Strigatella, SWAINSON, 1840

Fedosov, Alexander, Puillandre, Nicolas, Herrmann, Manfred, Kantor, Yuri, Oliverio, Marco, Dgebuadze, Polina, Modica, Maria Vittoria & Bouchet, Philippe, 2018, The collapse of Mitra: molecular systematics and morphology of the Mitridae (Gastropoda: Neogastropoda), Zoological Journal of the Linnean Society 183, pp. 253-337 : 300-303

GENUS STRIGATELLA SWAINSON, 1840

Type species: Mitra zebra Lamarck, 1811 ; SD, Gray (1847: 141).

Synonyms: Chrysame H. Adams & A. Adams, 1853 ; Type species: Mitra coronata Lamarck, 1811 ; SD, Cox (1927: 91). Phaeomitra Martens, 1880 ; Type species: Mitra fulva Swainson, 1829 (= Mitra coffea Schubert & Wagner, 1829 ); SD, Coan (1966: 131).

Diagnosis: Shell small (12–40 mm), broadly fusiform, solid and stout in appearance, protoconch pointed, narrowly conical, of about 2.5 to three smooth, very slightly convex whorls. Suture deeply impressed. Spire whorls gently convex or flattened to subcylindrical, sometimes with narrow subsutural area, giving spire a somewhat telescopic outline. Sculpture typically not developed; sometimes shell sculptured with very faint to strong rounded spiral cords over all the shell surface or limited to shell base. Last adult whorl usually strongly convex, siphonal canal typically short and stout to moderately long, with distinct siphonal fasciole. Siphonal notch shallow or absent. Aperture elongate, narrow; outer lip straight adapically and strongly convex in its abapical portion, often thickened adapically, forming a callous inner varix, constricting aperture. Inner lip with three to five fine oblique columellar folds. Shell orange to dark brown, typically with a pattern of white bands and blotches. Radula tri- or monoseriate. In triseriate radulae, rachidian narrow, with five to seven very short and robust cusps, unpaired central cusp always present ( Fig. 23); in uniseriate radulae, rachidian bearing 20–25 pointed cusps with unpaired central cusp distinctly exceeding others. Laterals broad, wavy, with their distal halves smooth and seven to ten rather short and robust cusps situated proximally.

Distribution: Indo-Pacific and Panamic provinces, intertidal and subtidal depths, mostly on hard substrates (rocky shores, reef crevices or coral rubble).

Species included: Strigatella abacophora (Melvill, 1888) 3 comb. nov., S. amaura (Hervier, 1897) 3, S. ambigua (Swainson, 1829) 3 comb. nov., S. assimilis (Pease, 1868) 3, S. aurantia (Gmelin, 1791) 1 comb. nov., S. auriculoides (Reeve, 1845) 3, S. aurora (Dohrn, 1861) 2 comb. nov., S. colombelliformis (Kiener, 1838) 2, S. coronata (Lamarck, 1811) 1 comb. nov., S. crassicostata (G. B. Sowerby II, 1874) 3 comb. nov., S. decurtata (Reeve, 1844) 1, S. fasciolaris (Deshayes, 1834) 3 comb. nov., S. flavocingulata (Lamy, 1938) 3, S. fulvescens (Broderip, 1836) 1 comb. nov., S. holkosa (B.Q. Li, 2005) 3 comb. nov., S. imperialis (Röding, 1798) 1 comb. nov., S. litterata (Lamarck, 1811) 1, S. luctuosa (A. Adams, 1853) 1, S. lugubris (Swainson, 1821) 1 comb. nov., S. nana (Reeve, 1844) 3 comb. nov., S. paupercula (Linnaeus, 1758) 1, S. pica (Dillwyn, 1817) 3, S. retusa (Lamarck, 1811) 3, S. scutulata (Gmelin, 1791) 1 comb. nov., S. subruppeli (Finlay, 1927) 3 comb. nov., S. telescopium (Reeve, 1844) 3, S. testacea (Broderip, 1836) 3 comb. nov., S. ticaonica (Reeve, 1844) 3 comb. nov., S. tristis (Broderip, 1836) 1, S. vexillum (Reeve, 1844) 1, S. vultuosa (Reeve, 1845) 3 comb. nov.,? S. coffea (Schubert & J. A. Wagner, 1829) 2 comb. nov.,? S. pudica (Pease, 1860) 2,? S. tabida (Herrmann & Salisbury, 2013) 3 comb. nov., S. zebra (Lamarck, 1811) 1.

Remarks: The sculpture of strong rounded cords of some species of the Strigatella clade may lead to a wrong generic allocation; for instance, Cernohorsky (1976) placed S. vexillum , S. aurantia , S. lugubris and even S. fulvescens in Nebularia , whereas our phylogenetic analysis unequivocally places them in Strigatella .

There are three conchologically more or less distinct groups of Strigatella : (1) a S. paupercula group with typical broadly fusiform Strigatella shell, (2) a S. fulvescens group with more elongate shell, distinctly recurved siphonal canal and lack of inner callous varix on the outer aperture lip and (3) a S. coronata group with a fusiform shell also lacking a callous varix on the outer aperture lip, and also distinguished by a uniserial radula. Strigatella coronata and S. lugubris form a very distinct clade in our phylogenetic tree, and the name Chrysame is available for it. Given its distinctive morphology and its long branch on the molecular tree, the S. coronata group could be treated as a subgenus of Strigatella . However, we prefer to abstain from recognizing Chrysame , as it would necessitate to also recognize as subgenera the other two Strigatella groups – a level of taxonomic splitting that we are not currently prepared to defend.

SUBFAMILY IMBRICARIINAE TROSCHEL, 1867

( FIGS 24–30)