Sphaerodromia nux Alcock 1900
Creators: name: Padate Sherine Sonia Cubelio Masatsune Takeda, Vinay P.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Dromiidae
Sphaerodromia
Sphaerodromia nux

description: Sphaerodromia nux Alcock, 1900
(Figs. 2D, E, 4)
Sphaerodromia nux Alcock, 1900a: 154 (type locality: Gulf of Martaban). — Alcock, 1901: 40, 78, pl. 4, fig. 19. — Ihle, 1913: 92 (list). — Lewinsohn, 1984: 115, pl. 3, fig. B, pl. 4, figs. C–D. — McLay, 1991: 463, 465 (discussion), tab. 1 (comparison). — McLay and Crosnier, 1991: 186 (discussion). — McLay, 1993: 126 (list), 127 (key). — Crosnier, 1994: 347 (remarks). — McLay, 2001: 821 (key, description). — Guinot and Tavares, 2003: 107, 108, figs. 22B, 23A–B. — Ng et al., 2008: 36 (list). — Trivedi et al., 2018: 36 (tab. 1).
Material examined. 1 male (CL 29.3 mm, CW 33.1 mm) (IO /SS/BRC/00295), west of South Andaman Island, Bay of Bengal, FORVSS stn. 349 (leg II) 09, 11.93°N 92.28°E, 290 m, coll. Dr. Aneesh Kumar K. V., HSDT (CV), 12 April 2016.
Remarks. Sphaerodromia nux was originally described from supposedly juvenile specimens (1 male of undetermined size, 1 female 10 × 11 mm) from the Gulf of Martaban off Myanmar at 129 m depth (Alcock, 1900a). The original description by Alcock (1900a) described only the carapace, and a subsequent monograph by Alcock (1901) provided a short description of the third maxilliped, chelipeds, and the vestigial male pleopods on pleonal somites 3–5 supplemented with a line illustration of the dorsal habitus (Alcock, 1901: fig. 19). Lewinsohn (1984) redescribed this species from adult specimens from Madagascar, and reported differences from the type specimen in the absence of a gap between the anterior margin of the third maxillipeds and the buccal cavern. McLay(1991)provided a detailed comparison between S. nux and Sphaerodromia ducoussoi McLay, 1991, and supplemented with a table comparing the diagnostic morphological characters of all Sphaerodromia species. Crosnier (1994) commented that S. nux possessed well-developed podobranchs on the cheliped and pereopod 2, and vestigial bud-like podobranchs on pereopod 3. McLay (2001) amended Lewinsohn’s redescription and added morphological details of female specimens from the Philippines. A systematic revision of the family Dromiidae by Guinot and Tavares (2003) included illustrations of the vestigial male pleopods, P5 coxa and G2.
The present specimen agrees with the updated description by McLay (2001), except for the presence of lines of compressed granules on the P2–P3 meri (Fig. 4F–G) and a relatively higher dactylus length/ propodus length of 0.90 for P2–P3. The present observation is a new record in Indian waters.
Distribution. Gulf of Martaban at 129 m depth (Alcock, 1900a; 1901), Madagascar (Guinot and Tavares, 2003), and Andaman Sea, India at 290 m depth (present study).
description: Published as part of Padate Sherine Sonia Cubelio Masatsune Takeda, Vinay P., 2021, Rare deep-water crabs (Crustacea: Decapoda) from Indian waters, with description of one new species, pp. 1-21 in Nauplius (e 2021034) (e 2021034) 29 on page 6, DOI: 10.1590/2358-2936e2021034, http://zenodo.org/record/14668449