Fecundity of orange roughy (Hoplostethus atlanticus) in New Zealand waters

Abstract

Abstract Fecundity estimates were made from late‐vitellogenic ovaries of orange roughy sampled from five spawning grounds in New Zealand waters: Challenger Plateau (1987, 1988, 1989, 1990), Cook Canyon (1988, 1989), Chatham Rise (1990), Ritchie Banks (1990), and Puysegur Bank (1991). Total fecundity of fish from the different areas ranged from 11 000 to 180 000 eggs per fish, with mean relative fecundity ranging between 26 000 and 49 000 eggs per kg body weight. Total fecundity was positively related to length in all samples except from the Ritchie Banks. Comparisons of size‐fecundity relationships were made between years from Challenger Plateau samples, and between Challenger Plateau, Cook Canyon, Chatham Rise, and Puysegur Bank samples. There was no apparent trend in fecundity over time on the Challenger Plateau. There were significant differences revealed by analysis of covariance between areas, with fecundity of orange roughy from the Puysegur Bank being greater than on the Chatham Rise, which was in turn greater than that of fish from Cook Canyon and Challenger Plateau regions.