Strobiligera picta, Fernandes, 2024

Fernandes, Maurício Romulo, 2024, The deep-sea species of Triphoridae (Gastropoda, Triphoroidea) from Guadeloupe, sampled by the Karubenthos 2 expedition, European Journal of Taxonomy 972, pp. 1-52 : 18-19

Strobiligera picta sp. nov.

urn:lsid:zoobank.org:act:124616F8-440A-4554-8AC3-0A4921BD84C7

Fig. 9

Diagnosis

A species of Strobiligera with a brown band in the adapical spiral cord of the teleoconch.

Etymology

Latin, ‘ pictus ’ = ‘painted’. The specific name alludes to the brown band on the adapical spiral cord of the teleoconch, unusual for a deep-sea triphorid species.

Type material

Holotype

GUADELOUPE (Karubenthos 2 expedition) • sh; stn DW4635; MNHN-IM-2000-38781.

Paratypes

GUADELOUPE (Karubenthos 2 expedition) • 1 sh; stn DW4634; MNHN-IM-2000-38782 • 1 sh; stn DW4635; MNHN-IM-2000-38783.

Type locality

Guadeloupe, 15°50′ N, 61°26′ W, 265–268 m depth.

Description

Shell sinistral, conical-fusiform, up to 8.9 mm long (incomplete base), 1.8 mm wide, length/width ratio 4.8–4.9, apical angle of early whorls 13–17°. Protoconch paucispiral, sub-columnar, 2.75–3.5 whorls, 0.60–0.69 mm long, 0.47 mm wide; small nucleus rises in an adapical direction and further goes abapical in an oblique descent; two smooth, wide spiral cords of equal size, situated at 42–45% and 72–73% of last whorl height, in addition to a very narrow subsutural cord; gradual transition to teleoconch, from a smooth spiral sculpture to a nodulous one. Teleoconch with up to 15 whorls; three main spiral cords, two of them (median and abapical) stronger at beginning and continuous to those of protoconch, adapical spiral cord initially narrow but gradually strengthening along teleoconch, reaching same size as other cords in 13 th or 14 th whorl (but with a similar size since eighth whorl); suture shallow, with a smooth to slightly wavy sutural cord; 19–22 slightly opisthocline axial ribs on tenth teleoconch whorl; medium-sized, nearly rounded to slightly elliptical nodules; slightly nodulous subperipheral cord, with a smooth, very thin basal cord right below it. Shell white, with a brown (or light brown) band on adapical spiral cord and on subperipheral and basal cords, sometimes with protoconch slightly brownish.

Remarks

In addition to the obvious difference in shell color, Strobiligera picta sp. nov. is differentiated from S. cf. enopla by its non-inflated protoconch, its spiral cords of nearly the same strength and the adapical spiral cord of teleoconch reaching the same size as other cords in the 13 th –14 th whorl in S. picta , but only in the 21 th –23 th in S. cf. enopla . Unfortunately, the incomplete base of S. picta precluded further comparisons.

The most similar shells to S. picta sp. nov. are the Brazilian records of I. apexbilirata and Inella sp. 1 ( Fernandes & Pimenta 2019a), which, however, have a different color pattern. The Brazilian shells are from the lower continental shelf (69–163 m for I. apexbilirata ; 65–80 m for Inella sp. 1 ), whereas S. picta is recorded from 265–310 m and it was absent from the expedition Karubenthos 1, conducted in the shallow waters of Guadeloupe. The Brazilian record of I. apexbilirata is here described as a new species (see below).

Geographic distribution

Guadeloupe.

Bathymetric distribution

265–310 m (empty shells).

Figures

Fig. 9. Strobiligera picta sp. nov. A, E. Holotype, MNHN-IM-2000-38781, 8.4 mm. B, D. Paratype, MNHN-IM-2000-38783, 8.9 mm. C. Paratype, MNHN-IM-2000-38782, 3.3 mm. Scale bars: A–C = 1 mm; D–E = 500 µm.