Spirotropis guancha, Ortega & Gofas, 2019

Ortega, José Rafael & Gofas, Serge, 2019, The unknown bathyal of the Canaries: new species and new records of deep-sea Mollusca, Zoosystema 41 (26), pp. 513-551 : 536-537

Spirotropis guancha n. sp. ( Fig. 20 D-F)

urn:lsid:zoobank.org:act:3CA92AAD-586D-47F5-9AD7-D00450C50F6E

TYPE MATERIAL. — Holotype. spm., MNHN-IM-2000-34271 and 1 paratype (sh.) from SEAMOUNT 2 DW128 .

Paratypes. 1 sh., MNHN-IM-2000-34272 from DW126. — 1 spm., MNHN-IM-2000-34273 from DW130 .

TYPE LOCALITY. — Off NW Gran Canaria, 28°08.26’N, 15°51.99’W / 28°08.47’N, 15°51.66’W, 470- 485 m.

ETYMOLOGY. — An adjective derived from the name of the aboriginal people of Canary Islands, the Guanches.

DESCRIPTION

Shell medium-sized, biconical with a tall and turreted spire, and the last whorl a little more than half of the total height. Protoconch of 1.5 whorls, globose, with the last half-whorl ornamented by a few flexuous incremental lines, separated from the teleoconch by an indistinct line.Teleoconch of about 7 regularly increasing whorls; teleoconch whorls distinctly shouldered, with a distinct subsutural rim, then a concave subsutural ramp between this and the shoulder. Shoulder bearing a series of axially elongate knobs (about 15 on penultimate whorl, becoming attenuated on the last whorl where approaching the outer lip). Labial notch well developed and deep, situated at the termination of the subsutural ramp, as is usual in the genus. Siphonal canal short and wide. Colour opaque white, without gloss. Dimensions of holotype, 16.2 mm height × 6.4 mm diameter, of paratypes, 10.7 × 4.3 to 20.1 × 7.6 mm.

REMARKS

Spirotropis guancha n. sp. most resembles S. centimata (Dall, 1889) , originally described from SE United States and subsequently reported from the Azores and from off western Morocco ( Bouchet & Warén 1980). Spirotropis guancha n. sp. has a globose and smooth, whitish, paucispiral protoconch denoting non-planktotrophic development whereas S. centimata has a conical, yellowish protoconch of c. 2.5 whorls, with a suprasutural keel, denoting a planktotrophic development. The thick subsutural rim of S. guancha n. sp. is not seen in S. centimata , which also has much more prominent knobs along the shoulder. The aperture of S. guancha n. sp. is wider, the siphonal canal is shorter and broader than in S. centimata . We figure for comparison ( Fig. 20 A-C) a specimen of the latter species collected off SW Morocco by R/V Talisman .

Figures

FIG. 20. — A, B, Spirotropis centimata (Dall,1889),shell from off Cap Ghir, Morocco, “Talisman” 1883 sta.43-44 (28.7 mm); C, protoconch of the same specimen; D-F, Spirotropis guancha n. sp., holotype from DW128 (spm., 16.2 mm); F, protoconch of the holotype. Scale bars: 1 mm.