Naushonia japonica Komai, 2004

Komai, Tomoyuki & Anker, Arthur, 2015, Additional records of the laomediid mud-shrimp genus Naushonia Kingsley, 1897 (Crustacea: Decapoda: Gebiidea), with a revised identification key, Zootaxa 3974 (3), pp. 341-360 : 346

Naushonia japonica Komai, 2004

Fig. 1 B

Naushonia japonica Komai 2004: 17 , figs. 1A, 2–4 (type locality: Yoshimi Beach, Shimonoseki, Yamaguchi Prefecture, Japan).

Material examined. Japan: 1 female (pocl 5.3 mm), Chiba Prefecture, Katsuura, Ubara, scuba diving, 5 m, sand, under rock, coll. S. Komai and N. Nakamura, 30 September 2013, CBM-ZC 12594.

Description. See Komai (2004).

Colouration in life. Body and appendages whitish; cornea dark grey ( Fig. 1 B).

Distribution. Northwestern Pacific: Japan (Yamaguchi, Chiba and possibly Mie Prefectures).

Habitat. Shallow subtidal sand flats, 5– 7 m.

Remarks. Naushonia japonica is presently known only from Japan. This species was originally described on the basis of a single adult male specimen from Yoshimi, Yamaguchi Prefecture, although prior to the collection of the holotype, Konishi (2001) reported larvae of an unidentified species of Naushonia from Gokasyo Bay, Mie Prefecture, which possibly also represent N. japonica (see Komai 2004). The herein reported female specimen from Chiba Prefecture agrees well with the male holotype, except for some sexual characters and the possession of minute denticles on the lateral margins of the telson (three on the left side and two on the right side); no such denticles are present in the holotype. The first pair of pleopods of the female is uniramous and the articulation between the protopod and ramus is obsolete.

Among the species characterized by the non-carinate pleomeres and rounded, unarmed pleura, N. japonica is most similar to the western Atlantic N. crangonoides , for instance, sharing the presence of numerous (10 or more) teeth on the lateral margin of the antennal scaphocerite. However, N. japonica may be readily distinguished from N. crangonoides by the cheliped dactylus distinctly broadened proximally to mid-length vs. not particularly broadened in N. crangonoides , as well as by the better-defined gastric carinae (cf. Thompson 1903; Goy & Provenzano 1979; Williams 1984).

Komai (2004) did not fully examine the gill formula of the holotype of N. japonica , in order not to damage the holotype, the only specimen available at that time. The more detailed examination of the present specimen revealed that N. japonica has a gill formula typical for the genus, as summarized in Table 1. The arthrobranch associated with the first maxilliped is well developed and has multiple lamellae.

Figures

FIGURE 1. A, Naushonia carinata Dworschak, Marin & Anker, 2006, female (pocl 7.1 mm) from Iriomote, Japan, RUMF-ZC 3677, living individual, dorsal view; B, Naushonia japonica Komai, 2004, female (pocl 5.3 mm) from Katsuura, Japan, CBM- ZC 12594, living individual, dorsal view.