“Tentaoculus haptricola
Fig. 6D, 9J-O, 13M; Table 17
Description. Shell up to 3.00 mm long, translucent, thin and fragile, moderately arched, anterior end occupying 86.54-93.02% of shell length. Aperture elliptical, more or less flat. Anterior and posterior ends narrowly and similarly rounded, sides broadly rounded. Anterior slope strongly convex, posterior slope concave, lateral slopes more or less flat. Internal septum thin, arcuate, 400-500 µm wide, left side longer and inserted nearer the apex.
Protoconch 180-200 µm long and 110-133 µm wide. Apical fold long, narrow and tapered, tip fully fused, suture at folding axis an incised groove.
Table 17 Tentaoculus haptricola. Shell measurements (mm) and proportions, n=16 (From James Cook stations J6/20/84, J6/21/84).
Character
Range
Mean
SD
Length
2.00- 3.00
2.34
0.31
Width
1.30- 2.20
1.61
0.27
Height
0.75- 1.30
1.00
0.18
Length/width
1.36- 1.55
1.46
0.06
Length/height
2.11- 2.66
2.36
0.13
Anterior length %
86.54-93.02
89.44
2.04
Sculptured throughout with minute, steep-walled pits, crowded and mostly coalescent on posterior half, smaller, sparser and discrete on anterior half.
Teleoconch sculptured with rounded collabral growth lines and minute pits on earliest part. Thereafter sculptured throughout with fine, raised, collabral growth lines, with the addition, on the anterior half, of faint radial grooves and narrow radial bands of fine, crisp, concentric threads.
Animal (Fig. 6D) externally similar to that of T. lithodicola.
Radula (Fig. 13M). Central tooth with a broad, weakly serrate cutting area. Cutting area on lateral 1 broad, with 7-9 blunt cusps. Cutting areas on laterals 2-4 small and narrowly tapered, laterals 2 and 3 weakly serrate, lateral 4 smooth. Lateral 5 massive, cutting area very broad, with 4 or 5 stout cusps. Lateromarginal plate present. Marginal 1 shorter than marginal 2, outer marginals regularly decreasing in size outwards. Inner marginals each with a strong terminal cusp, small lateral cusps and a groove in the shaft face. Marginals otherwise typical of the family.
Type data. Holotype NMNZ M.75180 (length 2.15 mm, width 1.45 mm, height 0.90 mm, anterior length 2.00 mm) and 1079 paratypes (AMS, BMNH, LACM, MNHN, NMNZ, NMNH): 41°11.0'S, 176°40.0'E, off Castlepoint, New Zealand, alive on Macrocystis holdfast (diameter 40 cm), 1070-1198 m, 4 Apr 1984, FRV James Cook stn J6/20/84. Paratypes (56 NMNZ): 41°09.7'5, 176°31.3'E, off Castlepoint, 20 alive on Macrocystis holdfast (diameter 38 cm), 1198-1211 m, 4 Apr 1984, FRV James Cook stn J6/21/84; 41°10.5'S, 176°34.8'E, off Castlepoint, 36 alive on Macrocystis holdfast (diameter 30 cm), 1191-1200 m, 6 Apr 1984, FRV James Cook stn J6/30/84.
Known Distribution. Off Castlepoint, New Zealand, 1070-1200 m.
Remarks. Tentaoculus haptricola differs from both T. lithodicola n. sp. and T. neolithodicola n. sp. in having weaker cusps on laterals 2 and 3, no cusps on lateral 4, fewer and stouter cusps on lateral 5, and a much stronger terminal cusp on each inner marginal tooth. It differs from T. perlucida in lacking eyes and in having a more coarsely serrate lateral 5.
The three Macrocystis holdfasts supporting T. haptricola were all substantially degraded by microbial activity. The limpets appear to consume mainly the soft medullary tissue, which is reached by rasping through the tough cortex, or by tunnelling longitudinally through the holdfast rami. A fourth Macrocystis holdfast (diameter 32 cm) obtained in the same vicinity, at 1073-1116 m, was in very fresh condition and yielded no limpets, though an undescribed species of the Skeneidae (Gastropoda: Trochoidea) was well represented (description in prep.)
The algal holdfasts supporting T. haptricola are clearly remnants of dislodged plants that have drifted over deep water and fallen to the bottom after detachment from the flotational parts. T. haptricola is not a component of the molluscan fauna of in situ algal holdfasts.”
(Marshall, 1985: 534-535)
Tentaoculus haptricola 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.
Tentaoculus haptricola is a species of small sea snail, a marine gastropod mollusk in the family Pseudococculinidae, the false limpets.
