Stingrays are some of the very few truly venomous animals in Louisiana waters. I say “some” rather than “one” because four species of rays with spines on top of their tails occur off of and in Louisiana.
The largest species — and the one we will look at here — is the southern stingray, Dasyatis americana.
The genus part of the scientific name, Dasyatis, is derived from Greek words, with “dasys” meaning rough or dense and “(b)atus” meaning shark.
The species part of the name, americana, is easy to figure out. It is, indeed, the stingray of the Americas, ranging along much of the coast of North, Central and South America.
Identifying the four species of stingrays by shape is fairly easy. Viewed from above, our hero here has an almost-perfect diamond shape and, more importantly, the huge, flattened pectoral fins (what makes a ray a ray) have tips that come to sharp points.
The other two common stingrays of Louisiana, the Atlantic and the bluntnose, have rounded “wing” tips. These two can be differentiated by the shape of their noses. The Atlantic stingray has a sharply pointed nose tip; the bluntnose, of course, has a blunt nose.
The final stingray that can occur in Louisiana, although it is uncommon, is the yellow stingray. It has a very oval, almost round body, viewed from the top, and is the only one with a mottled yellow pattern. It’s also small — 14 inches across is a large one.
The southern stingray is also the largest — a real bruiser, growing up to 6 feet across wing tip to wing tip. The Louisiana state record is 185.8 pounds and was caught at Lake Pelto by Bebe McElroy in July 2013. The IGFA world record is even larger at 246 pounds. It was caught in Galveston Bay, Texas in 1998.
The fishes of the earth are divided into three groups: jawless fishes (lampreys and hagfish), cartilaginous fish and boney fish.
Rays and sharks are cartilaginous fish, which means that they have skeletons of cartilage (although often quite calcified) rather than bone like all other fish.
Rays include sawfish, guitar fish, electric rays, skates, stingrays, eagle rays and mantas.
While classified as cartilaginous fishes, rays do have some hard parts: teeth, varying amounts of primitive scales called dermal denticles and, of course the hard, barbed spines on their tails.
Southern stingrays vary a great deal in color, ranging from green to brown to gray — even almost black — on their upper surface. Adult males are half as large as adult females. Females mature at 5 to 6 years of age and males at 3 or 4 years old.
Mating takes place by the male grabbing a female’s wing in its mouth and sliding his upside-down body beneath hers. There he inserts one of his two claspers into the female to inseminate her internally. Claspers are simply large, penis-shaped modifications of the male’s anal fins.
In captivity, two to 10 young are born 4 ½ to 7 ½ months after mating.
Southern stingrays are ovoviviparous, which means the female holds the eggs internally until they hatch. After the young consume the yolk sac, the mother secretes a protein and fatty acid-rich liquid called histotroph or uterine milk to nourish the young rays until birth.
Southern stingrays are bottom creatures, and can be found from shallow, inshore lakes and bays out to 170 feet of water. They prefer soft or sandy bottoms, in which they will often bury themselves enough to break their outline.
Their eyes are set high on their humped head, so even if buried they can remain alert for predators or prey.
They breathe by sucking water into their spiracles — large holes also located high on the head and right behind each eye. After the water passes over the ray’s gills, it is forced out through the gill slits on the underside of the animal.
The spiracle and gill arrangement also play an important part in their feeding technique, called hydraulic mining. Powerful jets of water from their gill slits blow bottom sediment away, exposing the smaller creatures that live in it. They will also vigorously flap their wing-like pectoral fins to disturb the bottom.
Southern stingrays are not feeding specialists, instead eating a wide range of foods including fish, worms, crabs, clams and many kinds of shrimp. The feeding behavior of southern stingrays attracts followers that pick off creatures disturbed by the hunting activity of rays.
Many species of fish, including several kinds of jacks, follow feeding rays. Also documented are cormorants that dive into the water and swim behind the rays.
Feeding is done day and night, although it seems to be more vigorous at night.
The rays detect their prey by smell, and use their lateral lines to detect vibrations from prey movements. Also important are thousands of electroreceptors called ampullae of Lorenzini. Located on the rays’ underside, they sense electrical fields given off by buried prey.
The most-serious predator of southern stingrays is the hammerhead shark. It is thought that the shape of this shark’s head is an adaptation that assists in holding these large rays down while the shark feeds on them.
Humans are not a predator of southern stingrays, in spite of all the idiotic blather of uncredentialed pseudo-experts on the internet who claim to have inside knowledge that plugs of flesh are taken from stingrays’ wings and sold as scallops.
To call this modern urban legend preposterous is to dignify it. Using any cookie-cutter type of device to punch through a ray fin is incredibly difficult. Sandwiched between a top and bottom muscle layer in each wing is a very tough layer of inedible (and unchewable) cartilage.
Additionally, the muscle fibers of a scallop run from top to bottom — from flat side to flat side. The muscle fibers of ray fins run horizontally to allow the ray to swim by flapping its wings.
Even if a plug could be cleanly punched from the wing and the cartilage layer somehow magically disposed of, the muscle fibers running the wrong way would be a dead giveaway that what is in a person’s mouth is not a scallop.
By the way, stingray wings are good to eat if one takes the time to skin the wings and fillet the top and bottom meat layers off the cartilage. The meat is sweet and white.