Not just Shark
Pictures: Elasmodiver contains photos of sharks, skates, rays, and
chimaera's from around the world. It began as a simple web based
field guide to help divers find the best places to encounter
different species of sharks and rays but it has slowly evolved into
a much larger project containing information on all aspects of shark
diving and photography. There are now more than a thousand shark
pictures and sections on shark evolution, biology, and
conservation. There is a large library of reviewed shark books, a
constantly outdated shark taxonomy page, a monster list of shark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:
If you're looking
for a broader range of marine life pictures the following links
represent a new area of elasmodiver.com that contains pictures of
other marine organisms and of marine habitats. This expansion of
Elasmodiver is in its first stages but will eventually include pages
on all types of marine mammals, bony fishes and marine invertebrates
as well as coastal habitats, reefscapes and other imagess relating
to the ocean. Please return regularly to enjoy the progress.
Dorsum black or
very dark brown. No tail spines. Base of tail laterally compressed. Relatively
short cephalic lobes and long caudal filament (tail) compared to other
mobulids. Pale spot near free tip of dorsal fin.
Size: Maximum
disc width 120cm. Size at birth 55cm
Habitat:
Shallow inshore waters. From surface to sea
floor.
Abundance and distribution:
The Atlantic devilray is restricted to the Western
Atlantic from New Jersey in the north to Santos, Brazil in the south including
the Gulf of Mexico. Possibly also present in the Azores.
Diet:
The
Atlantic mobula feeds mostly of planktonic crustaceans
(mysid shrimp) but will also consume very small fishes.
Reproduction:
Ovoviviparous with one pup per lItter.
Atlantic devilrays reportedly swim venter to venter towards the surface while
mating.
Vulnerability:
The Atlantic devilray is assessed as 'data deficient' by the IUCN.
IUCN Quote: It
[the Atlantic devilray] is taken as bycatch in longline, net and possibly other
fisheries, but very little specific information is currently available on its
capture, abundance and population trends from across its range. Although trawl
survey data from the east coast of the USA suggests possible increasing trends
there, this represents the northern extent of its range, and further information
is required on its abundance and interaction with fisheries from the Caribbean
Sea and South America. This species is therefore assessed as Data Deficient
until population trends and the impact of fisheries can be determined.
Photographs:
Gulf of Mexico near Panama City, USA.
Similar species:
Mobula rays are very difficult to differentiate in the field. The Atlantic
devilray shares its range with the sicklefin devil ray Mobula tarapacana
which can be distinguished by its larger size, swept back pectoral fins, bluish
to olive grey dorsum and ventral markings which are pale anterially and dark
posterially with a distinct demarcation between the two shades. Other mobulas
have not been confirmed from the western Atlantic but some may be cicumtropical.
Reaction to divers:
Devil rays do not usually allow divers to get close
especially if they are producing noisy scuba bubbles. Patience and some skill at
breath holding may produce better results.
Diving logistics:
In the Pan Handle of Florida (Northern Gulf of Mexico) it may be possible to
encounter Atlantic devilrays while snorkeling off of the beaches. The images
shown here were taken during a jetty dive in Panama City in July. Mobulas often
migrate into warmer water in the winter so the best time to look for them in
their northern range is probably in mid to late summer.
