Marine Field Studies 2021: Spotted Eagle Ray: Courtney Collins

Spotted Eagle Ray Aetobatus narinari

Background:

Thursday May 22 while snorkeling Looe Key, a popular diving and snorkeling spot here in the Florida Keys, a Spotted Eagle Ray was sited. Spotted Eagle Rays got their common name because of how they flay through the water like an eagle fly’s through the sky.

Feeding:

Like other rays the spotted eagle rays diet consists of bivalves, shrimp, crabs, worms, whelks, and the occasional squid. The duck-like shape of their mouth and plate-like teeth allow them to stick their mouth in the sand to catch and crush benthic animals.

Habitat:

These rays are found in warmer subtropical waters near coral reefs or in bays. Although most sightings are between 0-80 meters spotted eagle rays have been seen at lower depths. Once believed to be found all around the world scientists are now questioning whether they are all the same species or if they are actually different species.

Reproduction:

Male spotted eagle rays will chase the females nibbling at their dorsum, or dorsal surface, and bite their pectoral fin before attempting abdomen-to-abdomen copulation. This typically lasts for about 30-90 seconds. The spotted eagle ray is ovoviviparous meaning they have internal reproduction where eggs develop and hatch inside the mother’s body. Once the eggs have hatched it receives nutrients from the yolk sac. Only when the pups can survive on their own will the mother give birth, typically to 4 pups.

Morphology:

Although the Spotted Eagle Ray can commonly be mistaken for a Manta Ray at first glance due the similar body structure these rays are actually very different. Two of the most distinguishing characteristics is the structure of their mouth as well as their color morphology. The spotted eagle ray has a flat rounded duck-like mouth that allows them to collect food from the sand. The pearly white spots on their dark gray back help differentiate them from other rays. The Spotted Eagle Ray can grow to a max width of 3 m, length 5 m, and a max weight of 230 kg.