Image Number: Pacific Nurse Shark 001
shark, nurse shark, Eastern Pacific nurse shark, cat shark, tiburon gato.
brown or grayish brown body, paling slightly towards belly. Two dorsal fins of almost
equal size close to tail. Head bulbous with small mouth. Mouth has a barbell on
each side. Tail narrow with a large upper caudal lobe and no distinct lower lobe.
The Pacific nurse is very similar to the more widely distributed Atlantic nurse
This species differs
posterior end of the second dorsal
the beginning of the caudal lobe, both being shorter; the new species also
differs by the position of the insertion of the first dorsal fin with regard to
in the form and number of keels on
the dermal denticles and teeth morphology.
Maximum recorded size 2.8m but may exceed 3m.
around rocky reefs from intertidal to at least 30m.
The recorded range of the Pacific Nurse Shark
is from the Sea of Cortez to Peru but it is more common in the centralk part of
its range around Panama and Costa Rica.
Sleeps under overhangs of reefs, or in mangroves during the day. Often found
sleeping in small groups. At night forages for spiny lobsters, crabs, octopus,
and sea urchins etc.
Not yet assessed by the IUCN but
Pacific nurse shark is
extremely scarce in comparison to its Atlantic cousin.
Although it is not directly targeted due to its paucity, the Pacific coast of
Central America is heavily fished so it is likely that when assessed, this shark
will eventually be listed as vulnerable if not endangered.
Playa Del Coco, Costa Rica.
The Pacific nurse shark is the only member of the
nurse shark family found in the Eastern Pacific and the only large brown shark
with barbells in the region. Reports of Atlantic (common) nurse sharks
Ginglymostoma cirratum from the Eastern Pacific are misidentifications of
Reaction to divers:
Much shyer than its Atlantic congener, probably due to its lack
of contact with divers. Often bolts when
approached but may allow divers and photographers to settle next to it if
approached slowly and in a non-threatening manner.
The Pacific nurse shark can be encountered by divers in Playa Del
Coco at a dive site called the Washing Machine. This is a shallow site at Isla
Catalina where up to a dozen or more animals congregate in a small hole in the
reef. Likely, they remain in this surge swept area because it is noticeably
warmer than deeper sites nearby. Unfortunately, the dive site is heavily
affected by the omnipresent Pacific swells so it is difficult to reach unless
conditions are very good. Even then, visibility can be poor, and the sharks tend
to bolt almost immediately.
The nurse shark aggregation at the Washing Machine was only recently discovered
so it is unclear if the sharks utilize the site all year long or if they remain
there only when the surrounding water is too cold. Six sharks were present when
I dove at this site in March 2019.
The Pacific nurse shark can also be encountered during the warmer months at one
or two sites around Coiba Island in Panama.
Image Number: Pacific Nurse Shark
Flores, Luis Fernando & Ramírez-Antonio,
Emmanuel & Angulo, Arturo & León, Gerardo. (2015). Ginglymostoma unami sp. nov.
(Chondrichthyes: Orectolobiformes: Ginglymostomatidae): una especie nueva de
tiburón gata del Pacífico oriental tropical. REVISTA MEXICANA DE BIODIVERSIDAD.
86. 48–58. 10.7550/rmb.46192.
Rosa, R.S., Castro, A.L.F., Furtado, M., Monzini, J. & Grubbs, R.D. 2006. Ginglymostoma
IUCN Red List of Threatened Species 2006:
on 02 April 2019.