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WHAT IS ELASMODIVER? Not just Shark Pictures: Elasmodiver contains photos of sharks, skates, rays, and chimaera's from around the world. Elasmodiver began as a simple web based shark field guide to help divers find the best places to encounter the different species of sharks and rays that live in shallow water but it has slowly evolved into a much larger project containing information on all aspects of shark diving and shark photography. There are now more than 5000 shark pictures and sections on shark evolution, biology, and conservation. There is a large library of reviewed shark books, a constantly updated shark taxonomy page, a monster list of shark links, and deeper in the site there are numerous articles and stories about shark encounters. Elasmodiver is now so difficult to check for updates, that new information and pictures are listed on an Elasmodiver Updates Page that can be accessed here:
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SPINY BUTTERFLY RAY |
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Photograph copyright Andy Murch all rights reserved View all available Spiny Butterfly Ray Pictures Spiny Butterfly Ray, moth ray, butterflyray. More common names below text. Latin Name: Gymnura altavela Family: Gymnuridae Identification: Disc width roughly twice length. Dorsum covered in an intricate pattern of tiny lines and swirls that form light and dark brown spots and larger irregular circles fringed with white. Ventrum white, cream or with a pinkish hue. Short tail has one or two tail stings (unborn embryos already have fully formed tail stings). Dorsal fin absent. Very low dorsal and ventral finfolds on tail. Size: Wing span to 400cm. Habitat: Sandy or muddy bays and brackish estuaries, sometimes near rocky reef faces, and over sand flats. 2 to 100m depth. Abundance and distribution: Occurs in the eastern Atlantic Ocean from Portugal to Angola including the Canary Islands, Madeira, and the Mediterranean and Black Seas. Also occurs in the western Atlantic Ocean from Massachusetts to Argentina. Behavior: Lays motionless for much of the time under a thin covering of sand. Butterfly ray footprints or beds (indentations left in the sand) can often be seen days after the animal has moved on. Feeds on fishes, crustaceans, mollusks and plankton. Reproduction: Ovoviviparous. 4-7 embryos. Gestation lasts for about 6 months. Once the unborn spiny butterfly rays have completely used up the reserves in the yolk sac, the mother secretes uterine milk. Long villi (filaments) grow from the uterus walls into the embryo's spiracles. Milk can then be directed more efficiently into the embryo's mouth and throat. Photographs: Los Gigantes, Tenerife, Canary Islands, Eastern Atlantic Ocean. Similar species: Another species that shares the western range of the spiny butterfly ray is the Smooth Butterfly Ray Gymnura micrura. Reaction to divers: If buried in the sand, the spiny butterfly ray will often remain motionless while divers pass. Even after most of the sand has been fanned away (as in the above picture) these rays are likely to remain stationary as long as the observer uses slow, non threatening movements. Diving logistics: Spiny butterfly rays are fairly abundant around the Canary Islands. Reportedly, there is one that has taken up residence in the harbor on El Hiero. I have seen many beds in the El Cabron Marine Park but no actual animals. Occasionally spiny butterfly rays attend the organized ray feeds at Los Gigantes on Tenerife (where the featured specimen was seen). Los Gigantes Diving offers freestyle feeds once or twice per week. The divemaster takes a huge barrel of fish scraps to 60ft and offers them to the eagerly gathering ray species. After a while the human participants usually help themselves to some fish and wander off to interact with the rays on their own. The feed can be rather chaotic but the ray action is almost guaranteed. Attending species include common eagle rays, common stingrays, roughtail rays, round stingrays and occasionally angel sharks, butterfly rays, and marbled torpedo rays. Very occasionally a large Bull Ray swims by. Contact Los Gigantes Dive Centre for further information. Further reading: Sharks
and Rays - Elasmobranch Guide of the World. Ralf M. Hennemann. IKAN. Other names of the Spiny Butterfly Ray:
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