Mating Behavior of Southern Stingrays, Dasyatis americana (Dasyatidae)

Abstract

We document in detail the first complete sequence of mating events in the southern stingray, Dasyatis americana, based on observations of four matings (five separate copulations) at Grand Cayman, British West Indies and Bimini, Bahamas. These observations are significant because almost nothing is known about this important aspect of the life cycle of batoids, due to the rarity of encounters with mating animals in natural settings. Similar to mating behavior described in the manta ray, Manta birostris, the mating sequence of D. americana can be characterized as (1) 'close-following', (2) 'pre-copulatory biting', (3) 'insertion/copulation', (4) 'resting' and (5) 'separation'. Additional information gained from these observations includes the fact that (1) two of the females were mated very shortly (i.e. within minutes–hours) after parturition and (2) one of the mating events involved a single female that copulated (unforced) with two males in rapid succession. The latter observation suggests that polyandry and multiple paternity may be elements of the mating system of D. americana.