Gordonodius zelleri ( Berge, Vader and Coleman,

Kim, Young-Hyo & Heo, Jun-Haeng, 2016, Four new records of the gammarids (Crustacea, Amphipoda) from Korean waters, Journal of Species Research 5 (3), pp. 498-502 : 6

4. Gordonodius zelleri ( Berge, Vader and Coleman,

1999) ẖ"ÜặăNjẹ (ṳAE) ( Fig. 4 ) Postodius zelleri Berge, Vader and Coleman, 1999: 246 ,

figs. 3-7. Gordonodius zelleri : Ariyama, 2011: 27, figs. 17- 20, 21E.

Material examined. 1 female (NIBRIV0000597283), Korea, Jeollanam­do, Yeosu­si, Samsan­myeon , Geomundo Is., 31 May 2014, by light trap, collected by SS Hong and SH Kim.

Diagnosis. Body medium sized, about 5.3 mm, somewhat stout; rostrum well developed. Cephalic lobe subrounded. Eye large, reniform. Maxillipedal palp triarticulate. Antenna 1 short and stout; accessory flagellum present, slender, uniarticulate in male, vestigial in female. Antenna 2 shorter than antenna 1. Pereonite 1, anterodorsal corner produced forward. Pereonites 5­7 and pleonites 1­3 with distinct dorsal projections. Pleonite 3 without projection posterolaterally. Urosomites smooth, without dorsal projections. Gnathopod 1 simple, slen­ der. Gnathopod 2 subchelate, larger than gnathopod 1; palm transverse, serrulate; dactylus fitting palm, with small nail. Pereopod 7, basis relatively broad, posterodistal lobe roundly expanded ventrally; merus overhanging and tapering posterodistally, nearly reaching end of carpus. Uropod 1 longer than uropod 2. Uropod 3 biramous, outer ramus about 0.5 × inner ramus. Telson entire, narrowing distally.

Distribution. Japan, Korea.

Remarks. The monotypic genus Gordonodius Ariyama, 2011 is characterized by the presence of dorsal distinct projections and accessory flagellum in male and presently only one species, G. zelleri , has been reported from Japan. Our female specimen is accorded with Ariyama (2011) ’s description, however, Korean specimen also display some important differences, such as the longer and slenderer peduncular articles 1­3 of antenna 1, coxa 1 more acute distally, and variation in color pattern. However, as we have not had the opportunity to examine the Japanese material of Ariyama (2011), we cannot confi­ dently determine whether our species is novel. Therefore at this time we conservatively maintain our Korean specimens as G. zelleri until a detailed, comparative study can be made on the Japanese material.

Figures

Fig. 4. Gordonodius zelleri(Berge, Vader and Coleman, 1999), female:A, habitus, lateral view; B, pereonites and pleonites. Scale bars=0.5 mm (A, B).