Ericthonius pugnax (Dana, 1853)

Azman, B. A. R. & Othman, B. H. R., 2013, Shallow water marine gammaridean amphipods of Pulau Tioman, Malaysia, with the description of a new species, ZooKeys 335, pp. 1-31 : 9

Ericthonius pugnax (Dana, 1853) Figure 6

Pyctilus macrodactylus Synonymy: Dana, 1853: 974.

Ericthonius macrodactylus Stebbing, 1906: 672; Walker 1904: 292, fig. 48.

Ericthonius pugnax Stebbing, 1906: 672; Pirlot 1938: 352; Hurley 1954: 445, figs 40-61; Nagata 1960: 179, pl. 179, figs 99-102; Nagata 1965b: 320, fig. 40; Nayar 1967:162; Ledoyer 1969: 179, fig. 1; Hirayama 1985: 52, Ledoyer 1982a: 628, fig. 239; Moore 1988: 727-730, fig. 14; Kim and Kim 1991: 246-247, figs 13-14.

Material.

2 specimens, TIO 5, Monkey Bay, Pulau Tioman, 2 2°49'33"N, 104°9'45"E, coral rubble, Azman, Josim, 22 August 1996; 86 specimens, TIO 15, Renggis, Pulau Tioman, 2°48'35"N, 104°8'6"E, seagrass, Azman, Rayida, 15 July 1999, UKM I.D. 5712-5719; 2 specimens, TIO 33, Tomok, Pulau Tioman, 2°47'38"N, 104°7'16"E, live corals ( Porites sp., Montipora sp., Acropora sp.), Azman, B.A.R, Kee, A.A., Zuhaimi, S., Maekawa, T., Okashita, T., 22 March 2004.

Remarks.

The Pulau Tioman specimens agree well with figures of Ericthonius pugnax from Walker (1904), Nagata (1960, 1965c), Ledoyer (1982c) and Moore (1988). This species seems to have a wide-ranging distribution as far as the Arabian Sea. From closer examination of the specimens, the males not only have distally bidentate carpal spur of gnathopod 2 but also a mixture of single dentate carpal spur (see also Nagata 1960; Ledoyer 1969, 1986). As mentioned by Moore (1988) the carpal bidentate spur of ganthopod 2 will eventually be lost in hyperadult males. Unfortunately the stipulation over hyper adult morphological changes has brought several descriptions of new species that actually represented a single species (i.e Ericthonius macrodactylus ). Prior to this, Ledoyer (1969) synonymized Ericthonius macrodactylus as a hyperadult form of Ericthonius pugnax . Examination of the Pulau Tioman specimens confirms the presence of this hyper adult morphology: that the basis of pereopod 5 possesses a strongly developed posterodistal lobe. The Pulau Tioman specimens are undoubtedly assigned to Ericthonius pugnax and constitute the first record of this species for Peninsular Malaysia.