Reticulate Whipray

The reticulate whipray, also known as the honeycomb stingray (Himantura uarnak), is a stingray species found in the western 🌊 Indian Ocean, including the 🌊 Red Sea, Natal, and the Arabian Sea. It is also found in the eastern Mediterranean as a Lessepsian transmigrant. This large species can reach a width of 2 m (6.6 ft) and is characterized by its diamond-shaped pectoral fin disc and long tail without fin folds. The name "reticulate whipray" refers to its intricate dorsal color pattern of small dark spots on a lighter background. However, due to its similarity to other large spotted stingrays in the Indo-Pacific and the variation in its coloration with age and location, there has been confusion regarding its taxonomy.

The reticulate whipray is a predator, feeding on bottom-dwelling invertebrates and bony fishes. It is aplacental viviparous, meaning the developing embryos are initially nourished by yolk and later by histotroph ("uterine milk"). Females give birth to litters of up to five pups after a gestation period of one year. This species is fished for its meat, skin, cartilage, and other purposes in certain parts of the 🌊 Indian Ocean. However, its large size, preference for inshore habitats, and low rate of reproduction make it highly susceptible to population depletion. Additionally, extensive habitat degradation poses a significant threat to its survival. As a result, the International Union for Conservation of Nature (IUCN) has classified the reticulate whipray as Endangered.

In terms of physical characteristics, the reticulate whipray has a diamond-shaped pectoral fin disc that is wider than it is long. It has small eyes followed by spiracles (paired respiratory openings) and a short curtain of skin with fringed margins between its thin nostrils. The mouth is relatively small with a deep concavity at the center of the lower jaw. The pelvic fins are small and triangular. The tail of the reticulate whipray is whip-like and extremely thin, measuring 3-3.5 times the length of the disc. It lacks fin folds and usually has one serrated stinging spine on its upper surface, located some distance from the base. Adults have a wide band of flattened dermal denticles extending from between the eyes to the tail spine, with density increasing with age. The coloration of this species varies with age and location, with adults having a pattern of dark spots or reticulations on a lighter background. Juveniles are yellowish with densely packed dark spots.

The reticulate whipray can be found in coastal waters of the western 🌊 Indian Ocean, including the 🌊 Red Sea, Natal, and the Arabian Sea. It has also entered the eastern Mediterranean through the Suez Canal (🇪🇬 Egypt) and is now common in the southeastern Mediterranean. This species prefers sandy flats near beaches, lagoons, and coral reefs, ranging from coastal areas to offshore waters up to 50 m (160 ft) deep. It can tolerate low salinities and has been known to enter estuaries and mangrove swamps. The reticulate whipray prefers water temperatures between 23-26 °C (73-79 °F).

During the day, the reticulate whipray is primarily inactive and spends much of its time resting motionless on the sea floor, sometimes buried in sand. It has a lateral line that extends to the tip of its long tail, giving it advanced warning of approaching predators such as bottlenose dolphins and hammerhead sharks. This species is known to rest in small groups in shallow water during high tide, often in a "rosette" formation with their tails pointing outward for maximum predator awareness. The reticulate whipray preys on a variety of bottom-dwelling and neritic organisms, including crabs, shrimps, mantis shrimps, bivalves, gastropods, worms, jellyfish, and bony fishes.

The reticulate whipray is often sought after by recreational anglers for its strong fight on hook-and-line. It is also caught by artisanal and commercial fisheries in the western 🌊 Indian Ocean using various methods. Although not highly valued as a food fish, its meat, skin, and cartilage are utilized. This species is also used in Chinese medicine, and its tail may be sold as a curio. Due to its susceptibility to overfishing, habitat degradation, and other threats, the reticulate whipray is considered endangered by the IUCN.

While the reticulate whipray is occasionally available in the home aquarium trade, its massive size makes it best avoided. It is also kept in some public aquariums, such as the Aquarium of the Pacific, the Atlantis Dubai hotel aquarium, and the California Academy of Sciences' Steinhart Aquarium.