KAVANAUGH, S.I.*; POWELL, M.L.; DAVIS, J.E.; SOWER, S.A.: Sexuality and Embryogenesis of the Atlantic Hagfish, Myxine glutinosa

The objectives of these experiments were to determine gonadal development under controlled laboratory conditions and to stimulate gonadal development through injection of lamprey GnRH-III to potentially obtain fertilized eggs. Atlantic hagfish, Myxine glutinosa were obtained from the Gulf of Maine. For the first objective a total of thirty hagfish were held for five months at 40C in a recirculating saltwater tank at the University of New Hampshire Anadromous Fish and Invertebrate Research Laboratory (AFAIR Lab.). Maintenance of these hagfish required daily temperature checks, and transfer of new seawater every two weeks from the Coastal Marine Laboratory. Hagfish were sampled once a month for five months from November through March for weight, length, and to determine the stage of gonadal development through histological examination. In November, most of the hagfish were classified as undetermined, i.e., they had not undergone sexual differentiation. During the next few months, the majority of the hagfish were found to be female. For the second objective, six hagfish were injected in February with 48 ug of micorencapsulated lamprey GnRH-III in an attempt to stimulate gametogenesis. Hagfish were sampled after one month for comparison to a control non-injected group (n=6). Subsequent histological analysis showed that lamprey GnRH-III appeared to stimulate reproductive development in female hagfish compared to controls. (This project was funded by UNH/UME Sea Grant #NA16RG1035, Sea Grant Project NOAA Sea Grant, R/FMD-168 and UNH Hubbard Endowed Funds)