Scaphander solomonensis, Siegwald & Malaquias, 2025

Siegwald, Justine & Malaquias, Manuel António E., 2025, Bringing light into deep-sea biodiversity: a systematic revision and molecular phylogeny of the genus Scaphander Montfort, 1810 (Gastropoda: Cephalaspidea), with a focus on the Indo-Pacific, Zoological Journal of the Linnean Society 203, pp. 1-60 : 51-53

Scaphander solomonensis sp. nov.

( Figs 21 , 36 , 37 ; Table 2)

Scaphander sp.4 — Siegwald et al. 2022.

ZooBank LSID: urn:lsid:zoobank.org:act:AB362B0B-586D-4B6D-892C-B42C4F841A04

Etymology: After its type locality, the Solomon Islands .

Type material: Solomon Islands: northwest of Choiseul, holotype, dissected and sequenced, MNHN-IM-2019-7924 , H = 12 mm ; northwest of Isabel, one paratype, dissected and sequenced, MNHN-IM-2013-52483 , H = 11 mm .

Other material examined: Solomon Islands: northwest of Choiseul, one spc., dissected and sequenced, MNHN-IM-2013-52480 , H = 7 mm; one spc., MNHN-IM-2019-11703 , H = 11 mm; northwest of Isabel, one spc., sequenced, MNHN-IM-2019-7923 , H = 10 mm; one spc., MNHN-IM-2013-52481 , H = 10 mm .

Diagnosis: Shell ovoid to attenuate, dirty white. Spiral sculpture composed of punctuated grooves or rows of distinct punctuations. Apex rounded. Posterior edge of outer lip rising above apex, in a small rounded wing. Rachidian teeth quadrate to H-shaped. Prostate cylindrical, separated from penial chamber by prostatic duct. Penial chamber lined with soft longitudinal ridges.

Shell ( Fig. 36 ): Maximum H observed = 12 mm. Shell ovoid to attenuate, only one whorl visible. Aperture wide, as long as shell, narrowing posteriorly. Apex rounded, spire slightly umbilicate. Posterior edge of outer lip rising in small rounded wing protruding beyond apex. Parietal wall covered with white callus; thick, smooth in anterior half; thin to inconspicuous in posterior half. Spiral sculpture composed of punctuated striations or grooves. Punctations ovoid, separate or interconnected in spiral grooves of uneven width. Thin, white to translucent periostracum. Shell dirty white.

Radula ( Fig. 37A–C ): Radular formula 17 × 1.1.1 (H = 11 mm). Lateral teeth curved, with fine denticulation on inner edge. Rachidian teeth sub-rectangular to H-shaped, with upper cusps curved inwards.

Digestive tract ( Fig. 37D, E ): Salivary glands medium long; surface smooth. Paired gizzard plates sub-triangular to kidney or crescent-shaped.

Male reproductive system ( Fig. 37F, G ): Penial chamber cylindrical, narrower towards genital opening, widening towards prostatic duct, lined with soft longitudinal ridges. Muscular papilla absent. Penial chamber separated from prostate by thin prostatic duct, widening towards prostate. Prostate cylindrical, distal end narrower.

Ecology: Found between 718 and 1100 m depth. Feeds on foraminifera (present study).

Distribution ( Fig. 21 ): Solomon Islands (present study).

Remarks: Scaphander solomonensis resembles its sister species S. teramachii from Japan, but has a wider and more ovate shell. In addition, the wart structure lining the penial chamber of S. teramachii was not found in S. solomonensis , which has soft longitudinal ridges lining the interior of the chamber.

Figures

Figure 21. Geographical distribution of Scaphander semicallus, Scaphander solomonensis, and Scaphander teramachii. Geographical records are based on studied material and reliable literature records.

Figure 36. Shells and SEM image of the shell sculpture of Scaphander solomonensis. A, Solomon Islands, northwest of Choiseul (holotype, MNHN-IM-2019-7924, H = 12 mm). B, Solomon Islands, northwest of Choiseul (paratype, MNHN-IM-2013-52483, H = 11 mm). C, Solomon Islands, northwest of Isabel (MNHN-IM-2019-7923, H = 10 mm). Scale bar: C = 200 µm.

Figure 37. Anatomical details of Scaphander solomonensis. A, radula, Solomon Islands, northwest of Choiseul (paratype, MNHN-IM-2013-52483, H = 11 mm).B, rachidian teeth, Solomon Islands, northwest of Choiseul (MNHN-IM-2013-52480, H = 7 mm). C, detail of lateral teeth, Solomon Islands, northwest of Choiseul (holotype, MNHN-IM-2019-7924, H = 12 mm).D, anterior part of digestive tract (MNHN-IM-2013-52480, H = 7 mm). E, gizzard plates (MNHN-IM-2013-52480, H = 7 mm). F, male reproductive system (holotype, MNHN-IM-2019-7924, H = 12 mm). G, lining of penial chamber (MNHN-IM-2013-52480, H = 7 mm). Scale bars: A = 200 µm; B, C = 10 µm; D, F = 500 µm; E = 1 mm; G = 100 µm.