Record of the Shark Carcharhinus longimanas,
Accompanied by Naucrates and Remora}
from the East-Central Pacific'
CARL 1. H UBBS2
IN THEIR MASTERLY TREATISE on th e sharks
T he lack of previous records from the
of th e western N orth Atlantic, Bigelow and eastern Pacific (see Beebe and Tee-Van, 1941,
Schroeder (1948: 354-364, figs. 64-65), in and Fowler, 1944) is explicable, for nearly all
unt angling some c omplicated synonymies, previous collecting has been near sho re, and
showed th at the pelagic species commonly Bigelow and Schroeder ind icate that th is
known as. Carcharhinus lamia (Risso) cannot species is more strictly pelagic than any other
bear thi s name, but sho uld be called C. in the Atlantic and is more definitely tropical
longimanus (Poey). Th e literature is in such than mo st of them . The new Pacific record
confusion that the y were unable to verify the . station lies far off Me xico and east-southeast
occurrence of this species in any ocean other of the Hawaiian Islands.
The circumstances of the capture of the
th an the Atlantic. It is therefore gratifying to
obtain evidence promptly that it also inhabits Pacific specimen are given in the log of the
the eastern tropical Pacific. This evidence is " Serrano, " as follows:
provi ded in the form of a photograph of an 27 May 1949, 1516 PST. A gray shark with
adult female specimen caught at Lat. 080 16' white fin and tail tips was observed swimming
N ., Long. 1250 43' W., by A. J. Carsola and around the ship about this time; three fish,
Jeremiah F. Black of the United States Navy each about one foot long and deco rated by
Electronics Laboratory, on the ship " Serrano."! transverse black and silver stripes maint ained
This picture ~Fig. 1) correspo nds very closely formation with the shark , one being about a
with Bigelow and Schroeder's figure of an foot in front of him , another just below his
adult female, especially in the highl y diagnos- body mid-section and another just above him.
The shark was baited with a ligh t hoo k and
tic feature s of the broadly round ed first dorsal
line, shot, and pulled onto deck (see picture).
fin, th e markedl y enlarged and round-tipped
The banded fish were of cour se Nau crates
pectoral fin, the con vex posterior border of the
ductor
(Linnaeus). Like the Carcharhinus th at
lower caudal lobe, the size and position of
they
were
accompanying, the pilotfish are rethe anal and second dor sal fins, the extremely
ferable
to
a circum tro pical species. It is true
short snout in front of the nos trils, and the
that
Fowler
(1905: 62-65, fig . 3) described
coloration. There can be virtually no doubt as
the
Pacific
form
as a distinct species, Nau to the identifi cation.
crates polysarcus, partly on the basis of difICo ntribu tions from the Scripps Instit uti on of O cean- ferences pointed out by Gilt (1862: 440- 441),
ography, N ew Series, No . 493. M anu script received
but it now seems likely that th e distinction
Febru ary 1, 1950.
was
based on juvenile characters . The sup' Professor of Biolog y, Scripps Institution of Oc eanograph y, Uni versity of Californ ia, La J olla.
po sedly deeper bod y and the lon ger fins may
3T hanks are due E. R . And erson of the United States
well be characters of the young . Meek and
Nav y Electro nics Labor ator y for the tran smissio n of
Hildebrand
(1925: 401) stated th at "the
data, ph ot ograph , and specimen.
[78 ]
Carcharhinus longimanus- HuBBs
FI G. 1. Adult
U. S. N AVY.
fem ale of Carcharhinus /ongimanus (Poey), from the east-central Pacific.
79
OFFICIAL PH OTOGRAPH,
young appear to be deeper and more stron gly fins ascribed by Fowler to the Atlantic form.
' compressed than the adult"; Wakiya (1924 : Recentl y, Fowler (1944: 423, 500) treated
' 232, pI. 38, fig. 2), however , indicated that polysareus as a subspecies of ducto r.
the young of " N auerates indices" are more
From the shark there was taken a specimen ,
slender than the adult. The original figure of 105 mm. long, of another circumtropical
N . polysarcus sug gests that the extreme depth species, Remora remora (Linnaeus). It agrees
ascribed to the type may be attributed to its satisfactorily with material from southern
poor preservation. The different scale count, California.
also emphasized by Fowler, is prob ably not
The specific integrity of such circum significant, for the scales are too irregularly tropical pelagic fishes poses a problem in
arranged to be counted precisely. J ordan and speciation, since widespread littoral types of
Starks (1907: 72) foun d that the supposed the tropics ? as well as mos t pantemperate
characters do not hold for a Pacific species, types, in contrast, are ordinarily differentiated
and Meek and Hilde brand , though failing to into allopatric subspecies or species, though
include polysareus in their synonymy, refer their period of isolation has ordinarily been
Pacific material to N. duetor. Walford (1937: no longer, often briefer, than that of the land66-68) likewise referred the Pacific form to separated popul ations of the tropical pelagic
N. duetor (and by mistake labeled the figure, forms . The explanation seems to lie both in
which was taken from J ordan and Evermann , the uniformity of the tropical pelagic enas " from Jordan an~ Mc Gregor , 1898" ). An vironment and in the relationship between the
adult specimen 325 mm . in standard length, population structure and the rate of speciarecentl y received from off the Pacific coast of tion . Large, widespread populations that are
Me xico, has the slender form and the short no t disrupted into effective reproductive units
·PACIFIC SCIENCE, Vol. V, January, 1951
80
are now generally held, on the basis of
Wright's analyses (1940a, b; 1942), to be
little sub ject to differentiation.
ADDENDUM
catch is not specified, but the context indicates that it was in the South Equatorial
Current somewhere between Peru and the
T uamotu Archipelago.
REFERENCES
After this manuscript was submitted for
publication, Springer (1950: 2, 7-8) erected a BEEBE, WILLIAM, and J OHN TEE-VAN. 1941.
distinct gen us, Pterolamia, for th e reception of
Eastern Pacific expedi tions of the New
Carcharhinus longimanus and , probably also, of
York Zoological Society . XXV. Fishes
C. insularum (Snyder), a species described
from the tropical eastern Pacific. [From
from the Hawaiian Islands. He separated th is
Cedros Island, Lower California, south to
nominal genus from Eulamia solely on the
the Galapagos Islands and northern Peru .]
basis of the rou nded tips of the dorsal and
Part 2. Sharks . Zoologica 26: 93":'122, figs.
pectoral fins. Since the sharpness of these fins
1- 34, pls, 1- 2.
varies considerably and since the round ed
BIGELOW, HENRY B., and WILLIAM C.
tips seem to invo lve merely the reten tion of
SCHROEDER. 1948. Fishes of th e western
an embryonic feature, I am disinclined to acN orth Atlantic. Sharks . Sears Found. M ar.
cept the generic separation. Some other
Res., M em. 1, Pt. 1, Chap. 3: 59-5 76, figs.
species of Carcharhinus, for examp le, C. falci6-106.
formis (M uller and Henle) as described by
Bigelow and Schroeder (1948 : 329-333, figs. FOWLER, HENRY W . 1905. New, rare or littleknown scombroids. No. II. A cad. Nat.
56-57), have the pectoral scarcely more
Sci. Phila., Proc. 57: 56-88, figs. 1-5.
pointed than in C. longimanus and have the
dors al distinctly though less broadly rounded . - - -. 1944. Results of the Fifth George
Nor does Springer's separation of Eulamia
Vanderbilt Expedition (1941) (Bahamas,
from Carcharhinus seem justified on the basis
Caribbean Sea, Panama , Galapagos Archi of the presence or absence of a middorsal
pelago and Mexican Pacific islands). The
ridge-a very ten uous distinction that defishes. A cad. N at. Sci. Phila., Monogr. 6:
pends in large part on the condition of preser 57-529, figs. 1- 268, pls. 1-20.
vation and that seems to be inconsistent, in
GILL, THEODORE. - 1862. Synopsis of the
some species at least .
carangoids of the eastern coast of North
That Carcharhinus longimanus may be coinAmerica.
A cad. Nat. Sci. Phila., Proc. 1862:
mon in the open equatorial Pacific is sug430-443.
gested by a picture in the recently published
book Kon-Tiki, sho wing nine sharks caught HEYERDAHL, THOR. 1950. Kon-Tiki. Across the
in one day (Heyerdahl, 1950: lower figure of
Pacific by raft. 304 pp ., 40 pls. Rand
2d pl. following p . 176; accompanying text
M cN ally & Co., Chicago.
apparently on pp . 205-206). So far as is ob vious all sharks in this picture seem referable J ORDAN, D AVID STARR, and EDWIN CHAPIN
STARKS. 1907. Notes on fishes from the
to the pelagic species under discussion. This
island
of Santa Catalina, sou thern Caliidentification is ventured on the basis of the
fornia . U. S. Natl. Mus., Proc. 32: 67-77,
showing of certain diagnostic characters, in
figs.
1-8.
particular the broadly rounded pectoral fins,
MEEK,
SETH E., and SAMUEL F. HILDEBRAND.
much lon ger than the head; the far-forward
1925.
Th e marine fishes of Panama. Field
position of the nostrils on the very short,
Mus. N at. Hist., Publ. 226 (Zoo1. Ser., 15):
strongly rounded, laterally angulated snout;
i-xix, 331- 707, pls. 25-71 .
and the plain coloration. The location of the
Carcharhinus longimanus- HuBBS
SPRINGER, STEWART. 1950. A revision of
N orth American sharks allied to the genus
Carcharhinus. Amer. Mus. Novitates 1451:
1-13.
81
WRIGHT, SEWALL. 1940a. Breeding structure
of populations in relation to speciatio n.
Amer. Nat. 74: 232-248, figs. 1- 3.
WAKIYA, YO]IRO. 1924. The carangoid fishes .
ofJapan. Carnegie Mus ., Ann. 15: 139-292,
pls, 15- 38.
- -- 1940b. The statistical consequences of
heredity in relation to speciation. In: The
N ew Systematics, pp . 161-183, figs. 1-7.
Oxford Uni versity Press, Oxford.
WALFORD, LIONELA. 1937. Marine gamefishes
of the Pacific Coast from A laska to the Equator. xxix+205 pp ., many figs., pis. 1- 69.
University of California Press, Berkeley.
- -- 1942. Statistical genetics and evolution. Amer. M ath. Soc., Bul. 48: 223-2 46,
.figs. 1-10.