Common
Names: Diamond
stingray
Latin
Name: Dasyatis dipterura, a.k.a. Dasyatis brevis.
Family:
Dasyatidae
Identification:
Rhomboid
disc. Anterior disc margins mildly
convex. Posterior disc margins more rounded. Dorsum tan to brown without obvious
markings. Ventrum pale. Tail thick for about one third of length followed by
deep dorsal and ventral finfolds. Last third of tail whiplike. Row of tubercles
down centre line of back from behind eyes to tail spine in front of dorsal fin
fold. Pronounced central body mass behind eyes often appears ribbed.
Size:
Maximum
length 1.5m maximum disc width 1.2m.
Habitat:
Sand,
mud, or rubble bottoms often near rocky reefs or kelp forests. Generally in
shallow water but recorded at 65m.
Abundance
and distribution: Eastern Pacific, from
Southern
California
to northern
Chile
and the
Galapagos
Islands
. Said to visit as far north as
British
Columbia
during periods of extreme
warm weather i.e. El Nino years. Uncommon in
Southern Cali
.
Common in Baja where it breeds in shallow water.
Behavior:
Rests
on bottom during day usually partially buried with only eyes and tail
protruding. At night hunts for crustaceans; crabs, shrimps, and bony fishes.
Often found in groups segregated by sex.
Reproduction:
Viviparous.
Litter size about 1 to 4. Males mature at 50 to 65cm disc width, females at
65cm. Gestation period is around 2 to 3 months and newborn pups have a disc
width of around 19 to 23cm.
Observations:
Photographs:
Los
Morros Reef, Cabo Pulmo, Baja.
Similar
species: Longtail
stingray – Dasyatis longus.
Reaction
to divers: Reputed
to be easily approachable I found these rays to be skittish and difficult to
approach. Perhaps in their cooler southern Californian range they are a little
more sluggish.
Diving
logistics: Cabo
Pulmo on Baja’s
Eastern Cape
has one of the best reef systems in the
Sea
of
Cortez
and is very popular with Diamond stingrays. One particularly reef is Los Morros
which is a favorite of Pepe – Owner of Pepe’s dive centre. The reef is ten
minutes from shore by panga and all supplies can be obtained from Pepe. I also
saw a Bentfin devil ray cruising over this site and all the reefs in this area
are meeting points for pelagics.
Getting
to Cabo Pulmo is half the fun as the last 15km is on a semi graded dirt road.
There are two other dive shops in the village but Pepe is the most
knowledgeable.
Other
diving locations submitted by readers:
References
and further reading:
Sharks,
Rays, and Chimaeras of
California
.
David A. Ebert.
University
of
California
Press.
Coastal
Fish Identification -
California
to
Alaska
.
Paul Humann. New World Publications Inc.
Reef
Sharks and Rays of the World. Scott W. Michael. Sea Challengers.
