Vellumnus pygmaeus ( Takeda, 1977 )

Shaga, I Bevin, Priya, K, Ramar, Selvakumar, Srinidhi, S, Mohan, G Chandra, Ranganathan, Sukanya, Moulvi, S M M & Mani, Bhuvaneswari, 2023, A Small Collection of Subtidal Crabs (Crustacea: Decapoda: Brachyura) from the Palau Islands Collected by Dredging, Bulletin of the National Museum of Nature and Science. Series A, Zoology 49 (1), pp. 7-42 : 30-32

publication ID	https://doi.org/10.50826/bnmnszool.49.1_7
DOI	https://doi.org/10.5281/zenodo.13826529
persistent identifier	https://treatment.plazi.org/id/1B153E3A-FF92-FFA2-F02D-CDC45E5EFA12
treatment provided by	Felipe (2024-06-17 17:09:32, last updated 2024-11-25 18:32:22)
scientific name	Vellumnus pygmaeus ( Takeda, 1977 )
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Vellumnus pygmaeus ( Takeda, 1977) View in CoL

( Fig. 9D View Fig )

Planopilumnus pygmaeus Takeda, 1977, p. 131 , fig.

5A–C, pl. 6 figs. C–D.

Vellumnus pygmaeus (Takeda) : Takeda and Komatsu, 2018, p.181, fig. 6G.

Material examined. Inside of Gesodokkuru Reef , off Arumonogui, Babelthuap I., Palau Is., dredged, ca. 20 m in depth; 1♂(cb 5.7×cl 4.5 mm), NSMT-Cr 30994; July 13, 1980; K. Baba leg.

Remarks. Ng (2010) referred three Pilumnus species ( P. vermiculatus A. Milne-Edwards, 1873 , P. labyrinthicus Miers, 1884 and P. penicillatus Gordon, 1930 ) and two Planopilumnus species ( P. minabensis Sakai, 1969 and P. pygmaeus Takeda, 1977 ) to his new genus Vellumnus . All the species have typical Pilumnus - type characters, but are distinctive in having the clearly-patterned symmetrical areolets or labyrinth-like pattern of setae on the carapace. Of five known species, V. labyrinthicus , V. penicillatus and V. pygmaeus are generally close to each other in having the labyrinth-like pattern of setae, but their patterns are distinctly different from each other: Miers (1884) and Ng (2010) for V. labyrinthicus ; Gordon (1931) for V. penicillatus ; Takeda (1977) and Takeda and Komatsu (2018) for V. pygmaeus . The specimen at hand agrees well with V. pygmaeus , especially in having the heartshaped protogastric region, although the epigastric regions of both sides are distinctly isolated by a median longitudinal groove from the median incision of the front.

Distribution. Vellumnus pygmaeus is known from the Ogasawara Islands, 41–105.6 m in depth, and now from the Palau Islands, ca. 20 m in depth, as new to Micronesian waters.

References

Gordon, I. 1930. Seven new species of Brachyura from the coasts of China. Annals and Magazine of Natural History, including Zoology, Botany, and Geology, (10) 6: 519 - 525.

Gordon, I. 1931. Brachyura from the coasts of China. The Journal of the Linnean Society, London, (Zoology) 37: 525 - 558.

Miers, E. J. 1884. Crustacea. In: Report on the Zoological Collections made in the Indo-Pacific Ocean during the Voyage of H. M. S. bAlert` 1881 - 2. Part I. The collections from Melanesia, pp. 178 - 322, pls. 18 - 35. Part II. Collections from the western Indian Ocean, pp. 513 - 575, pls. 46 - 52.

Sakai, T. 1969. Two new genera and twenty-two new species of crabs from Japan. Proceedings of the Biological Society of Washington 82: 243 - 280.

Takeda, M. 1977. Crabs of the Ogasawara Islands, V. A collection made by dredging. Memoirs of the National Science Museum, Tokyo 10: 113 - 140, pls. 12 - 17.

Takeda, M. and H. Komatsu 2018. Offshore crabs of the family Xanthidae and some related families (Crustacea, Decapoda, Brachyura) from the Ogasawara Islands, Japan. Memoirs of the National Museum of Nature and Science, Tokyo 52: 153 - 189.

Figures

Fig. 9. A: Gaillardiellus rueppellii (Krauss), ♂ (NSMT-Cr 30985; cb 8.8×cl 6.6mm). B: Metaxanthops acutus Serène, ♂ (NSMT-Cr 30987; cb 6.8×cl 5.5mm). C: Lophoplax sextuberculata Takeda and Kurata, ovig.♀ (NSMT-Cr 30992; cb 5.2×cl 4.0mm). D: Vellumnus pygmaeus (Takeda), ♂ (NSMT-Cr 30994; cb 5.7×cl 4.5mm). E: Chlorodiella corallicola Miyake and Takeda, ovig.♀ (NSMT-Cr 30980; cb 4.8×cl 3.2mm). F: Chlorodiella xishaensis Chen and Lan, ♂ (NSMT-Cr 30983; cb 8.0×cl 5.7mm).