Ecological data of Spiny Butterfly Ray (Gymnura altavela) off Gran Canaria

Abstract

Overfishing and climate change are causing different effects on marine populations. Not only the target species are affected by overfishing, but also non-target species, which implies the degradation or elimination of their stocks. As a result, shark or ray populations are commonly affected, and Gymnura altavela is an example of colateral effects of nonselective fishing, according the IUCN Red List. Although this species is present along the Atlantic and Mediterranean coasts, incluiding the Canary Island, its biology and ecology is poorly know. The Spiny Butterfly Ray is present the year round in shallow waters of the island of Gran Canaria, being more frequent from May to September, in a temperatura range from 17 to 24ºC. It is normally observed resting alone on sandy bottoms, and probably it displays homing behaviour because, in the 35% of the reports, divers claim that some individuals are recurrent in certain places.