAO, CSIRO, NP and NMFS, Contains Comprehensive reviews of present knowledge on species and stocks of aquatic organisms of present or potential economic interest. The Fishery Resources and Environment Division of FAO is responsible for the overall coordination of the series. The primary purpose of this series is to make existing information readily available to fishery scientists according to a standard pattern, and by so doing also to draw attention to gaps ¡n knowledge. It is hoped that synopses in this series will be useful to other scientists initiating investigations of the species concerned or of related ones, as a means of exchange of knowledge among those already working on the species, and as the basis for comparative study of fisheries resources. They will be brought up to date from time to time as further information becomes available.