“Kurilabyssia antipodensis n. sp.
Fig. 6G, H, 10E-H, 14A-D; Table 19
Description. Shell up to 8.70 mm long, weakly arched, thin, translucent white, anterior end occupying 56.32-56.88% of shell length. Periostracum thin, smooth and transparent. Aperture elliptical, shallowly convex from side to side. Anterior and posterior ends broadly and similarly rounded, sides more broadly rounded. Anterior, posterior and lateral slopes very shallowly convex.
Table 19. Kurilabyssia antipodensis. Shell measurements (mm) and proportions. Holotype in italics.
Length
Width
Height
Length/width
Length/height
Anterior length %
Locality
3.95
2.90
0.80
1.36
4.94
69.62
N.Z.
4.20
3.15
0.80
1.33
5.25
70.24
N.Z.
6.60
4.80
1.75
1.37
3.77
63.64
N.Z.
6.90
5.30
1.60
1.30
4.31
56.52
N.S.W.
7.60
5.70
2.10
1.33
3.62
60.53
N.Z.
8.00
5.20
2.60
1.54
3.08
56.88
N.S.W.
8.00
6.40
2.00
1.25
4.00
60.62
N.Z.
8.60
6.30
2.60
1.36
3.31
59.30
N.Z.
8.70
6.45
2.30
1.35
3.78
56.32
N.S.W.
Protoconch 230 µm long and 170 µm wide. Apical fold long and narrow, its tip fused, suture at folding axis an arcuate groove. Sculptured throughout with fine, crisp, threads forming a subreticulate pattern.
Teleoconch sculptured with fine, crisp, closely spaced, broken anastomosing radial threads; and very fine, crowded, collabral growth lines.
Animal (Fig. 6G, H). Mantle very broad and thin, a large secondary gill with 10-14 leaflets extending along its right ventral surface. Cephalic tentacles similar in shape and size, rather long, dorsoventrally flattened, gradually tapered to rounded tips, set with sensory papillae. Left tentacle simple. Seminal groove inconspicuous, gently descending to base of right tentacle, passing through it and opening into a very fine dorsal groove in distal half. Two large flattened epipodial tentacles at posterior end. No 'eyes'.
Radula (Fig. 14A—D). Central tooth shaped like an arrow-head, large, tip pointed and finely and irregularly convoluted. Lateral 1 large, tip bluntly pointed and strongly thickened in front. Laterals 2-4 small and similar, unicuspid. Lateral 5 massive, cutting area broad, without true cusps. Marginal 2 longer than marginals 1 and 3, innermost marginals unicuspid, outer marginals typical of the family.
Type data. Holotype (AMS C.142212) and 4 paratypes (3 AMS, 1 NMNZ): 33°30'S, 152°05'E, off Port Jackson, New South Wales, 823 m, alive on wood, 21 Dec 1976, FRV Kapala stn K 76/24/04.
Other material examined. (20 New Zealand specimens taken from wood): 44°44.2'S, 173°07.8'E, off Timaru, 920-926 m, 24 August 1984, FRV James Cook stn J14/35/84 (4 NMNZ); 44°45.I'S, 173°05.2'E, off Timaru, 922 m, 10 June 1984, FRV James Cook stn J 10/16/84 (2 NMNZ); 44°46.1'S, 173°36.0'E, off Timaru, 952-962 m, 17 April 1984, FRV James Cook sin J7/36/84 (9 NMNZ, 1 AMS); 44°47.9'S, 174°05.9'E, off Timaru, 845-860 m, 27 Aug 1984, FRV James Cook stn J 14/49/84 (4 NMNZ).
Known distribution. New South Wales and Southern New Zealand 823-962 m.
Remarks. Kurilabyssia antipodensis is rendered extremely distinctive by its large, thin, flattened shell, distinctive sculpture, and unique secondary gill. I can detect no significant differences between New South Wales and New Zealand specimens.
All New Zealand records are from relatively fresh pieces of wood that support very few associated epifaunal molluscs or none at all. The species was absent on all wood with surfaces extensively worked by boring bivalves and dense limpet populations. Evidently, therefore, K. antipodensis is an initial coloniser and preempter of wood surfaces and is perhaps unable to compete with later successional species. The condition of the New South Wales log is unknown.”
(Marshall, 1985: 536-537)
Kurilabyssia antipodensis is a species of small sea snail, a marine gastropod mollusk in the family Pseudococculinidae, the false limpets.[2]
This marine species is endemic to New Zealand.
Kurilabyssia antipodensis is a species of small sea snail, a marine gastropod mollusk in the family Pseudococculinidae, the false limpets.
