Scalpellum stearnsi Pilsbry, 1890

Pitriana, Pipit, Jones, Diana S., Corbari, Laure & Rintelen, Kristina von, 2020, New insights gained from museum collections: Deep-sea barnacles (Crustacea, Cirripedia, Thoracica) in the Museum National d'Histoire Naturelle, Paris, collected during the Karubar expedition in 1991, Zoosystematics and Evolution 96 (2), pp. 649-698 : 649

Scalpellum stearnsi Pilsbry, 1890 Figure 12

Scalpellum magnum Darwin, 1852: 18, pl. I, fig. 1.

Scalpellum calcariferum Fischer, 1891: 116.

Scalpellum stearnsii var. gemina and var. robusta Hoek, 1907: 69, pl. VI, figs 2, 3, 8-12.

Scalpellum stearnsii var. inerme Annandale, 1916a: 293.

Scalpellum stearnsii forma typica Broch, 1931: 16.

Scalpellum stearnsii Pilsbry, 1890a: 96. - 1890b: 441, pl. IV, figs 1-5. - 1907a: 14, pl. 4, figs 1-5. - Nilsson-Cantell 1921: 175. - 1934: 33. - Broch 1922: 235, fig. 6. - Hiro 1933: 22, fig. 4, pl. 1, figs 5, 5a. - 1939a: 237. - Zevina 1981: 98, fig. 68. - Rosell 1991: 15. - Jones 1992: 146, figs 1, 2. - Liu and Ren 2007: 226, fig. 95. - Chan et al. 2009b: 89, figs 73-76. - Chan et al. 2010: 24, figs 2C, 18A-G.

Scalpellum stearnsi : Gruvel, 1905: 44, fig. 46. - Gale 2016: fig. 5, table 1.

Material examined.

- Tanimbar Island: 1 specimen, MNHN-IU-2019-4888, Stn. CP 71, 08°38'S, 131°44'E, 477-480 m depth, 2 November 1991; 1 specimen, MNHN-IU-2019-4889, Stn. CC 58, 08°19'S, 132°02'E, 457-461 m depth, 31 October 1991; 6 specimens, MNHN-IU-2019-4890, Stn. CC 42, 07°53'S, 132°42'E, 350-354 m depth, 28 October 1991; 3 specimens, MNHN-IU-2019-4891, Stn. CP 69, 08°42'S, 131°53'E, 356-368 m depth, 2 November 1991; 5 specimens, MNHN-IU-2019-4892, Stn. CC 41, 07°45'S, 132°42'E, 393-401 m depth, 28 October 1991; 5 specimens, MNHN-IU-2019-4893, Stn. CP 59, 08°20'S, 132°11'E, 399-405 m depth, 31 October 1991, 2 specimens attached to glass rope sponge.

- Kei Islands: 8 specimens, MNHN-IU-2019-4894, Stn. CP 06, 05°49'S, 132°21'E, 287-298 m depth, 22 October 1991.

Diagnosis.

Capitulum rhomboidal, compressed; carina strongly angled at umbo; scutum large, umbo at tergo-occludent angle; tergum triangular; inframedian latus pentagonal; carinolateral horn-shaped.

Description.

Capitulum with 14 fully calcified plates. Scutum large, longer than broad, apex slightly projecting over tergum; tergum large, triangular, apex erect, slightly recurved. Carina distinctly bent near middle, umbo distant from apex. Cirrus I with anterior ramus oval (12-segments), posterior ramus slender, long (15-segments); cirri II-VI slender, long, rami almost equal length; cirrus VI with short caudal appendages (six segments). Maxillule not notched, with numerous setae; mandible with six teeth excluding inferior angle. Measurements of five specimens: height of capitulum 31.69-52.00 mm, width 28.20-40.11 mm, thickness 11.19-18.56 mm; peduncle length 28.29-86.59 mm, width 11.39-17.94 mm.

Distribution.

Indo-west Pacific: Indian Ocean, off Nicobar Island; Indonesia: Java Sea, Bali Straits; north west & north east Australia; Malay Archipelago; Celebes; Sulu Arch.; Sulu Sea; South China Sea; East China Sea; Philippines; Taiwan; east coast of south Japan, Sagami Bay, off Hondo; attached to mollusc shells, anchor filaments of hexactinellid sponges, telegraph cables, carapaces of crabs, stones; 146-2117 m depth ( Jones and Hosie 2016). In this study, Scalpellum stearnsi was found at Tanimbar Island and Kei Islands, Indonesia.

Type locality.

East coast of Japan, between the Bay of Tokyo and the Inland Sea ( Jones 1992).

Remarks.

For the first time, Scalpellum stearnsi was found in Japan and described by Pilsbry (1890). During the Siboga expedition (1899), S. stearnsi was collected from different locations in the Malay Archipelago with the depths varying from 204 m to 450 m. Hoek (1907) found intraspecific variations of the shell plate morphology. He then divided S. stearnsi into two groups, i.e. variety robusta and var. gemina , which differed in the shape of the tergum. The species S. stearnsi in this study belongs to the group of var. gemina because of the V-shaped tergum.

Scalpellum stearnsi has a low period of larval development ( Ozaki et al. 2008) and a slow growth rate ( Yusa et al. 2018). This can result in the broad geographical distribution of this species. Recently, Lin et al. (2020) examined the diversity and genetic differentiation of populations of S. stearnsi from the East China Sea, West Philippine Basin, Sulu Sea and Caroline Trenches, which resulted in four distinct clades of S. stearnsi .

Figures

Figure 12. Scalpellum stearnsi Pilsbry, 1890 (MNHN-IU- 2019 - 4888). a. left lateral view, capitulum and peduncle; b. right lateral view, capitulum and peduncle; c. rostral view, capitulum and peduncle; d. carinal view. Scale bar: 14 mm (a-d).