Go to National Library of New Zealand Te Puna Mātauranga o Aotearoa
Volume 88, 1960-61
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Study Material

(a) New Zealand. Female, 966 mm. (Dom. Mus. No. 662), type of S. griffini, from Auckland; two females, 454 mm and 545 mm (Dom. Mus. Nos. 2760, 2759) from 75 fathoms, Bay of Plenty; three females, 923 mm to 1,008 mm (Dom. Mus. Nos. 2647, 2649 and 2646) from 20–30 fathoms, Kapiti and Foxton; one female, 1,025 mm, from 2–3 fathoms, Chatham Islands; two embryos 215 mm and 218 mm (Dom. Mus. No. 2246) from female taken off Cape Egmont; embryo 144 mm (Brit. Ant. Expd. 1910, from British Mus. 1913. 12.4.297) from 10 fathoms, North Cape.

(b) Elsewhere. Female, 323 mm (Mus. Comp. Zool. No. 39827) from 33° 31 'N. 76° 35' W.

Description. Based Mainly on Two Mature Females, 923 mm and 1,003 mm, the Latter a Melanistic Variant.

Proportional Dimensions in Per Cent. of Total Length.
♀ 215 mm (embryo) Dm. Mus. No. 2246 ♀ 545 mm Dm. Mus. No. 2759 ♀ 923 mm Dm. Mus. No. 2647 ♀ 1008 mm Dm. Mus. No. 2646
Trunk at pectoral origin: Breadth 14.0 13.2 14.4 15.2
Height 10.7 9.3 11.2 10.7
Snout length in front of: Outer nostrils 4.2 3 9 3 8 3.7
Mouth 11.6 9.9 8.7 8.9
Eye: Horizontal diameter 5.6 4.6 4.3 4.2
Mouth: Breadth 6.0 5.9 5.7 5.9
Nostrils: Breadth between inner corners 4.9 4.9 4.4 5.0
Preoral clefts: Breadth between inner corners 6.3 5.9 6.1 6.5
Gill-opening lengths: 1st 1.8 1.6 2.2 2.0
5th 2.3 2.1 2.5 2.4
1st dorsal fin: Vertical height 8.4 8.2 8.0 7.9
Length of base from origin of
spine 4.6 5.3 6.6 6.3
2nd dorsal fin: Vertical height 5.6 5.3 4.7 4.8
Length of base from origin of
spine 2.8 2.9 4.3 4.2
Caudal fin: Upper margin 21.8 22.4 20.6 20.8
Lower anterior margin 11.6 11.4 11.2 10.6
Pectoral fin: Anterior margin 11.6 13.6 14.3 15.4
Distance from snout to: Eye 7.0 6.8 5.9 6.2
1st gill-opening 20.5 17.2 16.9 17.4
5th gill-opening 24.2 20.4 20.8 21.3
1st dorsal spine 35.0 32.0 32.2 33.5
2nd dorsal spine 66.0 64.9 67.0 67.2
Upper caudal 79.0 77.5 80.2 81.0
Pelvic 49.4 48.0 53.0 52.0
Interspace between: 1st dorsal base and 2nd
dorsal spine 26.5 29.0 28.6 27.7
2nd dorsal base and upper
caudal 10.2 10.4 9.1 9.8
Pelvic and lower caudal 23.7 23.8 22.2 22.6
Distance from origin to origin of:
Pectoral and pelvic 24.9 27.5 31.9 30.4
Pelvic and lower caudal 28.8 28.6 26.2 27.7

Head strongly depressed, the eye large and the snout profile pointed; trunk moderately stout and subcircular in section. The dorsal profile more arched than the ventral, and highest at the level of the 1st dorsal fin from where it slopes downward both anteriorly and posteriorly. Height of trunk at origin of pectoral 7.1 to 7.5 in the length to origin of caudal. Length of body measured to cloaca 54.0% of the total length. Caudal peduncle rounded above but flat below, and with a prominent dermal keel along each side below the mid-level; the keels extend from just behind the posterior insertion of the 2nd dorsal base to about one-quarter

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Picture icon

Text-fig. 6. —Squalus blainvillii, female, 923 mm (Dom. Mus. No. 2647), from New Zealand. Fig. A—Lateral view and insets of transverse sections of snout and peduncle. Figs. B and C— Dorsal and ventral views of head. Fig. D—Right nostril. Figs. E and F —Upper and lower teeth, right side. C = Level of cloaca.

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of the distance along the caudal axis. Upper and lower precaudal pits are present at the origins of the epiural and hypural lobes; the upper pit deeper and better defined than the lower.

Dermal denticles on sides of trunk closely packed and overlapping, each with a near-horizontal, sub-circular, tridentate blade arising from a rhomboidal base; each blade carries a strong median dorsal ridge which is noticeably thick at its anterior end, and a low lateral ridge along each side. Denticles from the caudal axis are less tridentate and have heavier ridges; those from the interorbital region have bluntly pointed blades and no lateral teeth, but the median and lateral ridges are much stronger; while those from the upper and lower lips lack ridges and lateral teeth.

Head measured to 1st gill-opening 5.9 to 6.0 in the total lenth. Head strongly depressed and wedge-shaped in profile so that the snout tip is pointed. The least fleshy interorbital distance 2.3 to 2.0 in the head. Snout contour broad and pointed, expanding prominently at the level of the nostrils. Length of snout measured to the eye 2.9 to 2.8 in the head. Eye large, longer than high, and 2.0 to 2.1 in the preoral length. Spiracle large, placed so that its lower margin is just below the upper margin of the eye, and its anterior margin separated from the hind corner of the eye by a distance just less than the spiracular length. Gill-openings almost vertical, slightly concave, and in a horizontal series anterior to the pectoral base. Lengths of the gill-openings increasing slightly from the 1st to the 5th, the latter 1.7 to 1.8 in the horizontal diameter of the eye. Interspaces between the gill-openings subequal, though that between the 1st and 2nd slightly greater than any of the others. Nostrils almost transverse, and placed a little closer to tip of the snout than to mouth. Interspace between nostrils 1.3 to 1.2 in snout measured to eye. Each nostril subdivided into a circular lateral aperture and an elongate ovoid medial aperture by the anterior and posterior nasal flaps. The anterior nasal flap is essentially triangular, with its pointed tip directed posteriorly; however, about halfway along its medial margin there is a small lobe also directed rearwards, so that the whole flap appears unequally bifid. The posterior nasal flap fleshy, and internal to the anterior flap Mouth broad and little arched, its width about 1.5 in the preoral distance. Preoral clefts short, reaching less than half the distance from the angles of the mouth to the upper symphysis; posteriorly the clefts are continued by oblique furrows which extend one-quarter to one-third of the distance between the angles of the mouth and the 1st gill-openings.

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Teeth 14-13/12-11 in the 923 mm female, similar in the two jaws. Each tooth blade-like, the base broader than high, and with a single, smooth-edged, triangular cusp. The cups are deeply notched on their lateral margins, and so strongly oblique that their medial margins overlap from one tooth to the next to form a continuous cutting edge. The medial margins moderately convex in outline. In both jaws, the teeth at the centre of the mouth slightly smaller than those towards the corners; the lower teeth distinctly larger than the uppers. One or two rows of upper and lower teeth functional depending on the stage of replacement.

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1st dorsal large, triangular, originating about midway between the levels of the axil and posterior corner of the pectoral fin when the latter is laid back along the side of the trunk. The posterior insertion of the 1st dorsal base is slightly nearer to the level of the pectoral axil than to that of the pelvic origin in large specimens, but about midway between these levels in small specimens. Height of 1st dorsal greater than the posterior part of its base measured from the origin of the spine, and equal to distance from snout tip to midway along eye. 1st dorsal spine scarcely pigmented, straight, long and sturdy, its tip reaching at least halfway up the anterior margin of the fin. Anterior margin of 1st dorsal slightly convex, distal margin strongly concave, and posterior margin straight; apex acute, but rounded. Length of the posterior margin about 1.2 in the posterior part of the base measured from the origin of the spine; the posterior tip sharply pointed. 2nd dorsal originating by a shallow angel posterior to the rear tips of the pelvics; its height 1.8 to 1.7 in that of the 1st dorsal, and its base measured from the origin of the spine 1.5 to 1.7 in the base of the 1st dorsal. The distal margin more concave, the apex more acute, and the posterior margin equal to the length of base measured from the spine. 2nd dorsal spine slightly heavier and longer than the 1st, and dusky coloured near its base; it reaches 2/3 or more of the distance to the apex of the fin. Caudal measured from the hypural origin 4.7 to 4.8 in the total length; epiural lobe well developed and without a subterminal notch, its upper margin almost straight except for the distal portion, its lower margin somewhat sinuous, and the apex acutely rounded or bluntly pointed. Hypural lobe about half as long as the epiural, its anterior margin convex and its apex acutely rounded; the angle between the posterior margin of the hypural and that of the epiural more than a right angle and smoothly rounded. Origin of the hypural just anterior to that of the epiural. Pectorals large and triangular originating just behind the 5th gill-opening. Anterior pectoral margin slightly convex, especially distally, its length 1.3 to 1.4 times the width of the fin and much less than the distance from snout tip to 1st gill-

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opening; posterior margin almost straight, and distal margin slightly concave. Anterior angle of the pectoral acutely rounded, and posterior angle less than a right angle and rounded to the same degree. Pelvics well anterior to the 2nd dorsal fin, shallowly tringular, their length of base about equal to their height or to the base of the 2nd dorsal measured from the origin of the spine. Anterior, posterior and distal margins almost straight, apex smoothly rounded, and posterior tip sharply pointed.

Colour. Brown or greyish-brown above, merging to a lighter colour below. The 1,008 mm female described above is a melanistic variant, being black dorsally merging to creamy-white below, with numerous black patches on the ventral surface; the iris of this specimen is greyish blue. Embryos have the distal margins of the dorsal fins black, as well as the proximal parts of the epiural and hypural margins.

Squalus megalops (Macleay, 1882) Text-fig. 1, G-I; Text-fig. 3, O-T.

Although S. megalops has not been reported from New Zealand, its presence in southern Australia as a common shelf species ranging to 400 fathoms (Cowper & Downie, 1957) suggests a possibility that it may yet be added to the New Zealand fauna. It is illustrated here (Text-fig. 1) for comparison with the closely similar S. blainvillii from which it differs in its heavy-bodiedness, its pointed inner pectoral corner, its dermal denticles (Text-fig. 3) and its generally lighter colour. Proportional dimensions of three of the specimens that I have seen are also given for comparison. I am indebted to Messrs. T. R. Cowper and A. M. Olsen, C.S.I.R.O., Melbourne and Tasmania respectively, and to Mr. G. P. Whitley, Australian Museum, for providing specimens of S. megalops.

S. megalops was the first described of the S. megalops-cubensis group of species; consequently this name has priority should it be found that other species of the group cannot be separated from S. megalops. There seems little to distinguish the Japanese S. brevirostris Tanaka, 1917, but as I do not have comparative meterial of S. brevirostris I cannot be certain of this. The validity of S. cubensis Rivero, 1936, from Cuba, the Gulf of Mexico and southwards to Rio de Janeiro seems more likely, though it and S. megalops are strikingly similar. Bigelow & Schroeder (1957, p. 37) who have compared specimens of S. cubensis and S. megalops, reports that the former has a relatively longer 1st dorsal spine, differently shaped caudal and pectoral fins, and more rearwardly placed pelvic fins. My material of S. megalops, compared with Bigelow and Schroeder's (1948, fig. 89) figure of S. cubensis, agrees with their diagnosis in the shorter 1st dorsal spine of S. megalops, to some extent in the shapes of the fins, but not in the placing of the pelvic fins where there seems to be little difference between the two species. The comparison of more material is much to be desired.

Squalus megalops (Macleay, 1882).

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