Heteropilumnus decharmoyi ( Bouvier, 1915 )

Ng, Peter K. L., Lin, Chia-Wei & Ho, Ping-Ho, 2018, Psammoecus hiranoi Yoshida and Hirowatari 2013, Zoological Studies 57 (12), pp. 1-17 : 3

publication ID	https://doi.org/ 10.6620/ZS.2018.57-12
persistent identifier	https://treatment.plazi.org/id/039C87E6-2F10-115A-FF12-71C541C4FB33
treatment provided by	Felipe
scientific name	Heteropilumnus decharmoyi ( Bouvier, 1915 )
status

Treatment

Heteropilumnus decharmoyi ( Bouvier, 1915) View in CoL

( Figs. 1 View Fig A-C, 2-4)

Litochira de Charmoyi Bouvier, 1915: 298 , text-fig. 35, pl. 5 fig. 8,

pl. 6 fig. 9. Litocheira View in CoL de charmoyi - Tesch 1918: 165. Heteropilumnus de View in CoL charmoyi - Balss 1933: 44. Pseudolitochira View in CoL de charmoyi - Ward 1942: 52. Heteropilumnus decharmoyi View in CoL - Serène 1968: 85. Pseudolitochira decharmoyi View in CoL - Ng 1987: 79; Ng et al. 2008: 144;

Maenosono 2016: 39, figs. 1-3.

Material examined: Taiwan: 1 male (16.8 × 12.7 mm) ( NMNST), intertidal area, under rock in sand substrate, Lutao (= Green Island), Taiwan, coll. H.-D. Huang and H.- T. Hong, 30 March 2008; 1 male (13.3 × 9.3 mm) ( NMMBCD 4084), 1 female (8.6 × 5.9 mm) ( ZRC 2017.1042), under rocks, muddy substrate, northeastern cape, Taiwan, by SCUBA, coll. C.-W. Lin, 18 July 2014. Vanuatu: 1 male (14.5 × 10.3 mm) ( ZRC 2017.189), station VM53, intertidal reefs with soft and hard bottoms, east of Luganville Segond Channel, 15°31'S 167°11.9'E, Vanuatu, coll. Expédition SANTO 2006, 6 October 2006.

Colour: The colour is striking and agrees very well with what was described by Bouvier (1915) and Maenosono (2016). The red colour on the branchial, cardiac and intestinal regions varies slightly in coverage and intensity of colour. In the male from Vanuatu, these areas are brighter red and covers more of the carapace ( Fig. 1C View Fig ) compared to the Taiwanese ones ( Figs. 1A, B View Fig ).

Remarks: Maenosono (2016: 44) suggested that Heteropilumnus splendidus ( De Man, 1929) , may be a synonym of H. decharmoyi . De Man (1929: 10, pl. 1 fig. 3-3c, pl. 2 fig. 3d-f) described the species from two males (10.0 × 7.3 mm, 9.0 × 6.5 mm) and a female (9.4 × 6.5 mm) from Pulau Berhala in the Straits of Malacca and the general appearance and colour notes suggests that the two taxa are close. However, there are several differences that argue against synonymising the two species at this stage: in H. splendidus , the dorsal surface of the carapace is distinctly flatter in frontal view (cf. De Man 1929: pl. 1 fig. 3c) (vs. gently convex and higher dorsal surface of carapace in H. decharmoyi , Fig. 2E View Fig ); the anterolateral margin is not distinctly cut into any low teeth or lobes (cf. De Man, 1929: pl. 1 fig. 3, 3a) (vs. margin forming low teeth in H. decharmoyi , Fig. 2 View Fig A-D); and the male pleon is differently structured, with somite 3 proportionately less wide and the telson more semicircular in shape (cf. De Man 1929: pl. 2 fig. 3d) (vs. somite 3 distinctly wider with the telson more elongate in H. decharmoyi , Fig. 3B View Fig ).

Heteropilumnus decharmoyi is also superficially similar to H. satriai in external morphology and colour in life, and both species occur together in Taiwan. H. decharmoyi ; however, can easily be separated because its long setae lining the carapace and pereopods are stiff and translucent ( Figs. 1 View Fig A-C, 2A) (vs. setae are more flexible and opaque in H. satriai , Figs. 1 View Fig D-F, 6A, C); the posterolateral margins are less convergent towards the posterior carapace margin, giving the carapace a more rectangular appearance ( Figs. 2 View Fig A-D) (vs. posterolateral margins sharply converging towards posterior carapace margin, with the carapace appearing more hexagonal in H. satriai , Figs. 5A, B View Fig , 6 View Fig A-D); the ambulatory meri is proportionately shorter and stouter ( Figs. 3 View Fig E-G) (vs. meri are proportionately longer and more slender in H. satriai , Figs. 5G View Fig , 6E, F View Fig ); the median lobe of the posterior epistomal margin is approximately level with the lateral margins ( Fig. 2E View Fig ) (vs. the median lobe protrudes anteriorly of the lateral margins in H. satriai , Figs. 5C View Fig , 7A View Fig , 8A View Fig ); the ischium of the third maxilliped is relatively short ( Fig. 2F View Fig ) (vs. ischium is proportionately longer in H. satriai , Figs. 5D View Fig , 7B View Fig , 8B View Fig ); the adult male chelae are not swollen, but relatively slender ( Figs. 3C, D View Fig ) (vs. adult male chelae distinctly inflated and stout in H. satriai , Figs. 5E View Fig , 7E View Fig , 8E, F View Fig ); the male pleon is relatively wider ( Fig. 3B View Fig ) (vs. male pleon relatively narrower in H. satriai , Figs. 7D View Fig , 8D View Fig ); and the G1 is distinctly more sinuous, with the distal part relatively short and bent at around 45° from the horizontal ( Figs. 4 View Fig A-C) (vs. G1 relatively less sinuous with the distal part long and bent at almost 90° to the horizontal in H. satriai , Figs. 9 View Fig A-C, E-G).

Distribution and ecology: The species was described from Mauritius ( Bouvier 1915) but has been reported from Japan ( Maenosono 2016), and now from Taiwan and Vanuatu.