Common
Names: Banded Guitarfish.
Latin
Name: Zapteryx exasperata.
Family:
Rhinobatidae
Identification:
Disc width and length roughly equal. Snout
rounded. Anterior margin of disc fairly straight but pectoral fin tips and trailing
edges of pectoral fins broadly rounded. Body
narrows into a long tail
topped by two high dorsal fins of equal size. Thorns (enlarged denticles) extend in a single row along centre line of back and tail. Well developed
caudal fin. Dorsum color sandy brown with dark blotches and bands running
transversely across the body and tail. Bands between eyes and on snout are more
distinct. Rostral ridges run parallel along the snout. Ventrum pale.
Size:
Maximum
length 97cm. 15 - 22cm at birth.
Habitat:
Rocky reefs.
Intertidal
to about 20m. Maximum recorded depth
69m. Reports of banded guitarfish in tide pools.
Abundance
and distribution: Eastern Pacific from southern California to the Sea of Cortez
and possibly further south.
A common visitor to reefs in southern baja.
Behavior: Rests by day
in caves, under ledges, or in reef gullies. Rarely buries in sand. Feeds on
crustaceans and other benthic invertebrates. Swims by using powerful caudal fin.
Reproduction:
Banded Guitarfish are viviparous (without
a yolk
sac placenta).
Female Banded Guitarfish mate in March/April and give birth in shallow sandy bays in late
spring/summer.
Litters 4-11.
During copulation the male
holds onto the female's pectoral and pelvic fins with his teeth. When not enough
females are available the males may become frenzied in their attempts to
inseminate a partner. The female Banded Guitarfish pictured below, may have had
portions of her pectoral fins torn away from just such an encounter.
Photographs:
La Paz and Cabo Pulmo, Sea of Cortez,
Mexico.
Similar
species: The very similar Spotted Guitarfish
(Zapteryx xyster) displays scattered pupil sized yellow spots edged in black on
dorsum and ranges further south. The Shortnose Guitarfish (Zapteryx brevirostris)
differs in having rostral ridges that converge towards the tip of the snout.
Reaction
to divers: Very easy to approach.
The Banded Guitarfish usually remains motionless or moves slowly from rock to
rock in an effort to blend in. The female pictured above was so lifeless that I
was able to gently lift her up and move her into a better position to
photograph.
Diving logistics:
Banded Guitarfish congregate in the lower Sea of Cortez during the winter
months. In late February in Cabo Pulmo they were present during every dive on
the reef at about 50ft and I encountered one while snorkelling in a shallow bay
in the same area. Also during this time large schools of Mobula rays swarm over
the reefs making it a great location for ray enthusiasts.
Other diving locations submitted by readers:
Further
reading:
Sharks, Rays, and Chimaeras of
California. David A. Ebert
Reef Sharks and Rays of the World. Scott W. Michael. Sea Challengers.
Sharks
and Rays - Elasmobranch Guide of the World. Ralf M. Hennemann. IKAN.
