Seasonal changes of gonadotropin-releasing hormone in the Atlantic hagfish Myxine glutinosa
Abstract
To investigate seasonal reproduction in Myxine glutinosa, we measured total brain gonadotropin-releasing hormone (GnRH) and determined gonadal stages of hagfish collected from the Gulf of Maine once a month for 12 months. Thirty hagfish from each of three different size classes of small (20-35 cm), medium (35-45 cm), and large (50-60+ cm) were sampled for brains and gonads. In the medium and large class hagfish there was an increase in GnRH concentrations during April and May that correlated with male and female gonadal maturity. Also in these size classes of female hagfish, there was a similar rise in GnRH in November and then again in January that preceded the highest incidence of large eggs (stage 7). The elevated GnRH may be influencing the onset of ovarian recrudescence which has been shown in other vertebrates. These data suggest an association of the concentration of brain GnRH with gonadal maturity and provide supportive evidence of a possible seasonal reproductive cycle in M. glutinosa shown in recent studies of [J. Exp. Zool. 301 A (2004) 352], correlating steroid production with gonadal maturation. (C) 2004 Elsevier Inc. All rights reserved.
Publication Date
1-15-2005
Journal Title
General and comparative endocrinology
Publisher
Elsevier
Digital Object Identifier (DOI)
10.1016/j.ygcen.2004.10.015
Scientific Contribution Number
2241
Document Type
Article
Rights
© 2004 Elsevier. All rights reserved.
Recommended Citation
Kavanaugh, Scott I.; Powell, Mickie L.; and Sower, Stacia A., "Seasonal changes of gonadotropin-releasing hormone in the Atlantic hagfish Myxine glutinosa" (2005). General and comparative endocrinology. 57.
https://scholars.unh.edu/nhaes/57