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Zoology Publications from Victoria University of Wellington—Nos. 54 to 57

Cirrhigalevs Barbifer (Fam. Squalidae), A Little Known Japanese Shark from New Zealand Waters

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Cirrhigalevs Barbifer (Fam. Squalidae), A Little Known Japanese Shark from New Zealand Waters

Publication of this paper is assisted by a grant from the Victoria University of Wellington Publications Fund.

Abstract

Two female specimens of Cirrhigaleus barbifer, previously recorded only from two Japanese specimens, are described from the Bay of Plenty, New Zealand. Despite close similarities to Squalus, the genus Cirrhigaleus is regarded as valid because of the remarkable nasal barbels and the lack of precaudal pits.

Introduction

This account records two specimens of the rare spiny dogfish, Cirrhigaleus barbifer Tanaka, 1912, from New Zealand waters. The first of these specimens, a female of 922 mm total length, was long-lined in about 360 metres (about 200 fathoms) between Mayor Island and White Island in the Bay of Plenty during September, 1969, by Mr. Goldie Hitching on the commercial fishing vessel "Fair Isle". Mr. Hitching recognised the fish as unique, and sent it, via the New Zealand Marine Department, to Wellington for identification. The second specimen, a female of 1082 mm total length, was taken in similar circumstances a year later. It was long-lined in about 440 metres (about 240 fathoms), 10 miles off Mayor Island, on September 22, 1970, by Mr. J. I. Phillips on the fishing vessel "Moana". Both specimens are now deposited in the Dominion Museum, Wellington, where they bear the registration numbers 5105 and 5163 respectively.

These two specimens are the largest so far recorded, and the only ones known outside Japanese waters. They therefore provide a considerable range extension for the species, though it should be noted that they were taken in a latitude (c. 37°) south of the Equator comparable to that north for the Japanese specimens. Literature accounts of Cirrhigaleus barbifer refer only to the two other specimens mentioned below. However, Dr. T. Abe (pers. comm.) of Tokyo, Japan, informs us that he is aware of three other Japanese specimens (about 1000 mm long, taken near Hachijo Island, south of Tokyo), and Mr. Leonard Compagno (pers. comm.) of Stanford University, California, notes that in the fish collection of that institution there is another specimen (SU 14171, female, 840 mm, Sagami Sea, Japan) which apparently has not been reported in the literature.

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Previous Accounts

Tanaka (1912, p. 151) established the new genus and species Cirrhigaleus barbifer in the Squalidae, based on one male specimen, 855 mm total length, obtained from the Tokyo Fish Market but stated by Tanaka to be from the Sagami Sea. Subsequently Herre (1935, p. 122) proposed another new genus and species, Phaenopogon barbulifer, for a second specimen, a female 555 mm long, from Misaki Bay, Japan. Herre at that time was not aware of Tanaka's account; when it was brought to his attention he synonymised P. barbulifer with C. barbifer in a brief paper the following year (1936, p. 59). Using the accounts of the first or both of these specimens, Garman (1913), Fowler (1941), and Bigelow and Schroeder (1948, 1957) made judgments on the generic status of Cirrhigaleus in relation to Squalus.

Description of New Zealand Specimens

For proportional dimensions in percent of total length see Table 1.

Head depressed, eye rather large, and snout profile pointed; trunk moderately stout, the abdomen less inflated than shown in Plate 1, which was photographed when the specimen was thawed after deep-freezing and when the abdomen was partially filled with water; anterior half of trunk slightly depressed, flatter below than above, almost trihedral in cross-section owing to ventrolateral thickening of the body wall muscles on each side; posterior half of trunk slightly compressed; dorsal profile in front of the 1st dorsal smoothly and shallowly arched; caudal peduncle slightly flatter in transverse section below than above, with a low dermal keel ventrolaterally on each side extending from the level of the 2nd dorsal fin posteriorly on to the first quarter of the caudal axis (Plate 2); no precaudal pit above or below.

Dermal denticles (Fig. 1A) on sides of trunk rather closely packed, contiguous or only partly overlapping, large and rough to the touch, with essentially tridentate blades and rhomboidal bases; the central tooth of each blade much longer than the lateral teeth; in a few denticles of the 922 mm specimen and in many denticles of the 1082 mm specimen one or both of the lateral teeth are subdivided to give one or occasionally two additional teeth; outer surface of each blade with a high, spine-like median ridge extending the entire length of the blade, and a lower, less prominent ridge along each lateral margin.

Least fleshy interorbital distance 1.9 in head measured to 1st gill-opening; snout broad in contour but bluntly pointed at the snout tip; eye more than twice as long as high; spiracle large, placed slightly above eye and behind it by a distance equal to almost ¼ of horizontal diameter of eye; gill-openings almost vertical, slightly concave and in a horizontal series anterior to pectoral base; lengths of gill-openings subequal; interspaces between gill-openings subequal; nostrils slightly oblique, placed a little nearer tip of snout than mouth; each nostril subdivided into a circular anterolateral aperture and a larger ovoid medial aperture by the anterior and posterior nasal flaps; the anterior nasal flap is short and triangular, directed posteriorly, and external to the deeper and fleshy posterior flap; medial to the anterior nasal flap the anterior margin of the medial nasal aperture is strikingly extended posteriorly as a long, thin, tapered barbel projecting posteroventrally; this barbel (Fig. 1C) is denticle-covered to its tip, and when ad pressed to the lower surface of the head reaches almost or quite as far back as the angle of the mouth; mouth moderately broad and weakly arched; preoral clefts short, page 3

Fig. 1. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. A, dermal denticles from high on side at level of 1st dorsal fin; B, 2nd to 5th upper and lower teeth, right side; C, left nostril and nasal barbel; D, caudal fin, showing incipient subterminal notch (possibly due to damage).

Fig. 1. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. A, dermal denticles from high on side at level of 1st dorsal fin; B, 2nd to 5th upper and lower teeth, right side; C, left nostril and nasal barbel; D, caudal fin, showing incipient subterminal notch (possibly due to damage).

reaching less than 1/3 the distance from the angles of the mouth to the upper symphysis; posteriorly the clefts are continued by oblique furrows which extend about 1/5 of the distance between the angles of the mouth and the 1st gill-openings.

Teeth 14 - 13 over 12 -11, similar in the two jaws, their shape as in Fig. 1B; teeth at the centre of mouth slightly smaller than those further laterally, and upper teeth generally smaller than lower; two or three rows of teeth visible in both jaws.

First dorsal fin large, triangular, its origin behind the level of the posterior corner of the pectoral fin by a distance equal to ½ the horizontal diameter of eye;

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Table 1. Cirrhigaleus barbifer, proportional dimensions in per cent of total length

Part 1 of Table 1 page 5 Part 2 of Table 2 page 6

posterior insertion of 1st dorsal base nearer to origin of pelvic than to axil of pectoral by a distance almost equal to horizontal diameter of eye; exposed origin of 1st dorsal spine midway along 1st dorsal base; exposed spine in the 922 mm specimen extends halfway along that part of 1st dorsal anterior margin distal to exposed spine origin, but tip of spine is obliquely truncated and may have been longer than it is now; in the 1082 mm specimen the spine is broken; spine smooth edged, subtriangular in cross-section, its posterior surface grooved lengthwise; 2nd dorsal fin subequal to 1st dorsal, its base longer, its height slightly shorter; origin of 2nd dorsal not well marked, a little anterior to posterior tips of pelvic fins; exposed origin of 2nd dorsal spine above posterior 1/3 of 2nd dorsal base; exposed spine in the 922 mm specimen reaches almost to 2nd dorsal apex, but its tip is slightly worn or eroded like that of 1st dorsal; in the 1082 mm specimen its tip reaches beyond second dorsal apex; shape of 2nd dorsal spine similar to 1st dorsal; caudal fin shape as in Fig. 1D, with no definite subterminal notch, though in the 922 mm specimen there is a weak indentation, perhaps due to injury, in the margin behind the tip of the caudal axis; pectoral fins moderately large, short and broad, originating just behind the 5th gill-openings; when adpressed to the side of the trunk so that their anterior margins are horizontal their tips reach almost or quite to midway between levels of origin of 1st dorsal base and exposed 1st dorsal spine; pelvic fins large, their outer, anterior corners somewhat obtuse, broadly rounded.

Colour: when fresh brownish-grey above, paler to almost white below; after preservation in alcohol steel-grey above, paler below; in the 922 mm specimen most of underside pale grey with some small, irregular areas of white mottling on the ventral surface, particularly under the head and around the mouth; in the 1082 mm specimen most of underside white except for grey mottling below snout tip; trailing margins of all fins white; axils of pectoral and pelvic fins white; nasal barbel grey in the 922 mm specimen, white in the 1082 mm specimen.

Vertebrae: radiographs of the vertebral column are shown in Plate 3; both specimens have exactly the same vertebral counts; of the 87 precaudal centra (counted to upper caudal fin origin) 51 are monospondylous and 36 are diplospondylous; the transition from monospondyly to diplospondyly is accepted as occurring above the posterior 1/3 of the pelvic fin base, where there is an abrupt decrease in the length of the centra; caudal centra (posterior to the upper caudal fin origin) number 28.

Comparison with Japanese Specimens

We have not seen Tanaka's or Herre's specimens, but their descriptions of them were full, and these, together with the accompanying illustrations, give us no reason to believe that our specimens are specifically distinct from C. barbifer. In Table 1 we list the proportional dimensions of our specimens for comparison with those from Tanaka's and Herre's accounts. In extracting Tanaka's and Herre's dimensions we have excluded a few, such as head length to 1st gill-opening, which apparently were measured differently from ours, i.e., probably they were point to point measurements rather than projected distances along the main axis of the body. If it is assumed that the remaining dimensions which we include in Table 1 were measured in a comparable fashion with ours, it can be seen that there are still differences between all four specimens. Some of these between Tanaka's and Herre's specimens were no doubt what Herre referred to, but did page 7not itemise in his 1936 account, where he regarded them as being due to sex and age. We are not able to comment on the extent to which any of these differences are attributable to sex, but we do believe that many of them can feasibly be regarded as expressions of growth-change and hence age.

If we are correct in this view, then the growth changes in C. barbifer are generally in accord with those of other squaloid sharks, as outlined in Garrick (1960, p. 546). The data for C. barbifer indicate that with growth there is a proportionate decrease, relative to total length, in the length of the head (evidenced in this case only by length of snout in front of mouth), the length of the caudal fin, the horizontal diameter of the eye, and the height of the dorsal fins. The prominent nasal barbel of Cirrhigaleus, a unique structure in the Squaloidea, must also undergo a marked relative decrease in length with growth, since Herre's data for this in his 555 mm specimen translate to 7.4% of total length, whereas in Tanaka's 855 mm specimen and our 922 mm and 1082 mm specimens it is only 4.4%, 4.7% and 5.1% respectively. The only other feature which shows marked change is the length of the anterior margin of the pectoral fin—16.8% of total length in Herre's small specimen and 14.5% and 14.8% in our specimens. This decrease, if valid, is at variance with Garrick's (1960, p. 548) statement on the pectoral fin of other Squaloidea, which "compared with the total length ... may remain reasonably constant, or more often will show a slight increase".

Points of disagreement between Tanaka's and Herre's descriptions (including their illustrations) and our specimens are as follows. Tanaka stated (p. 152) "the anterior edge of upper lip beneath end of first third of eye and angle of mouth beneath beginning of last third", but his illustration (Plate 41) shows the anterior edge of the upper lip below about middle to last third of the eye, and angle of mouth behind the eye. Our specimens agree better with Tanaka's illustration than with his description. Tanaka noted in his generic diagnosis of Cirrhigaleus (p. 154) that there is "no pit or keel on root of caudal". We agree, from our specimens, that there are no precaudal pits, but there is a definite longitudinal dermal keel ventrolaterally on each side of the caudal peduncle. This keel, which is low and blunt-topped (see Plate 2) extends from the level of the posterior end of the second dorsal fin back on to the anterior part of the caudal fin. It is, therefore, similar to but less obvious than the comparable keels in Squalus species. Herre (1935, p. 124) described a similar keel from his specimen of C. barbifer. Herre's illustrations of his specimen agree with ours except that he shows the snout tip as much blunter in ventral view, while in lateral view the dorsal profile from the head back to the first dorsal fin is strongly convex and elevated. We do not place significance on the difference in snout tip shape, and we suggest that the elevated predorsal profile of Herre's specimen was probably due to distortion in preservation.

Relationship of Cirrhigaleus barbifer to Other Squalidae

Tanaka's (1912) account of Cirrhigaleus and Herre's (1935) account of Phaenopogon (= Cirrhigaleus) as new genera did not include any indication of their views on the relationship to other genera in the Squalidae. Garman (1913, p. 457) in an addendum to his revision of elasmobranch fishes reduced Cirrhigaleus to a sub-genus of Squalus; he noted that "the mouth, teeth, scales, spiracles, and fins are those of that genus", and indicated that only the nasal barbel was distinctive. Fowler (1941, p. 262) followed Garman in treating Cirrhigaleus as a sub-genus of Squalus, but did so without comment. Bigelow & Schroeder (1948, page 8p. 451; 1957, p. 37) accepted Cirrhigaleus as a full genus despite its similarity to Squalus, and in a discussion in the later of these two accounts noted that this was justified by the "presence of the nasal barbel, combined with the lack of precaudal pits and of longitudinal-lateral ridges on the caudal peduncle".

Study of our specimens leads us to accept Bigelow & Schroeders' view that Cirrhigaleus deserves full generic rank even though the third generic character they cite cannot be upheld; Cirrhigaleus does have a ventrolateral keel on each side of the caudal peduncle and hence resembles Squalus in this respect. Other resemblances to Squalus are strong. Similarity in proportional dimensions is exemplified in Table 1, where for cursory comparison we have listed those of one specimen each of three Squalus species previously reported on by one of us (Garrick, 1960). The essential differences in proportions between Squalus and Cirrhigaleus are that the latter has a shorter snout and head, shorter but higher dorsal fins, and the 2nd dorsal fin is little smaller than the 1st, whereas in Squalus it is markedly smaller. Similarities between the two genera in the shape and structure of the mouth, teeth, dermal denticles and fins were noted by Garman (1913). We confirm these strong similarities, and would highlight that of the caudal fin in particular, but we observe that the dermal denticles of Cirrhigaleus are proportionately much larger—about twice as long—as those of comparably sized Squalus illustrated in Garrick (1960, p. 525, text-fig. 3). Meristic characters—dental formulae and vertebral numbers—differ little between the two genera (for vertebral numbers of Squalus species see Springer & Garrick, 1964).

Despite the above strong similarities there remains the fact that Cirrhigaleus differs from Squalus not only in possessing the remarkable nasal barbels which suggested its generic name but also in lacking completely the precaudal pits which are characteristic of Squalus. We believe that in combination these two characters reasonably justify the retention of Cirrhigaleus as a separate genus, though we would agree that in any subdivision of the Squalidae it would be necessary to place Cirrhigaleus closer to Squalus than to any other genus. It might be argued that the nasal barbels are foreshadowed in Squalus, especially in S. blainvillei and the S. megalops-cubensis group, where the anterior nasal flap is bilobed and the medial lobelet is in a comparable position to the nasal barbel of Cirrhigaleus. Even if this is the case, and the medial lobelet is homologous with the nasal barbel, the gross differences in the degree of development of the two structures merit recognition. In Squalus the medial lobelet is a minor structure, smaller than the lateral lobelet (= anterior nasal flap), and not reaching even to the posterior margin of the medial nasal aperture, whereas in Cirrhigaleus the nasal barbel is a major feature extending not only beyond the anterior nasal flap but far posteriorly along the snout.

Significance of the Range-extension of C. barbifer

The present record of C. barbifer parallels the recent additions to the New Zealand fauna of the north Pacific Centroscymnus owstonii and the north Atlantic Centroscymnus crepidater (see Garrick, 1959). It is thus a further and substantiating contribution to the existing situation in which the New Zealand squaloid fauna is composed predominantly of widely distributed rather than local species. A survey of this fauna was given in Garrick (1960).

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Liver Oil of C. barbifer

A sample of liver oil from our 922 mm female C. barbifer, together with comparative samples from New Zealand Squalus acanthias and S. blainvillei, were analysed for squalene and vitamin A by Dr. R. W. Lewis at the Food Technology Division, C.S.I.R.O., Sydney. The C. barbifer oil contained 0.81% squalene; hence if one can assume that the liver had a lipid content of 50%, then squalene was present at a level of about 4000 ppm relative to tissue weight. By comparison the S. acanthias and S. blainvillei contained only 159 ppm and 51 ppm respectively of squalene relative to tissue weight.

The C. barbifer liver oil contained no vitamin A, S. blainvillei a small amount, and S. acanthias a large amount. Dr. Lewis suggests (pers. comm.) that "it may be possible to distinguish between sharks living in the photic zone, or just below it, and deep-water species by the vitamin A content of the liver oil. This would indicate trophic distance from plants". This suggestion is supported by the vitamin A content and depth-ranges of the three species, C. barbifer being a deep-water species, S. blainvillei living on the deep shelf and shelf edge, and S. acanthias ranging over the relatively shallow shelf.

Acknowledgements

We are grateful to Mr. Goldie Hitching and Mr. J. I. Phillips for recognising the unusual nature of their "whiskered sharks" and forwarding them to us for identification; to Mr. T. Bonnevie and Dr. G. R. Fish, Marine Department officers at Tauranga and Rotorua respectively, for ensuring safe delivery of the specimens to Wellington; and to Mr. J. A. Bahler, Fisheries Research Division, Marine Department, Wellington, who provided the photographs and radiographs reproduced here.

Literature Cited

Bigelow, H. B. & Schroeder, W. C. 1948: Fishes of the western North Atlantic Part 1. Mem. Sears Found. Mar. Res. 1 (1): 59–576. figs. 6–105.

Bigelow. H. B. & Schroeder, W. C. 1957: A study of sharks of the suborder Squaloidea. Bull. Mus. Comp. Zool. 117 (1): 1–150, 16 figs., 4 pls.

Fowler. H. W. 1941: Contributions to the biology of the Philippine Archipelago and adjacent regions. The fishes of the groups Elasmobranchii, Holocephali ... U.S. Nat. Mus. Bull. 100, Vol. 13, × + 879 pp., 30 figs.

Garman, S. 1913: The Plagiostomia. Mem. Mus. Comp. Zool. 36, xiii + 515pp., 77 pls.

Garrick, J. A. F. 1959: Studies on New Zealand Elasmobranchii. Part VIII, Two northern hemisphere species of Centroscymnus in New Zealand waters. Trans. Roy. Soc. N.Z. 87 (1 & 2): 75–89, 4 text-figs.

Garrick, J. A. F. 1960: Studies on New Zealand Elasmobranchii. Part XII, The species of Squalus from New Zealand and Australia and a general account and key to the New Zealand Squaloidea. Trans. Roy. Soc. N.Z. 88 (3): 519–557, 6 text-figs.

Herre, A. W. C. T. 1935: Notes on fishes in the zoological museum of Stanford University. II, Two new genera and species of Japanese sharks and a Japanese species of Narcetes. Copeia , 1935 (3): 122–127, 2 text-figs.

Herre, A. W. C. T. 1936: Phaenopogon a synonym of Cirrhigaleus . Copeia , 1936 (1): 59.

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Springer, V. G. & Garrick, J. A. F. 1964: A survey of vertebral numbers in sharks. Proc. U.S. Nat. Mus. 116 (3496): 73–96, 1 pl.

Tanaka. S. 1912: Figures and descriptions of the fishes of Japan including Riukiu Islands, Bonin Islands, Formosa, Kurile Islands, Korea, and southern Sakhalin. (Seen in 2nd edition form, 1935, Kazama Shobo, Tokyo, 12 + 557 pp., pls. 1–141.)

Addendum

Since the above account was submitted for publication a third New Zealand specimen has come to hand. It is also a female and is larger, being 1220 mm in total length. It was long-lined in about 146 metres (80 fathoms) off Mayor Island in November, 1970, by Mr. Bob Gray on the vessel "Rarangi". Its proportions agree well with those of the other specimens except that the 2nd dorsal base is a little shorter than the 1st dorsal base. The dental formula is 12–13/12–12. The underside of the body is about equally mottled with grey and with white. This specimen was pregnant (the other two were immature with undeveloped oviducts) and contained five embryos in the left oviduct and five in the right. Each embryo is about 85 mm total length and is attached to a yolk sac about 60 mm in diameter. The embryos (DM 5205) and the female (DM 5204) are deposited in the Dominion Museum, Wellington.

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Plate 1. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. Lateral and dorsal views.

Plate 1. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. Lateral and dorsal views.

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Plate 2. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. Ventral view of head, and lateral view of caudal peduncle and tail. Note in lower figure the low ventrolateral dermal keel extending from the level of the 2nd dorsal fin back on to the caudal axis.

Plate 2. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. Ventral view of head, and lateral view of caudal peduncle and tail. Note in lower figure the low ventrolateral dermal keel extending from the level of the 2nd dorsal fin back on to the caudal axis.

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Plate 3. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. Composite radiograph showing entire vertebral column; marker pin separates precaudal and caudal centra.

Plate 3. Cirrhigaleus barbifer, D.M. 5105, female 922 mm, New Zealand. Composite radiograph showing entire vertebral column; marker pin separates precaudal and caudal centra.

J. A. F. GARRICK
Department of Zoology,
Victoria University,
P.O. Box 196,
Wellington, NEW ZEALAND.

L. J. PAUL
Fisheries Research Division,
Marine Department,
P.O. Box 19062 Aro St.,
Wellington, NEW ZEALAND.