Halicarcinus planatus ( Fabricius, 1775 )

Poore, Gary C. B., Guinot, Danièle, Komai, Tomoyuki & Naruse, Tohru, 2016, Reappraisal of species attributed to Halicarcinus White, 1846 (Crustacea: Decapoda: Brachyura: Hymenosomatidae) with diagnosis of four new genera and one new species from New Ireland, Papua New Guinea, Zootaxa 4093 (4), pp. 480-514 : 488-489

Halicarcinus planatus ( Fabricius, 1775)

( Figs 1 d, 2)

Cancer planatus Fabricius, 1775: 403 .

Hymenosoma Leachii Guérin, 1832 , in Guérin-Méneville 1829–1837: 10, pl. 10 fig. 1 (see Low et al. 2013 for citation).

Hymonosema [sic] leachii— Guérin 1838: 22–23.

Halicarcinus planatus— White 1847: 33 –34. — Melrose 1975: 34 –39, figs 12, 13 (for extensive synonymy). — Gorny 1999: 372– 379 (distribution). — Diez & Loverich 2009: 389–401 (reproduction). — Poore 2004: 394, fig. 121d. — Webber 2010: 181, 226. — Aronson et al. 2015: 2 –4, fig. 2 (distribution).

Halicarcinus pubescens Dana, 1851: 253 .

Elamene [sic] mexicana H. Milne Edwards, 1853: 224 .

Elamena mexicana— Tavares & Santana 2015: 103, fig. 3B.

Halicarcinus patagoniensis Melrose, 1975 (unnecessary replacement name for Halicarcinus pubescens Dana, 1851 ).

Material examined. Lectotype of Hymenosoma leachii Guérin, 1832 , in Guérin-Méneville 1829–1837, herein selected. Côtes de Nouvelle-Hollande (southern Australia), MNHN IU-2000-647 (B647), (male, 10 mm, dry).

Holotype of Elamena mexicana H. Milne Edwards, 1853 . ‘ Côtes du Mexique ’ (see remarks below). MNHN IU-2000-655 (B655), (male, 7.3 mm, dry).

Other material. Kerguelen I., NMV J8080 (male, 10. 6 mm); MNHN IU-2014-0000 (B25953), (1 male, 17.0 mm; 1 ovigerous female, 15.0 mm).

Australia. Macquarie I., NMV J7543 (1 ovigerous female, 12.0 mm).

New Zealand, Campbell I., AM P.36830 (1 male, 20 mm; 1 ovigerous female, 20 mm) selected from numerous specimens at NMV and AM; MNHN IU-2014-0000 (B25960), (1 male, 15.0 mm, several males and females).

Distribution. Widespread throughout the subantarctic islands, southern New Zealand and South America (Gorny 1999), Deception I., South Shetland Is ( Aronson et al. 2015). The only Australian occurrence is at subantarctic Macquarie I.

Remarks. In her discussion of the homonymy of Halicarcinus pubescens Dana, 1851 , from Patagonia ( Argentina) with Hymenicus pubescens Dana, 1851 , from New Zealand that she placed together in Halicarcinus, Melrose (1975: 253, 254) proposed the replacement name Halicarcinus patagoniensis Melrose, 1975 , for the former. Halicarcinus pubescens Dana, 1851 , is now considered a junior synonym of H. planatus and Hymenicus pubescens Dana, 1851 , is now Neohymenicus pubescens ( Dana, 1851) following Lucas’s (1980) revision.

Melrose (1975: 34) included Hymenosoma leachii Guérin, 1832 , as a questionable synonym of Halicarcinus planatus . Having looked at a type specimen we can confirm this but doubt that the type locality ‘ les côtes de la Nouvelle-Hollande ’ (southern Australia) recorded by Guérin (1838) is correct; the species has not otherwise been recorded from southern Australia. Tavares & Santana (2015) proposed Elamena mexicana H. Milne Edwards, 1853 , as a synonym of Halicarcinus planatus . We agree with this and with their conclusion that the most likely type locality for this taxon is not Mexico but Peru or Chile. It clearly has a similar rostrum and preocular pseudorostral lobes, which are demarcated from the carapace by a distinct hymenosomian groove, and relatively wide maxillipeds 3 that cover almost the entire buccal cavern.

a1

a2

a b c

Figures

FIGURE 1. Halicarcinus cookii (Filhol, 1885): a – c, lectotype of Hymenicus cookii Filhol, 1885, MNHN IU- 2014 - 7143 (B 32572), (female, 6.1 mm). Halicarcinus planatus (Fabricius, 1775): d, holotype of Elamena mexicana (H. Milne Edwards, 1853), MNHN IU- 2000 - 655 (B 655), (male, 7.3 mm). Halicarcinus quoyi (H. Milne Edwards, 1853): e, lectotype of Elamena quoyi H. Milne Edwards, 1853, MNHN- 2000 - 667 (B 667), (male without rostrum, 6.4 mm); f, paralectotype, MNHN- 2000 - 32609 (B 32609), (sex unknown, dry fragments).