Allobathynella japonica Morimoto and Miura, 1957

Park, Jong-Geun & Cho, Joo-Lae, 2008, A preliminary inquiry into an Asian topsy-turvy Dom, Allobathynella with the description of a new species from South Korea and redescription of A. japonica (Crustacea, Syncarida, Parabathynellidae), Journal of Natural History 42 (3 - 4), pp. 223-238 : 224-229

publication ID	https://doi.org/ 10.1080/00222930701850018
persistent identifier	https://treatment.plazi.org/id/03DB87BA-FFF6-6004-FEC8-10B5FC1FB099
treatment provided by	Felipe
scientific name	Allobathynella japonica Morimoto and Miura, 1957
status

Treatment

( Figures 1–4 View Figure 1 View Figure 2 View Figure 3 View Figure 4 )

Material examined. Two male and two female specimens with a length between 1.86 and 2.10 mm.

Locality. A well in the town of Wadayama (type locality) in the district of the Japan Sea, Hyôgo Prefecture, 26 August 1956 (Morimoto, pers. comm.). Registration number: ( NIBR IV0000100013–16 View Materials ) .

Description

Size (mm). Body length: „ 1. 96, 2.10, ♀ 1.86, 1.92, approximately 12 times as long as wide. Head as long as anterior three thoracic segments combined. The female differs from the male in thoracopod VIII.

Antennule ( Figure 1A View Figure 1 ). Seven-segmented. First segment with one seta on inner distal margin, with two 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 four simple setae on inner distal margin. Third segment with two lateral setae including one plumose seta and three setae on inner distal margin. Inner flagellum of third segment with three simple setae. Fourth segment with two stub setae and one plumose seta on dorsal margin, and with two stub setae and two plumose setae on outer distal apophysis. Fifth segment with three simple setae and one dorsal seta. Sixth segment with three setae on inner margin, with two aesthetascs and one seta dorsally and with one more aesthetasc. Seventh segment with three subterminal aesthetascs and four simple setae.

Antenna ( Figure 1B View Figure 1 ). Seven-segmented, as long as the length of antennular segments 1–6. Setal formula: 0+0/0+0/1+0/1+1/0+0/0+2/4(1).

Labrum ( Figure 1C View Figure 1 ). Flat, with 18 teeth in total. Eight median teeth flanked by five lateral teeth on both sides.

Mandible ( Figure 1D View Figure 1 ). With incisor process of four teeth. Tooth of ventral edge absent. Spine row consisting of nine spines. Palp of one segment, three times as long as wide, with one apical seta.

Maxillule ( Figure 1E View Figure 1 ). Two-segmented. Proximal segment with four setae on inner distal margin. Distal segment with two terminal spines and four spines on inner edge, and with three simple setae on outer distal margin.

Maxilla ( Figure 1F View Figure 1 ). Four-segmented, setal formula 3-4-9-6. Thoracopods I–VII ( Figures 1G View Figure 1 , 3A–C View Figure 3 , 4A–C View Figure 4 ). Thoracopods I–IV increasing in size posteriorly. Thoracopods IV–VII similar in size. Thoracopods III–VII each bearing one epipod on the protopod. Basipod of thoracopods I–V with one distal seta. Basipod of thoracopods VI and VII with one distal and one median seta. The number of segments of the exopod of the thoracopods I–VII: 2-3-4-5-5-5-4; in

thoracopod I, dorsal seta absent in first segment; in thoracopods II–VII, dorsal seta present only in two distal segments. The endopod of thoracopods I–VII 4- segmented, setal formulae:

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

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

Thoracopod III: 1+1/1+2/0+1/4(2)

Thoracopod IV: 1+1/1+2/0+1/3(1)

Thoracopod V–VII: 0+1/1+2/0+1/3(1)

Thoracopod VIII ( Figures 2A–C View Figure 2 ). Thoracopod VIII of male perpendicular to body, in the form of a bell in lateral view, 1.5 times longer than wide. Protopod with a prominent penial region bearing a distal opening. Inner margin of penial region with numerous teeth. Epipod flat, round, its distal part barely reaching the bottom of the basipod. Basipod with one tiny seta, inner margin of basipod drawn out into projection. Exopod one third of the size of the basipod, round, serrated distally. Endopod small, round, with two distal setae of different size.

Thoracopod VIII ( Figure 2D View Figure 2 ). Thoracopod VIII of female tiny, round in ventral view, with two projections.

First pleopod. In form of stub bearing two distal setae.

Uropod ( Figures 2E, F View Figure 2 ). Bearing five spines of similar size on inner margin of sympod. Endopod 59% as long as sympod, with two dorsal plumose setae near the base, with two terminal setae and one subterminal plumose seta on outer margin and with one distal spine, one subterminal spine and two further spines on inner margin. Distal spine slightly thicker and stronger than subterminal one. The distal spine of the two inner-marginal spines 50% as large as the distal one and two times as large as the proximal spine. Exopod slightly shorter than endopod (50% of sympod), with four setae inclusive of one basi-ventral seta.

Pleotelson ( Figure 2E View Figure 2 ). Without setae. Anal operculum concave.

Furcal rami ( Figures 2E, F, G View Figure 2 ). 1.2 times as long as wide, with two large distal spines, and three smaller spines on inner margin, and with two dorsal setae.