Devil Ray in Mauritius: Everything You Need to Know

The Devil Ray (Mobula mobular), known in Mauritius as the Raie Diable, is one of the most spectacular marine animals that graces the island's waters. Belonging to the family Mobulidae — the same family as the iconic manta ray — the Devil Ray is distinguished by its cephalic fins, which curl forward like small horns, giving it its devilish nickname. Despite its fearsome appearance, this creature is entirely harmless to humans and feeds exclusively on zooplankton and small fish.

Physical Characteristics

The Devil Ray (Mobula mobular) is the largest of the mobula species, with a disc width that can reach up to 5.2 metres and a weight exceeding 350 kilograms. Its dorsal surface is a striking dark grey to black, while the ventral side is creamy white, a classic countershading pattern that provides camouflage from both above and below. The long, whip-like tail, often tipped with a small spine, adds to its dramatic silhouette. Unlike manta rays, Devil Rays are known for their spectacular acrobatic breaching behaviour — launching their entire bodies clear out of the water in breath-taking displays that can be witnessed from the surface.

Behaviour and Ecology

Devil Rays are highly social animals, frequently travelling in groups ranging from a few individuals to aggregations of hundreds. They are pelagic by nature, spending much of their lives in open water, though they are occasionally drawn closer to reef systems and seamounts where upwellings concentrate their planktonic prey. Their breaching behaviour is thought to serve several purposes, including communication, parasite removal, and courtship. In Mauritius, divers and snorkellers lucky enough to encounter these rays are often treated to fly-past formations as the animals cruise gracefully in loose groups.

Where to See Devil Rays in Mauritius

While encounters with Devil Rays in Mauritius are inherently unpredictable given their pelagic lifestyle, certain dive sites and areas have become known for seasonal sightings. The west and north coasts of Mauritius, with their clear blue waters and proximity to deep oceanic channels, provide ideal corridors for these rays. The waters around Coin de Mire (Gunner's Quoin) in the north are particularly renowned, as the island's seamount-like topography attracts large concentrations of marine life. Divers exploring the outer reef walls and blue water drop-offs stand the best chance of crossing paths with these magnificent animals.

When to See Them

Devil Rays are a seasonal visitor to Mauritian waters, with sightings most frequently reported between November and April, during the warmer austral summer months. During this period, water temperatures rise and plankton blooms increase, drawing these filter feeders closer to the island. Early morning dives tend to yield the best results, as rays are often more active near the surface during cooler parts of the day.

Conservation Status and Threats

The Mobula mobular is listed as Endangered on the IUCN Red List, facing significant pressures from targeted fisheries, bycatch in large-scale nets, and the international trade in gill plates. Their slow reproductive rate — producing only a single pup every one to three years — makes population recovery extremely difficult. In Mauritius, Devil Rays benefit from the country's growing commitment to marine conservation, and encounters are always conducted respectfully, with a no-touch, maintain-distance policy encouraged by responsible dive operators.

Tips for Divers

• Keep your distance: Approach slowly and avoid sudden movements that may startle the rays.
• Avoid bubbles near the animals: Fin gently and remain calm to extend the encounter.
• Go blue water diving: Devil Rays are pelagic; be prepared for open water conditions and potentially strong currents.
• Choose responsible operators: Book with dive centres that follow marine wildlife interaction guidelines.

An encounter with a Devil Ray in Mauritius is one of the most humbling experiences the Indian Ocean can offer — a reminder of the extraordinary wildness still thriving beneath the surface.