Porcupine Ray

When encountering a porcupine ray, maintain neutral buoyancy and stay slightly above or to the side of the animal to avoid kicking up silt from the seabed. Because these rays spend much of their time on soft bottoms, a careless fin stroke can instantly ruin visibility. While the species lacks a venomous stinging spine, its dermal thorns are exceptionally sharp and can cause painful lacerations; never attempt to touch or ride the ray. Approach slowly and smoothly without sudden movements. For underwater photographers, a wide-angle lens is essential to capture the ray's large, circular disc alongside its surrounding habitat. Use dual strobes pulled wide to highlight the intricate texture of the thorn-covered skin while minimising backscatter from sand clouds.

The porcupine ray can be observed year-round in tropical Indo-Pacific destinations, though peak liveaboard seasons offer the best visibility and conditions. In the Red Sea of Egypt and Sudan, encounters peak between May and October when waters are warmest. In Raja Ampat, Indonesia, the calmest seas and best diving run from October to April, whereas Komodo National Park offers superb encounters from May to October. For divers visiting Australia's Great Barrier Reef, the dry months between June and November deliver optimum water clarity on outer reefs. In the Maldives, the dry northeast monsoon from January to April offers excellent sandy lagoon and channel visibility.

The porcupine ray inhabits shallow coastal waters, continental shelves, and offshore coral reefs across depth ranges spanning from 1 to 50 metres, occasionally venturing deeper to around 100 metres. It displays a strong preference for soft sandy plains, rubble patches, seagrass beds, and the sandy margins of fringing reefs and drop-offs. Juveniles are frequently found in sheltered coastal lagoons and mangrove fringes, whereas adults favour exposed outer-reef sand chutes and coral overhangs. The waters this animal calls home encompass the tropical Indo-West Pacific, including the Red Sea, the East Coast of Africa, the Seychelles, the Maldives, Indonesia, the Philippines, northern Australia, and eastwards toward the Fiji islands.

The porcupine ray is a specialised benthic predator that feeds primarily on hard-shelled and infaunal invertebrates. Its diet consists of burrowing crabs, mantis shrimps, bivalve molluscs, polychaete worms, sipunculids, and small bottom-dwelling bony fishes. Hunting predominantly around dusk, through the night, and during overcast periods, the ray uses its sensitive electro-receptive ampullae of Lorenzini to detect prey hidden beneath the sand. Upon locating an organism, it uses its heavy disc and strong pectoral margins to forcefully blast water jets and excavate deep pits, sometimes digging over thirty centimetres into the sediment. Once exposed, prey items are crushed using broad, flattened pavement-like tooth plates capable of easily pulverising robust crustacean carapaces and mollusc shells before being ingested.