Gonadal Development in Eptatretus cirrhatus Based on Fishery Sampling

A hagfish fishery has been operating in New Zealand waters for the last six years, harvesting the bearded hagfish, Eptatretus cirrhatus. The fishery has been unregulated. Samples collected dockside over a two-year period provided information on the size and weight of the harvested animals.  Analysis of reproductive status profiled the sizes at the onset of gonadal development and the minimum sizes at sexual maturation for males and females, and indicates that E. cirrhatus has no specific breeding season. Females begin maturation earlier than males, and as a result they appear in the population samples at smaller sizes.  However the sex ratio for mature animals is 1:1 and the sizes of the largest males and females are comparable. The observed variations in sex ratio as a function of TL indicate differences in the timing and rates of gonadal development rather than protogyny. The size distribution of the sample population indicates that this is a juvenile fishery. It is clear that E. cirrhatus, like other hagfish species, are potentially vulnerable to overexploitation, especially when an unregulated targeted fishery is operating in the absence of (1) basic information about life history and distribution, (2)  stock assessment, (3) determination of the resource biomass.