Anekes spiralis Gofas & Luque, 2021

Gofas, Serge, Luque, Ángel A., Oliver, Joan Daniel, Templado, José & Serrano, Alberto, 2021, The Mollusca of Galicia Bank (NE Atlantic Ocean), European Journal of Taxonomy 785 (1), pp. 1-114 : 48-51

Anekes spiralis Gofas & Luque sp. nov.

urn:lsid:zoobank.org:act:CBA7FA0B-5656-47A2-ADE8-DEFE58E98B81

Fig. 17A‒H

Etymology

The specific name refers to the characteristic spiral sculpture.

Type material

Holotype GALICIA BANK • 1 sh ( Fig. 17 A ‒ G , 1.7 mm in diameter); 42°56.77′ N, 11°58.53′ W; 1631 m; 2 Aug. 2011; BANGAL 0711 V5; MNCN 15.05 /200139H.

Paratypes GALICIA BANK • 1 spm and 7 sh; same collection data as for holotype; MNCN 15.05 /200139P .

Other material examined

GALICIA BANK • 1 sh; 43°00.12′ N, 11°57.67′ W; 1706 m; 29 Jul. 2011; BANGAL 0711 V2; MNCN .

Description

Shell minute, very fragile and translucent, up to 2.1 mm height and maximum diameter, trochiform, with a moderately low, slightly cyrtoconoid spire, a rounded periphery and body whorl, and a small but definite umbilicus. Protoconch of ¾ whorl, about 260 µm in maximum diameter, terminated by a simple, curved edge; protoconch sculpture of minute, irregularly spaced granules. Teleoconch with up to 3 convex whorls. First whorls sculptured by minute spiral threads, irregular in size and spacing, about half the size of interspaces; occasionally these threads are interrupted or anastomosing. The spiral threads become inconspicuous on the later whorls, persisting in the subsutural zone and within the umbilical area, but lacking in the median part of the body whorl, where only growth lines can be seen. Umbilicus narrow and deep, not delimited from the rest the whorl. Aperture evenly rounded except for a slight angle at the termination of the suture; outer lip very thin, slightly flexuous, slightly prosocline. Colour slightly yellowish on fresh shells, otherwise whitish.

Remarks

Species of Anekes are mostly characterized by a peculiar “ Anekes sculpture” which consists of minute raised lines, anastomosing in a criss-cross pattern. In Anekes affinis (Jeffreys, 1883) this sculpture is spread over the entire surface and quite noticeable. Anekes sculpturata Warén, 1992 is similar but smaller (hardly exceeds 1 mm) and the microsculpture has a preferential orientation in the spiral direction, while in A. affinis it forms a non-directional network. In Anekes paucistriata Warén, 1992 the sculpture is evident only on the first whorl and may also occur in the umbilicus, but it is almost completely missing in intermediate surface and an attentive examination is required, under strong magnification and preferably under SEM, to detect it. This kind of sculpture is not exclusive of the genus Anekes , and it is also present on Granigyra inflata ( Warén, 1992) , originally described in Anekes but later ( Warén 1996) found to have radular characters closer to Granigyra Dall, 1889 .

Anekes spiralis sp. nov. differs from the other species of Anekes in that the microsculpture is definitely spiral, not just with a preferential orientation like in A. sculpturata or in A. undulisculpta , but a limited anastomosing pattern occurs on some (especially the very early) parts of the shell of A. spiralis sp. nov., supporting the generic placement.

Figures

Fig. 17. Skeneimorph species 4. A–H. Anekes spiralis Gofas & Luque sp. nov. A–B. Holotype (MNCN 15.05/200139H), BANGAL 0711, V5, 1631 m, diameter 1.7 mm.C–D. SEM micrograph of the holotype. E. Apical view, protoconch and early teleoconch whorl of the holotype. F. Detail of the microsculpture of the adapical part of the last whorl. G. Detail of the umbilical area of the holotype. H. Paratype (MNCN 15.05/200139P), SEM micrograph, same locality, 2.0 mm. I–J. Granigyra inflata (Warén, 1992), BANGAL 0711, V5, 1631 m, diameter 1.8 mm. K–L. Same shell, SEM micrograph and detail of the microsculpture of the last whorl. Scale bars: A–D, H–K = 1 mm; E, G, L = 200 µm; F = 50 µm.

Fig. 1. The NW Iberian continental margin, with situation of the Galicia Bank (hereafter GB) and other geomorphological features of the area: Vasco da Gama Seamounts (BVG), Vigo Bank (BV), Oporto Bank (BP), Galicia Inner Basin (CIG), transition zone (ZT), northwestern flank (FNO), Rucabado and García seamounts (BR), the deep margin of Galicia (MPG), the Bay of Biscay abyssal plain (LLAV) and the Iberian abyssal plain (LLAI). Source: EEZ Project (multibeam echo sounder bathymetry) and GEBCO Digital Atlas.