Scaphander cancellatus Martens 1902
Creators: name: Siegwald, Justine
name: Malaquias, Manuel António E.
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Cephalaspidea
Scaphandridae
Scaphander
Scaphander cancellatus

description: 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.
description: Published as part of 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, pp. 1-60 in Zoological Journal of the Linnean Society 203 on pages 22-26, DOI: 10.1093/zoolinnean/zlad201, http://zenodo.org/record/15006324