Scaphander, Montfort, 1810

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 667-669

Genus SCAPHANDER Montfort, 1810

Scaphander Montfort, 1810: 334-336 . Type species: Bulla lignaria Linné, 1758 [Recent, Mediterranean and eastern Atlantic], by original designation.

Synonyms:

Gioeni Gioeni, 1783: 1-34 (suppressed by ICZN 1954). Type species: Gioeni sicula Bruguière, 1789 [= Scaphander lignarius (Linné, 1758) ; Recent, Mediterranean and eastern Atlantic], by subsequent monotypy.

Tricla Philipsson, 1788: 8 (suppressed by ICZN 1954). Type species: Tricla gioeni Philipsson, 1788 [= Scaphander lignarius (Linné, 1758) ; Recent, Mediterranean], by monotypy.

Gioenia Bruguière, 1789: 12 (suppressed by ICZN 1954). Type species: Gioenia sicula Bruguière, 1792 [= Scaphander lignarius (Linné, 1758) ; Recent, Mediterranean and eastern Atlantic], by monotypy.

Assula Schumacher, 1817: 78 , 258. Type species: Assula convoluta Schumacher, 1817 [= Scaphander lignarius (Linné, 1758) ; Recent, Mediterranean and eastern Atlantic], by monotypy.

Bucconia Dall, 1890: 16-17 . Type species: Scaphander nobilis Verrill, 1884 [Recent, western Atlantic], by original designation.

Eoscaphander Habe, 1952 a: 75. Type species: Eoscaphander fragilis Habe, 1952 [Recent, Japan], by monotypy.

Nipponoscaphander Kuroda & Habe in Kuroda, Habe & Oyama, 1971: 292. Type species: Scaphander japonicus A. Adams, 1862 [Recent, Indo-Pacific], by original designation.

Bullocardia Nordsieck, 1972: 29 . Type species: Bulla millepunctata Locard, 1897 [= Scaphander nobilis (Verrill, 1884) ; Recent, north Atlantic], by original designation.

DIAGNOSIS. — Shell morphology. Shell external, solid, oval, with only 1 whorl visible. Aperture longitudinal, as long as the shell, anteriorly rounded. Columella thickened, with no callus. Operculum absent.

Anatomy. Large headshield, entire, with no posterior lobes. Digestive system with 3 irregular gizzard plates. Radula with a single hamate lateral tooth. Rachidian teeth present in some species. Reproductive system monaulic. Penis armed or not.

REMARKS. — Gioeni (1783) first described a gizzard of Scaphander lignarius (Linné, 1758) , collected in the Mediterranean. Unaware of the nature of this structure and that it was part of an already described species, he named this new taxon Gioeni, with no species names assigned to it. According to the Code (ICZN 1999: Article 11.4.1), a published work containing family-group or genus-group names without associated nominal species is accepted as consistent with the Principle of Binominal Nomenclature in the absence of evidence to the contrary.

Philipsson (1788) regarded Gioeni’s new name as a species-group name, and introduced the binomen Tricla gioeni for this taxon. On the contrary, Bruguière (1789) considered Gioeni’s to be a genus name, which he Latinized as Gioenia , and introduced the binomen Gioenia sicula Bruguière, 1792 for it. With this act, Bruguière (1789) established Gioenia sicula Bruguière, 1789 as the type species of Gioeni Gioeni, 1783 by subsequent monotypy.

Draparnaud (1800) discovered for the first time the true nature of Gioeni. Later, Montfort (1810) introduced the new genus name Scaphander for the shell of Bulla lignaria Linné, 1758 . Subsequent authors refused to use the names introduced for the gizzard of this species and universally accepted Scaphander , the name to be applied to the shell proper. Winckworth (1932) argued in favor of reverting to the name Tricla , but Lemche (1951) proposed to the International Commission on Zoological Nomenclature the suppression of Tricla Philipsson, 1788 and Gioenia Bruguière, 1789 , which was endorsed by Opinion 287 (ICZN 1954). Even though Gioeni Gioeni, 1783 was not officially suppressed, because it was considered unavailable by Lemche (1951), the intention of Opinion 287 was to preserve the usage of the universally used name Scaphander Montfort, 1810 . I here continue to use Scaphander Montfort, 1810 , although its validity needs to be confirmed in accordance with the Code (ICZN 1999: Article 23.9).

Assula Schumacher, 1817 is based on Assula convoluta Schumacher, 1817 , a synonym of S. lignarius ; thus this genus name is a synonym of Scaphander .

The subgenus Bucconia was introduced by Dall (1890) for Scaphander nobilis Verrill, 1884 , a species with a posterior pillar supporting an extension of the outer lip. Subsequent authors maintained Bucconia as a valid subgenus ( Bullis 1956) or a genus (Habe 1955). However, Bouchet (1975) considered that there are no consistent anatomical differences between Bucconia and Scaphander . In the species here examined I have found a large anatomical variability that is not correlated with the shell morphology nor the presence or absence of a supporting pillar. Therefore Bucconia is regarded as a synonym of Scaphander . Bullocardia Nordsieck, 1972 is based on Bulla millepunctata Locard, 1897 , which is a synonym of S. nobilis , so Bullocardia is a synonym of Bucconia and hence of Scaphander .

Habe (1952a) described the new genus Eoscaphander for the new species Eoscaphander fragilis Habe, 1952 , which apparently differs from Scaphander sibogae (the closest relative according to the author) in the radular morphology. No details or other reasons were given for the separation of this genus. Eoscaphander has been used only for E. fragilis . There are no consistent anatomical differences between this species and other members of Scaphander here studied.

Kuroda et al. (1971) introduced the new name Nipponoscaphander for species having smaller and more ovate shells than other Scaphander , and with the surface covered with punctuated spiral grooves. Examination of the type species of this genus, Scaphander japonicus , revealed that there are no consistent anatomical or shell characters that separate it from other species of Scaphander .

Meloscaphander Schepman, 1913 appears to be different from Scaphander in having an elevated spire on the posterior end of the shell ( Bouchet 1975).