Dichelaspis orthogonia Darwin, 1852

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

Dichelaspis orthogonia Darwin, 1852 Figure 6

Dichelaspis orthogonia Darwin, 1852: 130, pl. II, fig. 10a, b.

Dichelaspis versluysi Hoek, 1907: 28, pl. III, figs 8-13.

Octolasmis (Dichelaspis) orthogonia . - Pilsbry, 1907a: 94.

Octolasmis orthogonia . - Krüger, 1911: 462. - Pilsbry 1911: 70, pl. 11, figs 6, 7. - Broch 1922: 279. - 1931: 38, fig. 14. - Nilsson-Cantell 1925: 21, fig. 8. - 1928: 18, fig. 8. - Hiro 1933: 55, fig. 16, pl. 2, figs 5a, 5. - 1937a: 91, fig. 71. - 1937b: 415, fig. 12. - Stubbings 1963: 327, fig. 1. - Dong et al. 1982: 79. - Zevina et al. 1992: 26, fig. 15. - Chan 2009: 68, fig. 2 B and fig. 17A-F.

Material examined.

- Kei Islands: 4 specimens, MNHN-IU-2019-4864, Stn. CP 27, 05°33'S, 132°51'E, 314-304 m depth, 27 October 1991.

- Tanimbar Island: 6 specimens, MNHN-IU-2019-4862, Stn. DW 24, 05°32'S, 132°51'E, 230-243 m depth, 26 October 1991.

Diagnosis.

Capitulum flattened; five plates, separated by thin membrane; scutum consisting of two distinct segments, with point of junction perfectly calcified; base of carina oval.

Description.

Capitulum and peduncle yellowish. Scutum with basal segment narrow, L-shaped; tergum triangular, three prominent ridges at scutal margin; base of carina crescent-formed cup. Cirrus I with anterior ramus (6-segmented) shorter than posterior ramus (8-segmented); cirrus VI with small caudal appendage. Maxillule notched, three large setae on upper notch; mandible with four teeth, inferior angle produced into single strong spine; labrum concave, with numerous teeth. Measurements of specimen: basal diameter of capitulum 1.89 mm; capitular height 8.69 mm; total height 10.47 mm; scutal width 3.5 mm; scutal length 7.16 mm; tergal width 0.80 mm; tergal length 6.53 mm.

Distribution.

Indo-west Pacific: East and South African Coast, Indian Ocean, Australia, Indonesia, Malay Archipelago, Vietnam, South China Sea, East China Sea, Philippines, Taiwan, South Japan; attached to hydroid, gorgonians, antipatharians, sea urchin spines, nylon cord, sometimes fouling; 14-818 m depth ( Jones and Hosie 2016). In this study, Dichelaspis orthogonia was found at Kei Islands and Tanimbar Island, Indonesia.

Type locality.

Unknown.

Remarks.

The type locality of this species is unknown. The species was re-discovered in the Malay Archipelago by the Siboga Expedition in 40-112 m depth ( Hoek 1907) and the Albatross Expedition, off Kagoshima Gulf, Japan, in 87 m depth ( Pilsbry 1907d).

Figures

Figure 6. Dichelaspis orthogonia Darwin, 1852 (MNHN-IU- 2019 - 4864). a. left lateral view capitulum and peduncle; b. right lateral view, capitulum and peduncle. Scale bar: 2 mm (a-b).