Scaphander cornus, Siegwald & Malaquias, 2025

Scaphander cornus View in CoL sp. nov.

( Figs 3 View Figure 3 , 30 View Figure 30 , 31 View Figure 31 ; Table 2)

Scaphander mundus — Valdés 2008 (in part): 674–676, figs 40B, 42A, B.

Scaphander sp.1 — Siegwald et al. 2022.

ZooBank LSID: urn:lsid:zoobank.org:act:BA92D17E-7185-487F-A1E1-88CDDCBF6BD5

Etymology: Latin, cornu; horn. Named after the shape of the posterior wing of the shell, which resembles a small horn.

Type material: Australia: Victoria, East Gippsland Commonwealth Marine Reserve , holotype, dissected and sequenced, AM C.590968 , H = 23 mm; Bass Strait , one paratype, sequenced, AM C.563069 , H = 34 mm .

Other material examined: Australia: Victoria, East Gippsland Commonwealth Marine Reserve, one spc., AM C.590962, H = 27 mm; New South Wales, Jervis Commonwealth Marine Reserve, one spc., dissected and sequenced, AM C.519368, H = 26 mm; Bass Strait, one spc., dissected and sequenced, AM C.590959, H = 30 mm. New Caledonia: Loyalty Basin, one sh., MNHN-IM-2010-2061, H = 27 mm.

Diagnosis: Shell ovoid, white. Spiral sculpture composed of sub-rectangular punctuations. Apex rounded. Posterior edge of outer lip rising above apex, in sharp curved wing. Rachidian teeth sub-rectangular. Prostate ovoid. Penial papilla absent. Penial chamber lined with soft warts around prostatic duct entrance.

Shell ( Fig. 30 View Figure 30 ): Maximum H observed = 34 mm. Shell ovoid, only one whorl visible. Aperture wide, as long as shell, narrowing posteriorly. Spire concealed. Posterior edge of outer lip rising in sharp curved wing protruding well beyond apex. Parietal wall covered with slight, smooth white callus. Spiral sculpture composed of punctuated striations. Punctations sub-rectangular, of variable shape and size. Thin, translucent periostracum. Shell white.

Radula ( Fig. 31A–C View Figure 31 ): Radular formula 16 × 1.1.1 (H = 30 mm). Lateral teeth curved, with weak denticulation on inner edge. Rachidian teeth sub-rectangular, with rounded cusps.

Digestive tract ( Fig. 31D, E View Figure 31 ): Salivary glands medium long; surface uneven. Paired gizzard plates kidney-shaped.

Male reproductive system ( Fig. 31F, G View Figure 31 ): Penial chamber cylindrical, widening towards prostatic duct, lined with soft longitudinal ridges towards genital opening, bulged and lined with warts around prostatic duct entrance. Prostatic duct short. Muscular penial papilla absent. Prostate ovoid.

Ecology: Found between 2338 and 2760 m depth. Feeds on foraminifera (present study).

Distribution ( Fig.3 View Figure 3 ): Southeastern Australia and New Caledonia.

Remarks: Scaphander cornus is remarkably similar to its sister species S. nobilis , but has a slightly more rounded shell and lacks a penial papilla.It is also similar to S. mundus , another white-shelled species found in Eastern Australia and New Caledonia. This resemblance led, for example, Valdés (2008) to include specimens of this new species among the lots used in his redescription of S. mundus . However, S. mundus has a less rounded, more elongated shell, with a thinner, less curved wing at the posterior edge of the outer lip of the shell. The species S. cornus also seems to dwell in deeper bottoms (2338–2760 m) than S. mundus (900–1800 m).