PUSIA, Swainson, 1840

SUBGENUS PUSIA ( PUSIA ) SWAINSON, 1840

FIGURES 18A – G View Figure 18 AND 19A – C View Figure 19

Diagnosis

Shell small, fusiform to broadly fusiform or ovate, last adult whorl 64 – 74% of shell height. Protoconch multispiral, narrowly conical, with three or more glossy whorls. Suture distinct, impressed. Sculpture of dense, rounded, axial ribs on early spire whorls (sometimes absent), turning into broad and low folds on last teleoconch whorls; spiral sculpture of fine regular grooves, pronounced in interstices between axials. Shell base sculptured with several broad and flattenned, somewhat gemmate, spiral cords. Siphonal canal short or very short, stout, bearing several strong oblique cords. Aperture narrow, elongate, its outer lip lirate within. Inner apertural lip with three or four strong columellar folds, adapicalmost fold strongest. Shell intensely coloured, either orange or dark brown, with spiral row of lighter blotches on periphery of last adult whorl. Head-foot intensely pigmented, dark brown or black. Radula with three teeth in each row; rachidian tricuspidate with width of base and length of cusps of variable proportions. Laterals sickle-shaped, unicuspidate. Seminal canal closed.

Included species

Pusia (Pusia) microzonias (Lamarck, 1811) ( Fig. 18A – D View Figure 18 ), Pusia (Pusia) lauta (Reeve, 1845) ( Fig. 18E View Figure 18 ), 1 Pusia (Pusia) vassardi sp. nov. ( Fig. 18F – H View Figure 18 ). 1

Distribution and habitat

All over the Indo-Pacific from Madagascar to French Polynesia, in shallow water.

Remarks

The subgenus Pusia (Pusia) as defined herein contains only a handful of species, the affinities of which are convincingly demonstrated by the molecular data for Pusia lauta (Reeve, 1845) and Pusia vassardi sp. nov. We suggest close relationships of these two with Pusia microzonias ( Fig. 18A – D View Figure 18 ), based on an unmistakable similarity in shell morphology and coloration, as well as in radula structure: the radula of Pusia microzonias was studied by Risbec (1928: fig. 35) and herein ( Fig. 19A View Figure 19 ). As a matter of fact, the identity of Pusia microzonias has been questioned by Poppe et al. (2009), who suggested that the lectotype selected by Cernohorsky (1969) from among ten syntypes ( Fig. 18A, B View Figure 18 ) with an Indian Ocean type locality in fact belongs to an Atlantic species, an opinion based on consistent conchological differences between the lectotype of Pusia microzonias and specimens routinely collected from the Indo-Pacific, and the presence of a conchologically very similar species in the Caribbean. Having made this conclusion, the authors described the Indo-Pacific Pusia microzonias -like species as Vexillum geronimae Poppe et al., 2009 ( Fig. 18I View Figure 18 ), to which they attributed many specimens from the Indo-Pacific illustrated by earlier authors as Pusia microzonias . Instead, we advocate for an Indo-Pacific origin of the lectotype, as the probable holotype of Tiara semiplicata Broderip, 1836 ( Fig. 18C View Figure 18 ), the origin of which is more precisely documented (Society Islands), and is undoubtedly conspecific with the lectotype of Pusia microzonias .

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Admittedly, a Pusia -like general appearance is widespread in shallow-water Costellariidae , in particular in species allocated here to Vexillum s.s., and often shell morphology alone is not sufficient to tell whether a species belongs to Pusia (Pusia) or not. The three species here assigned to Pusia (Pusia) are overall characterized by the same colour pattern (which is shared with other subgenera of Pusia ) and the siphonal canal, not notched at its tip, which destinguishes them from Vexillum s.s.

The species of Pusia (Ebenomitra) – see below – are easily destinguishable by their large paucispiral protoconch and lack of spiral sculpture. The species of Pusia (Vexillena) are generally larger than Pusia (Pusia) , and are characterized by a higher spire, although some species in these two subgenera may be strikingly similar. Pusia (Pusia) and Pusia (Vexillena) do not overlap in bathymetry: Pusia (Pusia) inhabits shallow waters and is commonly found intertidally, whereas Pusia (Vexillena) occurs in depths of several hundred metres and, as far as we know, is not found at shallower depths.

PUSIA (PUSIA) VASSARDI SP. NOV. FEDOSOV, HERRMANN & BOUCHET

FIGURE 18F – H View Figure 18

Type data

Holotype: MNHN IM-2013-40682, 25 ° 02.3 0 S, 47 ° 00.3 0 E, 22 – 24 m, South Madagascar, Fort-Dauphin area (ATIMO VATAE, station TS04), lv, 13.0 mm ( Fig. 18F, G View Figure 18 ).

Paratypes: Paratype 1, MNHN IM-2000-30207, ATIMO VATAE, station TA50, 24 ° 59.5 0 S, 47 ° 06.0 0 E, 10 m, South Madagascar, lv, 16.8 mm; paratype 2, MNHN IM-2000-30208, ATIMO VATAE, station TR02, 25 ° 01.3 0 S, 47 ° 00.5 0 E, 17 m, South Madagascar, lv, 14.6 mm ( Fig. 18H View Figure 18 ) .

Diagnosis

Shell small to medium sized (13 – 14 mm), broadly fusiform. Suture deeply impressed, spire slightly acuminate, with spire whorls flattened in outline. Axial sculpture of dense rounded ribs with narrow interspaces, well pronounced on spire whorls; ribs widened on last adult whorl, vanishing below periphery and on latest half of whorl. Interspaces between axial ribs sculptured with low rounded cords on early spire whorls, the pattern changes later to multiple fine grooves, very weak on last adult whorl. Siphonal canal short, tapering. Aperture elongate, its outer lip lirate within, inner lip with strong callosity, bearing four strong columellar folds, adapicalmost fold strongest. Shell orange to light brown, with darker spire and lighter spiral band along periphery of penultimate and last adult whorls.

Description

Shell small to medium sized, broadly fusiform (w / h 0.43; a / h 0.51), with slightly acuminated spire. Protoconch missing or worn in all specimens studied. Suture distinct, deeply impressed. Teleoconch of about 7.5 whorls, spire whorls with flattened profile, sculptured with multiple, rounded orthocline ribs (30 on fourth adult whorl) with narrow interspaces. Axial ribs forming weak subsutural ‘caps’ on early spire whorls, interspaces between axials with five or six closely set, broad, rounded cords that are more pronounced on early spire whorls, and become indistinct, with only shallow grooves remaining, on later whorls. Axial ribs broadened on penultimate and last adult whorls, not pronounced below periphery and on latest half of last adult whorl. Spiral grooves also very weak on adapical portion and periphery of last adult whorl. Shell base gradually extending towards short, tapering siphonal canal, sculptured with three very weak, vaguely gemmate, spiral cords. Siphonal fasciole with three strong rounded cords. Aperture elongate, with evenly convex outer lip, slightly extended towards tip of siphonal canal, lirate within. Inner lip with strong callosity, bearing four strong columellar folds, adapicalmost fold strongest, subsequent folds gradually weakening. Shell orange to light brown, with darker spire and lighter spiral band, widened on crests of axial ribs, at periphery of penultimate and last adult whorls.

Radula (of holotype, Fig. 19B View Figure 19 ): Radula about 0.12 mm wide. Rachidian with wide base and three closely set cusps, rather short and stout. Laterals strong, sickle shaped, unicuspid.

Distribution and habitat

Known only from Southern Madagascar, in shallow water, depth range 15 – 24 m.

Etymology

The new species is named after Emmanuel Vassard, who has used his diving skills on multiple MNHN expeditions, among others the ATIMO VATAE expedition to the ‘Deep South’ of Madagascar.

Remarks

Pusia vassardi sp. nov. resembles the type species Pusia microzonias , as well some Pusia (Vexillena) species, like Pusia balutensis , Pusia jenyai sp. nov., and Pusia dautzenbergi , primarily in shell proportions and colour pattern; however, Pusia vassardi sp. nov. can be easily distinguished from Pusia microzonias by its lighter and stouter shell with proportionally higher last adult whorl. Pusia vassardi sp. nov. is easily separated from species of Pusia (Vexillena) by the characteristic dark spire and weakly sculptured last adult whorl. Apart from that, Pusia vassardi sp. nov. can be readily distinguished from Pusia balutensis by the smaller shell, flattened outline of spire whorl, and notably widened axials on last adult whorl, and also by the dark color of the spire. Similarly, Pusia jenyai sp. nov. is recognized by its distinct, though very wide and flattened, axials that extend to shell base. Pusia dautzenbergi has a higher spire and stronger axials; however, paratype 5 of the latter species from the Philippines shows an extraordinary resemblance to Pusia vassardi sp. nov. Finally, Vexillum geronimae resembles Pusia vassardi sp. nov. in proportions and colour pattern, but the robust base and deeply notched siphonal canal, commonly found in true Vexillum species, are distinctive.

SUBGENUS PUSIA (EBENOMITRA) MONTEROSATO, 1917

FIGURES 18H, I View Figure 18 AND 19D – G View Figure 19

Type species: Mitra ebenus Lamarck, 1811 (SD, Coan, 1966: 130).

Synonyms

Pusiola Monterosato, 1912 View in CoL (invalid: junior homonym of Pusiola Wallengren, 1863 View in CoL [ Lepidoptera View in CoL ]; Pusiolina Cossmann, 1821 is a replacement name); type species Voluta tricolor Gmelin, 1791 (SD: Lamy, 1920: 316).

Pusiolina Cossmann, 1921 ; type species Voluta tricolor Gmelin, 1791 (type by typification by replaced name).

Diagnosis

Shell small, turriform or fusiform to widely fusiform, polished and glossy. Protoconch bulbous, paucispiral, with about two glossy whorls. Teleoconch of up to 7.5 moderately or strongly convex whorls. Early spire whorls with strong ribs or very strong and wide folds; later whorls with strong wide folds vanishing below periphery of last adult whorl, or smooth; spiral sculpture not pronounced. Microsculpture of fine dense collabral growth lines. Siphonal canal short to moderately long, sculptured with between two and four strong oblique cords. Aperture ovate to elongate, sometimes constricted towards siphonal canal; outer aperture lip lirate within. Inner apertural lip with three strong oblique columellar folds, adapicalmost fold strongest. Shell light brown to almost black, with lighter spiral band on shell periphery.

Anatomy

Pusia (Ebenomitra) ebenus , off Calahonda, prov. Malaga, Spain, 36 ° 29.4 0 N, 04 ° 41.8 0 W, 18 m, 14.35 mm ( Fig. 19D – G View Figure 19 ).

Head-foot with intense black pigmentation, head with eyes situated laterally at the base of tentacles ( Fig. 19D View Figure 19 ). Seminal groove closed along its entire length ( Fig. 19E View Figure 19 ). Proboscis moderately long, occupying about two-thirds of rhynchocoel length; proboscis retractors represented by two strong muscular bundles attached laterally to rhynchodaeum ( Fig. 19F View Figure 19 ). Radular sac situated within the proboscis, occupying about half of its length. Radula triserial with wide tricuspidate rachidian, and strong unicuspidate laterals ( Fig. 19G View Figure 19 ). Salivary gland white, with two ducts adjoining oesophagus anterior to valve of Leiblein. Bulky gland of Leiblein rather small, pale, translucent. Mid-oesophagus notably widened, obviously glandular.

Included species

Pusia (Ebenomitra) ebenus (Lamarck, 1811) , 1 Pusia (Ebenomitra) granum (Forbes, 1844) , 2 Pusia (Ebenomitra) savignyi (Payraudeau, 1826) , 1 Pusia (Ebenomitra) tricolor (Gmelin, 1791) . 2

Distribution and habitat

Mediterranean at subtidal depths.

Remarks

The species of Ebenomitra (as defined here) are characterized by a paucispiral protoconch that is indicative of non-planktotrophic larval development – a character unique among species of Pusia . Ebenomitra species are the only costellariid species recorded in the Mediterranean, and their range does not overlap with the ranges of the other two subgenera of Pusia , or of other costellariid lineages. Overall, Ebenomitra shells, with their bulbous protoconch and axial sculpture alone (if any), superficially resemble Austromitra ; however, these two groups are apparently not related, and occur far apart in different hemispheres.