Spatial variation in reproduction, and occurrence of non-reproductive adults, in orange roughy, Hoplostethus atlanticus Collett (Trachichthyidae), from south-eastern Australia

摘要: This study was designed to determine whether orange roughy reproduce throughout their distribution in Australian waters, and if so, commencement of spawning length at maturity vary within the region. We found that females from four widely separated sampling areas reproduced 1988, but onset were not same all areas. In New South Wales, ovulation finished by mid‐June, 50% mature 28 cm standard (S.L.). On other hand, eastern western Tasmania Australia did spawn until mid‐July, 32 S.L. Females had oocytes with yolk granules least 5 months before ovulation. However, few spawning, some adult undergone vitellogenesis or resorbing yolky oocytes. The best estimates proportion these non‐reproductive made March April, when single batch eggs be spawned clearly distinguishable, aggregations formed. 1990 Tasmania, site a major aggregation, estimate fish 45%. suggest scarcity food, coupled cost joining may result intermittent this long‐lived species. Copyright © 1992, Wiley Blackwell. All rights reserved