Moolapheonoides acutifalcatus Kobayashi and Ishimaru, 2005

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 : 4-5

2. Moolapheonoides acutifalcatus Kobayashi and Ishimaru , 2005 ǧêėẚêŔqăNjẹ (ṳAE) ( Fig. 2 ) Moolapheonoides acutifalcatus Kobayashi and Ishimaru, 2005: 171 , figs. 1-3.

Material examined. 1 female, (NIBRIV0000325972), Korea, Ulreungdo Is., Tonggumi , 20 May 2015, by light trap, collected by YH Kim and JH Heo.

Diagnosis. Body rounded, small sized, about 4.8 mm. Eye red, rounded, medium sized. Pereonites 3­5 broad, deep, swollen in dorsal view. Coxae 1, 2 small, hidden by coxa 3. Coxae 3, 4 enlarged. Pleonites much narrow­ er than pereonites. Mandibular palp triarticulate. Antenna 1 short, stout, subequal to head and pereonite 1 combined. Antenna 2 slender, slightly shorter than antenna 1. Gnathopod 1 subchelate; carpus shorter than propodus, posteroventral lobe produced prominently; propodus rectangular, palm short, slanted, defined by 2 pinnate spines; dactylus falcate, 0.6 × propodus, strongly overlapping palm, with 1 accessory tooth and row of small spines. Gnathopod 2, propodus subrectangular, gradually widening distally, shorter than carpus, lacking posterior setae, palm concave, defined by 2 spines, palmar corner blunt; dactylus fitting palm, curved, with accessory tooth and row of 5 spines. Pereopod 5, basis slender, linear; ischium shorter than merus. Pereopods 6, 7, basis expanded posteriorly. Urosomite 1 dorsally keeled and truncate, elongate, subequal to pereonite 7. Uropods 1­3 slender, peduncles and rami medially pectinate. Telson subtriangular, entire, longer than wide.

Distribution. Japan, Korea.

Remarks. Presently, the genus Moolapheonoides contains 8 species worldwide ( WoRMS, 2016). Among them, M. acutifalcatus is closely similar to M. kadee Barnard, 1974 , but distinguished from the latter in having short accessory flagellum, strongly curved dactylus on gnathopod 2, and truncate dorsal keel of urosomite 1. Our male specimen is accorded with Kobayashi and Ishimaru (2005) ’s original description, except palmar corner of gnathopod 2 blunt. In this paper the genus Moolapheonoides is reported from Korea for the first time.

Figures

Fig. 2. Moolapheonoides acutifalcatus Kobayashi and Ishimaru, 2005; female: A, habitus, lateral view; B, Gnathopod 1; C, Gnathopod 2. Scale bars=0.5 mm (A), 0.1 mm (B, C).