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Facts About the Bluespotted Stingray

Rutuja Ghanekar
Bluespotted stingrays are well-known for their bright blue appearance with vivid spots. In this story, let's delve into what separates them from other stingrays.

Did You Know?

The genus of the current scientific name of the bluespotted stingray, Dasyatis, is of Greek origin, combining two words-dasys (rough or dense) and batus (skate).
Discovered in Java, Indonesia, by Heinrich Kuhl, the bluespotted stingray was earlier named Trygon kuhlii (Müller & Henle, 1841); later termed as Dasyatis kuhlii (Müller & Henle, 1841); followed by Neotrygon kuhlii (Müller & Henle, 1841). Today, all three scientific names of this species are in use.
Thorough research is absolutely essential to settle the ongoing taxonomic debate over the species' classification and current status.
Two forms of bluespotted stingrays-the Bali and Java-can be potentially classified as two different subgroups. But in spite of morphological and molecular evidences being made available, the status of this classification is not yet resolved.

Distribution and Habitat

This species has a wide distribution, ranging from the western Indian Ocean to the eastern Pacific. The Indo-Pacific range extends from Japan to Australia, and the Red Sea and East Africa to Tonga and Samoa. The bluespotted stingray is fairly common in Australian waters from New South Wales to western Australia.
It is common in South Africa, Kenya, and Madagascar, and inhabits parts of the continental waters of Asia. Several color morphs are also reported in certain areas like Indonesia, but detailed research is yet to be conducted.
Bluespotted stingrays are typically found in waters up to a depth of 90 meters; preferably in sandy surfaces closer to rocky areas and coral reefs.

Physical Features

This stingray is small- to medium-sized, with a maximum reported size of 27.6 inches. The main section of the body is flat, oval, and disc-shaped, having an angular snout. The jaw of the ray contains numerous teeth-like structures, and the eyes are large, present in a way that allows them wider visibility.
The skin of the ray is dominantly without thorns; small-sized thorns are present on middle portion of the disc.

Another prominent feature is its coloring-varying from brown to green, with brightly-colored blue spots on the surface. The dorsal surface also shows smaller-sized black spots.
The tail is broad, having two fin folds-upper and lower; the upper fin fold is shorter than the lower one. The length of the tail is twice the length of the body; two venomous spines are present on the tail.

Diet

Since these marine animals are bottom feeders, their diet consists of minimal variety. A major portion of the bluespotted stingray's diet consists of shrimp, followed by crabs and mollusks. The ray usually kills its prey with the help of its fins, by confining it down to the sea floor.

Reproduction

The bluespotted stingray uses the ovoviviparous mode of reproduction, that is, the embryos are developed inside the eggs, which are present inside the mother's body, feeding on yolk sacs and the uterine fluid. Once the eggs are ready to hatch, the mother gives birth to 1-2 pups; the gestation period is not yet known. The offspring have a length of 13 inches, and the disc is 6.3 inches in width.

Predators and Parasites

The main predators of the bluespotted stingray are killer whales, who generally attack juveniles and newborns.
Other fish, such as hammerhead sharks, pin down the ray until it is dead. The parasites that have been reported to be present on the skin of this stingray are Dendromonocotyle kuhlii and Acanthobothrium bengalense.
The bluespotted stingray is commonly confused with the bluespotted ribbontail ray. The major difference between the two is that the disc of the bluespotted stingray is more angular, and it has a more slender tail as compared to the bluespotted ribbontail ray.