Africonus insulae, Tenorio & Abalde & Pardos-Blas & Cmim, 2020

Tenorio, Manuel J., Abalde, Samuel, Pardos-Blas, José R. & Zardoya, Rafael, 2020, Taxonomic revision of West African cone snails (Gastropoda: Conidae) based upon mitogenomic studies: implications for conservation, European Journal of Taxonomy 663 (663), pp. 1-89 : 31-33

Africonus insulae sp. nov.

urn:lsid:zoobank.org:act:97702746-A650-4A17-AAEE-4D914E1026F5

Fig. 5 A–J

Conus curralensis (not C. curralensis Rolán, 1986 ) – Monteiro et al. 2004: pl. 87, figs 1–9.

Africonus curralensis (not C. curralensis Rolán, 1986 ) – Abalde et al. 2017a: not figured.

Africonus curralensis (not C. curralensis Rolán, 1986 ) – Monnier et al. 2018: 1143, figs 2–3, 5.

Etymology

The name insulae means ‘of the island’, in reference to the type locality of the deserted island of Santa Luzia.

Material examined

Holotype

CABO VERDE • 23.9 mm; Santa Luzia Island, Praia de Palmo Tostão ; 16º45ʹ19ʺ N, 24º45ʹ24ʺ W; 14 Apr. 2016; MNCN exped.; GenBank mitochondrion, partial genome: MF491602 ; MNCN 15.05/78581 ( Fig. 5 A–B)

Paratypes

CABO VERDE • 1 spec., 20.0 mm; same collection data as for holotype; MNCN 15.05/78585 ( Fig. 5C , paratype 1) • 1 spec., 18.8 mm; Santa Luzia Island, Curral ; 16º46ʹ23ʺ N, 24º47ʹ13ʺ W; 14 Apr. 2016; MNCN exped.; MNHN IM-2000-35016 ( Fig. 5D , paratype 2) • 1 spec., 24.1 mm; same collection data as for preceding; MNCN 15.05/78579 ( Fig. 5F , paratype 4) • 1 spec., 19.1 mm; same collection data as for preceding; MNCN 15.05/78590 ( Fig. 5G , paratype 5) • 1 spec., 16.2 mm; same collection data as for holotype; MNCN 15.05/78586 ( Fig. 5E , paratype 3) • 1 spec., 23.0 mm; same collection data as for holotype; MNCN 15.05/78582 ( Fig. 5H , paratype 6) • 1 spec., 22.6 mm; same collection data as for holotype; MNCN 15.05/78584 ( Fig. 5I , paratype 7) • 1 spec., 24.9 mm; same collection data as for holotype; UCV 2019/00015 ( Fig. 5J , paratype 8) .

Other material

CABO VERDE • 5 specs; same collection data as for holotype; MJT • 1 spec., 4 mm; Santa Luzia Island, Curral ; 16º46ʹ23ʺ N, 24º47ʹ13ʺ W; 14 Apr. 2016; MNCN exped.; MJT .

Description

MORPHOMETRIC PARAMETERS. S L = 16–30 mm (mean S L = 22 mm); RD = 0.68–0.76; RSH = 0.11–0.19; PMD = 0.78–0.86.

SHELL. Moderately small to small. Maximum length: 30.6 mm. Shell profile broadly and ventricosely conical to broadly conical, with convex sides adapically, and straight below. Spire of moderate height, of straight to concave outline. Protoconch not observed due to erosion, but assumed paucispiral. Teleoconch whorls flat or slightly concave, with 3–4 spiral cords becoming rather obsolete in late whorls. Shoulder angulate. Early teleoconch whorls white. Suture of spire whorls pigmented with dark brown. Late teleoconch whorls yellow to light brown with radial white irregular blotches. Ground color yellow to light brown. Last whorl overlaid in variable amount with oblique white lines forming zigzag pattern. Small white spots and axial flecks arranged in spiral band frequently present. Columella white to light purple. Aperture white and porcellanous inside, with pale purple to light brown diffuse area near the outer lip crossed by two narrow bands of a lighter color. Periostracum yellow-brown, thin and translucent.

RADULAR TEETH. Radula studied from two specimens. 27–35 teeth in radular sac. Radular tooth of medium relative size (S L /T L = 50–65), with well-developed apical barb. Anterior section shorter than posterior section of tooth (T L /AP L = 2.4–2.6). Waist evident. Blade rounded, covering most of anterior section (100B L /AP L = 83–87%). Serration with 10–15 denticles, which do not reach apical portion, arranged in one row ending in small terminating cusp. Base rounded, with small spur ( Fig. 4M ).

Distribution and habitat

Southwest coast of Santa Luzia Island (Curral and Praia de Palmo Tostão), Cabo Verde Archipelago. On rocks and under stones, in 2 to 5 m depth.

Conservation status in IUCN Red List

Not evaluated.

Remarks

This species was previously confused with A. curralensis , which lives sympatrically on Santa Luzia Island. In fact, the specimen identified as A. curralensis in Abalde et al. (2017a) actually corresponds to the taxon A. insulae sp. nov. Molecular examination of a specimen ( Fig. 5K ) morphologically perfectly matching the holotype of A. curralensis ( Fig. 3J ) showed a genetic divergence consistent with the separation at the species level. Hence, A. curralensis and A. insulae sp. nov. are two closely related sister species living in sympatry. Both species essentially have the same shell shape and almost identical radular teeth morphologies ( Fig. 4M ). However, they can easily be separated by differences in shell pattern. The ground color in A. curralensis is composed of different shades of olive green with two narrow spiral bands of a lighter color, whereas in A. insulae sp. nov. the ground color is plain yellow to light brown. The pattern in A. curralensis consists of irregularly shaped white flecks and blotches, whereas in A. insulae sp. nov. it is better defined, composed of fine white zigzag lines and small arrow head-shaped markings. This pattern of zigzag lines on the shell also resembles that present in certain forms of A. decoratus . This species however has a much darker ground color, usually dark brown to black, a white-colored aperture, and is phylogenetically divergent. The shell of the recently described A. santaluziensis Cossignani & Fiadeiro, 2015 (hereby considered as provisionally valid) has a similar ground color, but it is very sparsely patterned and with a white-colored aperture. Besides, the shell of this species has rounded shoulders and a more ventricose appearance, instead of conical.

Figures

Fig. 5 (opposite page). A–J, M. Africonus insulae sp. nov. A–B. Holotype (dorsal and ventral views), 23.9 mm (MNCN 15.05/78581). C. Paratype 1, 20.0 mm (MNCN 15.05/78585). D. Paratype 2, 18.8 mm (MNHN IM-2000-35016). E. Paratype 3, 16.2 mm (MNCN 15.05/78586). F. Paratype 4, 24.1 mm (MNCN 15.05/78579). G. Paratype 5, 19.1mm (MNCN 15.05/78590). H. Paratype 6, 23.0 mm (MNCN 15.05/78582). I. Paratype 7, 22.6 mm (MNCN 15.05/78584). J. Paratype 8, 24.9 mm (UCV 2019/00015). K. Africonus curralensis (Rolán, 1986), 23.0 mm (MNCN 15.05/78591). L. Africonus decoratus (Röckel, Rolán & Monteiro, 1980), 30.5 mm (MNCN 15.05/78578). M. Radular tooth, Africonus insulae sp. nov., Curral, Santa Luzia Island, Cabo Verde (MJT), SL = 29.2 mm. Scale bars = 10 mm unless otherwise indicated.

Fig. 4 (opposite page). A. Conus felitae Rolán, 1990, holotype, 12.7 mm (MNCN 15.05/1099). B. Africonus fernandesi (Tenorio, Afonso & Rolán, 2008), 14.5 mm (MNCN 15.05/78598). C. Africonus freitasi Tenorio, Afonso, Rolán, Pires, Vasconcelos, Abalde & Zardoya, 2018, holotype, 13.7 mm (MNCN 15.05/200008) D. Conus verdensis furnaeRolán, 1990,holotype, 21.1 mm (MNCN 15.05/1097). E. Africonus fuscoflavus (Röckel, Rolán & Monteiro, 1980), 22.3 mm (MNCN 15.05/80407). F. Conus damottai galeao Rolán, 1990, holotype, 21.3 mm (MNCN 15.05/1093). G. Africonus gonsaloi Afonso & Tenorio, 2014, holotype, 19.3 mm (MNCN 15.05/60119).H. Africonus grahami (Röckel, Cosel & Burnay, 1980), 24.0 mm (MNCN 15.05/78549). I. Conus infinitus Rolán, 1990, holotype, 20.8 mm (MNCN, 15.05/1095). J. Conus isabelarum Tenorio & Afonso, 2004, holotype, 22.8 mm (MNCN 15.05/46654). K. Conus josephinae Rolán, 1980, holotype, 25.8 mm (MNCN 15.05/1050). L. Africonus kersteni (Tenorio, Afonso & Rolán, 2008), holotype, 20.8 mm (MNCN 15.05/47051). M. Africonus longilineus (Röckel, Rolán & Monteiro, 1980), 21.7 mm (MNCN 15.05/79738). N. Africonus lugubris (Reeve, 1849), 14.5 mm (MNCN 15.05/90431). O. Africonus maioensis (Trovão, Rolán & Félix-Alves, 1990), 29.5 mm (MNCN 15.05/78689). P. Africonus miruchae (Röckel, Rolán & Monteiro, 1980), 12.9 mm (MNCN 15.05/79789). Scale bars = 10 mm.

Fig. 3 (opposite page). A. Africonus antoniaensis Cossignani & Fiadeiro, 2014, 14.5 mm (MNCN 15.05/79889). B. Conus antoniomonteiroi Rolán, 1990,holotype, 16.8 mm (MNCN 15.05/1100). C. Conus bellulus Rolán, 1990, holotype, 18.9 mm (MNCN 15.05/1098). D. Conus boavistensis Rolán & Fernandes in Rolán, 1990, holotype, 13.2 mm (MNCN, 15.05/1089). E. Africonus borgesi (Trovão, 1979), 30.5 mm (MNCN 15.05/88646). F. Conus navarroi calhetae Rolán, 1990, holotype, 26.8 mm (MNCN 15.05/1096). G. Conus crotchii Reeve, 1849, neotype, 22.5 mm (MNCN 15.05/79971). H. Conus irregularis G.B. Sowerby II, 1858, lectotype, 28.3 mm (NHMUK 197871/1). I. Africonus cuneolus (Reeve, 1843), 28.2 mm (MNCN, 15.05/79712). J. Conus curralensis Rolán, 1986, holotype, 17 mm (MNCN 15.05/1010). K. Africonus damottai (Trovão, 1979), 18.2 mm (MNCN 15.05/80401). L. Africonus decoratus (Röckel, Rolán & Monteiro, 1980), 23.1 mm (MNCN 15.05/78589). M. Africonus delanoyae (Trovão, 1979), 27.6 mm (MNCN 15.05/80397). N. Africonus denizi Afonso & Tenorio, 2011, holotype, 11.6 mm (MNCN 15.05/60000). O. Conus diminutus Trovão & Rolán, 1986, neotype, 14.8 mm (MNCN 15.05/80416). P. Africonus espingueirensis Cossignani & Fiadeiro, 2017, holotype, 9.7 mm (MMM). Scale bars = 10 mm