Elasmodiver contains photos of sharks, skates, rays, and chimaera's
from around the world. Elasmodiver began as a simple web based
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
crests (brow bones) moderately high. Small dark spots on tan or grey body (spots
occasionally absent). Large, blocky, pig-like head. Dorsal spines present,
terminating well below tips of dorsal fins. Pectoral fins large. Jaw contains
anterior, pointed, clutching teeth andrear
molars. Dentition changes with age (adults have more prominent molars).
reefs and Kelp forests. Juveniles often in open sandy areas.
and distribution: Central California
to the Sea
and possibly South
Hides in crevices or caves during the day venturing out to forage at night. May
swim freely but is usually seen sluggishly moving along the bottom on its
muscular pectoral fins. Hunts for Urchins, crabs, worms, anemones, and bony
Oviparous.Lays a distinctive auger shaped egg case with two threadlike filaments
extending from one end. Egg hatches in 7 to 9 months.
Data Deficient. According to the IUCN, California horn sharks have a small home
range and exhibit long term site fidelity. They are hardy species and can
survive capture if returned to the water; however, catches in Mexico are
sometimes left to die on beaches. They are of no commercial value, although they
are taken as bycatch (primarily off Mexico). If the gillnet fishery in Mexico
expands significantly in the future, the population could potentially face
problems, however, insufficient information is available at present to assess
Heterodontus francisci beyond Data Deficient. However, it could well be Least
Concern in US waters where its capture in fisheries is extremely rare with no
other apparent threats.
La Jolla Cove, CA and Avalon,
bullhead shark - Heterodontus mexicanusshares the south range of the California Horn shark.
to divers: Easily
approached. Remains motionless unless molested. Caution should be taken around
easily observed whilst night diving. Catalina offers an excellent opportunity to
encounter this shark. Air and equipment can be obtained on the pier in Avalon
for shore diving purposes. Head out on the road past Lovers Cove South of town
and enter from the beach. This is a long hike if you’re wheeling your gear
along in a rented cart. Small Horn sharks are usually present in around 30ft of
water. The DivePark
at Casino Point right in Avalon may also be a reasonable place to look at night
but this area gets too much traffic during the day for reliable sightings.
diving locations submitted by readers:
Rays, and Chimaeras of California.
David A. Ebert. University
Fish Identification - California
Paul Humann. New World Publications Inc.
Sharks and Rays of the World. Scott W. Michael. Sea Challengers.
and Rays - Elasmobranch Guide of the World. Ralf M. Hennemann. IKAN.