Scaphander cancellatus Martens, 1902

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 : 22-26

Scaphander cancellatus Martens, 1902

( Figs 10–13 ; Table 2)

Scaphander cancellatus Martens, 1902: 244 ; 1903: 131–133, pl. 5, fig. 19; Smith 1906: 247–248.

Scaphander subglobosa Schepman, 1913: 466 ; Valdés 2008: 678, figs 43, 44C–G, 45D–F.

Scaphander subglobosus Schepman, 1913 : pl. 32, fig. 1; Poppe 2010: pl. 760, fig. 3.

Scaphander attenuatus Schepman, 1913: 465 , pl. 31, fig. 11.

Bucconia attenuata — Habe 1955: 69.

Nipponoscaphander teramachii Kuroda & Habe, 1971 (in Kuroda et al. 1971): 293, pl. 64, fig. 27.

Taxonomic history: The species S. cancellatus was described by Martens (1902) from shells collected in Indonesia during the Valdivia expedition. Later, Schepman (1913) described S. subglobosa , S. attenuatus , and S. sibogae , also based on empty shells collected in Indonesia during the Siboga expedition . Valdés (2008) redescribed S. subglobosa and included details about the digestive system, but did not refer to the reproductive system. In addition, Valdés (2008) redescribed S. sibogae and considered S. attenuatus a synonym. Chaban et al. (2019a) subsequently used the name S. attenuatus to designate S. sibogae . However, the examination of the type material and original descriptions for these three species (present work) showed that S. subglobosa and S. attenuatus are both junior synonyms of S. cancellatus ( Fig. 11 ), and a distinct species from S. sibogae (see S. sibogae section). Scaphander cancellatus was reported from Japan as B. attenuata by Habe (1955), but was later depicted as N. teramachii by Kuroda and Habe (in Kuroda et al. 1971).

Type material: Scaphander cancellatus Martens, 1902 — Indonesia: west of Sumatra, Pulau Nias, Valdivia expedition, station 199, 0°15'00"N, 98°04'00"E, 470 m, one type, ZMB Moll 60055 , H = 24.6 mm, images seen ( Fig. 11A ) . Scaphander attenuatus Schepman, 1913 — Indonesia: Nusa Tenggara Timur, Laut Sawu, Siboga expedition , station 52, 9°3'24"S, 119°56'42"E, 959 m, four syntypes, ZMA.MOLL.138504, H = 23 mm, images seen ( Fig. 11C ). Scaphander subglobosus Schepman, 1913 — Indonesia: Maluku, Laut Seram, Siboga expedition , station 178, 2°40'00"S, 128°37'30"E, 835 m, one syntype, ZMA. MOLL.137604, H = 28 mm, images seen ( Fig. 11B ).

Other material examined: Indonesia: Tanimbar Islands , one sh., MNHN-IM-2010-2086, H = 28 mm; one spc., dissected and sequenced, MNHN-IM-2019-7925, H = 27 mm; one spc., dissected, MNHN-IM-2019-7931, H = 28 mm; one spc., MNHN-IM-2019-7928, H = 26 mm; one spc., MNHN-IM-2019-7929, H = 27 mm; one spc., MNHN-IM-2019-7927, H = 21 mm; one spc., dissected, MNHN-IM-2019-7930 H = 26.5 mm . Papua New Guinea: Kimbe Bay , one sh., MNHN-IM-2016-5759, H = 30 mm . Philippines: east of Marinduque, two sh., MNHN-IM-2010-2090, H = 21, 22 mm; Bohol Sea, off Balicasag Island , one spc., sequenced, MNHN-IM-2007-35413, H = 26 mm; Bohol Sea, one sh. plus DNA aliquot, sequenced, MNHN-IM-2007-35412, H = 17 mm; one spc., sequenced, MNHN-IM-2009-4339, H = 24 mm; one spc., MNHN-IM-2013-52485, H = 25 mm . Solomon Islands: west of Vella Lavella, one spc., dissected and sequenced, MNHN-IM-2013-52474, H = 32 mm; one spc., MNHN-IM-2013-52470, H = 31.4 mm; one spc., MNHN-IM-2019-11709, shell greatly damaged; one spc., MNHN-IM-2019-11710, H = 27.7 mm; one spc., MNHN-IM-2019-11711, H = 32.1 mm; one spc., MNHN-IM-2019-11712, H = 30 mm; one spc., MNHN-IM-2013-52473, H = 34.5 mm; east of San Cristobal, one spc., dissected and sequenced, MNHN-IM-2009-6678, H = 18 mm; one spc., sequenced, MNHN-IM-2009-6686, H = 12 mm; northwest of Santa Isabel, one spc., dissected, MNHN-IM-2013-52475, H = 24 mm; southeast of Choiseul, one spc., MNHN-IM-2013-52476, H = 28 mm; southwest of Santa Isabel, one spc., dissected and sequenced, MNHN-IM-2013-52472, H = 30 mm; southeast of Santa Isabel, one spc., MNHN-IM-2013-52479, H = 29 mm; New Georgia, one spc., sequenced, MNHN-IM-2013-52478, H = 18 mm . Japan: Kochi-ken, two sh., NSMT Mo-38721, H = 10.1–10.5 mm; Enshu-nada, four sh., NSMT Mo-55818, H = 15.1–17.9 mm; Tosa Bay , four spcs, NSMT Mo-90577, H = 6–14 mm; 14 spcs, NSMT Mo-90582, H = 6–11.5 mm; seven spcs, two dissected, NSMT Mo-90588, H = 16–31 mm; four spcs, NSMT Mo-90591, H = 27–31 mm .

Diagnosis: Shell ovoid to sub-rectangular, periostracum pale yellow to warm orange. Spiral sculpture composed of ovoid to sub-rectangular punctations, often interconnected and forming punctuated grooves. Apex rounded; posterior edge of outer lip wing-like, rounded or curved, rising above apex. Rachidian teeth elongate, with curved upper cusps. Prostate cylindrical, separated from penial chamber by short prostatic duct. Penial chamber bulged distally near prostatic duct; globose region lined internally with soft warts.

Shell ( Fig. 11 ): Maximum H observed = 34 mm. Shell ovoid to sub-rectangular; only one whorl visible. Aperture wide, as long as shell, narrowing posteriorly. Apex rounded; spire concealed. Posterior edge of outer lip wing-like, rounded, rising beyond apex. Parietal wall covered with callus; thick, smooth, white in anterior half; thin to inconspicuous in posterior half. Spiral sculpture composed of punctuated striations or grooves. Punctations ovoid to sub-rectangular pits, distinct from one another or interconnected, forming spiral grooves of uneven width. Periostracum pale yellow to warm orange. Shell dirty white.

Radula ( Fig. 12A–C ): Radular formula 21 × 1.1.1 (H = 28 mm). Lateral teeth curved, with weak denticulation on inner edge. Rachidian teeth elongate, with developed upper cusps curved inwards, with curved, pointed, developed upper cusps.

Digestive tract ( Fig. 12D, E ): Salivary glands medium long, surface uneven. Paired gizzard plates rounded kidney-shaped.

Male reproductive system ( Figs 12F, G , 13 ): Penial chamber cylindrical, bulged towards prostatic duct; globose region lined with warts. Muscular penial papilla absent. Penial chamber separated from prostate by short prostatic duct, widening towards prostate. Prostate cylindrical, rounded at distal end.

Ecology: Found between 440 and 869 m depth. Feeds on foraminifera (calcareous and agglutinating), tubicolous polychaetes, and small gastropods (present study).

Distribution ( Fig. 10 ): Western Pacific Ocean, from Indonesia ( Schepman 1913; present study), the Philippines ( Valdés 2008; present study), Papua New Guinea, Solomon Islands (present study), and Japan ( Habe 1955, Kuroda et al. 1971; present study).

Remarks: There is remarkable variability in the morphology of this species ( Fig. 11 ); the shell can be elongate, sub-rectangular, or wider and ovate, with the posterior outer lip wing-like and rounded, or significantly longer and acutely curved. This, for example, led to historical taxonomic confusion between S. cancellatus and S. sibogae (e.g. Valdés 2008, Chaban et al. 2019a). However, the shell of S. sibogae is rounder and has a thicker parietal callus (see Table 2).

It was not possible to obtain DNA sequences from Japanese specimens, and their occurrence in Japan is therefore confirmed here based only on shell and morphological characters. Around Japan, rounder shells of S. cancellatus can be confused with E. fragilis , but these two species are easily separated by their anatomy, because E. fragilis contains only two oval calcareous plates instead of the three plates that are characteristic of the genus Scaphander ( Siegwald et al. 2022) . Their shells can also be distinguished from each other, with adult shells of E. fragilis being larger and more inflated, with the posterior end being less rounded.

A dissected specimen from Japan had part of the male reproductive system everted ( Fig. 13 ), exposing the warts lining the interior of the penial chamber. This suggests that this part of the reproductive system is likely to be used functionally as a copulatory organ.

Figures

Figure 10. Geographical distribution of Scaphander andamanicos, Scaphander cancellatos, Scaphander illecebrosos, and Scaphander sibogae. Geographical records are based on studied material and reliable literature records.

Figure 11. Shells and SEM images of the shell sculpture of Scaphander cancellatos. A, Indonesia, west of Sumatra, Pulau Nias (type, ZMB Moll 60055, H = 24.6 mm). B, Indonesia, Maluku, Laut Seram (syntype, Scaphander sobglobosos, ZMA.MOLL.137604, H = 28 mm; images taken by K. Hasegawa and courtesy of Naturalis Biodiversity Center). C, Indonesia, Nusa Tenggara Timur, Laut Sawu (syntype, Scaphander atenoatos, ZMA.MOLL.138504, H = 23 mm; images taken by K. Hasegawa and courtesy of Naturalis Biodiversity Center). D, Solomon Islands, west of Vella Lavella (MNHN-IM-2013-52474, H = 32 mm). E, Solomon Islands, southwest of Santa Isabel (MNHN-IM-2013-52472, H = 30 mm). F, Philippines, Bohol Sea, off Balicasag Island (MNHN-IM-2007-35413, H = 26 mm). G, Japan, Tosa Bay (NSMT Mo-90588, H = 26 mm). H, Solomon Islands, southwest of Santa Isabel (MNHN-IM-2013-52472, H = 30 mm). I, Japan, Tosa Bay (NSMT Mo-90588, H = 26 mm). J, Philippines, Bohol Sea, off Balicasag Island (MNHN-IM-2007-35413, H = 26 mm). K, Solomon Islands, east of San Cristobal (MNHN-IM-2009-6686, H = 12 mm). L, Solomon Islands, southwest of Santa Isabel (MNHN-IM-2013-52472, H = 30 mm). Scale bars: K, L = 200 µm.

Figure 12. Anatomical details of Scaphander cancellatos. A, radula, Solomon Islands, west of Vella Lavella (MNHN-IM-2013-52474, H = 32 mm). B, rachidian teeth, Solomon Islands, east of San Cristobal (MNHN-IM-2009-6678, H = 18 mm). C, detail of lateral teeth, Indonesia, Tanimbar Islands (MNHN-IM-2019-7931, H = 28 mm). D, anterior part of digestive tract, Indonesia, Tanimbar Islands (MNHN-IM-2019-7925, H = 27 mm).E, gizzard plates (MNHN-IM-2019-7925, H = 27 mm). F, male reproductive system (MNHN-IM-2019-7925, H = 27 mm). G, lining of penial chamber, Japan, Tosa Bay (NSMT Mo-90588, H = 31 mm). Scale bars: A = 200 µm; B, C = 20 µm; D = 1 mm; E, F = 2 mm; G = 400 µm.

Figure 13. Anatomical details of Scaphander cancellatus, Japan, Tosa Bay (NSMT Mo-90588, H = 26 mm). A, dorso-anterior view of the dissected animal, with visible longitudinal incision across the cephalic shield made to access the interior of the body cavity.On the left side, part of the male reproductive system everted through the genital opening can be observed.B, complete male reproductive system. C, SEM detail of the everted warty walls of the penial chamber.Scale bars: A = 2 mm; B = 1 mm; C = 400 µm.