Gnathia bungoensis Nunomura, 1982

Ota, Yuzo, 2013, Redescription of five gnathiid species from Japan (Crustacea: Isopoda), Zootaxa 3737 (1), pp. 33-56 : 54-55

Gnathia bungoensis Nunomura, 1982

(Japanese name: Bungo-umi-kuwagata) ( Fig. 12 )

Gnathia bungoensis Nunomura, 1982: 17 –21, figs. 1, 2.—Cohen & Poore 1994: 288.—Nunomura, 1995: 208, fig. 21-196C.— Saito et al. 2000: 17. Nunomura 2012b: 80.—Nunomura & Shimomura 2013a: 142, 143.—Nunomura & Shimomura 2013b: 291, 292, fig. 131.

Material examined. Male adult, holotype, TOYA Cr-1455, 3.5 mm, from the estuary of Bansho River, Oita Pref., eastern coast of Kyusyu, southern Japan (32°58′N, 131°55′E), 14 Sep. 1981, coll. Michio Ohtani.

Redescription ( Fig. 12 ). Antennule ( Fig. 12 A) composed with 3 peduncle and 5 flagellar articles. One and 3 feather-like bristles on distal margins of peduncle article I and III, respectively. One feather-like bristle on flagellar article I. One aesthetasc on flagellar article III, IV, and V, respectively. Flagellar article V terminating in 3 setae.

Antenna ( Fig. 12 B) composed with 4 peduncle and 6 flagellar articles. Two and 4 feather-like bristles on peduncle III and IV, respectively. 1–4 setae on distal margins of flagellar articles I–V. Article VI terminates in 4 setae.

Pylopod ( Fig. 12 C) 3-articled. Article I semicircular with 3 areolae, 31 plumose setae on internal margin, 1 seta on external margin, 7 setae on distal margin. Article II elliptical with 4 setae. Article III minute.

Pereopod ( Fig. 12 D) sparsely covered with small setae on inner margin. Basis oblong with 1 feather-like bristle. Ischium shorter than basis, becoming larger distally. Merus with 1 projection on outer margin. Carpus with 1 projection on inner margin. Propodus rectangular, bearing 2 denticulate compound spines on inner-mid and innerdistal margins. Dactylus terminating in unguis.

Remarks. Gnathia bungoensis was originally described by Nunomura (1982) based on one male specimen. Unfortunately, most of the parts of the G. bungoensis holotype have been lost. Thus, only the antennule, antenna, pylopod, and pereopod could be redescribed. In Gnathia species, there are seven flagellar articles in the antenna, whereas G. bungoensis had six. However, this characteristic is insufficient to distinguish it from other Gnathia species. In fact, Gnathia cooki Müller, 1989 b, G. lignophila Müller, 1993 , and G. coralmaris Svavarsson & Bruce, 2012 have six flagellar articles in their antennae (Müller 1989b; Müller 1993; Svavarsson & Bruce 2012). New materials from the type locality will be necessary for an adequate redescription.

Figures

FIGURE 12. Gnathia bungoensis Nunomura, 1982 holotype (TOYA Cr- 1455): A, right or left antennule; B, right or left antenna; C, left pylopod, ventral view; D, pereopod, lateral view (left and right, where the appendage number was unknown).