Current knowledge of hagfish reproduction: implications for fisheries management

This review briefly summarizes the latest findings on reproductiveendocrinology of Atlantic hagfish (Myxine glutinosa) and implicationsfor fisheries management. In response to a major decline orcollapse of the fisheries (groundfish and anadromous species)industry in the Northeast, species that were once consideredalternative or underutilized have and are being identified thatmay be suitable for commercial harvest, one such example isthe hagfish. Hagfish in recent years have been sought afteras valuable fish not only for their flesh, but also their skin.Currently, there are no regulations governing the harvestingof hagfish along the East Coast. There has been little to noinformation of the life history of hagfish including growthrate, age determination, reproductive biology, life span, andlarval size at hatching. Thus, the level at which a sustainablefisheries for this species can be maintained is unknown. Insome parts of the world, hagfish stocks are being depleted dueto overfishing. In order for fisheries management to manageits hagfish stocks and develop a sustainable commercial hagfishfishery, critical information is needed to assist in determiningthe optimal use of this valuable resource. Key elements of the reproductive system have not been elucidatedin hagfish. However, there is new evidence from recent reproductivestudies that Atlantic hagfish may have a seasonal reproductivecycle. These data include seasonal changes in gonadotropin-releasinghormone (GnRH), gonadal steroids, estradiol and progesterone,corresponding to gonadal reproductive stages along with theputative identity of a functional corpus luteum. This newlyacquired data may provide important information to fisheriesmanagers of the East Coast.