Greenwald S.A., Bourdon J., Mollet, H.F. (1997). Tooth structure of male and female pelagic stingrays Dasyatis violacea.

ABSTRACT:
Two male (53 and 57 cm disk width) and 4 female pelagic stingrays (Dasyatis violacea) (69 to 83 cm disk width in December 1996) were maintained in a fiberglass tank (5.2 m diameter, 1.07 m water depth) at T = 20 C for a feeding and growth experiment. This represented a well defined and alternative source of Dasyatidae teeth compared to fossil teeth. Shed teeth and dermal denticles were collected weekly starting in Jan. 1997 and sorted according to morphological criteria. The objective of the study is the determination of 1) shed rates of teeth and dermal denticles, 2) distinguishing morphology of male and female teeth, 3) the location of the teeth in the jaws, and 4) possible changes of male teeth during the breeding season. The preliminary analysis based on 121 teeth in superb condition identified 7 types. Three types were high-cusped and likely male teeth. Four types were low-cusped and likely female teeth. Ten % of all teeth had a second cusp, an unexpected morphological feature. We hope that this investigation will help in the identification of fossil stingray teeth and provide information on sexual and ontogenic heterodonty of the pelagic stingray.
KEYWORDS:
Dasyatis violacea, tooth structure, tooth morphology, dermal denticles, placoid scales, bi-cuspidate