ELZEY, S.P.; University of New Hampshire: Sexual Dental Dimorphism in Four Species of Skates From The Western Gulf Of Maine

Tooth morphology of four species of skate found in the Western Gulf of Maine was examined. These species were the little skate (Leucoraja erinacea), the winter skate (L. ocellata), the smooth skate (Malacoraja senta), and the thorny skate (Amblyraja radiata). Differences in cusp length and angle were found between adult male and adult female skates as well as differences between juvenile and adult male skates. Adult males possess longer sharper teeth that protrude more prominently into the mouth than the females or the juveniles. Although this trend is seen in all four species it is more pronounced in the two smaller species, the little skate and the smooth skate. The tooth morphology change at the size of maturity in the males suggests that the teeth play a roll in the reproduction of the skate, most likely due to the need for the male to hold on to the female during mating. Bite scars were seen on female skates, which corroborates this theory. The results of an ongoing study examining hormone effect on tooth morphology and skin thickness in the little skate will also be discussed.