Common names
Porcupine Whipray, Porcupine ray.
Binomial
Urogymnus asperrimus.
Synonyms
Anacanthus africanus, Rachinotus africanus, Raja africana, Raja asperrima, Rhachinotus africanus, Urogymnosus africanus, Urogymnus africana, Urogymnus africanus, Urogymnus aperrimus, Urogymnus asperrimus solanderi , Urogymnus rhombeus.
Identification
A large stingray with a thick, oval disc that is equal to or very slightly narrower than long. Snout short, and obtusely angular or broadly rounded, with a small, protruding apical lobe at tip. Anterior margins of disc convex. Pectoral fin apices broadly rounded. Pelvic fins very short.
Eyes small and protuding. Snout length approximately 1.5-2x combined eye and spiracle length. Mouth wide with 3-5 short oral papillae. Lower jaw somewhat concave at symphysis. Labial furrows pronounced. Small, skirt-shaped nasal curtain with a long fringe on the posterior margin. Nostrils long and thin.
Disc densely covered in flattened plate-like denticles and large scattered thorns that are more concentrated near midline and dorsally on tail. Tail slender and short; length approximately equal to disc width. Tail tapers to caudal sting then slowly thins to tip. Caudal finfolds and stings absent.
Colour
Dorsum brownish, yellowish, pinkish grey, or black. Thorns often paler. Ventrum white, sometimes with a dusky margin. Tail beyond caudal sting black.
Size
Maximum disc width 115cm. Disc width at birth unknown.
Conservation Status
VULNERABLE
The porcupine whipray is a bycatch species that is retained in Indonesian net fisheries. It is now extremely rare in the Gulf of Thailand. The loss of coastal mangroves has likely been a major factor in this species’ declining numbers.
Previously caught in northern Australian trawl fisheries, but since the introduction of turtle exclusion devices, bycatch numbers have plummeted. The Porcupine Ray is considered to be potentially one of the most vulnerable chondrichthyans to the impacts of climate change in northern Australia.
Habitat
Tropical seas. In shallow sandy bays, coral reefs, sandy lagoons, mud flats, and mangroves. Intertiday to approximately 30m.
Distribution
Widespread but patchy throughout the Indo-West Pacific. Absent from the Americas. Possibly also in the eastern Atlantic around west Africa.
Reproduction
Matrotrophic viviparity. Litter size unknown.
Diet
The porcupine ray feeds mostly on marine worms, crabs, and bivalves.
Behavior
Feeds by ‘plowing’ through the substrate in search of buried prey species.
Reaction to divers
Quite easy to approach but will retreat if harassed.
Diving logistics
The porcupine whipray is an uncommon ray that is rarely encountered throughout most of its range. A nursery has been identified in the coastal lagoons near Ningaloo Reef in Western Australia. Sightings also occur with some regularity in shallow bays in Mozambique and further north in east Africa.
Numerous other locations likely exist where this ray can be found. Systematic searches of shallow lagoons virtually anywhere in the warmer parts of the Indian Ocean are the best places to start.
What’s new
View our full list of updates
Similar species
Mangrove Whipray Distinguishable by longer tail with caudal sting, and rough texture without large thorns.