Microcancilla brasiliensis ( Verhecken, 1991 ) Souza & Pimenta & Miyaji, 2021

Souza, Leonardo Santos de, Pimenta, Alexandre Dias & Miyaji, Cintia, 2021, A new species of Microcancilla from the southwestern Atlantic and notes on Microcancilla brasiliensis comb. nov. (Gastropoda, Cancellariidae), Papéis Avulsos de Zoologia 61, pp. 1-8 : 5

Microcancilla brasiliensis ( Verhecken, 1991) comb. nov. ( Figs. 3 A-G)

Axelella brasiliensis Verhecken, 1991: 549 , figs. 5-6.

Axelella brasiliensis – Rios, 1994: 155, pl. 51, fig. 684 [reproduced from original illustration]; Miyaji, 2004: 79; Veitenheimer-Mendes et al., 2004: 97; Petit & Harasewych, 2005:32 [annotated list]; Rios,2009:298, fig. 751 [reproduced from original illustration].

Pseudobabylonella brasiliensis – Petit, 2012: 4.

Type material: Holotype MNHN-IM-2000-2128.

Type locality: BRAZIL: Espírito Santo: MD-55 stn. SY 74 (18°58′S, 37°49′W, 682 m), coll. RV Marion Dufresne (P. Bouchet, J. Leal and B. Métivier), 27.v.1987.

Material examined: BRAZIL: São Paulo: Santos Basin (24°20′38″S, 43°50′32″W, 580 m), coll. 28.i.2009: MNRJ 28851 † [1] ; Paraná: REVIZEE-Sul stn. 6652: MNRJ 28182 † [1] .

Measurements: MNRJ 28851: Whorls = 4.75; SL = 4.54; BWL = 2.97 mm; AL = 1.84 mm; SW = 2.47 mm; AW = 1.17 mm.

Geographic distribution: BRAZIL: Pernambuco to Paraná ( Verhecken, 1991, 2002; Miyaji, 2004; Veitenheimer-Mendes et al., 2004).

Bathymetric range: From 206 m to 637 m.

Remarks: Petit (2012) included this species in Pseudobabylonella Brunetti, Bella, Forli & Vecchi, 2009 , possibly by the statement of Brunetti et al. (2009: 66): “The new genus [Pseubabylonella], which is characterized mainly by the sculpture of the protoconch,comprise species previously included in Axelella and Babylonella ” [translated from Italian]. Brunetti et al. (2009) described a protoconch with numerous well-developed spiral and axial cords of sinuous outline.

The holotype of Microcancilla brasiliensis comb. nov. has an eroded protoconch ( Verhecken, 1991: fig. 6) which precludes the analysis of microsculpture. Verhecken (2002) reported new records of M. brasiliensis (as “ Axelella brasiliensis ”) and figured a more preserved protoconch, but the illustrations do not allow for an assessment of the microsculpture and no sculpture was described.

The additional material M. brasiliensis studied here shows microscopic pustules arranged fairly in spiral lines and at irregular intervals ( Figs. 3E, G ) on the protoconch, which differ from the sculpture pattern of Pseudobabylonella . The protoconch-teleoconch transition in M. brasiliensis is not clearly marked like in Pseudobabylonella , in which the reticulated teleoconch sculpture starts as faint axial ribs ( Fig. 3E ). Thus, the protoconch morphology of M. brasiliensis is more similar to M. phoenix , and we decide to include this species in Microcancilla rather than in Pseudobabylonella despite uncertainties.

Microcancilla phoenix ( Figs. 1 A-H, 2A-F) has microscopic pustules covering the whole shell, not restrict- ed to the protoconch like M. brasiliensis . Additionally, M. phoenix has a more rounded aperture and subsutural region ( Figs. 1A, B ), while M. brasiliensis has a more triangular aperture and a flatter shoulder ( Fig. 3A ).

Microcancilla microscopica and M. jonasi also differ by the more rounded aperture and by the wider parietal region ( Barros & Petit, 2007: figs. 1-5, 9).

Miyaji (2004) and Veitenheimer-Mendes et al. (2004) reported M. brasiliensis (as “ Axelella brasiliensis ”) from South Brazil in an annotated list of species without illustrations. The records reported by those authors are the southernmost records of M. brasiliensis (~ 26°S) and one of them is the shallowest record of the species at 206 m (MNRJ 28182).

Figures

Figure 1. Microcancilla phoenix sp.nov.(A) Holotype,MNRJ60299 (2.85 mm long).(B-H) Paratype,MNRJ 28183 (4.25 mm long).(A-B) entire shell in ventral view. (C) same, lateral view. (D) same, dorsal view, white square enlarged in E. (E) Detail of teleoconch sculpture, white square enlarged in F. (F) Detail of microscopic pustules covering the shell.(G) Protoconch in frontal view.(H) Protoconch in apical view.Scale bars:A-D = 1 mm;E,G,H = 100 µm;F = 20µm.

Figure3. Microcancilla braziliensis comb.nov.(A-G) MNRJ28182 (4.49 mm long).(A) Entireshell in ventralview,white squareenlarged inD.(B) same,lateralview. (C) same, dorsal view.(D) Detail of teleoconch sculpture. (E) Protoconch in frontal view, white square enlarged in G. (F) same,apical view. (G) Detail of protoconch sculpture.Scale bars:A-C = 1 mm;D = 200 µm; E-F = 100 µm; G= 50 µm.