Bull Ray

Encounters with bull rays typically take place over open sandy seabeds, coastal bay slopes, or near estuaries and lagoon entrances in depths ranging from 10 to 65 metres. Juvenile rays are commonly spotted in shallow sandy coastal waters between 10 and 15 metres deep. Because bull rays are generally non-aggressive, observing them is safe provided divers maintain respectful etiquette and avoid harassing or startling the animals.

When approaching a bull ray resting on or feeding in the sand, swim slowly and stay low near the substrate without making sudden movements. Never approach a ray directly from behind or crowd above it, as cornering the ray may trigger a defensive reaction. Bull rays possess a long, sharp barb at the base of their tail capable of inflicting painful wounds if the animal feels threatened. Maintain a comfortable side-by-side distance, allowing the ray a clear escape path into deeper water. If the ray begins flapping its pectoral fins rapidly or swims away, do not pursue it. Divers can assist conservation efforts by photographing the unique blue patterns on the ray's back and submitting clear dorsal images to local elasmobranch tracking projects.

Bull rays display clear seasonal migration patterns and site fidelity, driven by changes in water temperature and breeding cycles. In the northeastern Atlantic and Canary Islands, sightings peak during the warmer months. For example, in Gran Canaria, rays and juveniles are frequently encountered in shallow bay environments and mixed coastal bottoms during winter (March to April) and late summer to autumn (August to October).

In the Mediterranean Sea, bull rays aggregate seasonally in specific coastal waters to reproduce. Schools have been documented crossing international maritime boundaries during warmer periods, such as in the northern Adriatic Sea off Italy, Slovenia, and Croatia, as well as along the coasts of Turkey, Tunisia, Israel, and Greece. In South Africa, tagged individuals have demonstrated extensive seasonal migrations exceeding 900 kilometres along the coast between Saldanha Bay and KwaZulu-Natal or Mozambique. Diving in these regions is best timed during local summer and autumn months when warmer sea temperatures draw mature rays into shallow coastal shelf zones and nursery bays for courtship and pup birth.

The bull ray is a benthopelagic and epipelagic elasmobranch that inhabits tropical to warm temperate coastal marine environments. Its recognized geographic distribution spans from the eastern Atlantic Ocean—from Portugal and Spain down past the Canary Islands and West Africa to South Africa—and extends into the western Indian Ocean up to Mozambique, Zanzibar, and Kenya. It is also widespread across the Mediterranean Sea, though its presence there is increasingly rare.

Vertically, the species occupies a broad depth range from the shallow surf zone and intertidal beaches down to 65 metres, with some records extending down to 150 metres. Adults spend significant time in shallow waters under 30 metres deep, where they are vulnerable to coastal fisheries. Bull rays frequently enter brackish coastal habitats, including estuaries and semi-enclosed coastal lagoons, where prey is abundant and sheltered bays serve as critical nursery grounds for growing juveniles. They utilize both soft sandy or muddy seabeds for foraging and open water columns for cruising and migrating between feeding grounds.

Bull rays are specialized benthopelagic feeders, actively hunting for food both directly on the seabed and within the surrounding water column. Their diet consists primarily of benthic invertebrates, including swimming crabs, hermit crabs, prawns, squids, and a wide variety of molluscs. They consume both gastropods and bivalves, such as clams and oysters, which sometimes brings them into conflict with commercial shellfish aquaculture farms.

To capture buried prey, the bull ray uses its long, flat, duckbill-like snout as a plow to excavate the sandy or muddy seafloor. Once an invertebrate is uncovered, the ray uses its mouth to capture the prey. To process hard-shelled organisms like crabs, clams, and snails, bull rays possess specialized heavy pavement-like tooth plates arranged in a mosaic pattern across their jaws. These flattened plates easily crush the protective shells of molluscs and crustaceans, allowing the ray to digest the soft tissues inside. Foraging typically occurs along coastal sandflats and estuarine channels where benthic invertebrates aggregate in high numbers.