Cerithiopsis aenea, 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 : 17-19

Cerithiopsis aenea sp. nov.

urn:lsid:zoobank.org:act:5ABBF68B-F7CE-4DB5-BBC7-E2BB4DFAE559

( Fig. 6 )

Type material. Holotype MNRJ 20000 ; Paratypes: Brazil: -- Espírito Santo state :

REVIZEE– Central sta. C1–VV38: IBUFRJ 20652 [8]; -- Rio de Janeiro state: 23°04ʹ48ʺS, 40°58ʹ30ʺW, 100 m: MNRJ 33009 [1], MZSP 131830 [1]; HAB 13 sta. H4: MNRJ 16198 [1*p]; HAB 16 sta. C4: MNRJ 16505 [2]; HAB 16 sta. E4: MNRJ 16506 [1]; 22°42ʹS, 40°40ʹW, viii/2002: MNRJ 31365 [1]; type locality: MNRJ 16504 [3].

Type locality. Brazil, off Rio de Janeiro state, continental shelf of Campos Basin , HAB 16 sta. B4 (23°10ʹ01ʺS, 41°03ʹ13ʺW, 107 m) .

Additional material. BRAZIL: -- Espírito Santo state: REVIZEE– Central sta. C1–VV38: IBUFRJ 14142 [12]; HAB 17 sta. I2: MNRJ 16508 [1*]; -- Rio de Janeiro state: HAB 16 sta. G3: MNRJ 16507 [1*]; HAB 11 sta. G3: MNRJ 16197 [1*]; HAB 16 sta. H2: MNRJ 16513 [3 lv *]; HAB 13 sta. H3: MNRJ 16196 [3*]; 22°42ʹS, 40°40ʹW, 110–120 m, 19/xi/2003: MNRJ 31359 [1*]; 23°05ʹS, 40°58ʹW, 100 m, 17/ix/2004: MNRJ 31351 [2*]; 23°13ʹ30ʺS, 41°02ʹ20ʺW, x/2008: MNRJ 32049 [1*].

Etymology. From the Latin word aeneus = brazen, of bronze, of cooper. This species is named after its bronzed color.

Diagnosis. Teleoconch with sharp sculpture and color pattern of bronze spots of irregular shape and disposition, often axial.

Description. Shell turriform, elongated, somewhat translucent, reaching 3.6 mm long, 1.0 mm wide, ratio length/wide 3.3 to 3.6. Protoconch white, 380–430 μm long, 225–244 μm wide, subcylindrical, with 3.75–4.0 whorls of convex outline, the first one dome-shaped; first and second whorls covered with microscopic granules, remaining whorls with less dense granules, concentrated below and above suture; a spiral cord appears in the second or third whorl, situated immediately above the suture (with a distance of 13–16% of whorl length), and abruptly disappears after less than one whorl. Teleoconch with up to seven whorls of convex profile; coloration white, with irregular bronze spots mainly distributed in an axial pattern, encompassing either of the spiral cords or the spaces between them; suture demarcated by a very thin spiral cord; sculpture of three spiral cords per whorl, crossed by orthocline axial ribs thinner than the spirals, forming a reticulated sculpture and well-projected, sharp, but small nodules (occupying 28–34% of body whorl length); around 15 axial ribs on sixth whorl; adapical spiral cord very close to the suture above and smaller than other cords, reaching a similar size on the body whorl; wide interspaces between spiral cords, about 3x the cord width and forming rectangular depressions with growth lines; subperipheral cord nearly smooth or slightly wavy; base concave, with three or four microscopic spiral lines below subperipheral cord; one smooth, thin basal cord, with microscopic spiral lines below it; aperture small, elliptical, 0.50–0.57 mm long, 0.34–0.37 mm wide, ratio length/width 1.5; very short anterior canal; inner lip slightly projected over parietal region.

Remarks. Cerithiopsis aenea sp. nov. ( Fig. 6A–H ) is easily distinguished from other species by its coloration pattern of irregular bronze spots over the teleoconch, with a main axial disposition ( Fig. 6A–B ).

The most similar species from the western Atlantic is Cerithiopsis singularis Rolán & Fernández-Garcés, 2013 (originally described as C. infrequens Rolán, Espinosa & Fernández-Garcés, 2007 , a preoccupied name), reported from Cuba, Nicaragua and Martinique, showing a similar turriform shell shape and teleoconch sculpture of sharp nodules (Rolán et al. 2007; Cecalupo & Perugia 2020). They also share a similar protoconch morphology, but C. singularis from the type locality has apparently one more whorl (Rolán et al. 2007). Specimens from Martinique have the same number of protoconch whorls as found in the material studied herein ( Cecalupo & Perugia 2020). Their main difference between C. singularis and C. aenea sp. nov. is the color pattern: C. singularis has a characteristic brown spiral band covering the suture, adapical and median spiral cords, but not the summit of the nodules; in C. aenea , the bronze spots are irregularly (but often axially) spaced and they may cover any spiral cord, including the summit of the nodules ( Fig. 6A–B ). In addition, the protoconch of C. aenea has minute granules (mainly distinct in the initial whorls) and a late emergence of a thin spiral cord, close to the suture ( Fig. 6G–H ), while the protoconch of C. singularis was described as smooth, with a small cord in the suture.

Geographic and bathymetric distribution. From Espírito Santo to Rio de Janeiro states, in the Tropical Southwestern Atlantic Province . From 71 m to 120 m.

Figures

FIGURE 6. Cerithiopsis aenea sp. nov. A: holotype, from Rio de Janeiro state (MNRJ 20000); B: paratype from Espírito Santo State (IBUFRJ 20652); C–H: paratypes from Rio de Janeiro state (C, E–F, H: MNRJ 16505; D, G: MNRJ 16504); E: detail of teleoconch sculpture of shell in D; F: body whorl of shell in C; G–H: protoconch of shells in D and C, respectively. Lengths of whole shells: A: 3.5 mm; B: 2.8 mm; C: 3.0 mm; D: 2.5 mm. Scale bars: A–D: 1 mm; E–F: 200 μm; G–H: 100 μm.