Deep-Sea Echinoderms of New Zealand
A family of deep-water asteroids, already recorded from Australia but not hitherto known from New Zealand. The familial characters include:
Rays five, long, stiff, tapering, with longitudinal series of abactinal plates, among which the carinals are prominent and carry a prominent spine. Primary plates prominent on the disc. Adambulacral plates of alternating large and small types, the large type projecting into the furrow like a keel, a keel on one side of the furrow occurring opposite a small adambulacral plate on the other side. Pedicellariae straight, never crossed.
Zoroaster Wyville Thomson, 1873
Plates of arm forming transverse, as well as longitudinal series, each plate covered by numerous small spinules or papillae, and usually bearing one enlarged spine. Mouth deep-set. Pedicellariae numerous, often large.
Zoroaster spinulosus Fisher. Plate 3, Fig. E.
- Zoroaster spinulosus Fisher, W. K., 1906. Bull. U.S. Fish Commission, 23 (3) p. 1102–4, Pl. 24, 41, 42.
- ? Zoroaster macracantha Clark, H. L., 1916. Rpt. Dept. Trade and Customs, Fisheries N.S.W., 4, p. 68–9, Pl. 28.
Material Examined: Two specimens, partly fragmented, from the following stations of the Chatham Islands 1954 Expedition: 280 fathoms, Chatham Rise, Station 7; 220 fathoms, Chatham Rise, Station 6.
Remarks: The spinules and papilliform granules of the arm-plates are apparently somewhat more attenuated and elongate than in Fisher's material, but in other respects the specimens agree closely with Zoroaster spinulosus. The species is especially distinguished by the adambulacral armature, and by the presence of one enlarged slender spinule on each of the plates between the superomarginals and the adambulacrals. These features are illustrated in Fig. E which was drawn from a section of the arm taken at the base in the individual from Station 7. The giant straight pedicellariae are a prominent feature of the spine adjoining the innermost (furrow-) spine. My material also appears to be conspecific with H. L. Clark's (1916) Zoroaster macracantha, from the Great Australian Bight, 250–450 fathoms. It agrees in particular in having a boss only on every second carinal plate in the distal part of the arm. As in Clark's material, the spines are nearly all lacking from these carinal tubercles. I consider that the characters by which he distinguished macracantha from spinulosus are variable and unreliable, and he indicates that in separating the Australian form he was influenced by the lack of material from the region between Australia and Hawaii (where Z. spinulosus occurs). That lacuna is now partly filled. The New Zealand material appears to be intermediate between the Australian and the Hawaiian types, but the differences are trivial and not of specific value. As I have not handled Clark's or Fisher's material the proposed synonymy given above has been prefixed by a question mark.
Opportunity will be taken in the official report of the Chatham Islands Expedition of giving photographic illustrations of the New Zealand specimens.