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constantly outdated shark taxonomy page, a monster list of shark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 that contains pictures on other marine organisms and on
marine habitats. This expansion of Elasmodiver is in its first
stages but will eventually include pages on everything from sea
stars to nudibranches. Creating this portal will take time and for
now it consists of a token offering of fish pictures. Please return
regularly to enjoy the progress.
Easily distinguished by bold pattern of large dark saddles extending from the
head along the back. Centre of saddles lighter in adults. Saddles are separated
by smaller dark spots on a cream to grey/brown background. Overall body shape is
elogated and slender. Second dorsal proportionately large. Pectoral fins
falcate. Snout broadly rounded with widely spaced nasal flaps that do not reach
mouth.
Albino Leopard sharks have rare but have been recorded.
Size:
Maximum recorded size 180cm. Size at birth 20cm.
Habitat:
Prefers shallow sand flats and
confined muddy bays. Likes turbid water. Occasionally in or near kelp beds on
rocky substrate.
Abundance
and distribution:
Confined to the temperate and tropical coastline between Oregon
and Southern Baja including the Sea of Cortez. Often seen in large aggregations
close to shore. Usually intertidal to 4m but has been recorded as deep as 91m.
Diet:
Hunts over sand in search of
burrowing invertebrates such as worms but will feed opportunistically on a wide
variety of animals including crustaceans, squid, bony fishes, and small sharks
and rays (mainly other smoothhounds, bat rays and guitarfishes).
Behavior:
The Leopard Shark sometimes forms nomadic schools with other species especially
the Grey Smoothhound (Mustelus californicus) and Spiny Dogfish (Squalus
acanthias). Usually maintains a small home range but can roam up to 150km. A
strong swimming shark that can occasionally be seen resting among rocks.
Reproduction:
Ovoviviparous
with no yolk sac placenta.
Recorded litter size 4-29. Gestation period approx. 12 months.Slow growing and late to mature.
Photographs:
The Marine Room,San Diego,
California.
Similar species:
Although the Leopard Shark can be found with other smoothhound sharks it's
striking pattern makes misidentification unlikely.
Reaction to divers:
Skittish. Best approached on snorkel but difficult to get close to. Apparently
easier to approach at night. Due to their small size Leopard Sharks do not pose
a threat to divers or snorkellers. But a Leopard Shark was responsible for an
attack on an Aquarium Diver (Dean Fessler of the Shark Research Institute) while
he was feeding the sharks in front of a large group of spectators. The way Dean
explains it, the offending Leopard Shark accidentally bit his cheek while
attempting to take the bait which was floating free in front of Deans face. A
large flap of skin was torn away resulting in a huge cloud of blood that
terrified the crowd and put an abrupt end to the "most sharks aren't really
dangerous" speech that he was conducting.
Diving
logistics:
It is usually possible to find Leopard Sharks throughout the summer and early
fall directly in front of the Marine Room Restaurant in La Jolla.
Why the sharks like this spot isn't clear but it may simply be that they patrol
the entire coastline and this is where the snorkellers enter the water to see
them.
A good way to get closer to the sharks is to carry some fish but note that La
Jolla is a protected area and feeding or harassing the marine life within the
park is illegal.
Other diving locations submitted by
readers:
Ron Clough (Organizer of the California Shark and Ray Count) suggests that any
places where warmer than normal water flows into the sea (e.g. from power
plants) Leopard Sharks are likely to be seen.
References
and further
reading:
Sharks, Rays, and Chimaeras of
California. David A. Ebert. U of C Press.
Sharks of the World. Leonard
Compagno.
Sharks
and Rays - Elasmobranch Guide of the World. Ralf M. Hennemann. IKAN.
