Seven Gill Sharks - Notorynchus cepedianus
Photo by PSRF
DESCRIPTION
7-gill sharks are distinguished by being the only shark species to have 7
gill slits. They also can be ID'd by having just one dorsal fin placed
way back near the tail which is very long. 7-gill sharks are a light
gray color with irregular dark or black spots or mottling.
7-gill sharks (Notorynchus cepedianus) are the principle large benthic
predator off of the coast of the central eastern pacific and can be
found in nearly all oceans and are rivaled only by the larger 6-gill
shark and the giant pacific sleeper shark.
7-gill sharks can be found seasonally in shallow waters 50'-100' but
they spend most of there time at great depths. 7-gill sharks can be
found in all of the worlds deepest oceans.
REPRODUCTION
Female 7-gill sharks give birth to live young that are approximately
14"-16" in. long. Gestation is believed to be around 10-12 months
with varying litters of 10-25 pups. 7-gill sharks mature at 8-12
years and at lengths of 7'-8' ft. maximum length is over 12' ft
and 1000 lbs.
BEHAVIOR
Not much is known about 7-gill shark movements or migrations but recent
tag and release studies have suggested a seasonal pattern residency.
In 1990 the Monterey Bay Aquarium captured an 11' ft long
7-gill shark in Humboldt bay and transported it to the
aquarium in Monterey, some 350 mile south of Humboldt.
The shark was the aquariums star attraction until 1994 when the
shark was released near the aquarium in Monterey. The shark had been
tagged with a Pelagic Shark Research Foundation tag and tracked
for several hours aboard "Pelagic I". In late 1996 the shark was
recaptured in Humboldt Bay very near where it had been previously
captured in 1990. This may indicate a strong association with
a "home range" or primary set of seasonal way points.
7-gill sharks have a wide selection of prey items and hunt and scavenge
at will. 7-gill harks eat other sharks and rays , black cod, hake, squid,
octopus, and dead whales. In alaska there are reports of large 7-gill
sharks attacking harbor seals.
| PSRF Director Sean Van Sommeran prepares to release a tagged seven-gill
shark, Notorynchus cepedianus during an excursion upon the San Francisco
bay. Seven-gill sharks are a principal benthic predator of the S.F bay
and
the PSRF is looking to gain insights into this creature's movements,
range
and distribution.
Sohst/PSRF
| 
Photo by PSRF
|
| 
