Redefinition of Nipponbathynella based on the four new species from East Asia (Crustacea: Bathynellacea: Parabathynellidae) Author Park, Jong-Geun Department of Environmental Education, Daegu University, Gyeongbuk, South Korea; Author Cho, Joo-Lae Animal Resources Division, National Institute of Biological Resources, Incheon, Korea text Journal of Natural History 2015 2015-03-31 49 37 2275 2307 journal article 21127 10.1080/00222933.2015.1023226 1f224900-83b8-4929-82cd-8cb454b83d19 1464-5262 4000033 Nipponbathynella leesookyungae sp. nov. ( Figures 1–5 ) Etymology The species name is derived from Mrs Soo-Kyung Lee, who helped in preparing the figures. Material examined Type material Holotype . Male , dissected on six slides. South Korea , Jeollanam-Do (province), Yeongam-Gun (county), Yeongam-Eup (town), Gaeshin Village , a stream near a temple ( 34°46'18.0 ''N , 126°42'59.3'' E ), 24 May 2014 ( J.-L. Cho and J.-G. Park ) ( NIBR IV0000267080 ). Figure 1. Nipponbathynella leesookyungae sp. nov. (♂: holotype, ♀: allotype). (A) General habitus ♀; (B) antennule ♂ (dorsal); (C) antenna ♂ (dorsal); (D) labrum ♂ (ventral); (E) mandible ♂ (ventral); (F) maxillule ♂ (dorsal). Scale bars = 0.05 mm (unless otherwise specified). Figure 2. Nipponbathynella leesookyungae sp. nov. (♂: holotype). (A) Maxilla (dorsal); (B) thoracopod I (frontal); (C) thoracopod II (frontal); (D) thoracopod III (frontal). Scale bars = 0.05 mm. Allotype . Female, dissected on six slides, same data as holotype ( NIBR IV0000267081 ). Paratypes . One male dissected on seven slides and one female kept as a whole specimen on a slide, same data as holotype ( NIBR IV0000267082 , 0000267083 ) . Figure 3. Nipponbathynella leesookyungae sp. nov. (♂: holotype, ♀: allotype). (A) Thoracopod IV ♂ (frontal); (B) thoracopod V ♂ (frontal); (C) thoracopod VI ♂ (frontal). (D) Thoracopod VII ♂ (frontal); (E) thoracopod VIII ♀ (ventral). Scale bars = 0.05 mm. Figure 4. Nipponbathynella leesookyungae sp. nov. (♂: holotype). (A) Thoracopod VIII (ventral); (B) thoracopod VIII (latero-external). Scale bar = 0.05 mm. Description of adult male ( holotype ) Body ( Figure 1A ). Elongated and cylindrical, length 1.20 mm (other male: 1.14 mm ), approximately 10 times as long as wide. Head as long as wide, shorter than anterior three thoracic segments combined. Antennule ( Figure 1B ) six-segmented. First segment with one seta on inner distal margin, with two simple dorsal setae and with each one plumose seta dorso-laterally, laterally and ventro-laterally. Second segment with one group of four plumose setae, with one simple seta on inner distal margin and with one ventral seta inner laterally. Third segment with two lateral setae, one seta on inner distal margin and with one ventral seta inner laterally. Inner flagellum of third segment with three simple setae. Fourth segment with one stub seta and one plumose seta on dorsal margin, and with two stub setae and two plumose setae on outer distal apophysis being slightly protruded. Fifth segment with a medial group of two inner setae, one dorsal aesthetasc and one dorsal simple seta, and distally with three setae, two dorsal aesthetascs, one dorsal seta and one lateral aesthetasc. Sixth segment as large as one half of the fifth segment, with three subterminal aesthetascs and four simple setae. Antenna ( Figure 1C ) two-segmented, as long as the length of the first antennular segment. Proximal segment without setae, distal segment with two simple terminal setae and one subterminal seta. Figure 5. Nipponbathynella leesookyungae sp. nov. (♂: holotype). (A) Uropod (dorsal); (B) pleotelson and furcal rami (dorsal). Scale bar = 0.05 mm. Labrum ( Figure 1D ) flat, with eight median teeth of more or less similar size flanked by one (left) or two (right) lateral teeth. Inner surface convex, with two pairs of nipple-like lateral protrusions and with ctenidia and one tiny projection in middle region. Mandible ( Figure 1E ) with incisor process of three teeth. Tooth of ventral edge triangular. Spine row consisting of four spines. Palp of one segment, with one apical seta exceeding incisor process in length. Maxillule ( Figure 1F ) two-segmented. Proximal segment with three setae on inner distal margin. Distal segment with two terminal spines, with three spines and one small spine on inner edge, and with three simple setae on outer distal margin. Distalmost spine smooth. Maxilla ( Figure 2A ) four-segmented, setal formula 2-4-9-7. Thoracopods I–VII ( Figures 2B–D , 3A–D ) slightly increasing in size up to thoracopod III, thoracopods III–VII similar in size. Thoracopods II–VII each bearing one epipod on protopod. Basis of thoracopods I–VII with one seta each. Exopod of thoracopod I one-segmented with one medial seta on ventral margin. Exopod of thoracopods II–VII two-segmented. Endopods of thoracopods I–VII four-segmented, setal formulae: Thoracopod I 1 + 0/1 + 1/0 + 1/3(1) Thoracopods II–VII 0 + 0/1 + 1/0 + 1/2(0). Thoracopod VIII ( Figure 4A, B ) bell-shaped tilting backwards in lateral view, 1.2 times longer than wide. Protopod massive, with penial region of three lobes: frontal lobe with four small spines; dentate lobe with nine teeth; inner lobe spinulated, in form of bur. Epipod small, round distal end not reaching penial region. Basis nearly trapezoid, without distal spur, with one seta. Exopod one-third as long as basis, longer than wide, medially with two spines, distally two-lobed. Upper lobe with two distal spines, lower lobe distally serrated. Endopod small, with two distal setae and one tiny spine. First pleopod absent ( Figure 1A ). Uropod ( Figure 5A, B ) with load-shaped sympod bearing seven spines on inner margin. distal-most spine significantly thicker than others decreasing slightly in size distally. Endopod 21.7% as long as sympod length, drawn into spur, with two setae on the outer basis of spur. Exopod longer than endopod, 47.0% as long as sympod, with one outer seta, two terminal setae and one inner medial seta. Inner seta strong, longer and thicker than outer terminal seta. Pleotelson ( Figure 5B ) without seta. Anal operculum protruded. Furcal rami ( Figure 5B ) nearly square, with two distal spines and four additional spines on inner margin, dorsally with two plumose setae of different length, and ventrally with furcal organ. Description of adult female ( allotype ) Female differing from male in protruded and undulated inner margin of the protopod of thoracopod VI and in the form of thoracopod VIII. Because of the failure of the preparation of thoracopod VI, the corresponding figure is not provided. Body length 1.15 mm (other females: 1.13 mm ). Thoracopod VIII ( Figure 3E ) in form of two radicles distally lobed slightly.