Current knowledge of hagfish reproduction: implications for fisheries management.

This review briefly summarizes the latest findings on reproductive endocrinology of Atlantic hagfish (Myxine glutinosa) and implications for fisheries management. In response to a major decline or collapse of the fisheries (groundfish and anadromous species) industry in the Northeast, species that were once considered alternative or underutilized have and are being identified that may be suitable for commercial harvest, one such example is the hagfish. Hagfish in recent years have been sought after as valuable fish not only for their flesh, but also their skin. Currently, there are no regulations governing the harvesting of hagfish along the East Coast. There has been little to no information of the life history of hagfish including growth rate, age determination, reproductive biology, life span, and larval size at hatching. Thus, the level at which a sustainable fisheries for this species can be maintained is unknown. In some parts of the world, hagfish stocks are being depleted due to overfishing. In order for fisheries management to manage its hagfish stocks and develop a sustainable commercial hagfish fishery, critical information is needed to assist in determining the optimal use of this valuable resource.Key elements of the reproductive system have not been elucidated in hagfish. However, there is new evidence from recent reproductive studies that Atlantic hagfish may have a seasonal reproductive cycle. These data include seasonal changes in gonadotropin-releasing hormone (GnRH), gonadal steroids, estradiol and progesterone, corresponding to gonadal reproductive stages along with the putative identity of a functional corpus luteum. This newly acquired data may provide important information to fisheries managers of the East Coast.