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constantly outdated shark taxonomy page, a monster list of shark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.
Other Names:維氏鰩China Mandarin, 维氏鳐China Mandarin Chinese,
Raie de VélezFranceFrench,
RaspstaartrogNetherlandsDutch,
Raya de VelezMexicoSpanish,
Raya de Velezi Spain Spanish.
Identification:
Disc width about 1.3 x length. Snout pointed. In
males, anterior margin of disc convex with distinct concavity about widway
towards wing tips. In females, anterior margin of disc is much straighter.
Posterior margin of disc rounded. Dorsum mid to dark brown. Prominent light
yellowish/tan occelli with two concentric dark rings, on each wing.
Patch of thorns
on each side of snout, level with eyes, close to disc margin. Centre line of
thorns runs from behind the eyes to the tip of the tail. Tail also has prominent
rows of thorns on each side running from base to tip - hence common name 'rasptail
ray/skate'.
Size: Maximum
length 75.6cm.
Habitat:
The velez skate can be found on sand bottoms and gravel substrates. From
35 to 300 meters but usually found between 35 and 140 meters.
Abundance and distribution: The velez ray can be found in the Eastern
Pacific from the Gulf of California to Peru including the Galapagos Islands.
Diet:
Crustaceans, polychaete worms and small
benthic fishes.
In Columbia, the main prey item of the velez skate was shown to be tiger shrimp
but fish were also heavily consumed
(Feeding ecology of elasmobranch fishes in coastal waters of
the Colombian Eastern Tropical Pacific
Andrés F Navia,1,2
Paola A Mejía-Falla,1,2 and Alan Giraldo2
- 2007)
Reproduction:
Oviparous. Little is known about the velez ray's reproductive cycle.
Vulnerability:
The IUCN is unable to estimate the catch trend or vulnrability due to the
deficiency of available data. However, the IUCN does provide this footnote:
Raja velezi is known to be taken in
shrimp trawl fisheries operating off Colombia, and is probably captured by trawl
and other demersal fisheries operating throughout its range. The shrimp trawl
fishery off Colombia operates from the shelf to depths of at least 300 m and
this species is a retained bycatch of this fishery (Puentes et al.
2007).
I have personally
witnessed velez skates being taken as bycatch by artisanal shark fishermen in La
Paz, Mexico. The fishermen released this skate and told me that it was not a
commercially sought after species.
Photographs:
Sea of Cortez, La Paz Bay, Baja, Mexico. Composite image.
Similar species:
There are a number of other skates inhabiting this region. In the Sea of Cortez,
the velez ray shares its range with R. cortezensis, R. equatorialis, Raja
inornata and R. rhina
Reaction to divers:
This skate does not inhabit depths frequented by recreational divers.
1,2
Paola A Mejía-Falla,1,2 and Alan Giraldo2
- 2007)
