Cadulus victori, Souza & Caetano & Scarabino & Costa, 2020

Souza, Leonardo S., Caetano, Carlos Henrique S., Scarabino, Fabrizio & Costa, Paulo Márcio S., 2020, New records and a new species of Scaphopoda (Mollusca) from the southwestern Atlantic Ocean, Iheringia, Série Zoologia (e 2020023) 110, pp. 1-12 : 7-9

Cadulus victori sp. nov. Souza, Caetano & Scarabino urn:lsid:zoobank.org:act:F1CFE103-905A-4022-AD25-F0DD321BE220

( Figs 36–41 )

Type material. Holotype ( CZUFS SCA-00005 , shell) . Paratype: BRAZIL, Bahia, Camamu-Almada Basin , 14°19ʼ48ˮS 38°32ʼ39ˮW, 2200 m, coll. 2011 ( MNRJ 34466 †, 1 shell) .

Type locality. BRAZIL, Alagoas, MARSEAL SED 4 sta. AN8, 10°21ʼ22ˮS 35°53ʼ36ˮW, 400 m, coll. R / V Seward Johnson, 08/x/2013 .

Description. Shell up to 4.97 mm long, 2.09 mm wide, strongly swollen, maximum diameter at equator; whitish, glossy. In lateral view, convexity is abrupt at both sides, markedly at posterior side; rapidly tapering towards the apertures. In anterior view, convexity more uniform at both sides, biconic. Oval in section. Dorsal aperture simple, compressed anteroposteriorly, slightly wider than long. Ventral aperture simple, wide, compressed anteroposteriorly, slightly wider than long. Measurements: see Tab.I.

Distribution. Brazil: Alagoas, Bahia. Empty shells from 400 to 2200 m.

Etymology. This species is named in honor of Dr. Victor Scarabino for his significant contribution to the systematics of Scaphopoda.

Remarks. The holotype (CZUFS SCA-00005) ( Figs 36, 37 ) of this newly described species is safely preserved, but the paratype (MNRJ 34466) ( Figs 38–41 ) was destroyed due to the fire at “Museu Nacional”. A detailed analysis of the shell morphology was conducted prior to the destruction of the specimen.

Cadulus victori sp. nov. is very inflated at the equator, having a strongly convex outline and a relatively bigger size ( Figs 36–40 ) than other Cadulus from the Atlantic. Cadulus tumidosus ( Figs 28–35 ) is the most similar species. STEINER & KABAT (2004) reported the occurrence of the latter species in Brazil, but there is no confirmed record of this species in this country ( SOUZA et al., 2013). Cadulus victori sp. nov. differs from C. tumidosus mainly by the less constricted apical region, the outline from the equator to the dorsal aperture is more sloping in the former ( Figs 36–40 ), while it is straighter in the latter ( Figs 28–35 ). Additionally, even the most swollen syntypes of C. tumidosus ( Figs 28, 29, 32, 33 ) do not have such a convex outline like in C. victori sp. nov. ( Figs 36–40 ) that reaches a greater width (2.1 vs. 1.9 mm) in shells of smaller length (5.0 vs. 5.5 mm) ( Tab. I).

Cadulus victori sp. nov. also resembles Cadulus exiguus Watson, 1879 ( Figs 42–44 ), from deep waters of the Caribbean, Cadulus gibbus Jeffreys, 1883 ( Figs 45–48 ), from the Northeast Atlantic, and Cadulus rossoi NicklÉs, 1979 , from Senegal, because all have an inflated shell. However, C. victori sp. nov. differs by the much broader dimensions than these species ( Tab. I).

Cadulus victori sp. nov. differs from C. platensis ( Figs 19–27 ), and from Cadulus jeffreysi (Monterosato, 1875) (see APPOLLONI et al., 2018: fig. 40P, for the illustration of the type material) by being more inflated, strongly increasing in diameter towards the equator.

Cadulus victori sp. nov. differs from Cadulus attenuatus Monterosato, 1875 (see APPOLLONI et al., 2018: fig. 40N, for the illustration of the type material), from the Mediterranean, by being more tapered and with a smooth apex, while C. attenuatus has an almost cylindrical shape and a coronated apex.

Cadulus victori sp. nov. differs from Cadulus obesus Watson, 1879 by having a more inflated equator and bigger dimensions based on WATSON’s (1886:pl. 3, fig. 8) illustrations. The four syntypes of C. obesus (NHMUK 1887.2.9.84–87) ( Fig. 49 ) are severely damaged by Byne’s disease ( STEINER & KABAT, 2004), and the original description is not useful as most Cadulus are similar. Thus, we consider C. obesus as a nomen dubium.

Cadulus victori sp. nov. differs from Cadulus cucurbitus Dall, 1881 (see HENDERSON, 1920: pl. 20 fig. 1, for the illustration of the holotype), from Caribbean, by having a more inflated and more convex equator, a smaller proportion between the total length and maximum width (2.3–2.4 vs. 3.2) ( Tab. I).

Figures

Figs 36–41. Cadulus victori sp. nov. 36, 37, holotype (CZUFS SCA-00005); 38–41, paratype (MNRJ 34466). 36, 38, 40, entire shell, lateral view; 37, 39, entire shell, anterior view; 41, detail of dorsal aperture; the arrow indicates the anterior region of the shell. Scale bars: 36–40= 1mm; 41= 0.1 mm.

Figs 28–35. Cadulus tumidosus Jeffreys, 1877: syntypes (USNM 169502): 28, 29, same shell; 30, 31, same shell; 32, 33, same shell; 34, 35, same shell. 28, 30, 32, 34, entire shell, lateral view. 29, 31, 33, 35, entire shell, anterior view. Scale bar: 2 mm (all images at same scale).

Figs 42–49. Cadulus species. 42–44, Cadulus exiguus Watson, 1879: syntypes, NHMUK 1887.2.9.94, both glued to a cardboard. 45–48, Cadulus gibbus Jeffreys, 1883: 45, 46, syntype (USNM 172858); 47, 48, syntype (NHMUK 1885.11.5.1287); 49, Cadulus obesus Watson, 1879: syntypes (NHMUK 1887.2.9.84–87, 4 shells), all inside a gelatin capsule.

Figs 19–27. Cadulus platensis Henderson, 1920. 19–22, holotype (USNM 887476); 23–26, MNRJ 27204: 23, 24, same shell; 25, 26, same shell; 27, MZSP 119362.19, 23, 25, 27, entire shell, lateral view; 20, 24, 26, entire shell, anterior view; 21, detail of dorsal aperture; 24, detail of ventral aperture. Scale bars: 19, 20,23–27= 1 mm; 21, 22= 0.4 mm.