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Much Maligned Rays Part Two

Five years ago, All At Sea published an article titled An Underwater Mystery. Part of that mystery was solved when I eventually identified the cartilaginous skeleton as that of a stingray. Without DNA, we will never know whether the skeleton was a Southern or Caribbean Stingray because they are so similar and common to the Caribbean.

One difference is the shape of the 'wings'. Southern Stingrays are diamond shaped whereas the wings of the Caribbean are oval. The second difference is range. Southern rays are found from New Jersey, throughout the Gulf of Mexico, and down the western Atlantic to southern Brazil. Caribbean rays are found throughout the Caribbean from Cuba to Guyana.

Coloration of the upper bodies of both Caribbean and Southern Stingrays can be light gray to a dark olive/brown, often with darker edges. The rays' undersides vary from white or cream to a light grayish yellow. Females are larger than males with wingspans to six-and-a-half feet, and weights reaching almost 300 pounds.

The Southern and Caribbean Stingrays glide along sandy or muddy bottoms using their vacuum-like mouths to pick up mollusks and crustaceans, their main food sources. Their jaws are lined with multiple rows of small, triangular shaped teeth designed for crushing.

When lying in wait, the rays often flutter their wings in order to bury themselves, leaving only their eyes and spiracles exposed. Although the gills located on the underside of their bodies are buried, the spiracles, located beside the eyes, allow them to breathe. Like their shark cousins, rays have the remarkable characteristic of electro-reception; they can detect prey long before the prey is aware of them.

Rays have fascinating eyes. When diving, I frequently swim just inches above the bottom surveying the sand for small critters and buried rays. Rounding a coral head, I once saw the telltale eyes of a buried ray and cautiously worked my way toward her, allowing her plenty of time with a wide exit path. She was quite docile and let me lie next to her where I looked into her left eye. What a marvelous eye it was! I wondered what she had seen and where she had been, and what she thought of me.

Surprisingly, as common as Southern and Caribbean Stingrays are, little is known about them. Scientists believe they may mate biannually but that is not confirmed. Laboratory studies seem to indicate that the mother's size determines the number of pups; however, no one is certain. Estimates of the gestational period vary from four to 11 months with litters of two to ten pups.

What we do know is that rays are ovoviviparous – meaning the females produce eggs that are fertilized and develop within their bodies. As the embryos grow, they first feed from the eggs' yolk sacs. Once the yolk sacs are depleted, the young hatch within the mother's body where they feed upon a milk-like substance in which they 'swim'. Once the pups are ready to face the world on their own, they are born into the sea as small yet fully developed rays complete with barbed tails for defense.

Contrary to popular belief, stingrays are quite peaceful and are often passed by swimmers and divers who are completely unaware of their presence. The ray's only protection is a spined tail. These boney spines are barbed and covered in a mildly venomous mucous.

When threatened, both Southern and Caribbean Stingrays, members of the whip-tailed ray family, use their tails like a whip. The protein-based venom is rarely fatal, causing pain for a few hours. Application of hot packs or soaking the wound site in hot water can alleviate the pain. If the barb remains in the wound, a physician's attention is in order.

Although there was a highly publicized incident wherein a diver died due to a ray's barb piercing his heart, such incidents are extremely rare and avoidable. Unless deliberately cornering or harassing a ray, the only real concern is accidentally stepping on one. They are no different from any other wild animal whether in the sea or on land … observe from a safe distance and do not invade the animal's space.

Becky Bauer became a scuba instructor and award-winning journalist covering the marine environment in the Caribbean after 30 years as a wild and domestic animal rescuer, rehabber, and educator in the states. She is a contributing photographer to NOAA.

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