Echinoderms from Southern New Zealand
Goniocidaris Agassiz and Desor, 1846
Goniocidaris umbraculum (Hutt., 1872)
- East coast of Canterbury, between Moeraki and Timaru, 40 to 60 fathoms, January, 1951; coll. P. M. Ralph; one specimen.
The species is restricted to New Zealand, where it is known only between Cook Strait and Stewart Island, on the eastern coast of the South Island. The single specimen does not differ from Mortensen's account, and is similarly coloured to his specimens. Among the epizoic animals carried on the spines is an acorn-barnacle (Balanus sp.), a calcareous sponge, and miscellaneous polyzoa. The majority of the upper spines are completely invested by these organisms. To a lesser extent, the same is to be observed in Ogmocidaris benhami, where I have also noted the tubicolous annelid Spirorbis attached to the proximal parts of spines; O. benhami, however, is as yet unknown from southern New Zealand waters.
Pseudechinus Mrtsn. 1903
Pseudechinus huttoni Benham, 1908
- Station NGH 2; seven tests.
- Ruapuke oyster beds, Foveaux Strait, 12 fathoms, February, 1951; coll. B. M. Bary; two specimens.
- Off coast of Canterbury, between Moeraki and Timaru, 40 fathoms, January, 1951; coll. P. M. Ralph; three specimens.
- Off Otago coast, between Moeraki and Taiaroa Head, 40 fathoms, November, 1951; three large specimens.
Pseudechinus albocinctus (Hutton, 1872)
- Alert stations: 11, three dead tests; 13, ten dead tests of very young individuals; 23, three immature living specimens.
- Ruapuke oyster beds, Foveaux Strait, 12 fathoms, February, 1951; coll. B. M. Bary and C. A. Fleming; three specimens.
- Off Otago and Canterbury coasts, between Taiaroa Head and Timaru, 40 fathoms, January and November, 1951; coll. P. M. Ralph; six specimens.
Pseudechinus novae-zelandiae (Mrtsn., 1921)
- Alert stations: 11, two dead tests of young individuals; 13, five young dead tests; 23, five young living specimens; 24, one young specimen.page 34
- Ruapuke oyster beds, Foveaux Strait, 12 fathoms, February, 1951; B. M. Bary; one specimen.
- Off East Canterbury coast, between Timaru and Moeraki, 40 fathoms, November, 1951; P. M. Ralph; two large specimens.
It would appear that in the southern part of New Zealand the three species of Pseudechinus occur side by side. In the material examined, it was notable that wherever specimens were taken in either young or old stages, large forms or small, dead or living, the particular character, whatever it might be, applied pretty well equally to all three species. A consistently small size of individuals from the Fiords is notably in contrast with an equally consistent occurrence of large specimens off the east coast of the South Island. In both the New Golden Hind and the Alert dredgings, there was a surprising preponderance of dead tests of immature and even post-embryonic individuals in the Fiords region. Some had annelid tubes or small corals growing on them. The reason for this is not clear. Some specimens, especially from station NGH 2, had adhering mud, as if from a soft bottom—a habitat not frequented by Pseudechinus. On the other hand, Mr. C. A. Fleming, of the New Zealand Geological Survey, informs me (private communication, 1952) that the mollusca from the same station indicate a hard bottom, though the species present are few. It is possible that there are rapid transitions from hard to soft bottom in the Fiords, and that mud frequently overwhelms the hard-bottom communities. Fleming has found analogous sequences in the Castlecliffian strata (Upper Pliocene), hard and soft-bottom communities alternating. This probably accounts for the presence in the Castlecliffian of Pseudechinus in mud marl, a matrix not otherwise to be expected for the genus; the Castlecliffian specimens are small, like those from the Fiords.
Evechinus Verrill, 1871
Evechinus chloroticus (Valenciennes, 1846)
- Alert station 11, fragments of the test of a large individual.
- Also, Dusky Sound, littoral, one large test washed ashore.
The absence of the species from other stations is accountable by the fact of its being especially a reef-dwelling, eulittoral form. It is seldom found fossil for the same reason. It has not hitherto been taken from 50 fathoms (as at Alert station 11); but, as fragments alone were found there, the record should not be treated as evidence that the species lives in such deep water.
Apatopygus Hawkins, 1920
Apatopygus recens (M. Edwards. 1836)
- Station NGH 2, a single test of a small individual, bearing tubicolous annelids and coral.page 35
- Ruapuke oyster beds, Foveaux Strait, 12 fathoms, February, 1951; B. M. Bary; two specimens; also from the same locality, one specimen; coll. C. A. Fleming.
- Off Chatham Islands, taken from stomachs of groper (Polyprion oxygeneios); coll. F. Abernethy; numerous specimens.
Peronella Gray, 1855
Peronella hinemoae Mrtsn., 1921
- Station NGH 3, one specimen.
- Alert stations: 13, four dead tests; 18, three dead tests.
These records extend the range of Peronella hinemoae southward by over 70 miles; it has hitherto been known only from Hauraki Gulf, Colville Channel, and North Cape. The largest specimen measures 40 mm. horizontal diameter. The records also indicate a shallower habitat than formerly was known.
Spatangus Mueller, 1776
Spatangus multispinus Mrtsn., 1925
- Cape Campbell, 20 fathoms, soft mud bottom, September, 1949; one specimen.
In life, the species is bright purple, fading after preservation to dull mauve. It is known so far only from the Cape Campbell area.
Echinocardium Gray, 1825
Echinocardium cordatum (Pennant, 1777)
Synonym: Echinocardium australe Gray, 1851, et auctt.
- New Golden Hind stations: NGH 1, two specimens; NGH 3, three specimens; NGH 56a, two specimens.
- Alert stations: 1, one specimen, not common; 3, two specimens, but very abundant; 4, one specimen, not common; 6, one specimen, not common; 10, one specimen, but abundant here; 12, one specimen, not common; 19, eight specimens, one very large; 29, two specimens, abundant.
- Also, near entrance to Queen Charlotte Sound. 20 to 30 fathoms, May, 1950; W. H. Dawbin; one specimen.
The large specimen from Alert station 19 (Stewart Island) measures as follows: Length, 69 mm.; breadth, 66 mm.; height, 38 mm.page 36
H. L. Clark (1946), who has taken the step of merging the Australian Echino-cardium australe with the Atlantic species E. cordatum, states that specimens from the southern hemisphere attain only about half the size of those from Great Britain, rarely exceeding 45 mm. in length. The above record shows that large forms do occur. Mortensen (1921) considers the New Zealand and Australian forms to be identical, and so, in view of the change in nomenclature in Australia, it seems desirable to follow suit in New Zealand.
That the species occurs in Chalky Inlet was shown by Farquhar in 1898.