NOTES ON FISHES FROM THE STOMACHS OF
WHALES TAKEN IN THE ANTARCTICI.

KENOCYTTUS NEMOTOI, A NEW GENUS AND NEW SPECIES OFZEOMORPH FISH OF THE SUBFAMILY OREOSOMINAE
GOODE AND BEAN, 1895

TOKIHARU ABE*
Since April, 1948, some fishes from the stomachs of whales taken by
the Japanese whaling fleets in the Antarctic have been brought backand passed on to the writer for study. The collections include large
specimens presenting difficulties in preserving, and this, coupled withother pressing duties, has deferred the preparation of the report ofthe study. The writer takes pleasure in presenting here the first ofa series of papers dealing with these antarctic fishes, and in expressing his sincere thanks to Dr. H. OMURA (Director, Whales ResearchInstitute, Tokyo), Dr. M. NISHIWAKI, Mr. K. FUJINO, Mr. T. NEMOTO(all of the same institute), Mr. T. KAWAKAMI and the other biologists
at the Research Division, Fisheries Agency, Mr. K. OTSURU (Nihon
Suisan Co.) and several other biologists at the whaling companies inJapan for their courtesy and the trouble they have taken. The writer
has to thank Miss Y. TAKASHIMA (Tokai Regional Fisheries ResearchLaboratory) for her help in preparing this paper.

Xenocyttus, New Genus**
Generic type.-Xenocyttus nemotoi, new species, described below.
Diagnosis.-The body is deep and compressed, and the caudal peduncle
is slender (resembling some of the so-called zeomorph fishes of thegenera Allocyttus, Pseudocyttus, Cyttosoma, Xenodermichhtys, Grammicolepis, etc., on the one hand, and some caproid fishes on the other).
Despite pronounced differences in general appearance, the present new
genus is, as will be seen below, very closely related to Oreosoma, and it
is highly probable that the former will prove to be not distinct fromthe latter, which was introduced by CUVIER in 1829 with atlanticum as
type. The single specimen upon which he based his discription was
only 16 lines (=ea. 33mm***) long. In view of the remarkable changes* Tokai Regional Fisheries Research Laboratory, and Zoological Institute, Facultyof Science; University of Tokyo.
** gevor=strange; 1>ui..ro(=an unknown fish (vide~GDNTHER, 1860, p. 396, foot-note).
*** According to VAILLANT, 36mm.
225

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T. ABE

in body shape, and more especially in armature, with advancing age incertain fishes, the writer wishes to give the diagnosis paying special
attention to the other characters.
The total number of vertebrae (examined by radiograph) is a little
more than 40 (ea. 43). The fin-formula of the ventral is 15 (=4+i, or,all branched); the spine is long, and soft*. The ventral origin is behindthe pectoral base ; the distance from the former to the anal origin isequal to the length of head and very slightly less than the distancefrom the ventral origin to the anterior end of the scaled part of thebreast. The ventral fins are widely separated from one another, andeach fitted in a shallow depression. The lateral line is rather gently
curved anteriorly. The belly is very weakly keeled along the mid-ventral
line just in advance of the vent for a short distance, but in front of
the ventral origins, the ventral surface of the body is almost flat, forming an ill-defined, high isosceles triangle. There are no spiny bucklers
on each side of the dorsal and anal bases; they are covered on eachside by a low skinny fold which bears very small scales. The dorsal
and anal spines are not widely separated from the soft rays of the fins.
The shape and arrangement of scales are very characteristic. They
are firmly adherent and spiny excepting for those on the belly. At
first sight the shape of scales varies greatly in different parts of thebody, but there are gradations between the peculiar scales on the belly
and those on the other parts of the body. The former scales are low
pyramidal plates of moderate size, each with contour-line-like, concentrically arranged rings on the central part, and each separated fromneighboring scales by narrow naked area of varying width (thus forming a mosaic as in the specimen of Oreosoma atlanticum described andfigured by WAITE, 1912, p. 198, pl. 11). The contour of these scales iseither nearly quadrilineal, or nearly pentagonal (or further, nearly circular), and the outskirts of the central elevation is flattened. There isusually a short spine near the posterior margin of each of these scales.
The scales on the back and the other parts of the body and head, excepting for the belly, are rough to the touch; they bear one to three
distinct spines behind the central elevation and near the posterior margin.
Some scales lack these spines, and may be called circular.
The pockets receiving scales are arranged fairly regularlly on theposterior part of the body, but the number of scales below the dorsal* Probably because of the strong preservative? The writer can not be certain of therigidity of the spine. In Zen the ventral fins lack spine. In the present genus, it is difficult to see whether the outermost fin-ray (which is here regarded as a spine) is divided ornot, because only one specimen (which has been in strong formalin) is available. But there
seem to be no segments in this ray, and its thickness is much greater than the inner fin-rays.

FISHES FROM STOMACHS OF THE ANT ARCTIC WHALES

227

origin is difficult to count because of the irregular arrangement. Approximatly the number of scales in an oblique row passing the dorsal
origin down and backward to the scale just above the lateral line is
1/2 (just in front of the anterior end of the base of the lst dorsal spine)+2 (smaller than those below)+19-25 (left), and 1/2+2+20-23 (right).
The number of scales in the lateral line is ea. 110 (to the end of thevertebral column)+ea. 6 (left), and ea. 107 +ea. 6 (right). The numberof the scale rows from the left orbital rim to the right is ea. 17.
Taking into consideration the dissapearance of certain armature in
the adult of certain fishes, the presence of three low outgrowths on the
belly above the ventral fin on each side of the present specimen shouldbe specifically mentioned here. They are each formed of a few slightly
modified scales with a higher projecting part. The hindmost outgrowthis the largest, and fairly widely apart from the middle one, which isalso more conspicuous than the anteriormost. On the right side, theanterior two projections are less pronounced than on the left side of
the body. The sclaes are the smallest on the interorbital area, in frontof the nearly vertical ridge of the operculum, on the pectoral base, andon the folds along the dorsal and anal bases; they are the largest on
the belly (excepting for the abdominal projections which are composedof more elevated scales).
The eyes are not so large as in large specimens of the members of
Allocyttus and Neocyttus. The eye-diameter is about 1/3 of the lengthof head, and almost equal to the interorbital breadth (above eye-centers).
The mouth is not so small as in Grammieolepidae, oblique, and protractile. The hind end of the maxillary nearly reaches the verticalthrough the anterior margin of the eye.
The interorbital area is broad, medially scaled, separated by an extremely fine naked line from the posterior part of the head which iscovered by much larger scales. The lateral parts of the interorbital area,
namely, the parts just above the eyes, are dark brown, with irregulardepressions and with bristle-like projections along the orbital rim. The
median broad scaled part just mentioned, like the ground color of thebody, is bluish gray. There are few, low spines along the ventral
margin of the orbit. The preorbital has shallow concavites, and anteriorly
provided with one or two small spines which are directed downwards.
The ventral side of the head, snout and jaws are naked. The cheek andpostocular parts of the head are scaled, only the hind margin and two
diverging long ridges of the operculum, exposed branchiostegal membrane** The general appearance of the breast and postero-ventral part of the head resemble
that of the figure of Oreosoma atlaticum given in CUVIER and VALENCIENNES' ' Histoire
naturelle des poissons ', pl. 99 (the figures are designated 0. coniferum).

228

T. ABEand neighboring parts of the opercular bones being naked. There is asmall knob at the symphysis of the lower jaw. It has three spines
directed downward. The posterior end of the lower jaw is angular, andseparated from the gular thickening and branchiostegal membrane by afairly wide concavity. The branchiostegal membrane on each side is ventrally connected with its partner, and free from the isthmus posteriorly.
The gills are three and a half in number, and there is no slit behindthe last gill. The pseudobranchiae are well developed. The number ofthe branchiostegals is seven on each side. The gill-rakers on the firstgill-arch are rather soft, and the length of the longest gill-rakers areabout one-third of the horizontal eye-diameter. The number of thegill-rakers just mentioned is 5+1+19 (left) and 5+1+18 (right).
Teeth are present on the lower jaw only. They are small, simple,
well separted from one another, few in number, and arranged in asingle or two (anteriorly only) rows. The vomer, palatines, tongue andinner side of upper jaw bear close-set, tooth-like, slender projections.
They are probably papillae.
The upper lip is broad, and inflected inward as a thin skinny flap
covering entirely the edge of the premaxillaries. When seen from theventral side, this skinny fold (which may be called a curtain) narrows
at the mid-dorsal point of the upper jaw. The greatest width of theinner portion of this kinny flap is almost equal to the greatest breadthof the skinny membrane just inside of the edge of the premaxillaries(which is commonly met with in Decapterus, Cypselurus, etc.). The
tongue is short, slightly concave dorsally, and bears prominent papillae(see above). The nostrils are paired on each side of the head. The
posterior nostril is slit-like, stretched nearly vertically, and situatednear the anterior margin of the orbit. The anterior nostril is just in
front of the posterior one, oblong or kidney-shaped, and its vertical lengthis smaller than in the latter. A bony roof protrudes between the posterior and anterior nostrils.
Xenocyttus nemotoi, New Species*'Tsubu-mat6dai' (new Japanese name**)
Plates 1 & 2Material examined. - Holotype (Cat. No. 49756, Zoological Institute,* The writer takes pleasure in naming this new species after Mr. T. NEMOTO whocollected the type specimen.
** Japanese names for antarctic fishes are necessary in order to expedite collecting ofadditional specimens and gathering information about the habits of these fishes. ' Tsubu 'means tubercles; 'mat6dai' means John Dory, member of Zeus.

FISHES FROM STOMACHS OF THE ANT ARCTIC WHALES

229

Faculty of Science, University of Tokyo=Cat. No. '55-111, ABE), collected by Mr. NEMOTO from the stomach of a fin whale along withnumerous euphausids. The whale was killed on January 15, 1955, in
64°32' S and 115°25' E. So far, only the holotype has been available
for study.
Description of the holotype.-Total length 162 mm, standard length
140 mm. The belly is swollen because of the stomach contents (contrary
to expectation consisting of numerous copepods; this specimen was
found along with numerous euphausids as stated above). The generalappearance of the specimen is mentioned in the description of thegeneric characters given above. The following measurements are given
in hundredths of the standard length: Greatest depth of body (neardorsal origin) 74.3, greatest breadth of body (belly, above ventral fins;
belly is well swollen) 22.1, breadth of body at upper edges of pectoral
bases 18.6, breadth of body at anterior ends of lateral lines 15.4, least
depth of caudal peduncle 7.1, length of head 35.0, horizontal diameterof eye 12.0 (left) and 11.4 (right), vertical diameter of eye 11.1 (leftand right), length of snout 10.0 (left) and 9.6 (right), interorbital
breadth (above eye-centers) 11.6, greatest depth of preorbital at theantero-dorsal corner of scaled part of cheek 2.9 (left) and 3.2 (right),
length of longest (lst) dorsal spine 12.9, length of longest (ea. 15th20th) dorsal fin-rays ea. 11.1, length of longest (lst) anal spine 6.4,
length of longest (ea. 15th-20th) anal fin-rays ea. 11.4, length of ventral
spine 18.6 (left) and 19.1 (right), length of longest (outermost) ventral
fin-ray 16.6 (left) and 18.6 (right), length of longest (8th from top)
pectoral fin-ray 13.6 (left) and 13.2 (right), length of longest (4th-6th
from the raker just below the one at the joint of the upper and lower
limbs) gill-rakers 3.9 (left) and 4.3 (right), greatest diameter of scales
on postero-dorsal part of body ea. 1.2, greatest diameter of exposedpart of larger scales on belly ea. 1.4.
D. VI 35 (all fin-rays unbranched and segmented; hindmost 2 rays
close together). A. II 33 (all fin-rays unbranched and segmented; hindmost 2 rays close together). P. 21 (all fin-rays unbranched and segmented) on both sides. V. I 5 (outer 4 soft rays branched; innermost
ray unbranched or branched) on both sides. Caudal fin dorsally injured;
below the end of lateral line are 7 principal rays, of which upper 6
rays are branched.
The body-wall is thick; the muscles there are white and fairly hard(resembling boiled squid meat) although they are seemingly oily. On
the right side of the belly, embedded in these muscles, and just above
the posterior margin of the vent, lies a posteriorly curved spine-likebone of a size nearly equal to the longest anal spine. The bone is230

T. ABE

pointed at the ventral end. The left side of the belly has not been dissected. The peritoneum is blackish. The air-bladder seems to be absent. The pyloric caeca are numerous. The gonads are still very small,but the present example is believed to be a male.
The color in formalin is bluish or pinkish gray, with many rounded,dark blue markings of varying size; some of them are slightly larger
than the pupil, and some are much smaller than the latter. The membranes of the ventral fins are blackish. The dorsal and anal spines,
and the exposed parts of the bones of the head are brownish orange.
Color prior to preservation, according to Mr. NEMOTO, who collected thespecimen, was light orange, with blue markings.
Relationships.-Though resembling caproid fishes, Lampris, Leiognathus,
etc., at first sight, the present new genus and species is undoubtedly
closely related to some zeomorph fishes, and more especially, to Allocyttus verrucosus (GILCHRIST) and Oreosoma atlanticum CUVIER. In the
total number of vertebrae*, Xenocyttus nemotoi resembles Grammicolepis
and Neocyttus, and considerably differs from Zeus, Cyttus and Caproidae.
As the change with advancing age in the shape of body, armature,
relative size of eyes, relative size and number of fin-rays in the ventrals, coloration, etc., are very remarkable in certain fishes, and as
there have been some discrepancies in the diagnostic descriptions of thegenera of the so-called Zeidae, Grammicolepidae and Caproidae, nopretence is made here to introduction of a new family for Xenocyttus,
Oreosoma, Allocyttus and allies. The difference in the number of ventral fin-rays between Oreosoma atlanticum described by CuvrnR** andthe specimen described under the same name as above by WAITE (1912)(which was later named 0. waitei by WHITLEY) on the one hand, and
Xenocyttus nemotoi on the other, and the presence of the orifice behindthe last gill in WAITE's specimen perplexes the present writer. Furthermore, GILCHRIST'S account (1922, p. 71) of the change with advancing
age of the coloration, relative depth of body and the development of
the enlarged scales (namely, the so-called tubercles) is in the reverse
direction if Oreosoma atlanticum is presumed to be the young of* It is regretted that the total number of vertebrae (N) in Oreosoma and Allocyttus is
not known to the writer. This number in Zeus and Cyttus (31 or 32), Grammicolepis (46),
Neocyttus (40) is cited from REGAN, 1910; that of Capros aper (10/12-13) from GUNTHER,
1860; that of Antigonia rubescens (9+ 11+1) from STARKS, 1902. The present writer has
examined the skeleton of Zeus japonicus and Antigonia capros; N is 31 (=13+18) for theformer, and 22 ( = 10+ 12) for the latter. There is a slit behind the 4th gill in A. capros,
whereas it is absent in Z. japonicus. V. I 5 (all branched) in eapros; I 7 (all branched)in japonieus.
** VAILLANT, 1893, re-examined the type and another specimens of the species, andcorrected the number of ventral fin-rays erroneously given by CUVIER. According to
VAILLANT, this number is I 7.

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321

Xenocyttus nemotoi. The adoption of the name Oreosominae for Oreosoma, Xenocyttus, Allocyttus and allies (if any) is only for convenience'sake. MYERS' statement (1937, pp. 146 and 147) that he was inclined
to think ' there may be more than one family type among them ' (theword ' them ' refers to the genera usually ref erred to Zeidae) fits forexpressing the opinion of the present writer.

LITERATURE CITEDBARNARD, K. H. (1925). A monograph of the marine fishes of South Africa, pt. 1. Ann.
South African Mus., 21: 1-418, 17 pls.
BARNARD & DAVIES, D. H. (1946). Description of a new fish of the family Zeidae from theCape. Ann. Mag. Nat. Hist., ser. 11, vol. 13: 790-792.
BERG, L. S. (1940). Classification of fishes both recent and fossil. Trav. l' Inst. Zool.
l'Acad. Sci. l'URSS., 5 (2): 87-517. (1947, American edition).
BOULENGER, G. A. (1902). Notes on the classification of teleostean fishes. IV. On thesystematic position of the Peluronectidae. Ann. Mag. Nat. Hist., ser. 7, 10: 295-304.
(1903). Sur Jes affinite du genre Oreosoma. C. R. A cad. Sci. Paris, 1903, 137:
523-5.
CUVIER, G. (1829). Le regne animal. ... 2 ed., 2. Paris. This edition not seen in the original.
- - - (1829). In CUVIER and V ALENCIENNES', Histoir naturelle des poissons, 6: xxvi +2+518 pp., pls.
FRASER-BRUNNER, A. (1950). Notes on the fishes of the genus Antigonia (Caproidae). Ann.
Mag. Nat. Hist., ser. 12, 3: 721-4.
FROST, G. A. (1927). A comparative study of the otoliths of the neoptrygian fishes (continued).-Orders Allotrioganthi, Berycomorphi, Zeomorphi. Ann. Mag. Nat. Hist.,
ser. 9, 19: 439-45, pl. 8.
GILBERT, C. H. (1905). The aquatic resources of the Hawaiian islands. pt. 2, sect. 2.The deep-sea fishes. Bull. U.S. Fish. Comm., 22, pt. 2: 575-715, pls. 66-101.
GILCHRIST, J. D. F. (1904). Descriptions of new South African fishes. Marine. Invest.
South Africa, 3: 1-16, 18 pls. Not seen in the original.
- - - (1908). Description of fifteen new South African fishes with notes on other species.
Marine Invest. South Africa, 4: 143-71. Not seen in the original.
- - - (1922). Deep-sea fishes procured by the S.S. 'Pickle' (Part I). Fish. and Mar:
Biol. Survey, Rept. no. 2, For the year 1921. (Union of South Africa). Spee. Repts,
no. 3: 41-79, pls. 7-12.
GOODE, G. B. & BEAN, T. H. (1896). Oceanic ichthyology, a treatise on the deep-sea andpelagic fishes of the world. Mem. Mus. Comp. Zoiil. Harvard Coll., 22: i-xxxv, 126, 1-553, i-xxiii, 1-26, pls. 1-123.
GUNTHER, A. (1859). Catalogue of the acanthO'pterygian fishes in the collection of the
British Museum, 1: xxxii+524 pp. (Oreosoma, p. 214).
- - - (1860). The same work as above, 2: xxii+548 pp.
- - - (1880). An introduction to the study of fishes, xvi+720 pp. Edinburgh.
- - - (1887). Report on the deep-sea fishes collected by H. M. S. Challenger during theyears 1973-76 (In Report on the scientific results of the voyage of H. M. S. Challenger
during the years 1873-76. Zool., 22, pt. 57: i-ixv, 1-335, pls. 1-73.
HOLT, E. W. L. & BYRNE, L. W. (1908). New deep-sea fishes from the south-west coastof Ireland. Ann. Mag. Nat. Hist., ser. 8, 1: 86-95, pl. 3.

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JORDAN, D. S. (1923). A classification of fishes, including families and genera as far as
known. Stanford Univ. Publ., Univ. Ser., Biol. Sci. 3(2): 79-243.
JORDAN, D. s. & EYERMANN, B. w. (1896). The fishes of North and Middle America.
U.S. Nat. Mus. Bull., 47, pt. 1: ix+1240 pp.
LOWE, R. T. (1843). A history of the fishes of Madeira .. .. xvi+196 pp., 27 pls. (pl. 1827 not accessible to the writer), London. (on page xii is given a brief statement on
Oreosoma).
·
MCCULLOCH, A. R. (1914). Biological results of the fishing experiments carried on by theF. I. S. 'Endeavour', 1909-14, vol. ii, pt. 3. III. Report on some fishes obtained by
the F. I. S. 'Endeavour' on the coasts of Queensland, New South Wales, Victoria,
Tasmania, South and South-Western Australia. Pt. 2: 77-165, pls. 13-34.
MATSUBARA, K. (1955). Fish-morphology and hierarchy, vols. 1-3: iv+xii+1605+v pp.,xiii, pp., 135 pls, Tokyo. (In Japanese)
MAUL, G. E. (1948). Quatro peixes novos dos mares da Madeira. Bol. Mus. Municipal
do Funchal, no. 3, art 6: 41-55.
- - - - (1949). Notes sobre dois peixes descripto no boletim anterior. Bol. Mus. Municipal do Funchal, no. 4, art 10: 20-22.
MYERS, G. S. (1937). The deep-sea zeomorph fishes of the family Grammicolepidae. Proc.
U. S. Nat. Mus., 74(3008): 145-56, pls. 6 and 7.
PHILLIPPS, W. J. (1927). Bibliography of New Zealand fishes. N. Z. Mar. Dept. Fish.
Bull., 1: 1-68.
REGAN, C. T. (1908). Report on the marine fishes collected by Mr. J. Stanley GARDINER
in the Indian Ocean. Trans. Linn. Soc. London, 21: 217-255, pls. 23-32.
(1910). The anatomy and classification of the teleostean fishes of the order
Zeomorphi. Ann. Mag. Nat. Hist., ser. 8, 6: 481-4.
RICHARDSON, J. (1848). Fishes (In The zoology of the voyage of H. H. M. S. 'Errebus andTerror', under the command of Capt. Sir J. C. ROSS .... ), pt. VII, nos. 17 and 18:
i-viii, 97-139, plas. 51-60.
SMITH, J. L. B. (1949). The sea fishes of southern Africa, xvi+564 pp., 107 pls. Central
News Agency, Ltd., South Africa.
STARKS, E. C. (1898). The osteology and relationships of Zeidae. Proc. U.S. Nat. ilfus.,
21(1155): 469-76, pls. 33-38.
- - - (1902). The relationship and osteology of the caproid fishes or Antigoniidae. Proc.
U. S. Nat. Mus., 25(1297): 565-72.
VAILLANr, L. L. (1893). Sur Jes affinites du genre Oreosome CuvIER. C. R. Acad. Sci.
Paris, 116: 598-600.
WAITE, E. R. (1912). Notes on New Zealand fishes. Trans. N. Z. Inst., 44(1911): art xx,
193-202, pls. 10-12.
- - - (1921). Illustrated catalogue of the fishes of South Australia. Ree. S. Aust. Mus.,2(1): 1-208.
WEBER, MAX. (1913). Die Fische der Siboga-Expedition. Siboga-Expeditie, 57: xii+710
pp., 12 pls.
WHITLEY, G. P. (1929). Studies in ichthyology. No. 3. Ree. Aust. Mus., 17(3): 101-43,
pls. 30-34. Oreosoma waitei, nom. nov., is given to WAITE. s 0. atlanticum, 1912.
(1947). New sharks and fishes from Western Australia. Pt. 3, Aust. Zool., 11:129-50' 1 pl.

FISHES FROM STOMACHS OF THE ANT ARCTIC WHALES233

EXPLANATION OF PLATES 1 & 2
PLATE

1

Fig. 1. Xerwcyttus nemotoi, new genus, new species. Type. Cat. No. 49756, Zoological
Institute, Faculty of Science, University of Tokyo.
Fig. 2. Left side of the belly of the same specimen as above, showing three low outgrowths.
PLATE 2
Fig. 1. Dorsal view of the head of the same specimen as above.
Fig. 2. Ventral view of the belly of the same specimen as above.

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