Cerithiopsis claudioi, 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 : 22-24

Cerithiopsis claudioi sp. nov.

urn:lsid:zoobank.org:act:6F75E45F-8735-4561-A05B-E73B81E60966

( Fig. 9 )

Type material. Holotype: IBUFRJ 19630 . Paratypes: Brazil: -- Pernambuco state: Fernando de Noronha Archipelago , J. Colella coll., 10/viii/1978: MZSP 155539 [1]; -- Rio de Janeiro state: HAB 16 sta. H4: MNRJ 16559 [1*p]; HAB 16 sta. B4: MNRJ 16558 [3*p].

Type locality. Brazil, off Rio de Janeiro state, REVIZEE– Central sta. C1–D3 (22°04ʹ30ʺS, 40°04ʹ55ʺW, 80 m) .

Additional material. Brazil: -- Espírito Santo state: MNRJ 16560 [1*]: HAB 17 sta. I1; -- Rio de Janeiro state: 23°05ʹ22.7ʺS, 40°58ʹ30.69ʺW, 100 m, 17/xii/2004: MNRJ 33011 [1*]; 23°06ʹS, 41°06ʹW, 88 m, x/2008: MNRJ 32226 [1*].

Etymology. This species is named in honor to Claudio José Fernandes da Costa, a friend and technician of the institution MNRJ, since the decade of 1980 working in the collection of molluscs. During the fire of MNRJ in 2018, Claudio saved all type material of the Mollusca Collection, including types of species that were not yet formally published (such as most new species in this paper). This is a small tribute to the huge effort that Claudio did during the rescue of types.

Diagnosis. Shell light brown, apex lighter; protoconch with 4.5 convex whorls, body whorl with around 15 sigmoid, opisthocline axial ribs.

Description. Shell conical, elongated, reaching 4.1 mm long, 1.1 mm wide, ratio length/width 3.0–3.4. Protoconch conical, whitish, 402–520 μm long, 289–324 μm wide, with 4.5 much convex whorls; embryonic whorl smooth, dome-shaped; larval shell mainly smooth, with minute granules in the suture; body whorl of protoconch with ~15 sigmoid, opisthocline axial ribs, and a spiral cord emerges in the last half whorl, situated at 28% of whorl length above suture. Teleoconch with up to 8.5 whorls, color light brown; three spiral cords, adapical one initially reduced in size and close to the median one, gradually strengthening and reaching same size than other cords in the sixth whorl, with the three cords equidistant at body whorl; ~18 nearly orthocline axial ribs on the body whorl; rounded, medium-sized nodules (occupying 49–58% of body whorl length); suture shallow, with a thin sutural cord; smooth subperipheral cord; base concave, with one or two very thin spiral threads; aperture ovate, ~ 0.46 mm long, 0.34–0.36 mm wide, ratio length/width 1.3; anterior canal short, open; inner lip slightly reflected over the parietal wall.

Remarks. Cerithiopsis claudioi sp. nov. ( Fig 9 ) resembles C. nimia and C. rabilleri in overall shell shape and sculpture. Similarly to C. nimia , the adapical spiral cord of the teleoconch is initially weak and close to the median one, but the nodules are more prominent in C. claudioi . The protoconch of Cerithiopsis claudioi ( Fig. 9E–F, H ) is quite similar in shape to that of Cerithiopsis rabilleri , with strongly convex whorls, but C. claudioi has ~15 sigmoid axial ribs at the transition to the teleoconch. In addition, C. rabilleri has one or two distinct basal cords ( Fig. 7C–F ), whereas the apparently complete base of C. claudioi is mainly smooth, except of two very thin spiral threads ( Fig. 9G ).

Differently from almost all other species in the western Atlantic, Cerithiopsis claudioi has several (~15) sigmoid axial ribs emerging in the body whorl of the protoconch ( Fig. 9E–F, H ). Only Cerithiopsis pisinna sp. nov. has a similar sculpture, but it is less pronounced in the latter, with only three or four ribs ( Fig. 5D ), whereas in C. claudioi , besides being more abundant, it also shows a suprasutural spiral cord, which corresponds to the abapical spiral cord of the protoconch ( Fig. 9E, H ). Other cerithiopsids also have axial ribs at the transition from the protoconch to the teleoconch, e.g., Zaclys sarissa ( Murdoch, 1905) ( Marshall, 1978: fig. 12E; Nützel, 1998: tafel 2C) and Krachia cylindrata ( Jeffreys, 1885) ( Manousis et al. 2023: figure 8b).

Geographic and bathymetric distribution. Only known from the Tropical Southwestern Atlantic Province (Espírito Santo to Rio de Janeiro states and a single record in the Fernando de Noronha Archipelago ). From 26 m to 107 m.

Figures

FIGURE 5. Cerithiopsis pisinna sp. nov. A: holotype, from Espírito Santo State (MNRJ 15391); B–D: paratype, from type locality (IBUFRJ 14137); C–D: body whorl and protoconch of paratype. Lengths of whole shells: A: 2.6 mm; B: 2.5 mm. Scale bars: A–B: 1 mm; C–D: 200 µm.

FIGURE 7. Cerithiopsis rabilleri Cecalupo & Perugia, 2020. A–C, F: shells from Rio de Janeiro state (A: MNRJ 17367; B–C: MNRJ 16268; F: MZSP 155541); D–E, G–J: shells from Bahia state (IBUFRJ 20651); G: body whorl of shell in D; H–I: protoconchs of shells in D and E, respectively; J: detail of sculpture of protoconch in I. Lengths of whole shells: A: 3.0 mm; B: 3.0 mm; C: 3.0 mm; D: 3.7 mm; E: 3.0 mm; F: 3.1 mm. Scale bars: A–F: 1 mm; G: 500 μm; H–I: 200 μm; J: 50 μm.

FIGURE 9. Cerithiopsis claudioi sp. nov. A: holotype, from Rio de Janeiro state (IBUFRJ 19630); B–I: paratypes from Rio de Janeiro state (B: MNRJ 16559; C–I: MNRJ 16558); E–F: protoconchs (F: detail of shell in D); G: body whorl of shell in C; H: protoconch of shell in C, in apical view; I: detail of protoconch sculpture in F. Lengths of whole shells: A: 2.5 mm; B: 3.2 mm; C: 3.1 mm; D: 3.1 mm. Scale bars: A–D: 1 mm; E–F, H: 100 µm; G: 200 µm; I: 20 µm.