Similiphora lucida, Fernandes & Pimenta, 2020

Fernandes, Maurício Romulo & Pimenta, Alexandre Dias, 2020, Unraveling one of the ‘ Big Five’: update of the taxonomy of Triphoridae (Gastropoda, Triphoroidea) from Brazil, European Journal of Taxonomy 665 (665), pp. 1-170 : 38-40

Similiphora lucida sp. nov.

urn:lsid:zoobank.org:act:A3AA98F7-3D0C-4487-9857-82223BBF954E

Figs 17 , 24G , 66

Diagnosis

Median spiral cord usually emerges in the third or fourth whorl of the teleoconch; snow-white shell, adapical spiral cord of the teleoconch usually with a faint to much distinct brown color throughout midlate whorls.

Etymology

The specific name is derived from the latin ‘ lucidus ’, meaning ‘lucid, bright’ and alluding to the white shell color.

Material examined

Holotype

BRAZIL – Maranhão • 01º53′ S, 43º20′ W; depth 33 m; 22 Nov. 2008; MZSP 92075 .

Other material

BRAZIL – Amapá • 2 specs; 03º58′43″ N, 49º33′24″ W; 2001; MNRJ 32565 *• 1 spec.; 03º58′43″ N, 49º33′24″ W; 2001; MNRJ 32578 * • 2 specs; 03º58′43″ N, 49º33′24″ W; 2001; MNRJ 32581 * • 1 spec.; 03º58′43″ N, 49º33′24″ W; 2001; MNRJ 32584 *. – Rio Grande do Norte • 10 specs; BPot 1-MR32; MNRJ 31602 * • 4 specs; BPot 1-MR41; MNRJ 31603 * • 3 specs; BPot 1-MR42; MNRJ 31604 * • 7 specs; BPot 1-MR43; MNRJ 31605 * • 1 spec.; BPot 1-MR44; MNRJ 31606 * • 1 spec.; BPot 1-MR45; MNRJ 31607 * • 1 spec.; BPot 2-MR32; MNRJ 31608 * • 1 spec.; BPot 2-MR34; MNRJ 31609 * • 2 specs; BPot 2-MR41; MNRJ 31610 * • 6 specs; BPot 2-MR42; MNRJ 31611 * • 1 spec.; BPot 2-MR44; MNRJ 29396 * • 1 spec.; BPot 2-MR44; MNRJ 31612 *.

Description

Shell sinistral, elongated, cyrtoconoid, nearly rectilinear profile, up to 4.7 mm long, 1.3 mm wide, length/ width ratio 3.2 to 3.4. Protoconch multispiral, conical, five to 5.5 convex whorls, 0.54–0.65 mm long, 0.41–0.49 mm wide; embryonic shell dome-shaped, entirely covered by small rounded granules; larval shell with two faint and close spiral cords occupying mid (adapical cord) and abapical (abapical cord) portion of each whorl, respectively situated at ~45%–46% and ~66%–72% of last whorl height; abapical cord weakening and disappearing before transition to teleoconch; ~30 rectilinear to slightly sigmoid axial ribs. Teleoconch with up to 9.5 whorls; two spiral cords (adapical and abapical) at beginning, the abapical one continuous to adapical cord of protoconch; median spiral cord emerging in third or fourth whorl (rarely as late as beginning of fifth whorl), reaching same size of abapical cord (adapical one slightly more prominent in late whorls) after one to two whorls; on body whorl, spiral cords are 1.0– 1.4 × as wide as distance between them; 17–20 orthocline to slightly opisthocline axial ribs; rounded to slightly elliptical (especially in abapical cord), medium-sized nodules; distinct, well-developed suture, with small sutural cord; wavy subperipheral cord, usually not developing nodules, two slightly wavy to smooth basal cords; small supranumerical cord may emerge between median and abapical spiral cords; ovate aperture, 0.55–0.72 mm long, 0.42–0.51 mm wide, length/width ratio 1.3–1.4; anterior canal short, curved downwards, widely open, but almost crossed in its base by projection of outer lip, 0.18–0.24 mm long, 0.19–0.29 mm wide, length/width ratio 0.8–0.9; posterior canal is small to considerably deep and wide sinus, 0.12–0.19 mm long, not detached from aperture. Snow-white shell, but adapical spiral cord of teleoconch usually acquires faint to much distinct brown color throughout mid-late whorls; base usually white.

Remarks

Similiphora lucida sp. nov. is markedly different from any other triphorid, especially considering the typical larval shell of the genus ( Fig. 17 I–J) and the pattern of shell coloration. Some intraspecific variation exists in shells of S. lucida sp. nov., mainly related to the emergence of the median spiral cord of the teleoconch and the coloration of the adapical spiral cord, white to weakly or distinctly tinted with brown ( Fig. 17 A–D).

Geographical records

Brazil: Amapá, Maranhão and Rio Grande do Norte.

Bathymetric distribution

Depth: 20– 58 m.

Figures

Fig. 17. Similiphora lucida sp. nov. A. MZSP 92075, holotype, 4.14 mm. B. MNRJ 29396*, 4.73 mm. C. MNRJ 31603*, 2.84 mm. D. MNRJ 31602*, 3.97 mm. E–H. Same shell as B. I–K. Same shell as C. Scale bars: A–E = 1 mm; F–H = 500 µm; I–J = 100 µm; K = 50 µm. Photo credits A: Daniel Abbate (MZUSP).

Fig. 24. Triphoridae from Brazil (3). A. Nototriphora decorata (C.B. Adams, 1850). B. Sagenotriphora albocaput sp. nov. C. Sagenotriphora osclausum (Rolán & Fernández-Garcés, 1995). D. Sagenotriphora sp. 1. E. Sagenotriphora sp. 2. F. Similiphora intermedia (C.B. Adams, 1850). G. Similiphora lucida sp. nov. H. Similiphora sp. 1. I. Strobiligera campista Fernandes & Pimenta, 2019. J. Strobiligera delicata Fernandes & Pimenta, 2014. K. Strobiligera dinea (Dall, 1927). L. Strobiligera gaesona (Dall, 1927). M. Strobiligera inaudita (Rolán & Lee, 2008). N. Strobiligera santista Fernandes & Pimenta, 2019. O. Strobiligera unicornium (Simone, 2006). P. Strobiligera sp. 1. Q. Strobiligera sp. 2. R. Triphora atlantica Smith, 1890. S. Triphora charybdis Fernandes & Pimenta, 2015. T. Triphora ellyae De Jong & Coomans, 1988. U. Triphora elvirae De Jong & Coomans, 1988. V. Triphora portoricensis Rolán & Redfern, 2008. W. Triphora scylla Fernandes & Pimenta, 2015. Scale bars: 1 mm.

Fig. 66. Distribution map of Similiphora lucida sp. nov.; red circle = type locality.