Antalis albatrossae, Scarabino, 2008

Scarabino, Victor, 2008, New species and new records of scaphopods from New Caledonia, Mémoires du Muséum national d'Histoire naturelle 196, pp. 215-268 : 224-225

Antalis albatrossae n. sp.

Fig. 1j

Antalis phaneum - Scarabino 1995: 233, figs 41, 45i (in part, non Antalis phaneum ( Dall, 1895)) . Material cited: 6 lots (41 spms) from New Caledonia and Loyalty Ridge, live in 705- 825 m.

TYPE MATERIAL. — Holotype (dd) MNHN 20076 and 13 paratypes (4 lv, 9 dd) MNHN 20077-20079 .

TYPE LOCALITY. — New Caledonia, Passe SE of Ngoe, 21°43’S, 166°39’E, 550-580 m [BATHUS 1: stn CP 708] .

NEW MATERIAL EXAMINED. — New Caledonia proper. de Boulari, 22°36’S, 166°26’E, 713-950 m, 10 dd; stn CP 767, BATHUS 1: stn CP 660, Passe de Canala , 21°10’S, 165°53’E, Passe de Uitoé , 22°10’S, 166°00’E, 1060-1450 m, 1 lv, 82 dd 786-800 m, 5 dd; stn CP 708, Passe southeast of Ngoe, 21°43’S, (6 paratypes MNHN 20078 ) . — BATHUS 4: stn DW 884, Passe 166°39’E, 550-580 m, 11 dd, 2 lv (holotype MNHN 20076 , 4 de St Vincent, 22°05’S, 165°57’E, 1100-1200 m, 2 lv, 19 dd (3 paratypes MNHN 20077 ). — BATHUS 2: stn DW 743, Passe paratypes MNHN 20079 ) .

DISTRIBUTION. — Global distribution: central and southwest Pacific from Hawaii to French Polynesia (live in 614 m, Scarabino 1995) and New Caledonia, live in 580-1100 m. Distribution in the New Caledonian region: east and southwest of New Caledonia, and Loyalty Ridge.

DESCRIPTION. — Shell up to 47.3 mm long, solid, slightly curved, profile irregular, not smooth, shiny, white. Sculpture of 30 low, narrow ribs, better distinguishable under magnification and visible only in the anterior 1/4 of the shell to the mouth. Secondary ribs present, reaching the oral aperture, 39 in number. Distinct growth lines provide dense transverse sculpture. Apical section to 1/5 of total length of shell sculptured only with dense growth lines and almost imperceptible longitudinal threads. Apex simple, circular in section; mouth oblique, circular in section, shell at mouth thin and fragile.

Measurements of holotype: L 47.3, W 3.3, w 0.6, arc 2.4.

REMARKS. — This species was identified by Scarabino (1995: 233) as Antalis phaneum ( Dall, 1895: 686, pl. 26, fig. 1). However, examination of the type material (holotype USNM 107025 and 2 paratypes USNM 107026 ; near Sandwich [Hawaiian] Is., Albatross stn 3476, 298 fms [545 m]), demostrated the presence of two species, the figured one, with the figure identified as the holotype by Dall, and the other two specimens (as paratypes), which are a different species, here described as new. Further examination of all the relevant material deposited in the USNM confirmed the presence of two species .

Antalis phaneum is regularly tapering, with a regular outline slightly curved with the arc close to the posterior end. It is shiny, and white to pale cream. The 20 ribs are well defined, similar to each other, closer to each other on the ventral side than on the dorsal, and slightly nodulose (shown in Dall’s figure, and in Figs 1k, l herein) suggesting the characters of Coccodentalium . Secondary ribs initiate early, and reach 35 in number at the anterior aperture. Well preserved specimens show a shallow apical notch in the ventral side. In contrast, A. albatrossae has an irregular profile and the arc is not so close to the apex. The ribs, low and not well defined, do not begin at the apex; they are irregularly distributed around the shell, best observed on the dorsal side and fading toward the mouth. The surface is shiny, and chalky white, to pale brown in worn specimens. Over the anterior 1/5 of the shell, only dense growth lines and hardly noticeable longitudinal threads are visible. This characteristic apical part was noticed by Dall in the USNM lots. Dall separated some of them and labelled them as “ var. evanescens ”, but he never described this variety. The apex is simple and circular in section as is the mouth.

In the Hawaiian region, according to the USNM lots, the bathymetric distribution also seems to be different. The two species were collected together at only two Albatross stations (3810 and 4084). Antalis phaneum was represented by empty shells. Dall’s species seems to be endemic to the Hawaiian region, live in 232-238 m and shells down to 644 m, while A. albatrossae is distributed widely through the Indo-Pacific from Hawaii, live in 460-973 m (herein), and French Polynesia to New Caledonia.

ETYMOLOGY. — Named after the research vessel Albatross.