Cowtail stingray
A widespread Indo-Pacific stingray valued for its shagreen leather.
The cowtail stingray (Pastinachus sephen) belongs to the Dasyatidae family and is found across the Indo-Pacific, sometimes venturing into freshwater. It is also called the banana-tail ray, drab stingray, fantail ray, feathertail stingray, or frill tailed sting ray. Taxonomically, it has been placed in the genera *Dasyatis* or *Hypolophus* (an outdated synonym for *Pastinachus*). Its most recognizable feature is the large, flag-like fold of skin on the underside of its tail, which becomes especially visible when the ray swims. This species is heavily fished for its high-quality shagreen leather, and its populations are now threatened by this intense exploitation.
**Distribution and habitat** These rays inhabit tropical waters of the Indo-Pacific, ranging from South Africa and the Red Sea to Japan and Australia, including Melanesia and Micronesia. They are amphidromous, meaning they move between salt and fresh water, and are known to enter estuaries and rivers. In Southeast Asia, they are the stingray species most often reported from freshwater, with one record from the Ganges River 2,200 km (1,400 mi) inland. They typically live on sandy bottoms in coastal waters and coral reefs, down to a depth of 60 meters (200 feet).
**Description** The pectoral fin disk is very thick, with nearly straight front edges and rounded tips; its length is 1.1 to 1.3 times its width. The snout is broadly rounded and blunt. The eyes are very small and set far apart. The narrow mouth holds 20 rows of distinctive hexagonal, high-crowned teeth in each jaw, along with five papillae on the floor of the mouth. The tail is broad at the base, ends in a filamentous tip, and carries a single venomous spine located well behind the pelvic fins. There is no upper tail fold, but the high ventral fold is 2 to 3 times the height of the tail and does not reach the tip. A broad band of fine dermal denticles covers the disk from near the snout tip to the upper tail surface, leaving only the disk margins bare. Newborns are smooth but develop denticles soon after birth. Juveniles have four circular tubercles at the disk center, which often become indistinct in adults. The upper body is a uniform grayish brown to black, while the underside is mostly white; the tail fold and tip are black. This ray can reach 3 meters (9.8 ft) in total length, 1.8 meters (5.9 ft) across, and weigh up to 250 kg (550 lb)
Quick Facts
- Genus
- Pastinachus
- Species
- sephen
Facts from the source article.
Lore & Background
The cowtail stingray has a widespread distribution in the tropical waters of the Indo-Pacific, from South Africa and the Red Sea to Japan and Australia, including Melanesia and Micronesia. It is amphidromous and known to enter estuaries and rivers; it is the most commonly reported stingray from fresh water in Southeast Asia, with a record from the Ganges River some 2,200 km from the sea. It is usually found on sandy bottoms in coastal waters and on coral reefs to a depth of 60 meters.
The most distinctive characteristic is the large, flag-like ventral fold on its tail, which is especially prominent when swimming. The pectoral fin disk is very thick, with almost straight anterior margins and rounded apices. The snout is broadly rounded and blunt, the eyes are very small and widely spaced, and the mouth is narrow with 20 rows of distinctive hexagonal, high-crowned teeth in each jaw and five papillae on the mouth floor. The tail is broad-based with a filamentous tip and a single venomous spine located well backwards of the pelvic fins. The disk surface is covered by a broad band of fine dermal denticles; newborns are entirely smooth but develop denticles quickly after birth. Coloration is uniform grayish brown to black above and mostly white below, with the tail fold and tip black.
Cowtail stingrays are solitary foragers that feed on bony fishes, crustaceans, polychaete worms, sipunculids, and molluscs. They are preyed upon by various species of hammerhead and requiem sharks, as well as by the bottlenose dolphin. When threatened, they consistently flee at a 45° angle away from the predator. Reproduction is ovoviviparous, with females giving birth to live young. In Shark Bay, Australia, they enter shallow, sandy flats during high tide to rest for a minimum of four hours, often forming small groups of three individuals in a 'rosette' formation with tails pointing outward as an anti-predator behavior.
Reader's Guide
The cowtail stingray holds significant economic and cultural importance as the primary source of shagreen or galuchat, a type of leather valued since ancient times due to the large size and regular arrangement of its dorsal tubercles, called 'pearls' in the trade. This species is targeted by commercial fisheries for this high-quality leather, and a boom in the international shagreen trade since the 1990s has led to enormous numbers being harvested in Southeast Asia. The material is used in many fashion accessories, from wallets to fancy pens. As stingrays are slow-reproducing, long-lived animals, there are fears that this unregulated exploitation is unsustainable and will lead to a population collapse. Additionally, small to moderate numbers are caught as bycatch in trawls and marketed for meat throughout their range, and their tough skin is used to polish wood. The serrated spine is potentially dangerous, and this species is regarded as particularly dangerous to handle because its long tail can reach over its back to strike someone gripping it from the front.
Did You Know?
- The cowtail stingray's ventral tail fold measures 2-3 times the height of the tail but does not reach the tip.
- In Shark Bay, Australia, they form resting groups of typically three individuals arranged in a 'rosette' formation with tails pointing outward.
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