SQUIDS FOUND IN THE STOMACH OF SPERM WHALESIN THE NORTHWESTERN PACIFIC*T AKEHIKO KAWAKAMI
Tokai Regional Fisheries Research Laboratory, TokyoABSTRACT

The squids obtained from the stomachs of sperm whales caught offJoban, the northwestern Pacific in November, 1972 were examined.
It was found that the squids were the most important food for sperm
whales in this sea area. The species found were Moroteuthis robusta,
Gonatus sp., Gonatopsis borealis, a member of Gonatidae, Ommastrephes bartrami
and Histioteuthis dofieini.
INTRODUCTION

It is well known that squids are the important food for sperm whales, Physetercatodon (Linnaeus).
Omura (1950) and Mizue (1951) also reported that squids were the mostimportant for the food of sperm whales in the waters adjacent to Ja pan.
Ishikawa and Wakiya (1914) reported a gigantic squid, Moroteuthis robusta(Verrill), from the stomach of a sperm whale caught " in the open sea off thesouth of the strait of Tugaru" in August, 1911.
The specimens of squids in the stomachs of eight sperm whales caught in
the waters off Joban in November, 1972 were examined. Here this reportdeals with the result of identification of these specimens.
MATERIALS

The present samples were collected through the surveys carried out at thewhaling station in Ayukawa in November, 1972.
The field observations were made on all sperm whales caught, and thecontents of stomachs were classified into squids, fish and others. The observation
was made on the first stomach contents. The squids were preliminary classified
into A, B, C, D, E and F, and a part of samples were preserved in 10% formalinwater to be brought home for close examination.
The localities of the capture of the sperm whales observed are shown inFig. 1.
* Contribution from Tokai Reg. Fish. Res. Lab., B628.
Sci. Rep. Whales Res. Inst.,
No. 28, 1976, 145-151.

146

KAWAKAMI
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Numerals in the figure suggest the animals given in Table !.

SYNOPSIS OF THE SPECIES IDENTIFIED
The species of squids are shown in Table I. On the basis of the samples
brought to the Whales Research Institute, each group was found to be composedof the species as follows :A: Histioteiithis dofleini (Pfeffer, 1912)
B : Moroteuthis robusta (Verrill, 1876)
Gonatidae (species is unknown)
Gonatus sp.
Gonatopsis borealis Sasaki, 1923
E : Moroteuthis robusta (Verrill, 1876)
F : Ommastrephes bartrami (Lesueur, 1821)
The exact identification for C and D could not be made, because no
specimens of these two groups were brought home. The reason why only theGroup B contained four species may be due to that they are much looked
alike each other since specimens removed from stomach are so frequently badly
mutilated and lost the characters such as hooks and suckers. Sometimes samples
are only stripped mantles without arm-head part.
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

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"

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Squid (A)Kind (Group)

rr

r

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Quantity

Stomach contentsRemarks) R, rrr, rr and r indicate the relative quantity in decreasing order.
F, fff, ff and f indicate 4 grades of freshness in decreasing order.

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5MaleFemale

37-24 N
142-07 E..

FemaleSex

Sperm whale

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Freshness

Species of squid

Ommastrephes bartrami (Lesueur)

Moroteuthis robusta (Verrill)

Moroteuthis robusta (Verrill)

Gonatus sp.
Gonatopsis borealis Sasaki
Histioteuthis dofieini (Pfeffer)

Gonatidae (species is unknown)
Histioteuthis dofieini (Pfeffer)

M oroteuthis rob us ta (Verrill)
Histioteuthis dofieini (Pfeffer)

Moroteuthis robusta (Verrill)
Gonatopsis borealis Sasaki

Histioteuthis dofieini (Pfeffer)

SPERM WHALES OBSERVED AND THEIR STOMACH CONTENTS

37-11 N
142-05 E

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16"

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37-21 N
142-04 E

Locality ofcapture

14 Nov. '72

Date ofcapture

32I

No.

TABLE I.

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148

KAWAKAMIOEGOPSIDA

Onychoteuthidae
Moroteuthis robusta (Verrill, 1876)
This species was found in the stomachs of four of eight sperm whales.
The specimens brought home were measured about 43.5 cm, 30 cm, 26.5 cm,ea. 80 cm and ea. 90 cm. The last two specimens are only of very large broken
mantles like waste pieces of cloth. But, characteristic warty sculptures of theintegument showed that they belong to M. robusta.
Gonatidae
Gonatus sp.
This species was found in the stomach of only one of eight sperm whales.
The dorsal length (on only remaining portion) was measured 12 cm, but thegladius length was 16.5 cm. The specimen has very long tentacles of about
30 cm (right) and 28 cm (left) long. Both of them have a single large hookon their club. This is decidedly one of a species so far called G. fabrieii(Lichtenstein, 1818) (Plate I, fig. 1).

Gonatopsis borealis Sasaki, 1923
This species was found in the stomachs of two of eight sperm whales. The
mantle of one specimen without head and arms is about 26 cm long and has alarge rhombic fin (length: ea. 10.5 cm, width: ea. 16 cm). The posterior end of
the mantle is obtuse (Plate I, fig. 2). The mantle of the other specimen isabout 22.5 cm long and the width and the length of the fin is about 16 cm
and 8 cm respectively. The ends of the both sides of the fin are deformed
to be sharp as shown in Plate II, fig. I. The mantle and fin might haveshrinked lengthwise in formalin water. Arm formula is 3, 2, 1 · . 4. From thecharacters of general shape, skin and mantle cartilage these specimens wereidentified to be this species.
A member of Gonatidae, the species of which is unknown
A specimen of only mantle of about 14 cm long was found from the stomachof a sperm whale. It has no fin, which seems to have been attached to theposterior part of the mantle. It has no character for identification to species,
but seeing from its shape and the feature of muscle, it seems to belong toGonatidae (Plate II, fig. 2).

Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

SQUIDS IN THE STOMACH OF SPERM WHALES

149

Ommastrephidae
Ommastrephinae
Ommastrephes bartrami (Lesueur, 1821)
This species was found in the stomach of only one of eight sperm whales.
The specimen is lacking in head and arms. The mantles is about 40.5 cm longand has a muscular and rhomboidal fin of ea. 15.5 cm long and 25.5 cm wide
(Plate III, fig. 1). The inverted T-shaped funnel elements of the mantle-funnel
fusion are easily separated from the mantle elements. A lot of photogenic tissues
are observed in the ventral integument of the mantle.
Histioteuthidae
Histioteuthis dofieini (Pfeffer, 1912)
Nine specimens from the stomachs of four of eight sperm whales were examined,
the dorsal mantle length of which measured from about 6.5 cm to about 12 cm.
The neck is separated from the mantle. Arms have no hooks, the both sidesof the fin attached to the posterior part of the mantle are muscular and convex.
All specimens have tentacles missing. Because of numbers of photophores
over the surface of the mantle, head and arms, these specimens were easily
discriminated to belong to Histioteuthidae. The final identification to thespecies was made because of the triserial photophores on the arm IV and theshape of the funnel organs (Plate III, fig. 2).
THE OCCURRENCES OF SQUIDS

Among the sperm whales caught off J oban and Sanriku and dissected at thewhaling stations at Onagawa and Ayukawa in November, 1972, 65 whales wereobserved of their stomachs, all of which had only squids. Though the numberof samples may not be large enough for discussing the important species as foodfor sperm whales, Histioteuthis dofieini and Moroteuthis robiista might beconsidered the most important for this sea area (Table 1). The members ofHistioteuthidae have not been reported as the food for the sperm whales in
the North Pacific, but were reported numerically dominantly in the dietof sperm whales from the Azores Region (R. Clarke, 1956) and Madeira (M. R.
Clarke, 1962). The members of Onychoteuthidae have already been reported as
the most important food for sperm whales in the waters adjacent to the AleutianIslands (Okutani and Nemoto, 1964: M. robusta), off central California (Rice,1963: M. robusta) and in the Antarctic (Korabelnikov, 1959: Onychoteuthisbanksii). The members of Gonatidae also seem to be important as the foodfor sperm whales in the waters off Joban, because Beteshava and Akimushkin(1955) and Sleptozov (1955) reported that the members of Gonatidae are the mostimportant diet of sperm whales in the Kuril waters. Okutani and Nemoto (1964)
also found considerable number of Gonatid family in the sperm whale's foodSci. Rep. Whales Res. Inst.,
No. 28, 1976.

150

KAWAKAMI

in the Bering Sea and the northern North Pacific. This time Ommastrephes
bartrami was found in the stomach of one sperm whale. It is noteworthy that
this species has not hitherto been reported as the food for sperm whales before
the present finding.
ACKNOWLEDGMENTS

My thanks are due to Dr. H. Omura, the Director of the Whales ResearchInstitute, who encouraged me to carry out this investigation, and Dr. S. Ohsumiof Far Seas Fisheries Research Laboratory and the staffs of the Ayukawa
whaling station of Taiyo Gyogyo K. K. for their kindness of collecting thesamples. I also like to thank Dr. T. Okutani of the Tokai Regional Fisheries
Research Laboratory for his help in identifying the specimens.
REFERENCES
BETESHAVA, E. I. and I.I. AKIMUSHKIN, 1955. Food of sperm whale (P. catodon) in the Kuril
Islands. Trans. Oceanogr. Inst. Moscow, 18: 86-94 (Fide CLARKE, M. R., 1962).
CLARKE, M. R., 1962. Stomach contents of sperm whales caught off Madeira. Norsk HvalfangstTid., 51 (5) : 173-191.
CLARKE, M. R., 1966. A review of the systematics and ecology of oceanic squids. Adv. Mar.
Biol., 4: 91-300.
CLARKE, R., 1955. A giant squid swallowed by a sperm whale. Norsk Hvaljangst-Tid., 44(10):589-593.
CLARKE, R., 1956. Sperm whales of the Azores. Discovery Rep., 28: 237-298.
ISHIKAWA C. and Y. WAKIYA, 1914. Note on a gigantic squid obtained from the stomach of asperm whale. J. Coll. Agric. Imp. Univ., 4(7) : 435-443.
KORABELNIKOV, L. V., 1959. The diet of sperm whales in the Antarctic. Priroda, 310: 103-104.
(In Russian) (Fide CLARKE, M. R., 1962)
MATTHEWS, L.H., 1938. The sperm whale (Physeter catodon). Discovery Rep., 17: 93-168.
MIZUE, K., 1950. Food of whales in the adjacent waters of Japan. Sci. Rep. Whales Res. Inst.,
5: 81-90.
NESIS, K. N., 1971. New form of squid, Genus Histioteuthis, from the eastern Pacific. Zool. J.,
50(10): 1463-1471. (In Russian)
OKUTANI, T. and T. NEMOTO, 1964. Squids as the food of sperm whales in the Bering Seaand Alaskan Gulf. Sci. Rep. Whales Res. Inst., 18: 111-122.
OMURA, H., 1950. Whales in the adjacent waters of Japan. Sci. Rep. Whales Res. Inst., 4: 27113.
PIKE, G. C., 1950. Stomach contents of whales caught off British Columbia. Prog. Rep. Pacific
Coast St., 83; 27-28.
RICE, D. W., 1963. Progress report on biological studies of the larger cetacea in the waters off
California. Norsk Hvalfangst-Tid., 52(7): 181-187.
SLEPTOZOV, M. M., 1955. On the biology of cephalopod molluscs of the far eastern seas andthe northwestern Pacific. Trans. Oceanolog. Inst. Moscow, 18: 69-77.
TAKI, I., 1964. On eleven new species of the Cephalopoda from Japan, including two newgenera of Octopodinae. J. Fae. Fish. Anim. Hush. Hiroshima Univ., 5(2): 277-330.
Voss, N. A., 1969. A monograph of the Cephalopoda of the North Atlantic. The family
Histioteuthidae. Bui. Mar. Sci., 19(4): 713-867.
YOUNG, R. E. 1972. The systematics and areal distribution of pelagic cephalopods from theseas off southern Calisfornia. Smithsonian Contr. Zool., 97: 1-159.
Sci. Rep. Whales Res. Inst.,
No. 28, 1976.

SQUIDS IN THE STOMACH OF SPERM WHALESEXPLANATION OF PLATESPLATE I
Fig. I.
Fig. 2.

Gonatus sp., gladius length 1.65 cm.
Gonatopsis borealis, dorsal mantle length ea. 26 cm.
PLATE II

Fig. I.
Fig. 2.

Gonatopsis borealis, dorsal mantle length ea. 22.5 cm.
A member of Gonatidae, dorsal mantle length ea. 14 cm.

Fig. I.
Fig. 2.

Ommastrephes bartrami, doral mantle length 40.5 cm.
Histioteuthis dojleini, dorsal mantle length ea. 12 cm.

PLATE III

Sei. Rep. Whales Res .Inst.,
No. 28, 1976.

151

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