Butterfly Ray

The Butterfly Ray, typified by the spiny butterfly ray (Gymnura altavela), belongs to the family Gymnuridae and is named for its extremely broad, wing-like disc that is proportionally wider than that of almost any other ray, giving it a butterfly-like silhouette. It is found in warm temperate to tropical waters of the eastern and western Atlantic, including the Mediterranean Sea, typically over sandy coastal seabeds. Unlike many other stingrays, it has a very short tail relative to its disc size. It is considered Vulnerable to Endangered in various parts of its range due to incidental capture in coastal trawl and net fisheries.

• Disc: extremely broad and flattened, diamond-shaped, noticeably wider than long
• Color: brownish-grey to olive above, often with faint mottling, pale to white below
• Tail: unusually short relative to disc size compared to most other stingrays
• Eyes: small, set close together on top of the head
• Size: disc width up to roughly 2.2 m

The exceptionally wide, flattened disc combined with a proportionally very short tail is the clearest way to distinguish butterfly rays from long-tailed whiptail stingrays of similar size.

Butterfly rays inhabit warm temperate and tropical coastal waters of the Atlantic Ocean, including the Mediterranean Sea, ranging from the northeastern United States and southern Europe south to West Africa and South America. They favor shallow, sandy or muddy seabeds in bays, estuaries, and nearshore coastal waters, typically at depths less than 100 m, often partially burying themselves in sediment. Their preference for soft-bottomed, sandy nearshore habitat makes them susceptible to bycatch in coastal bottom trawl fisheries operating in similar depths and substrates.

Butterfly rays are bottom-associated predators that lie partially buried in sand, ambushing small fish, crustaceans, and mollusks that venture close, and using rapid disc movements to trap and pin prey. Their short tail and broad disc make them efficient at sudden bursts of swimming just above the seabed rather than sustained cruising. Reproduction is ovoviviparous, with females giving birth to relatively large litters of pups compared to many other ray species after an internal gestation period. Because of their coastal, soft-bottom habitat preference, they are frequently caught incidentally in shrimp trawl and other coastal net fisheries, a major factor in regional population declines.