Cerithiopsis scobinata, Pimenta & Faria & Figueira & Fernandes, 2024

Pimenta, Alexandre Dias, Faria, Raquel Garofalo De Souza, Figueira, Raquel Medeiros Andrade & Fernandes, Maurício Romulo, 2024, Unraveling another of the ‘ Big Fiveʹ: new species and records of Cerithiopsidae from Brazil (Caenogastropoda: Triphoroidea), Zootaxa 5494 (1), pp. 1-71 : 37-39

Cerithiopsis scobinata sp. nov.

urn:lsid:zoobank.org:act:A5690A7E-FF67-4FC2-A96E-DA48612652AC

( Fig. 18 )

Cerithiopsis sp. : Krisberg (2010d: https://olram9.wixsite.com/letstalkseashells/copy-of-template-89).

Type material. Holotype: MNRJ 16568 . Paratypes: Brazil: -- Espírito Santo state: REVIZEE– Central sta. C6–Y7: IBUFRJ 19638 [1]; -- Rio de Janeiro state: HAB 11 sta. G3: MNRJ 16567 [1]; -- Paraná state, Ilha dos Ratos : MZSP 155543 [3].

Type locality. Brazil, off Rio de Janeiro state, c ontinental shelf of Campos Basin , HAB 11 sta. C3 (22°46ʹ51ʺS, 41°03ʹ39ʺW, 77 m) .

Additional material. Brazil: -- Rio de Janeiro state: HAB 16 sta. H3: MNRJ 16570 [3*p]; HAB 16 sta. G3: MNRJ 16569 [4*p]; HAB 11 sta. B4: MNRJ 17304 [1*p].

Etymology. From the Latin word scobina = rasp. This species is named after its microscopic spiral lines on teleoconch whorls, which resemble scratches.

Diagnosis. Protoconch conical with first whorl smooth, remainder whorls with prosocline to nearly orthocline axial ribs that usually cross the entire whorl face, and minute granules above suture; teleoconch whorls with the two adapical spiral cords fused together and becoming separated on subsequent whorls; squared interspaces between spiral cords sculptured with microscopic, very fine spiral lirae.

Description. Shell slightly pupoid, reaching 2.8 mm long, 1.0 mm wide, ratio length/width 2.6–2.9. Protoconch white, conical, 330–396 μm long, 234–264 μm wide, with 4.0–4.25 convex whorls; embryonic shell dome-shaped, mainly smooth, with minute granules above the suture; larval shell with prosocline to nearly orthocline axial ribs that usually (not always) cross the entire whorl, spacing between ribs two to five times rib width, and microscopic granules at the suture region. Teleoconch with up to seven whorls of slightly convex outline; color brownishorange to dark brown; sculpture formed by three spiral cords and around 20 orthocline axial ribs on the body whorl; elongated to rounded, large-sized nodules (occupying 64–68% of body whorl length); adapical and median spiral cords initially separated after transition between protoconch and teleoconch, but they soon fuse during first teleoconch whorl, starting to separate in the fourth to sixth whorl and becoming fully separated after one whorl or less, but the three spiral cords are equidistant only at the body whorl; interspaces between spiral cords sculptured with microscopic spiral lirae on last two whorls; suture somewhat channeled; subperipheral cord slightly nodulose; base concave, with two nearly smooth basal cords (the adapical one can be slightly nodulose), followed by very fine spiral striae; aperture rhomboid, 0.43–0.49 mm long, 0.33–0.41 mm wide, ratio length/width 1.2–1.3; short and open anterior canal, acute posterior sinus; inner lip somewhat projected over the parietal wall.

Remarks. Cerithiopsis scobinata sp. nov. ( Fig. 18 ) shares with C. capixaba ( Fig. 19 ), C. prieguei ( Fig. 20E–H ), C. balaustium ( Fig. 20I–L ), C. fusiformis ( Fig. 16A–E ) and C. vescula ( Fig. 17 ) the sculpture pattern of adapical and median spiral cords situated closely to each other on initial whorls of the teleoconch, being apparently or virtually fused, and then becoming separated in late whorls ( Figueira & Pimenta 2008). Although slight differences in the emergence of the adapical spiral cord of the teleoconch can be distinguished in some specimens, the main differences among those species rely in protoconch shape and sculpture. The most similar species to C. scobinata are C. capixaba and C. fusiformis , with very similar shell size, shape and the sculpture pattern of the two adapical cords.

The protoconch of C. scobinata ( Fig. 18L–N ) has much more convex whorls than C. capixaba ( Fig. 19 ). The larval shell of C. scobinata has fewer axial ribs and a different microsculpture on the embryonic shell: there are small granules restricted to the suture region in C. scobinata , but granules organized in spiral rows along the embryonic shell of C. capixaba ( Fig. 19F–H ). In addition, C. scobinata has a distinct spiral microsculpture between spiral cords on the last two teleoconch whorls ( Fig. 18K ) that is apparently absent in C. capixaba .

Cerithiopsis scobinata differs from C. fusiformis by having axial ribs on the protoconch ( Fig. 16D–E ). Cerithiopsis scobinata is also similar to C. balaustium . However, C. scobinata has continuous axial ribs on the larval shell extending from suture to suture ( Fig. 18L–N ), whereas the axial ribs of C. balaustium are mainly restricted to the abapical portion of the larval whorls and are absent in earliest and latest portions of the larval shellFig. 20K–L). Shells of C. scobinata (up to 2.8 mm long) also seem to be larger than those of C. balaustium (up to 2.0 mm long).

The protoconch of C. scobinata is also similar to that of Cerithiopsis micalii ( Cecalupo & Villari, 1997) , from the Mediterranean, and even more similar to the shell identified as C. cf. micalii by Oliver et al. (2012) However, C. scobinata apparently has fewer axial ribs on the larval shell than both morphs. Their main difference, however, relies in the teleoconch sculpture, because the adapical spiral cord is not fused with the median one in C. micalii .

In a survey of mollusks from Florida, Krisberg (2010d) indicated a single shell, named Cerithiopsis sp. , occurring in Fort Pierce, eastern Florida, which is identical to C. scobinata . Regarding the high quality of illustrations and description, we confidently assign this shell to the new species, considerably extending its geographical range.

Geographic and bathymetric distribution. Disjunct distribution, in the Tropical Northwestern Atlantic Province (eastern Florida) and the Warm Temperate Southwestern Atlantic (from Espírito Santo to Paraná states). Littoral ( Krisberg 2010d) to 107 m (this study).

Figures

FIGURE 16. Cerithiopsis fusiformis (C. B. Adams, 1850). A: holotype from Jamaica (MCZ 186127); B, D, F: shell from Rio de Janeiro state (IBUFRJ 13665); C, E, G: shell from Bahia state IBUFRJ 12906); A–C: whole shell; D–E: protoconchs of shells in B and C, respectively; F: detail of teleoconch sculpture of shell in B; G: body whorl of shell in C. Lengths of whole shells: A: 2.6 mm; B: 2.8 mm; C: 2.8 mm. Scale bars: A–C: 1 mm; D–F: 100 µm; G: 200 µm.

FIGURE 17. Cerithiopsis vescula sp. nov. A–B, D–F: paratypes from Rio de Janeiro state (A: MNRJ 33012; B, D–F: MNRJ 16529); C, G: holotype, from Bahia state (IBUFRJ 12907); D: detail of teleoconch sculpture and body whorl of shell in B; F–G: protoconchs of shells in B and C, respectively. Lengths of whole shells: A: 2.7 mm; B: 2.8 mm; C: 2.1 mm. Scale bars: A–C: 1 mm; D–G: 100 µm.

FIGURE 18. Cerithiopsis scobinata sp. nov. A–C, I–L: holotype, from Rio de Janeiro state (MNRJ 16568); D, M–N: paratype from Espírito Santo state (IBUFRJ 19638); E–F: paratype from Rio de Janeiro state (MNRJ 16567); G–H: shells from Rio de Janeiro state (G: MNRJ 17304; H: MNRJ 16570); I–L: body whorl, detail of teleoconch sculpture, detail of microsculpture on teleoconch and protoconch of holotype; M–N: protoconch of paratype in D. Lengths of whole shells: A–C: 2.4 mm; D: 1.7 mm; E–F: 2.2 mm; G: 2.8 mm; H: 3.0 mm; Scale bars: A–H: 1 mm; I–J: 200 µm; K–N: 100 µm.

FIGURE 19. Cerithiopsis capixaba Figueira & Pimenta, 2008. A: holotype, from Espírito Santo state (IBUFRJ 15221); B–H: shells from Rio de Janeiro state (B: MNRJ 33007; C, E: MNRJ 32947; D, F–H: MNRJ 16552); E: detail of teleoconch sculpture of shell in C; F–H: protoconch and details of protoconch sculpture of shell in D. Lengths of whole shells:A: 2.8 mm; B: 3.2 mm; C: 3.1 mm; D: 2.8 mm. Scale bars: A–D: 1 mm; E: 200 µm; F–G: 100 µm; H: 20 µm.

FIGURE 20A–D. Cerithiopsis aimen Rolán & Espinosa, 1996. Shell from Rio de Janeiro state (MNRJ 16531). FIGURE 20E–H. Cerithiopsis prieguei Rolán & Espinosa, 1996. Shell from Rio de Janeiro state (MNRJ 32617). FIGURE 20I–L. Cerithiopsis balaustium Figueira & Pimenta, 2008. Shell from Rio de Janeiro state (MNRJ 16527). C, G, K: protoconch of shells in B, F and J, respectively; D: detail of teleoconch whorls of shell in B; H, L: detail of protoconch sculpture of protoconchs in G and K, respectively. Lengths of whole shells: A–B: 1.8 mm; E–F: 2.4 mm; I: 1.8 mm; J: 1.7 mm. Scale bars: A–B, E–F, I–J: 1 mm; C–D, G–H, K–L: 100 µm.