New species of Atopobathynella, Kimberleybathynella and Hexabathynella (Parabathynellidae, Bathynellacea) from the arid zones of Western Australia Perina, Giulia Camacho, Ana I. Morgan, Liesel Lawrie, Angus Floeckner, Stephanie Guzik, Michelle T. Zootaxa 2025 2025-07-01 5655 1 1 103 Perina & Camacho Perina & Camacho & Morgan & Lawrie & Floeckner & Guzik 2025 [151,737,1734,1761] Malacostraca Parabathynellidae Atopobathynella Animalia Bathynellacea 46 47 Arthropoda species pervulgata sp. nov.  ( Figs. 18–19)   Material examined.   Holotypemale. AUSTRALIA:  Western Australia: Rhodes Ridge, Pilbara, karaman RRWON54, 23°7'11.2152"S, 119°4'43.0422"E,  12 February 2021, P. Runham, A. Mittra( WAMC 82071— BES10623— BMR03982, permanent slide).   FIGURE 18.  Atopobathynella pervulgata  sp. nov.male holotype (WAMC 82071). A, AI; B, AII; C, Lb; D, Md; E, MxI; F, MxII: G, ThI; H, male ThVIII (latero-external view); I, AI second article (female paratype WAMC 78944); J. female ThVIII (female paratype WAMC 82073). (O.Lb) outer lobe, (Bsp) basipod, (D. Lb) dentate lobe, (I. Lb) inner lobe). Scale bar: 0.05 mm.   FIGURE 19.  Atopobathynella pervulgata  sp. nov.male holotype (WAMC 82071). A, ThII; B, ThIII; C, ThIV; D, ThV; E, ThVI; F, uropod; G, furcal rami (dorsal view); H, pleopod (female paratype WAMC 82070). Scale bar: 0.05 mm.    Paratypes: AUSTRALIA:  Western Australia: 1 female( WAMC 82073— BES11526b, permanent slide) and  1 male( WAMC 82074— BES11526c, permanent slide), same detail as holotype;  1 female, Rhodes Ridge, Pilbara, karaman RRWONKC050, 23°5'2.6586"S, 119°9'20.3436"E,  7 February 2021, P. Runham, A. Mittra( WAMC 82066— BES10831— BMR03989, permanent slide);  1 female, Rhodes Ridge, Pilbara, karaman RRWONKC051, 23°05'20.8400"S, 119°08'12.8958"E,  9 February 2021, P. Runham, A. Mittra( WAMC 82068— BES10703— BMR04001, permanent slide);  1 male( WAMC 82070— BES11621a, permanent slide), details as above;  1 male, Gudai Darri, Pilbara, Bore MB19K58W0001, 22°31'52.1862"S, 119°0'20.0772"E,  10 June 2021, C. Norris, F. Rudin, ( WAMC 76664— BES12768— BMR03941, permanent slide);  1 female( WAMC 76677— BES10454— BMR03369, permanent slide) details as above;  1 male Gudai Darri, Pilbara, Bore200NB13768, 22°30'45.5004"S, 119°1'16.9422"E,  10 June 2021, S. Paget, J. Huey, ( WAMC 76679— BES11525— BMR02766, permanent slide);  1 female Gudai Darri, Pilbara, Bore MB21G101W0002, 22°28'18.1272"S, 118°53'57.0978"E,  17 September 2022, F. Rudin, A. Umbrello, ( WAMC 78944— BES17446— BMR05155, permanent slide;  1 male West Angelas, Pilbara, bore at 23°08`31.01"S, 118°39`17.67"E,  21 March 2016, S. Callan, E.S. Volschenk, ( WAMC 78973, permanent slide);  1 female( WAMC 78974, permanent slide), same detail as above;  1 male West Angelas, Pilbara, bore at 23°08`31.53"S, 118°38`47.74"E,  16 March 2016, S. Callan, E.S. Volschenk, ( WAMC 78976, permanent slide);  1 male( WAMC 78977, permanent slide) same detail as above;  1 female Yandi Creek, Pilbara, karaman at 22°47'S, 119°9'E,  20 April 2022, A. Riemer, I. Johansson, ( WAMC 82076— BES15605— BMR05460, permanent slide);  1 female, Yandi Creek, Pilbara, karaman at 22°43'S, 118°57'E,  11 September 2022, J. Delaney, S. Rodman, C. Wilkins, ( WAMC 82078— BES22638a, permanent slide);  1 male( WAMC 82079— BES22638b, permanent slide), same details as above.    Additional material: AUSTRALIA:  Western Australia: 49 specimensin alcohol, West Angelas, Pilbara, bore at 23°08`31.01"S, 118°39`17.67"E,  21March 2016, S. Callan, E.S.Volschenk, ( WAMC 70169);  91 specimensin alcohol, West Angelas, Pilbara, bore at 23°08`31.53"S, 118°38`47.74"E,  16 March 2016, S. Callan, E.S. Volschenk, ( WAMC 70170);  1 juvenilein alcohol, Rhodes Ridge, Pilbara, karaman RRWONKC050, 23°5'2.6586"S, 119°9'20.3436"E,  7 February 2021, P. Runham, A. Mittra( WAMC 82067— BES11534);  3 juveniles, 1 femalein alcohol, Rhodes Ridge, Pilbara, karaman RRWONKC051, 23°05'20.8400"S, 119°08'12.8958"E,  9 February 2021, P. Runham, A. Mittra( WAMC 82069— BES11621);  56 specimensin alcohol, ( WAMC 82072— BES11526), same detail as holotype;  1 juvenilein alcohol, Rhodes Ridge, Pilbara, karaman RRGINKARA01, 23°09'45.7424"S, 119°01'04.0861"E,  9 February 2021, P. Runham, A. Mittra( WAMC 82075— BES12774— BMR03955);  1 femalein alcohol, Yandi Creek, karaman at 22°43'S, 118°56'E,  1 April 2023, J. Delaney, K. Nguyen, S. Paget( WAMC 82077— BES19803— BMR08587);  1 male, 5 female, 5 juvenilesin alcohol, Yandi Creek, Pilbara, karaman at 22°43'S, 118°57'E,  11 September 2022, J. Delaney, S. Rodman, C. Wilkins, ( WAMC 82080— BES22638).   Diagnosis.  Atopobathynella pervulgata  sp. nov.belongs to a group of  Atopobathynellaspeciesthat have antennal organ (AO) without protuberance, with one long and strong seta that reaches over half of the length of article four; distal endite of maxillula with five claws; sympod of the uropod with inhomonomous spines; exopod of the uropod with two distal setae. It differs from the rest of  Atopobathynellaspeciesby the presence of only six pairs of thoracopods. The sequenced specimens differ from all the other  Atopobathynellaspeciessequenced by COI = 11.2–20.5% and 12S = 11.4–37.2% (Appendices 3, 4). The COI intraspecific variation ranges between 0– 7.9% (Supplementary Material Table S1), with average 5.1% (Appendix 2). The 12S intraspecific variation ranges between 0–7.5% (Supplementary Material Table S2), with average 4.2% (Appendix 3).   Description male holotype(WAMC82071).Body length of 0.9 mm. Body about nine times as long as maximum width, elongated, almost cylindrical, segments slightly widening and lengthening towards posterior end of the body.   Antennula( Fig. 18A): six-segmented. Articles wide, gradually shortening and thinning from article one to six, with article six half as wide as the first two. Antennal organ represented by one long and thick ventral seta which reaches half the length of article four. Inner flagellum small with three setae. Ventral seta present in article two and three. Plumose seta present on the inner distal end of article four, in addition to the two typical outer plumose setae on protuberances on the outer corner of article four, one short and one extending beyond the distal end of the fifth article. Articles five and six with three terminal aesthetascs each, one slightly longer on article five, and two long and one shorter on article six. Antennular setation as in Fig. 18A.  Antenna( Fig. 18B): one-segmented with four setae, two terminal and one subterminal smooth, and one terminal plumose seta.   FIGURE 20.  Atopobathynella pervulgata  sp. nov.distribution in the Pilbara. At the bottom:  A. pervulgataclade extracted from the three-genes ML tree.  Labrum( Fig. 18C): slightly concave, free edge with 16 teeth, seven long teeth on each side, and two central small triangular ones.  Paragnaths: absent.  Mandible( Fig. 18D): pars incisivawith three teeth; pars molariswith five claws, the most distal one slightly modified and separated from the rest, the two most proximal claws joined together; tooth on ventral edge very small. Mandibular palp with one distal seta that reaches the distal end of the pars molaris.  Maxillula( Fig. 18E): proximal endite with four unequal claws, two thick with denticles and two thinner; distal endite with five claws, two distal ones smooth, three proximal ones with some spines; three smooth subterminal setae on the outer distal margin.  Maxilla( Fig. 18F): four-segmented, setal formula 2, 4, 12, 1.  Thoracopods I to VI( Figs. 18Gand 19A–E): length slightly increasing from thoracopod one to four, the last two thoracopods similar in length. Epipod present in ThII to VI, with length about half the corresponding basipod. All basipods with one distolateral seta slightly shorter than the first article of the endopod (except in ThI). Exopod one-segmented in all thoracopods; exopod of ThI( Fig. 18G) and II ( Fig. 19A) reaching the distal end of the second article of the endopod; exopod of ThIII to VI ( Fig. 19B–E) slightly longer than the first two articles of the endopod. Exopod of all thoracopods bearing three setae, two terminal ones of different length, with the outer smooth seta half of the length of the barbed subterminal seta, barbed inner seta not reaching the distal end of the claws of the endopod in ThI, while it extends beyond the distal claw of the endopod, progressively increasing in length from ThII to VI. Endopod four-segmented, first article short, half the length of the second and third article, with one seta on thoracopod I, and no seta on the rest of thoracopods; second and third articles long, second article slightly longer than the third one in all thoracopods; second article with one outer plumose seta in all thoracopods and two smooth inner setae on ThIonly; third article with one inner seta on ThIand one small outer seta on the rest of thoracopods; fourth article very reduced with two strong claws of different length on ThIand only one long strong claw on ThII to VI. Setal formula of endopods as follow:   ThI1+0/2+1/1+0/2  ThII to VI0+0/0+1/0+1/1  Thoracopod VIII( Figs. 18H): compact, like a balloon. Penial region with massive protopod, outer lobe oval shape, reaching the distal end of basipod, well defined at base in latero-external view. Inner lobe small, finger shape. Dentate lobe with seven teeth. Basipod without delimited base, with a projection and a seta of uncertain origin.  Pleopod I( Fig. 19H): one smooth seta on each side.  Uropod( Fig. 19F): sympod about 3 times as long as wide, about 3.5 times the length of the exopod and about six times the length of endopod, with six uneven spines, increasing in length from the proximal to the distal spine and occupying two thirds of the sympod. Exopod with two very long barbed terminal setae of similar length, and one basal plumose seta as long as exopod. Endopod distally drawn out into a very long dagger-shaped structure longer than the exopod, with distolateral angle bearing two setae, one outer barbed a third longer than the plumose inner one and almost twice the length of the dagger-shaped structure.  Pleotelson( Fig. 19G): anal operculum not protruded, short lateral seta.   Furca( Fig. 19G): rami robust and almost square, with four barbed spines, three distal ones of similar length and the basal one two thirds of the others. Two dorsal plumose setae, inner seta very short, and the outer seta more than twice the length of the distal spines. Female paratypediffers from male in the second antennular segment ( Fig. 18I) that bears no antennal organ, and ThVIII, which is very small and tooth/denticle shaped ( Fig. 18J).  Variability.Variability was observed in body size (males 0.78–1.1 mmand females 0.6–1.07 mm); number of teeth on labrum (16–22); number of setae on exopod of the ThI(2 or 3) and number of setae on exopod of the ThV– VI (2 or 3); number of inner setae on the second article of ThI(1 or 2); length of setae on distolateral angle of the endopod of the uropod (2 short, 2 long, 1 long and 1 short); and number of spines on sympod of uropod (5–11). One specimen(WAMC 76679) has endopod and exopod of uropod deformed (see Supplementary Material Fig. S2).   Distribution and remarks.  Atopobathynella pervulgata  sp. nov.has been recorded from three bores from the Gudai Darri area (south Hamersley Range), four sites in the hyporheic habitat near Yandy Creek, four sites in the hyporheic habitat south of the Weeli Wolli Creek, and two bores at West Angelas ( Figs. 1, 20), which represent four disconnected aquifers. This species was previously known by Biologic Environmental Surveys as  Atopobathynellasp.“Biologic-PBAT019, PBAT029, PBAT030, PBAT042, and PBAT054”. Despite being collected in several sites geographically closer to eight other  Atopobathynellaspecies(see Fig. 20), our results indicate that  Atopobathynella pervulgataisgenetically closest to  A. degreyensis, collected in the De Grey River Catchment, 250 kmnortheast ( Figs. 1, 5). This is the first example of relatively wide distribution (about 80 km) of Parabathynellidaespecies in the Pilbara, and the first case of  Atopobathynellaspecieswith only six pairs of thoracopods.   Etymology.The name of the species derives from the Latin word “pervulgata” (singular, feminine) meaning widespread, which refers to the distribution of this species.  Genus  Kimberleybathynella Cho, Park & Humphreys, 2005   Type species:  Kimberleybathynella gigantea Cho, Park & Humphreys, 2005  Other species: see Table 7.   Amended diagnosis(after Cho, Park & Humphreys, 2005). Body elongated and cylindrical. Antennula six-segmented. Antenna two-segmented. Labrum flat. Maxilla four-segmented, second and third segments of maxilla half-fused. Exopod of thoracopods I–VII one-segmented. Male thoracopod VIII hemispherical, protopodite protruded, basipod without setae, inner margin of basipod drawn out into projection. Distal spine of uropodal sympod longer and thicker than other spines. Uropodal exopod bearing two terminal setae, of which the outer seta is longer than inner one. 2021-02-12 RRWON, WAMC, BES, BMR P. Runham & A. Mittra Australia -23.119781 Pilbara 1 119.07862 Rhodes Ridge 46 47 RRWON54, WAMC 82071, BES10623, BMR03982 1 Western Australia holotype [199,1414,150,177] WAMC, BES Australia Western Australia 49 50 WAMC 82073, BES11526 1 1 Western Australia paratype WAMC, BES Australia 49 50 WAMC 82074, BES11526 1 1 Western Australia paratype 2021-02-07 WAMC, BES, BMR P. Runham & A. Mittra Australia -23.084072 Pilbara 1 119.155655 Rhodes Ridge 49 50 WAMC 82066, BES10831, BMR03989 1 1 Western Australia paratype 2021-02-09 WAMC, BES, BMR P. Runham & A. Mittra Australia -23.089123 Pilbara 1 119.13692 Rhodes Ridge 49 50 WAMC 82068, BES10703, BMR04001 1 1 Western Australia paratype [507,1337,331,357] WAMC, BES Australia 49 50 WAMC 82070, BES11621 1 1 Western Australia paratype 2021-06-10 MB, WAMC, BES, BMR C. Norris & F. Rudin Australia Gudai Darri -22.531162 Bore 1 119.00558 Pilbara 49 50 MB19, WAMC 76664, BES12768, BMR03941 1 1 Western Australia paratype WAMC, BES, BMR Australia 49 50 WAMC 76677, BES10454, BMR03369 1 1 Western Australia paratype 2021-06-10 WAMC, BES, BMR S. Paget & J. Huey Australia Gudai Darri -22.512638 Bore 1 119.02138 Pilbara 49 50 WAMC 76679, BES11525, BMR02766 1 1 Western Australia paratype 2022-09-17 MB, WAMC, BES, BMR F. Rudin & A. Umbrello Australia Gudai Darri -22.471703 Bore 1 118.89919 Pilbara 49 50 MB21, WAMC 78944, BES17446, BMR05155 1 1 Western Australia paratype 2016-03-21 WAMC S. Callan & E. S. Volschenk Australia -23.141947 Pilbara 1 118.65491 West Angelas 49 50 WAMC 78973 1 1 Western Australia paratype [355,1087,619,645] WAMC Australia 49 50 WAMC 78974 1 1 Western Australia paratype 2016-03-16 WAMC S. Callan & E. S. Volschenk Australia -23.142092 Pilbara 1 118.64659 West Angelas 49 50 WAMC 78976 1 1 Western Australia paratype [230,941,691,717] WAMC Australia 49 50 WAMC 78977 1 1 Western Australia paratype 2022-04-20 WAMC, BES, BMR A. Riemer & I. Johansson Australia -22.783333 Pilbara 1258 119.15 Yandi Creek 49 50 WAMC 82076, BES15605, BMR05460 1 1 Western Australia paratype 2022-09-11 WAMC, BES J. Delaney & S. Rodman & Wilkins Australia -22.716667 Pilbara 1258 118.95 Yandi Creek 49 50 WAMC 82078, BES22638 1 1 Western Australia paratype WAMC, BES Australia 49 50 WAMC 82079, BES22638 1 1 Western Australia paratype 2016-03-21 WAMC S. Callan & E. S. Volschenk Australia -23.141947 Pilbara 1 118.65491 West Angelas 49 50 WAMC 70169 49 Western Australia 2016-03-16 WAMC S. Callan & E. S. Volschenk Australia -23.142092 Pilbara 1 118.64659 West Angelas 49 50 WAMC 70170 91 Western Australia 2021-02-07 WAMC, BES P. Runham & A. Mittra Australia -23.084072 Pilbara 1 119.155655 Rhodes Ridge 49 50 WAMC 82067, BES11534 1 1 Western Australia 2021-02-09 WAMC, BES P. Runham & A. Mittra Australia -23.089123 Pilbara 1 119.13692 Rhodes Ridge 49 50 WAMC 82069, BES11621 4 1 3 Western Australia [504,1432,1086,1113] WAMC, BES Australia 49 50 WAMC 82072, BES11526 56 Western Australia 2021-02-09 WAMC, BES, BMR P. Runham & A. Mittra Australia -23.162706 Pilbara 1 119.01781 Rhodes Ridge 49 50 WAMC 82075, BES12774, BMR03955 1 1 Western Australia 2023-04-01 WAMC, BES, BMR J. Delaney & K. Nguyen & Paget Australia -22.716667 Yandi Creek 1258 118.933334 49 50 WAMC 82077, BES19803, BMR08587 1 1 Western Australia 2022-09-11 WAMC, BES J. Delaney & S. Rodman & Wilkins Australia -22.716667 Pilbara 1258 118.95 Yandi Creek 49 50 WAMC 82080, BES22638 11 5 5 1 Western Australia