NOTES 
Notes on the Coloration and Behavior of the Common Dolphin, 
Coryphaena hip pur us 
A. Earl Murchison and John J. Magnuson 1 
While studying scombrid fishes at the Kewalo 
Basin tank facility of the U. S. Bureau of Com- 
mercial Fisheries Biological Laboratory, Hono- 
lulu, Hawaii, we noted similarities between the 
behavior of the common dolphin, Coryphaena 
hippurus Linnaeus, and that of the scombrids. 
These similarities led us to observe the colora- 
tion, swimming speed, and behavior of C. hip- 
purus incidentally to the studies on scombrids. 
Most observations were made on five captive 
specimens in shoreside tanks during July- 
September 1962. Additional observations were 
made at sea through underwater viewing ports 
from a raft. 
The C. hippurus specimens had been caught 
by trolling with barbless hooks, transported in 
a baitwell of a commercial fishing boat, and 
transferred at shore by dip net to a portable 
2300-1 tank from which they were allowed to 
swim directly into the shoreside tank in the 
manner described by Nakamura (1962, Copeia 
1962 ( 3 ) : 449—5 05). The outdoor tank was 
circular, 24 ft in diameter, and 3 V 2 ft deep, and 
had an observation window in its wall. Water 
temperature in the tank was about 24° C dur- 
ing the day and 22° C at night. Salinity was 
33% 0 . 
All five fish eventually jumped out of the 
tank and died, the last after 45 days in cap- 
tivity. 
The C. hippurus averaged 76 cm in fork 
length and 3.7 kg in weight. They were fed 
5-7-gm pieces of beef liver and whole thawed 
night smelt, Spkinchus starksi (Fisk), which 
weighed approximately 12 gm. When fed at 
24-hr intervals, the fish ate 334 gm per feed- 
ing, approximately 9% of the body weight. 
Although C. hippurus have been reported 
1 U. S. Fish and Wildlife Service, Bureau of Com- 
mercial Fisheries Biological Laboratory, Honolulu, 
Hawaii 96822. Manuscript received May 18, 1965. 
by many authors to exhibit a changing array of 
many brilliant colors, their basic coloration in 
the tanks and at sea varied between two ex- 
tremes. One was a silver-blue phase similar to 
that illustrated by the Fisheries Society of Japan 
(1931, Illustrations of Japanese Aquatic Plants 
and Animals, I, PI. XXX). The other extreme 
was a yellowish phase similar to that illustrated 
by Walford (1937, Marine Game Fishes of 
the Pacific Coast, Alaska to the Equator, Univ. 
Calif. Press, Berkeley, PI. 43) and noted by 
Gibbs and Collette (1959, Bull. Mar. Sci. 
Gulf Carib. 9(2) :122) and Rothschild (1964, 
Copeia 1964 (2) : 445-447). Intermediate 
shades between these two extremes occurred. 
The intermediates were various hues of green- 
ish-blue or greenish-yellow and apparently 
resulted from the combined effects of the blue 
and the yellow coloration. 
In the extreme silver-blue phase the body 
and caudal fin were silver-blue. The extreme 
ventral body surface was silver-white. The 
dorsal fin, the dorsal surface of the pectoral 
fins, and the lateral surfaces of the pelvic fins 
were blue. Dark blue spots 3-5 mm in diameter 
were scattered over the body. 
In the extreme yellow coloration, more evi- 
dent at sea than in tanks, the caudal fin, the 
anal fin, the outer surface of the pelvic fins 
and the dorsal surface of the pectoral fins 
turned bright yellow while the head and body 
turned greenish-yellow. The same dark-blue 
spots were present. 
C. hippurus observed through underwater 
viewing ports from a raft, Nenue, described by 
Gooding 2 tended to take on the yellow colora- 
tion just after reacting to food or just after a 
transient barred coloration described below 
2 Gooding, Reginald M. 1965. A raft for direct 
subsurface observations at sea. U. S. Fish Wildl. 
Serv., Spec. Sci. Rep. Fish. 517. 5 p. 
515 
