Sinetectula naevosa ( Martens, 1880 ) Fraussen & Vermeij, 2021

Fraussen, Koen & Vermeij, Geerat J., 2021, Sinetectula gen. nov., a new genus of Pisaniidae (Gastropoda: Buccinoidea) from the tropical Indian and Pacific Oceans, European Journal of Taxonomy 748, pp. 155-176 : 168-169

Sinetectula naevosa ( Martens, 1880) gen. et comb. nov.

Figs 6 , 10H–Q

Pisania naevosa Martens, 1880: 240 , pl. 20 fig. 8 (see Fig. 10H ).

Engina egregia – Kilburn et al. 2010: 41, unnumbered fig.

Type locality

Mauritius.

Material examined

Syntypes

MAURITIUS • 4 dd; MFN ZMB / Moll-22029 mfn-e4d800 (see Fig. 10I –Q ) .

Other material

MOZAMBIQUE • 1 dd; “ off Mozambique ”; local collector; KF 5029 (see Fig. 6 ).

SOUTH AFRICA • 3 lv; Natal , Richards Bay; local collector; KDM .

Distribution

Sinetectula naevosa gen. et comb. nov. is an overlooked species, the few records we found being under former combinations of S. egregia gen. et comb. nov. from along the eastern African coast. The species is known from Mauritius (type locality) and we could confirm records from South Africa in the south and Somalia in the north. Further study may reveal a much wider range.

Remarks

We studied a limited number of specimens of Sinetectula naevosa gen. et comb. nov. and, therefore, we are not able to discuss the variability within the species. These shells conform to the original description, especially the characteristic number of spiral cords and axial ribs as well as the well-defined anal notch.

The shells differ from Sinetectula egregia gen. et comb. nov. by the larger protoconch (0.9 mm long and 0.9 mm in diameter (KF 5029) vs 0.6 to 0.7 mm long and 0.7 to 0.8 mm in diameter in S. egregia gen. et comb. nov.), in combination with a smaller teleoconch size, the slightly higher number of protoconch whorls (1½, instead of usually 1¼), the upper spire whorls that are higher and increase in size more quickly, resulting in a slenderer spire. Whereas in S. naevosa gen. et comb. nov. the transition from 3 rd to 4 th whorl falls within the first 5 mm of the teleoconch length, in S. egregia gen. et comb. nov. it is the transition from 4 th to 5 th whorl that falls within these first 5 mm. The spiral sculpture of S. naevosa gen. et comb. nov. is finer, starting with 3 finer primary spiral cords along the first teleoconch whorls (instead of 2 dominant ones), resulting in a more convex shape of the upper spire whorls. The secondary spiral cords, to the contrary, are slightly stronger when situated in the center between the primary spiral interspaces in S. naevosa gen. et comb. nov. but lower in number (1 to 3 vs 4 or 5 in S. egregia gen. et comb. nov.). Also, the axial ribs in S. egregia gen. et comb. nov. are weaker and lower in number. The brown pattern of S. naevosa gen. et comb. nov. appears to be more evenly arranged along slightly narrower spiral bands than is the case in S. egregia gen. et comb. nov.

Figures

Fig. 6A–E. Sinetectula naevosa (Martens, 1880) gen. et comb. nov., off Mozambique, 15.0 mm long (KF 5029). Scale bars: 2.0 mm.

Fig. 10. Original figures and types. A. Syntype ofTriton egregius Reeve, 1844, original figure taken from Reeve (1844b: pl. 18 fig. 78). B–C. Types of Phos amoenus Schwengel, 1950, taken from Schwengel (1950: pl. 5 fig. 4). B. Holotype, 15 mm long. C. Paratype, 13–14 mm long. D. Type of Buccinum cinis Reeve, 1846, original figure taken from Reeve (1846: pl. 11 no. 84). E. Syntype of Caducifer? thaleia Pilsbry & Lowe, 1932, original figure taken from Pilsbry & Lowe (1932: pl. 6 fig. 6), 26.3 mm long. F–G. Lectotype of Hindsia angicostata Pease, 1860, taken from Kay (1965: pl. 1; figs 15–16), 15.5 mm long. H. Syntype of Pisania naevosa Martens, 1880, original figure taken from Martens (1880: pl. 20 fig. 8), 16 mm long. I–Q. Syntypes of Pisania naevosa Martens, 1880, MFN, ZMB/Moll-22029, images courtesy of Christine Zorn, Berlin. I–K. 16.3 mm long. L–M. 15.1 mm long. N–O. 14.9 mm long. P–Q. 16.3 mm long. R. Type of Buccinum nigricostatum Reeve, 1846, original figure taken from Reeve (1846: pl. 10 fig. 73). S. Holotype of Pollia shepstonensis Tomlin, 1926, original figure taken from Tomlin (1926: pl. 16 fig. 4), 24 mm long. T. Holotype of Pollia shepstonensis Tomlin, 1926, NHM(UK) 1926.12.6.6, image courtesy of Yves Terryn, 24 mm long.