Polyonyx obesulus Miers, 1884, Miers, 1884

Osawa, Masayuki, 2007, Porcellanidae (Crustacea: Decapoda: Anomura) from New Caledonia and the Loyalty Islands, Zootaxa 1548, pp. 1-49: 36

publication ID

http://doi.org/ 10.5281/zenodo.178040

publication LSID

lsid:zoobank.org:pub:49DAF7AD-8803-4D20-82AC-6A1576DECCFE

persistent identifier

http://treatment.plazi.org/id/03809477-FFAD-BF31-ACF1-EF8D4F959CA8

treatment provided by

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scientific name

Polyonyx obesulus Miers, 1884
status

 

Polyonyx obesulus Miers, 1884  

( Fig. 11 View FIGURE 11 )

Porcellana obesula White, 1847   , 130 (nomen nudum).

Polyonyx obesulus Miers, 1884: 272   , pl. 29, fig. D (type locality: Madgica-Sima (=Sakishima) Islands, Ryukyu Islands). — Johnson, 1958: 108, fig, 4.— Haig, 1964: 378; 1966 c: 61; 1979: 132, fig. 20–22; 1992; 321, fig. 17.— Yang & Xu, 1994: 117, fig. 4.

Porcellana   ( Polyonyx   ) sp.—de Man, 1888: 424, pl. 19, fig. 1.

Porcellana (Polyonyx) tuberculosa   de Man, 1888: 424 (type locality: Amboina, Moluccas, Indonesia).

Polyonyx parvidens Nobili, 1905: 161   (type locality: Persian Gulf).

Polyonyx paucidens Nobili, 1906: 70   , pl. 5, fig. 16.

Material examined. Loyalty Islands. Lifou Island. Santal Bay. Atelier LIFOU. St. 1466 (St. 45), Hunete Bay, 20 ° 46.5 ’S, 167 °06.2’E, 25–45 m, 17 Nov. 2000, 1 male CL 2.6 mm. St. 1457 (St. 67), Ngoni, 20 ° 46.8 ’S, 167 °02.75’E, 5–10 m, 27 Nov. 2000, 1 male CL 2.6 mm.

Remarks. The type locality of Porcellana obesula White, 1847   (nomen nudum) is Madgica-Sima (=Sakishima) Islands, Ryukyu Islands.

Polyonyx obesulus   resembles P. biunguiculatus   but differs in having a less developed, broad median lobe of the rostrum ( Fig. 11 View FIGURE 11 B; narrow median lobe in P. biunguiculatus   , Fig. 9 View FIGURE 9 B) and dactyli of the ambulatory legs, each armed with a single corneous spine on the flexor margin ( Fig. 11 View FIGURE 11 E, F; two spines in P. biunguiculatus   , Fig. 9 View FIGURE 9 F –H).

The specimens examined have a proportionally longer carpus of the larger cheliped ( Fig. 11 View FIGURE 11 C), which differs from the original illustrations by Miers (1884, pl. 29, fig. D, d’) as well as figures by Johnson (1958, fig, 4 A) and Haig (1979, fig. 20). The male specimens examined also possess low protuberances on the dorsoextensor surface of smaller chela ( Fig. 11 View FIGURE 11 D) and a pair of gonopods. These characters agree with a specimen of P. obesulus   from the Nansha Islands reported by Yang & Xu (1994: 117, fig. 4 A, C). The elongate carpus of the larger cheliped is also illustrated in the Hong Kong material by Haig (1992: fig. 17 B). The specimens of the Loyalty Islands are tentatively referred to P. obesulus   until the type material and other specimens can be examined.

As pointed out by Johnson (1958: 96, 112), Polyonyx paucidens Nobili, 1906   is a lapsus calami for P. parvidens Nobili, 1905   . The holotype in the Muséum national d’Histoire naturelle, Paris, is labeled “ Polyonyx paucidens   ” (see Haig 1966 c). Haig (1966 c) concluded that the juvenile female holotype is referred to P. obesulu   s because the characters by which Nobili (1906) distinguished P. paucidens   from P. obesulu   s, including presence of spinules on the flexor margins of the merus and carpus of the chelipeds, are sometimes found in young P. obesulus   specimens (see Haig 1964).

Distribution. Indonesia, then westward through Malay Archipelago to Persian Gulf, south to tropical Australia, and northeast to Sakishima Islands; littoral to about 55 m, frequently in sponges and crevices of corals ( Haig 1979, 1992). The specimens examined were collected at depths of 5–45 m in the Loyalty Islands.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Decapoda

Family

Porcellanidae

Genus

Polyonyx

Loc

Polyonyx obesulus Miers, 1884

Osawa, Masayuki 2007
2007
Loc

Polyonyx paucidens

Nobili 1906: 70
1906
Loc

Polyonyx parvidens

Nobili 1905: 161
1905
Loc

Porcellana

Man 1888: 424
1888
Loc

Porcellana (Polyonyx) tuberculosa

Man 1888: 424
1888
Loc

Polyonyx obesulus

Yang 1994: 117
Haig 1964: 378
Johnson 1958: 108
Miers 1884: 272
1884