Allobathynella bangokensis, Park & Cho, 2016

Park, Jong-Geun & Cho, Joo-Lae, 2016, Fourteen new species of Allobathynella Morimoto and Miura, 1957 from South Korea: with a redescription of A. coreana Morimoto, 1970 (Crustacea, Bathynellacea, Parabathynellidae), Journal of Species Research 5 (1), pp. 49-156 : 109-116

Allobathynella bangokensis sp. nov. ( Figs. 52-57 )

Etymology

The species name is derived from the village (Bangok-Ri), where the material was collected.

Material examined

Holotype (adult female), allotype (adult male), paratype (19 adult females and two juveniles).

Holotype dissected on six slides ( NIBR IV0000266841 ) . Allotype dissected on six slides ( NIBR IV0000266842 ). Each one male and female paratypes dissected on six slides ( NIBR IV0000266843 , 0000266844 ) Seven female and five male paratypes each as a whole specimen on separate slides ( NIBR IV0000266845-0000266856 ), 11 adult females and 2 juveniles in a vial ( NIBR IV 0000 266857) .

Type locality

South-Korea, Ganwon-Do, Hongcheon-Gun, Seo-Myeon, Bangok-Ri (37°41′20.8″N, 127°40′52.6″E), 13. November 2012, leg. J.-L. Cho.

Description

Size (mm). Body length: Ş 2.24 (other females: 2.10- 2.24; ♂: 2.20; other males: 2.10-2.20), approximately 12 times as long as wide. Head as long as anterior three thoracic segments combined ( Fig. 52A ). Male differs from female in protopod of thoracopod VI and thoracopod VIII.

Antennule ( Fig. 52B ) 7-segmented. First segment with one seta on inner distal margin, with two simple dorsal setae and with four plumose setae. Position of each plumose setae: dorsally, dorso-laterally, laterally and ventro-laterally. Second segment with one group of four plumose setae and with each two simple setae dorsally and ventrally on inner distal margin. Third segment with two lateral setae including one plumose seta, with two ventrolateral setae, and two dorsal setae and one ventral seta on inner distal margin. Inner flagellum of third segment with three simple setae. Fourth segment with one stub setae and one plumose seta on dorsal margin, and with two stub setae and two plumose setae on outer distal apophysis. Fifth segment distally with two simple setae and one small plumose seta, two dorsal aesthetascs and one simple seta. Sixth segment with four setae including one plumose seta on inner margin, and with two aesthetascs and one simple seta and one aesthetasc dorsally. Seventh segment with three subterminal aesthetascs and four simple setae.

Labrum ( Fig. 52D ) flat, with eight main teeth flanked by three teeth on both lateral sides. Ventral surface concave, with one round median projections with two spinules, numerous combs of ctenidia and three or four teats on both lateral sides.

Mandible ( Fig. 52E ) with incisor process of four teeth. Tooth of ventral edge absent. Spine row consisting of 11 spines. Palp of one segment, four times as long as wide, with one long terminal seta and one subterminal seta. Terminal seta four times as long as subterminal seta.

Maxillule ( Fig. 53A) two-segmented. Proximal segment with four setae on inner distal margin. Distal segment with two terminal smooth spines, with four dentate spines followed by two smooth spines bearing basal bristles on inner edge, and with three simple setae on outer distal margin. Terminal spine two times as long as other ones.

Maxilla ( Fig. 53B) four-segmented, setal formula 3-5- 11-6.

Thoracopods I-VII ( Figs. 53C, D, 54A, B , 55A, B , 56A ). Thoracopod I-IV increasing in size posteriorly. Thoracopods IV-VII similar in size. Thoracopods IV-VII each bearing one epipod on protopod. Basipod with two distal setae in thoracopod I, with one distal seta in thoracopods II and III, with each one distal and median seta in thoracopods IV-VII. Number of segments of exopod of thoracopods I-VII: 3-5-5-6-6-6-6. Exopodal segments with each one dorsal and ventral seta, except basal segment bearing one additional ventral seta in thoracopod I, lacking dorsal seta in thoracopods II and IV. Tiny process present between two setae of distal segment. Dorsal seta on distal segment of exopod barbed with strong hairs. Endopod of thoracopods I-VII four-segmented, setal formulae:

Thoracopod I 2 + 1/3 + 2/1 + 1/4(2)

Thoracopod II 2 + 1/3 + 2/0 + 1/4(2)

Thoracopods III-IV 1 + 1/3 + 2/0 + 1/4(2)

Thoracopods V-VI 1 + 1/2 + 2/0 + 1/4(2)

Thoracopod VII 0 + 1/1 + 2/0 + 1/4(2)

Thoracopod VIII of male ( Fig. 56B, C ) perpendicular to body, in form of a bell in lateral view, 1.3 times longer than wide. Protopod with a prominent penial region bearing a distal opening. Inner margin of penial region (dental lobe) with eight teeth. Epipod flat, with round distal part barely reaching lower margin of exopod. Basipod with one small seta near base of endopod, inner margin dentate, distally drawn out into round projection. Basipodal seta one half as long as endopod. Exopod one third of size of basipod, round, with two distal lobes. Upper lobe dentate, lower lobe smooth. Endopod small, round, with two distal setae of different size. Outer seta 1.5 times longer than inner one. Thoracopod VIII of female ( Fig. 60C ) tiny, conical in ventral view, trifurcated

February 2016 PARK AND CHO-FOURTEEN SPECIES OF ALLOBATHYNELLA 111

D A B C A, B C, D

distally.

First pleopod ( Fig. 56D ) in form of stub bearing two distal setae.

Uropod ( Fig. 57A ) bearing ten spines on inner margin of sympod, two most distal spines significantly larger than other ones of similar size. Endopod 48% 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 spine, one subterminal spine and four additional spines along inner margin. Terminal spine longer than subterminal one. Distal spine of inner-margin smaller than subterminal one, 50% as large as terminal one. Three proximal spines of inner-margin small, one fourth as large as distal one. Exopod shorter than endopod (43% of sympod), with six setae inclusive of one basi-ventral seta.

Pleotelson ( Fig. 57B, C ) without seta. Anal operculum protruded somewhat sharply with round tip.

Furcal rami ( Fig. 57B, C ) 1.2 times as long as wide, with two large distal spines, and four successively small- er spines on inner margin, and with two dorsal plumose setae.

Figures

Fig. 52. Allobathynella bangokensis (holotype: Ş): (A) General habitus (lateral); (B) Antennule (dorsal, slightly lateral); (C) Antenna (dorsal); (D) Labrum(ventral); (E) Mandible(ventral). Scale bars=0.05mm, unless specified.

Fig. 54. Allobathynella bangokensis(holotype: Ş): (A) Thoracopod III (frontal); (B) Thoracopod IV(frontal). Scale bar=0.05 mm.

Fig. 55. Allobathynella bangokensis (holotype: Ş): (A) Thoracopod V (frontal); (B) Thoracopod VI (frontal); (C) Thoracopod VIII(ventral). Scale bars=0.05mm.

Fig. 56. Allobathynella bangokensis (holotype: Ş; allotype: ♂): (A) Thoracopod VII Ş(frontal); (B) Right and left thoracopods VIII ♂ (ventral, slightly lateral); (C) Thoracopod VIII ♂ (lateral); (D) Pleopod Ş (ventral). Scale bars=0.05 mm.

Fig. 60. Allobathynella yecheonensis (holotype: Ş) (A) Thoracopod IV (frontal); (B) Thoracopod V (frontal); (C) Thoracopod VI (frontal). Scale bar=0.05mm.

Fig. 57. Allobathynella bangokensis (holotype: Ş): (A) Uropod (dorsal); (B) Pleotelson and furcal rami(dorsal); (C) Furcal ramus (lateral). Scale bar=0.05mm.