Not just a
huge collection of
Shark
Pictures:
Elasmodiver.com contains images of sharks, skates, rays, and a few
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 10,000 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:
Identification:
Dorsum grey/tan or mottled tan and brown with
irregular dark spots and lines. Ventrum pale. Anterior margin of disc straight with slight
concavity. Rear margin of body disc rounded. Snout angular with translucent
patches on each side of central ridge. Row of thorns on dorsal ridge from behind
eyes to dorsal fins. Tail with two relatively large, equally sized dorsal
fins near tip. Secondary shorter rows of thorns just behind eyes.
Size: Maximum
length 84cm.
Habitat:
Sandy or muddy substrates. Sometimes around rocky reefs. Intertidal to 330m but
usually from shallows to 50m.
Abundance and distribution: Restricted
to the Western Atlantic from Massachusetts to the Gulf of Mexico.
Behavior: Enters estuarine
environments in search of food. The clearnose skate
feeds mainly on decapod crustaceans, bivalves, polychaete worms, squids and
small fishes
Reproduction:
Mates in inshore bays. Oviparous.
Lays flattened egg cases on the sand. Egg cases have stiff pointed horns at the
corners.
Conservation Status: Least
Concern. According to the IUCN, the primary threat to this species is capture as
bycatch of otter trawls during groundfish trawling and scallop dredge
operations. Age data for this species are old, but suggest that females mature
at 46 years (the three generation period for this species may therefore be ~18
years). National Marine Fisheries Service (NMFS) trawl surveys indicate that
biomass of this species has steadily decreased over the last five years.
Analysis of trends in abundance of this species in six different scientific
surveys on the eastern coast of the USA (during various periods from 19662005),
found it to be increasing in three surveys, decreasing in one, with no apparent
trend in two others. The NMFS does not consider this species overfished in its
2006 assessment and, given that the overall population trend does not appear to
be declining this species is assessed as Least Concern. However, the declines
observed in some areas, coupled with the species potentially limiting
life-history characteristics suggests that population trends should be carefully
monitored. Further research on this species life-history and population
structure is also required.
Citation: Ha, D., Luer,
C. & Sulikowski, J. 2009. Raja eglanteria. In: IUCN 2013. IUCN Red List of
Threatened Species. Version 2013.1. <www.iucnredlist.org>.
Photographs:
Rhode Island, USA.
Similar species:
The clearnose skate shares its range with a number of other skate species
present along the eastern seaboard but no other shallow water skates display the
line and spot patterns of the clearnose skate or the translucent areas around
the snout.
Reaction to divers: Tolerant.
Remains motionless unless molested.
Diving logistics:
Clearnose skates can occasionally be seen on shallow shore dives from southern
New England southwards. If you are aware of any area where clearnose skates are
particularly common, please email Elasmodiver.