Elaphognathia sugashimaensis ( Nunomura, 1981 )

Song, Ji-Hun & Min, Gi-Sik, 2016, New record of two cymothoid isopods (Crustacea: Malacostraca: Isopoda) from South Korea, Journal of Species Research 5 (3), pp. 313-317 : 314-315

1. Elaphognathia sugashimaensis ( Nunomura, 1981)

ĿṻṄŔ²ṚHNǖụḇNj (ṵAE) ( Fig. 1 )

Synonyms. Gnathia sugashimaensis Nunomura, 1981: 19 , figs. 1, 2; Muller, 1989: 25, figs. 1-4.

Elaphognathia sugashimaensis : Svavarsson and Gísladóttir, 2002: 161.

Material examined. Korea: 2♂♂, Ganggu harbor, Yeongdeok­gun , Gyeongsangbuk­do, 36°21′N, 129°23′E, August 27, 2014, depth 3­5 m, collected using light traps by Song J.­H .

Diagnosis. Body ( Fig. 1A, B ) flattened, about 3.5 mm, almost 3.3 times as long as wide. Cephalon ( Fig. 1A, B ) 1.5 times as wide as long, dorsally with depressions, medially excavated, with two frontal process bearing 4 short setae distally. Eyes ( Fig. 1A ) with dark pigment, ommatidia small. Mandible ( Fig. 1C ) with triangular projection with one seta. Maxilliped ( Fig. 1D ) comprise five segments with plumose setae on lateral margin. Pylopod ( Fig. 1E ) comprise three segments, distal article minute. Pereonite 1 immersed in cephalon; pereonites 2, 3 in similar length; pereonite 4 smaller than other pereonites; pereonite 7 longest ( Fig. 1A, B ). Telson ( Fig. 1A, B ) triangular, length as long as width.

Remarks. Elaphognathia sugashimaensis was described by Nunomura (1981) based on the specimens collected from the Sugashima, Ise Bay, Japan. This species was redescribed by Muller (1989), who provided a more detailed morphological description of the cephalon, and the species has been previously reported from Japan only. Elaphognathia sugashimaensis is similar to E. lucanoides (Monod, 1926) in external features. Howev­ er, E. sugashimaensis differs from E. lucanoides in having a less excavated cephalon and more robust mandible ( Muller, 1989). This species is also similar to E. discolor . However, E. sugashimaensis differs from E. discolor in having 3­articled pylopod (2­articled pylopod in E.

discolor). In general, the illustrations and descriptions of E. sugashimaensis specimens from South Korea agreed well with the illustrations and original description of Nunomura (1981) and redescription of Muller (1989).

Habitat. This species was found on the surface of an ascidian, Pyura sacciformis , at the type locality. The specimens were collected from the sandy bottom with seaweeds at a depth of 3­5 m.

World distribution. Japan ( Nunomura, 1981; Muller, 1989), Korea.

Deposition. NIBR No. NIBRIV0000437276 (1 male) .

Molecular characteristic. GenBank accession number: KX078775 (1 male).

Identifiers. Ji­Hun Song, Gi­Sik Min.

Figures

Fig. 1. Elaphognathia sugashimaensis, male. A, body, dorsal view; B, body, dorsal view, drawing; C, mandible; D, maxilliped; E, pylopod and enlargement of distal article. Scale bars: A, B=1 mm, C­E=0.1 mm.