POWELL, Mickie/L*; HEYL, Taylor; BAUKUS, Adam; SOWER, Stacia/A: Gonad Development in the North Atlantic hagfish, Myxine glutinosa

Hagfish represent the oldest form of extant vertebrates, however, much of their life history remains a mystery. They are an important part of the benthic community in the deep ocean, recycling nutrients through the consumption of decaying animal material. In recent years they have become the focus of a growing fishery in the North Atlantic. Successful management of a sustainable fishery will require information on age determination, age and time of reproduction, seasonality of reproduction and growth, which currently not known. The goal of our studies is to further understanding of growth and reproduction by testing the hypothesis that M. glutinosa exhibit seasonal reproductive growth. The specific objective of this study was to determine gonadal development by histological analysis in relation to maturity based on weight and length. M. glutinosa were trapped at a depth of 100-150m, 25 miles off the New Hampshire coast. Hagfish are thought to be protandric, beginning life as females and later differentiating into males. In our collections males were always the smallest percentage of the sampled animals (25% or less in all samples). The percentage of hagfish with undeveloped gonads decreased from almost 75% in November to zero in January, immature hagfish were also absent in the March sample. Mature females containing ovaries in various stages of development were present in samples. These data showed that females were more abundant and they were usually of equal or greater length than males. There were several hermaphrodites in this population -whether they were functional or not needs to be explored further. Supported by UNH/UME NOAA Sea Grant R/FMD-168 and NA16G1035 and UNH Hubbard Endowed Funds.