Ten new species of the genus Brevisomabathynella Cho, Park and Ranga Reddy, 2006 (Malacostraca, Bathynellacea, Parabathynellidae) from Western Australia Author Cho, Joo-Lae Author Humphreys, W. F. text Journal of Natural History 2010 2010-03-31 44 17 - 18 993 1079 http://dx.doi.org/10.1080/00222930903537066 journal article 10.1080/00222930903537066 1464-5262 4590640 Brevisomabathynella changjini sp. nov. ( Figures 5–8 ) Material examined Holotype (adult male), allotype (adult female), paratypes (five adult males and two adult females). Holotype : dissected on seven slides ( WAM C 40879) . Allotype : dissected on six slides ( WAM C 40880) . Paratypes : one male and one female each dissected on six slides, four males and one female each as a whole specimen on separate slides ( WAM C 40881–C 40887) . Type locality Australia , Western Australia , Carnegie Palaeodrainage , Lorna Glen Station Bore Site 42 ( 26°15′31″ S , 121°24′15″ E ), BES 12875(12876), 7 April 2005 , leg. W.F. Humphreys and R . Leijs . Description of adult male ( holotype ) Body. Length 4.24 mm . Elongated and cylindrical, approximately 10 times as long as wide. Head as long as anterior three thoracic segments combined. Antennule ( Figure 5A ). Seven-segmented. First segment with one seta on inner margin, with four simple dorsal setae and with one dorsal, one ventromedial and two lateral plumose setae. Second segment with one group of four plumose setae and with six simple setae on inner margin. Third segment with three outer lateral setae including one plumose seta, and with five setae on inner margin. 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. Fifth segment with four setae on inner margin and one dorsal seta. Sixth segment with three setae on inner margin and with dorsal group of two aesthetascs, one simple seta and one additional aesthetasc lateral to simple seta. Seventh segment with three subterminal aesthetascs and four simple setae. Antenna ( Figure 5B ). Five-segmented, as long as antennular segments 1–3 combined. Fourth segment as long as fifth segment. Setal formula: 0+0/0+0/1+1/2+1/4(1). Plumose seta of distal segment shorter than longest simple seta. Labrum ( Figure 5C ). Flat with 12 median teeth of more or less similar size flanked by four (left) or five (right) teeth decreasing in size laterally on each side. Ventral surface with numerous combs of ctenidia and teats. Mandible ( Figure 5D ). Incisor process of seven teeth. Tooth of ventral edge triangular. Spine row consisting of 12 spines. Palp of one segment, with one apical seta. Maxillule ( Figure 5E ). Two-segmented. Proximal segment with four setae on inner margin. Distal segment with two terminal spines, with five spines with denticles on inner edge, and with three simple setae on outer margin. Figure 5. Brevisomabathynella changjini sp. nov. (Ƌ, holotype): (A) right antennule (dorsal); (B) right antenna (dorsal); (C) labrum (ventral); (D) right mandible (ventral); (E) right maxillule I (ventral); (F) right maxilla II (dorsal); (G) right thoracopod VIII (lateral); (H) left thoracopod VIII (lateroventral); (I) exopod of left thoracopod VIII; (J) denticles of penial region of thoracopod VIII. Scale bars 0.1 mm. Figure 6. Brevisomabathynella changjini sp. nov. (Ƌ, holotype; ♀, allotype): (A) right thoracopod VII Ƌ (frontal); (B) right and left thoracopods VIII ♀ (ventral); (C) right and left pleopods I Ƌ (ventral); (D) left uropod Ƌ (dorsal); (E) pleotelson and furcal rami Ƌ (dorsal). Scale bars 0.1 mm. Figure 7. Brevisomabathynella changjini sp. nov. (Ƌ, holotype): (A) right thoracopod I (frontal); (B) right thoracopod II (frontal); (C) right thoracopod III (frontal). Scale bar 0.1 mm. Figure 8. Brevisomabathynella changjini sp. nov. (Ƌ, holotype): (A) right thoracopod IV (frontal); (B) right thoracopod V (frontal); (C) right thoracopod VI (frontal). Scale bar 0.1 mm. Maxilla ( Figure 5F ). Four-segmented, setal formula 6-7-17-13. Thoracopods I–VII ( Figures 6A , 7 A–C, 8A–C). Thoracopods I–IV increasing in size posteriorly. Thoracopods IV–VII similar in size. Thoracopods I–VII each bearing one epipod on protopod and one basipodal seta. Number of exopodal segments of thoracopods I–VII: 7-8-9-10-9,10-9-9. Endopod of thoracopods I–VII four-segmented, setal formulae: Th. I 5+1/11+1/4+1/6(4) Th. II 2+1/8+1/4+1/6(4) Th. III 2+1/7+1/5+1/6(4) Th. IV, V 2+1/7+1/4+1/6(4) Th. VI 2+1/8+1/4+1/5(3) Th. VII 2+1/6+1/4+1/6(4) Thoracopod VIII ( Figure 5 G–J). More or less rectangular in lateral view, 1.3 times as long as wide. Protopod massive, with prominent penial region with terminal opening. Epipod large, triangular, distal part barely reaching penial region of protopod. Basipod without setae, inner margin of basipod drawn out into projection. Exopod one-third size of basipod, round, terminally with five denticles, bearing two subterminal setae ( Figure 5I ). Endopod two-thirds size of exopod, with two terminal setae. First pleopod ( Figure 6C ). In form of two stubs attached to each other basally with a gap. Each stub bearing two terminal setae. Uropod ( Figure 6D ). Eighteen spines of similar size on inner margin of sympod. Exopod 50% as long as sympod, without basiventral setae, and with 12 setae on outer and terminal margin. Endopod 30% as long as sympod, with two dorsal plumose setae near base, with two terminal setae and one subterminal plumose seta on outer margin, and with one terminal, one subterminal and two inner-marginal spines. Terminal and subterminal spines similar in size. Two inner-marginal spines spike-like, two-thirds of length of terminal spine, but thinner. Pleotelson ( Figure 6E ). One seta near base of each furcal ramus on both sides. Anal operculum flat. Furcal rami ( Figure 6E ). Four times as long as wide, with two large terminal spines, and 13 spines on inner margin, and with two dorsal setae. Description of adult female ( allotype ) Body. Length 4.12 mm . Identical to male except for following characters. Antennule. Second segment with seven simple setae on inner margin. Third segment with six setae on inner margin. Mandible. Spine row with 13 spines. Thoracopods I–VII. Number of exopodal segments of thoracopods I–VII: 7-9-10-10- 10-10-9. Setal formulae of endopods: Th. I 4+1/8+1/4+1/5(3) Th. II 2+1/7+1/4+1/6(4) Th. III 2+1/6+1/4+1/6(4) Th. IV 2+1/7+1/4+1/6(4) Th. V, VI 2+1/6+1/4+1/6(4) Th. VII 2+1/5+2/4+1/5(3) Thoracopod VIII ( Figure 6B ). Conical, half as long as endopod of male thoracopod VIII, with four tiny teeth. Uropod. Sympod with 15 spines. Intraspecific variation Range of body length: male 3.60–4.24 mm ; female 3.60–4.12 mm . Variation in number of setae, spines or segments as listed in Table 2 . Etymology The specific name refers to Prof. Jin Chang ( Seoul , Korea ), who encouraged J. L. Cho to study taxonomy.