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Underwater Photo of the Week - January 21, 2019

Southern Stingray

POTW January 21, 2019

 

Hi Gang!

This week’s POTW is a shot of a southern stingray, Dasyatis Americana,that was captured several years ago in the shallow water of the Caribbean island of Grand Cayman where it is the featured species at Grand Cayman’s highly acclaimed site named Stingray City. This dive site is comprised of a series of sandbars where divers and snorkelers swim with southern stingrays on a daily basis

The southern stingray is the commonly seen, large, bottom dwelling ray that inhabits sand flats from New Jersey to Brazil. Along with the warm water species the spotted eagle ray (Aetobatus narinari) and the bat ray (Myliobatus californica) of the eastern Pacific, the southern stingray is one of the species North American divers most commonly think of when they hear the word stingray.

The southern stingray reaches a maximum size of roughly five feet across, although most specimens are considerably smaller. Southern stingrays have a dark gray to black upper body, whitish underbellies, numerous short spines extending down the back, and a long, thin tail equipped with one or more sheathed barbs. Southern stingrays use the serrated barbs as a means of defense against potential predators, including sharks, and as a means of discouraging other animals and humans from settling or stepping on top of them. Beach walkers pay heed! The barbs are toxic. They are commonly eight inches long and can inflict a painful wound. 

When at rest southern stingrays often bury themselves in sand to become less conspicuous. Their eyes are positioned high atop the head. This location allows the rays to bury the bulk of their body and still be able to use their vision to keep aware of their surroundings. The high positioning of their spiracles also helps the rays take in oxygenated water that is comparatively free of debris. 

Southern stingrays primarily feed on a variety of fishes, worms, clams and crustaceans that inhabit the sand and seagrass beds. Like so many other stingrays, southern stingrays actively dig through the sand to locate their prey. The mouth and nostrils of southern stingrays are located on the underside of the head close to the front of the body, an ideal position to help them locate hidden prey. Southern stingrays use their large, powerful jaws and plate-like teeth to crush their prey.

As is the case with the manta ray, southern stingrays are ovoviviparaous, meaning that the embryonic rays develop in eggs that are held within the mother’s body until they hatch. After hatching the pups are released from the mother’s body, thus being born alive.

I hope you enjoy this week’s POTW!

See you next week,

Marty

 

See you next week,