Strobiligera cupella Fernandes, 2024, sp. nov.

Strobiligera cupella sp. nov. urn:lsid:zoobank.org:act: B4B076E3-B74E-4727-B5BF-9258179D56DA Fig. 16A–G Diagnosis Elongated shell with a late adapical spiral cord on the teleoconch; protoconch beige to light brown, paucispiral, dome-shaped, mainly smooth. Etymology Latin, ‘ cupella ’ = ‘dome’. The specific epithet alludes to the dome-shaped first protoconch whorl of this species. Type material Holotype GUADELOUPE (Karubenthos 2 expedition) • spec. stored dry; stn DW4554; MNHN-IM-2000-38793. Paratypes GUADELOUPE (Karubenthos 2 expedition) • 1 sh; stn DW4538; MNHN-IM-2000-38794 • 1 sh; stn DW4556; MNHN-IM-2000-38795 • 2 sh; stn DW4572; MNHN-IM-2000-38796. Type locality Guadeloupe, 16°21′ N, 60°56′ W, 300–370 m depth. Description Shell sinistral, conical-fusiform, incomplete shells up to 15.8 mm long and 2.7 mm wide; apical angle of early whorls 12–14°. Protoconch paucispiral, 2.5–2.75 convex whorls, 0.54–0.64 mm long, 0.49–0.52 mm wide; first whorl dome-shaped, globose, mainly smooth but with few, minute pustules; subsequent whorls with two spiral cords, situated at 31–33% and 63–74% of whorl height, in addition to a much smaller subsutural cord; no axial sculpture. Teleoconch with up to 24.5 whorls (incomplete); three main spiral cords, continuous with those of protoconch; adapical spiral cord initially very narrow and gradually enlarges through teleoconch, but never reaches same size as other cords; shallow suture, almost indistinct, with a very narrow, smooth sutural cord; ~15 nearly orthocline to slightly opisthocline axial ribs on 12 th whorl; medium-sized to moderately large, nearly rounded to slightly elliptical nodules; unknown base. Protoconch beige to light brown, teleoconch white to dirty-white. Remarks Despite the moderately long shell, no adults (with a complete base) are known of Strobiligera cupella sp. nov. This species differs from all other Caribbean species (Rolán & Fernández-Garcés 2008), e.g., S. enopla has a reduced adapical spiral cord on the teleoconch and a white protoconch with the first whorl slightly inflated and the second whorl with unequal spiral cords (the abapical one more prominent, whereas the two spiral cords are nearly equal in the beige to light brown protoconch of S. cupella). The colored and dome-shaped (not inflated) protoconch of S. cupella also distinguishes it from S. dinea, which has a larger protoconch (shells from Guadeloupe: 0.75–1.25 mm long, 0.70–1.03 mm wide vs 0.54–0.64 mm long, 0.49–0.52 mm wide in S. cupella) and a more developed adapical spiral cord on the teleoconch. Strobiligera cupella is differentiated from Strobiligera colon (Dall, 1881) comb. nov. from Cuba by the slightly more pronounced adapical spiral cord on the teleoconch (almost indistinct in S. colon) and the more prominent and rounded nodules of the teleoconch; the protoconch of S. colon is unknown (Rolán & Fernández-Garcés 2008). The paucispiral protoconch of S. cupella distinguishes it from the multispiral protoconch of Strobiligera georgiana (Dall, 1927), although the type material of the latter is worn (Rolán & Fernández-Garcés 2008). Strobiligera cupella sp. nov. shares some similarities with three Brazilian species (Fernandes & Pimenta 2019a), but the absence of a complete base in the available shells of S. cupella precluded further comparisons. Its adapical spiral cord on the teleoconch has a similar development to that on some shells of Strobiligera unicornium Simone, 2006 (e.g., Fernandes & Pimenta 2019a: fig. 18a), but it develops later than on other shells (e.g., Fernandes & Pimenta 2019a: fig. 18b–c) and earlier than on others (e.g., the holotype); however, the protoconch of S. cupella is slightly shorter (0.54–0.64 mm long vs 0.69–0.76 mm long in S. unicornium) and has a less inflated first protoconch whorl. The adapical spiral cord on the teleoconch in S. cupella is considerably reduced if compared to Strobiligera campista Fernandes & Pimenta, 2019. Strobiligera cupella has nodules and internodular spaces on the spiral cords of the teleoconch with the same white color, but the internodular spaces are slightly darker than the nodules in the morph named Strobiligera sp. 2 by Fernandes & Pimenta (2019a). Geographic distribution Guadeloupe. Bathymetric distribution 320–428 m (empty shells), 300–370 m (live specimen).