Presently, the family Upogebiidae Borradaile, 1903 includes 179 species of 13 genera worldwide, however, only two species of the genus Upogebia (Leach, 1814) have been recorded from Korean waters, Upogebia major (De Haan, 1839) and Upogebia issaeffi (Balss, 1913) (see Kim, 1973; Hong and Lee, 2014). The genus Austinogebia (Ngoc-Ho, 2001) was established by the following characters: 1) the armature of the rostral spines, 2) the morphology of the gastric ridges, 3) the morphology of the pereiopods 3 and 4, and 4) the proximal knob on the lateral margin of the uropodal endopod. However, most of characters are shared by the genus Gebiacantha and the first and last characters can be seen in the genus Upogebia (see Sakai, 2006). So, this genus can not be clearly separated from the Upogebia. As the status of it has been subject of disagreement until now, the present study adopts a classification of Poore (2014) in the World Register of Marine Species. The genus Austinogebia (Ngoc-Ho, 2001) comprises six species, A. edulis (Ngoc-Ho and Chan, 1992), A. monospina (Liu and Liu, 2012), A. narutensis (Sakai, 1986), A. spinifrons (Haswell, 1882), A. takaoensis (Sakai and Türkay, 1995), and A. wuhsienweni (Yu, 1931) (see Poore, 2014). Among them, A. wuhsienweni has been found in Vietnam, Taiwan, China, and Japan (Sakai, 2006). Recently, a species of mud shrimps collected from Sanghwang-ri, Hongsong-gun was identified as A. wuhsienweni. It is new to Korean upogebiid fauna and the only species of the genus in the region. Therefore, it is briefly described and illustrated in the present study.

Carapace length and total length are abbreviated as “CL” and “TL”, which are used as an indication of the size of the specimen. CL is measured from the tip of the rostrum to the posterior border of the carapace, while TL is measured from the tip of the rostrum to the posterior border of the telson. All specimens were preserved in 95% ethanol. Materials examined in this study are deposited at the Tidal Flat Research Institute, National Fisheries Research and Development Institute.

Order Decapoda Latreille, 1803 Family Upogebiidae Borradaile, 1903 1*Genus Austinogebia Ngoc-Ho, 2001

2*Austinogebia wuhsienweni (Yu, 1931)

Upogebia Wuhsienweni Yu, 1931: 89, fig. 2 (type locality: Jiaozhou bay, China).

Upogebia wuhsienweni: Liu, 1955: 68, Pl. 24, figs. 7-12; Holthuis, 1991: 238, fig. 439; Ngoc-Ho and Chan, 1992: 38, fig. 4; Sakai, 1993: 92, figs. 1-2; Ngoc-Ho, 1994: 202, fig. 5E-H.

Upogebia (Upogebia) wuhsienweni: Sakai, 1982: 59 (in part, not figs. 11d, 12f-g, 13g-h, Pls. G1-2, and samples USNM 59070, 59071, 59072, 59073) [=A. edulis (Ngoc-Ho and Chan, 1992)].

Austinogebia wuhsienweni: Ngoc-Ho, 2001: 53, fig. 4.

Material examined. 2♂♂ (CL 21.3 mm, TL 69.1 mm; CL 22.6 mm, TL 73.3 mm), Korea coast of Yellow Sea, Hongseong (36˚34.4′N, 126˚27.4′E), at a manila clam farm, muddy sand bottom,16 May 2014, An HM, by shovel.

Description. Front trilobed (Fig. 1A) covered with dense setae, bearing rows of rounded teeth; rostrum (Figs. 1B, 3C) with 6-7 lateral teeth and 4 ventral spines; blunt tip projecting far beyond eyes; lateral frontal lobe projecting anteriorly, with 2 ventral spines. Carapace (Fig. 1A, B) covered with dense setae on gastric region, with 3-4 spines on anterolateral margin, gastric ridge divided by weak mid-dorsal notch, hepatic spine absent; linea thalassinica terminating in anterior thoracic region.

Antennular peduncle (Fig. 1C) 3-segmented, segment 2 shortest, segment 3 longest.

Antennal peduncle (Fig. 1D) 3-segmented, segment 1 with small subdistal spine ventrally, scaphocerite terminating in blunt tooth.

Epistome (Fig. 1B) with 2 distinct spines.

Third maxilliped (Fig. 1E) with exopod failing to reach distal margin of merus; epipod present.

First pereiopod (Figs. 1F, G, 3F, I) subcheliform; basis (Fig. 1F) with sharp ventral spine; ischium (Fig. 1F) with 2 spines on ventral margin; merus with subdistal spine on dorsal margin and 5 spines on ventral margin (Fig. 1F); carpus (Fig. 1G) bearing longitudinal crest on dorsal surface with conspicuous spinules and terminating in spine, large distal spine on ventral margin, inner surface with 3 spines on distal margin; propodus 1.5 times as long as broad, dorsal margin with row of 10 spines, of which distal one largest, outer surface (Figs. 1F, 3F) with distal spine near fixed finger; fixed finger curved distally, with large rounded tooth on middle of cutting edge, inner surface (Figs. 1G, 3I) with translucent longitudinal carina on distal fourth; dactylus two-thirds as long as propodus, with corneous tip, dorsal surface with shallow longitudinal median groove, dorsomesial surface with longitudinal carina terminating large tubercle distally, large tooth on cutting edge proximally.

Second pereiopod (Fig. 1H) shorter than first pereiopod; merus with subdistal spine on dorsal margin, 3 spines on ventral margin increasing in size proximally; carpus bearing distal spine on dorsal margin; propodus and dactylus relatively broad, unarmed.

Third pereiopod (Fig. 1I) shorter than second pereiopod; merus with 2 spines on ventral margin; carpus and propodus noticeably convex on dorsal margins; dactylus slender.

Fourth pereiopod (Fig. 1J) as long as third pereiopod, unarmed; dactylus slender.

Fifth pereiopod (Fig. 1K) unarmed; carpus slender; propodus longer than carpus, slender; dactylus extremely short.

First pleopod absent.

Uropod (Fig. 1L) broad; protopod with acute spine on posterior margin; endopod reaching beyond posterior margin of telson, proximal knob on lateral margin, with 2 longitudinal ridges; exopod convex on lateral margin, with 3 ridges; posterior margins of endopod and exopod without spinules.

Telson (Fig. 1L) 1.4 times as broad as long; posterior margin slightly convex.

Color. The body is light reddish brown overall. Pereiopods and uropod are ivory and hairs are light brown. Cobalt blue individuals are observed rarely in field.

Distribution. Vietnam, Taiwan, China, Japan (Sakai, 2006), and now Korea.

Remarks. The present materials agree well with the original description and figures by Yu (1931). As, they represent the first record of this rare species from Korean waters, three species of Upogebiidae are known in this region: Upogebia major (De Haan, 1839), U. issaeffi (Balss, 1913), and A. wuhsienweni (Yu, 1931). They are generally very similar to each other, however, they can be separated by characteristics of the rostrum and the male first pereiopod. Austinogebia wuhsienweni has a ventral spine of the rostrum, which is absent in the two species of Upogebia (Fig. 3A, B); in Austinogebia wuhsienweni a longitudinal carina on the inner surface of the palm of the male first pereiopod is present, which is also absent in the two species of Upogebia (Fig. 3G, H); and the inner median surface of the dactylus of the male first pereiopod bears some granules in A. wuhsienweni as compared to the three large oblique ridges in U. major (Fig. 3G) and a row of 10-12 oblique ridges in U. issaeffi (Fig. 3H).