Blue-spotted ribbon tail ray, (Biology – utilization – threats)

Photo credit:: Patricia Martin Cabrera (United Arab Emirates)

Review: Abdel Rahman El Gamal (Founder of the website)

The inserted picture was taken in Sharm El Sheikh (Egypt)

Blue spotted sting ray

Introduction: Blue spotted ribbon tail ray (Taeniura lymma) is a species of stingray in the family Dasyatidae. It is also known as aka blue-spotted fantail rays, blue spotted stingrays, blue spotted rays, and ribbontail stingrays.

Geographical range and habitats: Found in the Indo-West Pacific, the ribbontailed stingray ranges from South East Africa, the Red sea and Arabian Gulf, to the Solomon Islands, north to southern Japan and south to northern Australia.

The species is commonly found around coral reefs in shallow waters, to depths up to 20 meters (rarely found deeper than 30 meters). They are also found foraging near seagrass beds. Unlike most stingrays, ribbontailed stingrays rarely bury themselves in the sand.

Description: The ribbontailed stingray (Taeniura lymma) is recognizable by its striking color pattern with large, bright and neon blue spots on its oval, elongated body (disc) and distinctive blue stripes along either side of the tail. The upper surface of the body disc is grey-brown to yellow, olive-green or reddish brown, while the underside is white. They reach a maximum length about 70-80 cm with a disc diameter of about 30-35 cm across, and up to 5 kg weight. The tail is equipped with one or two sharp venomous spines at the tip, used by the ray to fend off predators.

The snout is rounded and the mouth is found on the underside of the body, along with the gills, adopted for scooping up animals hiding in the sand. The plates which exist within the mouth are used for crushing the shells of crabs, prawns and mollusks.

Feeding habits: Feeding most commonly occurs during the day, but sometimes also at night, where they migrate in groups into shallow sandy areas during the rising tide to excavates sand pits in search of worms, shrimps, crabs, mollusks and small benthic bony fish. Prey is often detected through electroreception, a system which senses the electrical fields produced by the prey.

Reproduction and life cycle: The reproduction of ribbontailed stingray starts by the courtship during which sexually mature males follow female mates, using their acutely sensitive ‘nose’ to detect a chemical signal emitted by females. After mating, and like other stingrays, ribbontailed stingray is ovoviviparous, meaning the embryos are initially sustained by yolk, supplemented by (“uterine milk”, containing mucus, fat, and proteins) produced by the female as the embryo develops. The gestation period is thought to be between four months to a year. A female ribbontailed stingray gives birth to up to seven 13-14 cm across young; each is born with the distinctive blue markings of its parents in miniature.

Utilization: Because of its attractive appearance and relatively small size, the bluespotted ribbontail ray is a popular stingray among marine aquarists despite their poor survival in captivity. The species is utilized as food in East Africa, Southeast Asia, and Australia.

Threats: The ribbontailed stingray is subject to a variety of human-imposed threats as they are commonly taken where heavy artisanal and small-scale commercial fisheries occur in or around coral reef habitats. Their beautiful coloration and high demand for home aquariums led to heavy fishing and in some places more harm occurs when illegal catching methods are used including dynamite fishing and use of cyanide. The widespread destruction of coral reef habitat added significantly to threats imposed on the species. Moreover, with such a low reproductive rate, consisting of long gestation periods and small number of litters, the ribbontailed stingray is particularly vulnerable to population collapses.



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