Summary

(i) Deania kaikourae of New Zealand and Australia and D. eglantina of Japan are recognised as D. calcea of the North Atlantic. In most specimens of D. calcea the length of the 2nd dorsal fin base (measured from point of emergence of spine to posterior end of base) is from 0.9 to 1.3 in that of the 1st dorsal base similarly measured; occasional specimens have a proportionately longer 2nd dorsal base as in the type of D. kaikourae. Males of New Zealand D. calcea generally have less oblique lower teeth than females, while one male of four examined has erect teeth at the centre of the lower jaw and a symmetrical median tooth; on this character it matches the condition described for the teeth of male Deania of Japan.

D. calcea differs from all other species of Deania in having a long and low first dorsal fin, its height 3.0 to 4.0 in the length of its base measured from the emergence of the spine; in D. elegans, D. natalense, D. profundorum, D. quadrispinosa and “D. eglantina” (the last as recognised by Smith, 1949, from South Africa) the 1st dorsal is relatively higher and shorter, its height about 1.5 in its base. “D. eglantina” of Smith is suggested as a synonym of D. quadrispinosa.

Dermal denticles of D. calcea are mostly four-toothed, but in juveniles there are three-toothed forms, and in large adults there are frequently denticles with six or more teeth.

(ii) Etmopterus baxteri, previously known only from the holotype, a female 742 mm long and the largest recorded etmopterid at the time of its description, is studied from eleven more specimens 261 mm to 750 mm long recently taken off New Zealand. This material shows that E. baxteri undergoes considerable change with growth, the tail region, and the head to a lesser extent, decreasing relative to the trunk region with increase in total length. The change is such that on proportional criteria E. baxteri cannot now be separated from the North Atlantic E. princeps when specimens of about equal size are compared. E. baxteri and E. princeps agree in having 3–5 cusped teeth in small specimens, and 5–7 or occasionally 9-cusped teeth in large specimens, and in showing a decrease in the extent of the naked areas of skin with increase in total length.

E. baxteri differs from E. princeps in having a strongly curved, long 2nd dorsal spine reaching almost to the fin apex (in E. princeps the spine is almost straight and reaches only ⅔ to the apex), and having sparser, more regularly arranged dermal denticles. E. baxteri is apparently more slender bodied, with smaller fins than E. princeps.

(iii) Etmopterus abernethyi, now known from five specimens in New Zealand waters, is shown to be a growth stage of the Indo-Pacific E. lucifer, and undergoes growth changes similar to those of E. baxteri—i.e., the head and tail decrease relative to the trunk length with increase in total length. Since E. lucifer is one of the smallest sharks its growth changes are considerable even with very small increases in total length. E. molleri of Australia is a synonym of E. lucifer.

(iv) Oxynotus bruniensis is described from New Zealand material for the first time. Nine specimens 525 mm to 722 mm long show that the height of the dorsal spines increases relative to the dorsal fin heights with increase in total length; the dorsal fin heights also decrease relative to the lengths of their bases; and the interspace between the dorsal fins increases relative to the length of the 2nd dorsal base.

Late embryos of O. bruniensis have slender, squaliform bodies and an erect or rearward sloping 1st dorsal spine; the high dorsal fins, deep body, and forward sloped first dorsal spine characteristic of immature and mature species evidently appear late in development.

Small specimens of O. bruniensis have three-toothed denticles, but larger specimens mostly have four-toothed denticles set nearly vertical in the skin.