Anaspides driesseni, G. & Stefan & T., 2023

G., Christoph, Stefan & T., Shane, 2023, A New Species of Tasmanian Mountain Shrimp, Anaspides driesseni sp. nov. (Malacostraca, Anaspidacea, Anaspidesidae), Records of the Australian Museum (Rec. Aust. Mus.) 75 (1), pp. 25-43 : 30-36

Anaspides driesseni sp. nov.

urn:lsid:zoobank.org:act:555CA468-CCA2-42FC-8985-239C251CFCCF

Figs 1– 5 , 10E–F

Anaspides tasmaniae .— Smith, 1909 a: 64, 70 (North West Bay River ).— Manton , 1930: pl. 2, 3 (dark form).— Tjønneland et al., 1984: 226, figs. 1–10 (heart ultrastructure).

Anaspides swaini .— Ahyong, 2016: 352, 353, 359: fig. 32 G–J, 33A–J.—HÖpel et al., 2021: 47, 52, fig. 2 [in part, form 3].

Holotype: TMAG G9228, ♂ (32 mm), Myrtle Forest Creek , Wellington Range, 42°51.6'S 147°10.3'E, 440 m asl, coll. R. Swain, Jun 1969 .

Paratypes: TMAG G6403, 4 ♂♂ (28–33 mm), 14 juv. ♂♂ (17–26 mm), 17 ♀♀ (24–38 mm), 3 juv. ♀♀ (18–21 mm), collected with holotype; ZSRO CR208, Ana777–Ana780 (sequenced), 1 juv. ♂ (23 mm), 3 juv. ♀♀ (21–23 mm), Myrtle Forest Creek , 42°51'34"S 147°09'33"E, 553 m asl, coll. M. Grams, C. HÖpel & S. Richter, 08 Dec 2022; ZSRO CR202, Ana710-712 (sequenced) 1 ♂ (34 mm), 1 juv.♂ (21 mm), 1 juv.♀ (22 mm), Myrtle Forest Creek , 42°51'50.1012"S 147°09'11.2788"E, 676 m asl, coll. A. Palfreyman, 8 Nov 2021; ZSRO CR66, Ana310–Ana312 (sequenced), 3 juv. ♀♀ (8–11 mm), Myrtle Forest Creek , 42°51'34"S 147°09'33"E, 553 m asl, coll. S. Ahyong, C. HÖpel, M. Reinhardt & S. Richter, 28 Feb 2017; ZSRO CR67, Ana146–148 (sequenced), Ana313–314 (sequenced), 2 juv. ♂♂ (13–15 mm), 3 juv.♀♀ (12–15 mm), Myrtle Forest Creek, 42°51'37"S 147°09'08"E, 734 m asl, coll. S. Ahyong, C. HÖpel, M. Reinhardt & S. Richter, 28 Feb 2017; AM P106558, 5 juv. ♂♂ (9–29 mm), 2 juv. ♀♀ (14–16 mm), Myrtle Forest Creek , 42°51'37"S 147°09'08"E, 734 m asl, coll. S.Ahyong, C. HÖpel, M.Reinhardt & S. Richter, 28 Feb 2017; TMAG G6402, 4 ♂♂ (26–31 mm), 1 juv. ♂ (22 mm), 10 ♀♀ (27–34 mm), Myrtle Forest Creek , 42°51.6'S 147°10.3'E, 440 m asl, coll. R. Swain, Jun 1969; TMAG G983, 19 juv. ♂♂ (18–25 mm), 12 juv. ♀♀ (14–26 mm), Sorell Creek, Myrtle Gully [ Myrtle Forest ], Collinsvale , 42°53.8'S 147°15.4'E, 400 m asl, coll. museum staff, 9 Dec 1964; TMAG G6315, 4 ♂♂ (24–28 mm), 6 ♀♀ (25–32 mm), Myrtle Forest , Collinsvale, 42°51.6'S 147°10.3'E, 440 m asl, coll. R. Swain, Sep 1969.

Other material examined. Southwest National Park, Snowy Mountains: ZSRO CR183, 6 ♂♂ (29–35 mm), 3 juv. ♂♂ (15–16 mm), 3 ♀♀ (32–35 mm), 7 juv.♀♀ (12–20 mm), Snowy North , road off Waterfall Creek Road, unnamed creek, tributary of Styx River , 42°49'39.03"S 146°39'41.70"E, 521 m asl, coll. S. Ahyong, M. Grams , C. HÖpel, S. Richter, 23 Feb 2019; AM P106559, 2 ♂♂ (29–34 mm), 2 juv. ♂♂ (13–17 mm), 6 ♀♀ (31–35 mm), 7 juv. ♀♀ (12–16 mm), Snowy North, logging road off Waterfall Creek Road, unnamed creek, tributary of Styx River , 42°45'13.1"S 146°37'25"E, 521 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, S. Richter, 23 Feb 2019; ZSRO CR79, 1 juv. ♀ (9 mm), Snowy North, tributary of South Styx River , 42°50'32.1"S 146°37'11.2"E, 439 m asl, coll. C. HÖpel, M. Reinhardt & S. Richter, 18 Mar 2017; TMAG 14369/G113, 2 ♂♂ (29 mm), 2 juv. ♂♂ (24–25 mm), 5 ♀♀ (24–34 mm), 1 juv. ♀ (23 mm) Snowy Mountains , 42°53.4'S 146°39'E, 2000 ft asl [600 m], coll. C.D. King, 20 Feb 1939; TMAG 14373/G117, 3 ♂♂ (29–32 mm), 2 juv. ♂♂ (25–26 mm), 3 ♀♀ (26–33 mm), 2 juv. ♀♀ (19–24 mm), Snowy Mountains , 42°55.5'S 146°40.5'E, 3000 ft asl [900 m], small Lake, coll. C.D.King, Feb 1939; AM P56374, 2 juv.♂♂ (22–29 mm), Lake Skinner , Snowy Mountains, 42°57'S 146°41'E, C.62T, small stream at end of track to Lake, coll.W.Ponder et al., 15 Jan 1982; AM P73044, 2 juv. ♂♂ (17–28 mm), 3 juv. ♀♀ (10–25 mm), Snowy North , stream flowing into Styx River, 42°53.26'S 146°39.30'E, 590 m asl, coll. S. Jarman; TMAG G397, 1 ♀ (40 mm), plateau on summit of Mt Snowy, small pool 3 inches deep, 3500 ft asl [1050 m], coll. J.F.Thompson, 31 Jan 1962; ZSRO CR207, 2 ♂♂ (40 mm), 2 juv. ♂♂ (28–29 mm), 1 ♀ (41 mm), nameless tarn near summit of Snowy South, Snowy Mountains, 42°56'25.7"S 146°39'53.0"E, 1260 m asl, coll.A. Palfreyman, 02 Dec 2022; ZSRO CR206, 3 juv. ♂♂ (21–23 mm), 2 ♀♀ (27–31 mm), 2 juv. ♀♀ (22 mm), Lake Skinner , Snowy Mountains, 42°56'25.3"S 146°40'43.9"E, 980 m asl, coll. M. Grams, C. HÖpel, A. Palfreyman, S. Richter, & M. Weiler, 02 Dec 2022; TMAG G3432, 4 ♀♀ (25–33 mm), 1 juv. ♀ (24 mm), Lake Skinner, Snowy Mountains , 42°56.8'S 146°40.5'E, 970 m asl], coll. D. Farnell , 28 Jan 1962; TMAG G130, 2 ♂♂ (32–34 mm), 1 juv. ♂ (25 mm), 3 ♀♀ (32–35 mm), 2 juv. ♀♀ (17–22 mm), Lake Denison , 42°57.4'S 146°41.0'E, 1900 ft asl [570 m], coll. C. King, Feb 1936; TMAG G127, 1 juv. ♂ (25 mm), 5 juv. ♀♀ (13–20 mm), Lake Denison , 42°57.4'S 146°41.0'E, 1900 ft asl [570 m], coll. C. King, Feb 1939; TMAG G112, 1 ♂ (28 mm), 2 juv. ♂♂ (23–25 mm), 7 ♀♀ (26–31 mm), 2 juv. ♀♀ (22–25 mm), Lake Skinner , Snowy Mountains, 42°56.8'S 146°40.1'E, c. 3000 ft asl [970 m], coll. C.D. King, Feb 1939; TMAG G6407, 2 ♂♂ (28–29 mm), 6 juv. ♂♂ (20–22 mm), 10 ♀♀ (23–26 mm), 9 juv.♀♀ (8–14 mm), Snowy Mountains, 42°54'S 146°42'E, tarn, coll. M. Fenton, 19 Nov 1970; TMAG G6361, 1 juv. ♂ (12 mm), Snowy South, 42°56.7'S 146°39.4'E, small Lake on slope, 1340 m asl, coll. P. Davies, Apr 1986; AM P99308, 1 ♂ (damaged), Lake Picton , 43°09.56'S 146°38.23'E, coll. S. Jarman; TMAG G6317, 10 juv. ♂♂ (15–28 mm), 20 ♀♀ (24–33 mm), 11 juv. ♀♀ (14–21), Lake Picton, 43°09.5'S 146°38.3'E, 900 m asl, 23 Jan 1969; TMAG G6424, 1 ♂ (24 mm), 2 juv. ♂♂ (26–28 mm), 25 ♀♀ (23–36 mm), Lake Picton, 43°09.5'S 146°38.2'E, 900 m asl, coll. P. Tyler, Jan 1969.

Arve Valley, Hartz: TMG G2214, 1 ♀ (25 mm),Arve Loop Road,Arve Valley, 43°07.7'S 146°44.9'E, from creek, 390 m asl, coll.R. Shoobridge,14 Feb 1980; TMAG G6382, 24 juv. ♂♂ (13–28 mm), 8 ♀♀ (26–32 mm), 39 juv. ♀♀ (8–24 mm), 1 indet juv.(7 mm), Hartz Mountains [almost certainly from northern Hartz], coll. R. Swain & G. Bert, Feb 1970.

Wellington Range: ZSRO CR209, 1 ♂ (35 mm), 7 juv. ♂♂ (16–25 mm), 1 ♀ (37 mm), 5 juv. ♀♀ (13–24 mm), 3 indet juv. (5–7 mm), Sorell Creek , 42°52'6.0492"S 147°10'9.9084"E, 600 m asl, coll. M. Grams, C. HÖpel, & S. Richter, 08 Dec 2022; ZSRO CR178, 5 indet juv. (6–11 mm), East-West track, roadside ditch, 42°52'26"S 147°08'36"E, 961 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, S. Richter, 20 Feb 2019; AM P106563, 1 juv. ♂ (24 mm), 2 ♀♀ (33–34 mm), 1 indet juv. (7 mm), East-West track, roadside ditch, 42°52'26"S 147°08'36"E, 961 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, S. Richter, 20 Feb 2019; ZSRO CR181, 1 ♀ (38 mm), silted pool near creek feeding Glen Dhu Creek, 42°52'56"S 147°08'05"E, 946 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, S. Richter, 20 Feb 2019; ZSRO CR180, 3 juv. ♀♀ (16–21 mm), 2 indet (9 mm), Glen Dhu Creek, 42°52'52"S 147°08'11"E, 930 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, S. Richter, 20 Feb 2019; AM P106564, 1 ♂ (30 mm), 3 ♀♀ (27–40 mm), Glen Dhu Creek , 42°52'52"S 147°08'11"E, 930 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, S. Richter, 20 Feb 2019; ZSRO CR179, 3 juv. ♂♂ (22–29 mm), 1 ♀ (33 mm) Knights Creek , 42°52'08"S 147°12'02"E, 687 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, S. Richter, 20 Feb 2019; AM P106565, 1 juv.♂ (24 mm), 3 ♀♀ (35–39 mm), Knights Creek , 42°52'08"S 147°12'02"E, 687 m asl, coll. S.Ahyong, M. Grams, C. HÖpel, S. Richter, 20 Feb 2019;AM P106780, 1 ♂ (34 mm), 1 juv.♂ (15 mm), 1 juv.♀ (21 mm), 3 ♀♀ (33–40 mm), Trestle Creek , 42°54'0.7812"S 147°08'10.9788"E, 480 m asl, coll. S.Ahyong, M. Grams, C. HÖpel,A. Palfreyman, S. Richter & M. Weiler , 02 Nov 2022; ZSRO CR205, 1 ♂ (30 mm), 2 juv. ♂♂ (18–21 mm), 9 ♀♀ (32–36 mm), 3 juv. ♀♀ (18–21 mm), Trestle Creek , 42°54'0.7812"S 147°08'10.9788"E, 480 m asl, coll. S. Ahyong, M. Grams, C. HÖpel, A. Palfreyman , S. Richter & M. Weiler, 02 Nov 2022; ZSRO CR204, 1 juv. ♀ (16 mm), Trestle Creek, 42°54'0.7812"S 147°08'10.9788"E, 480 m asl, coll. A. Palfreyman, 12 Nov 2021; AM P4143, 1 ♂ (32 mm), 1 ♀ (34 mm), Mt Wellington, 42°53.8'S 147°14.5'E, coll. E.A. Briggs, pre 1918; AM P14772, 2 ♂♂ (24–26 mm), 1 juv. ♂ (19 mm), 1 juv. ♀ (21 mm), Mt Wellington, 42°54'S 147°14'E, from University of Sydney Biology Dept , 1964;AM P14773, 1 ♂ (36 mm), Mt Wellington,from University of Sydney Biology Dept in 1964, possible Haswell label; AM G1779, 1 ♂ (24 mm), 3 ♀♀ (24–27 mm), 5 juv. ♀♀ (14–20 mm), summit of Mt Wellington , 42°54'S 147°14'E, pres. C. Hedley, pre 1898; AM P2266, 1 ♂ (34 mm), Mt Wellington , 42°54'S 147°14'E, pres. E.G. Goddard; AM P2551, 1 ♂ (32 mm), 4 juv. ♂♂ (19–22 mm), 3 ♀♀ (23–24 mm), 4 juv. ♀♀ (12–20 mm), Mt Wellington , 42°54'S 147°14'E, coll. T.T.Flynn; USNM 59126 (ex AM P 2551), 2 ♂♂ (24–25 mm), Mt Wellington , coll. T.T. Flynn; USNM 78433, 1 ♂ (29 mm), Mt Wellington , snow pools in swamp, coll. Mel Ward; USNM 25030, 1 ♂ (27 mm), 1 ♀ (25 mm), “Lakes (4000 ft) Tasmania ”, G.M. Thomson; AM P9217, 11 juv. ♂♂ (18–29 mm), 12 juv. ♀♀ (19–27 mm), Wishing Well, Mt Wellington , 42°55.67'S 147°14.76'E, 1450 feet asl [442 m], coll. C. Anderson, A. Musgrave, G.P. Whitley, 23 Jan 1928; AM P10724, 8 juv. ♂♂ (16–22 mm), 3 ♀♀ (26–37 mm), 15 juv. ♀♀ (8–24 mm), Mt Wellington , 42°54'S 147°14'E, coll. F.D. Manning, Jan 1935;AM P56375, 1 ♂ (32 mm), 3 juv. ♂♂ (14–18 mm), 7 juv. ♀♀ (12–20 mm), Mt Wellington , small pools (running water) 2500 ft [750 m], coll. J.W. Evans, Dec 1938; AM P82859, 1 ♂ (24 mm), 2 juv. ♂♂ (9–11 mm), 1 ♀ (23 mm), 15 juv. ♀♀ (8–12 mm), Mt Wellington , 12 Mar 1997; TMAG G794, 1 ♂ (23 mm), back of Mt Wellington , coll. G.E. Nicholls, 16 Dec 1933; WAM C58162, 2 ♀♀ (29–34 mm), Mt Wellington , coll. J. Searle; WAM C367 (ex No. 6613), 3 juv. ♀♀ (16–17 mm), Mt Wellington , coll. J. Searle, 29 Jan 1913; SAMA C473, 2 ♀♀ (shrivelled, previously dried; c. 25–26 mm), 2 juv. ♀♀ (9–13 mm), 2 indet juv. (6 mm), North West Bay River, Mt Wellington , 42°55.3'S 147°11.2'E, 2700 ft [810 m], coll. Prof. Osborn; ZSRO CR203, 3 ♂♂ (29–31 mm), 1 juv. ♂ (22 mm), 2 ♀♀ (30–32 mm), Billy Brown River , 42°54'56.0988"S 146°59'13.4988"E, 580 m asl, coll. A. Palfreyman, 21 Jan 2022; AM P9218, 2 ♂♂ (30–32 mm), 3 juv. ♂♂ (20–22 mm), 5 ♀♀ (28–34 mm), 7 juv. ♀♀ (15–23 mm), Fern Tree Glen, Mt Wellington , 42°55.5'S 147°15.7'E, coll. C. Anderson, A. Musgrave, G.P. Whitley, 23 Jan 1928; TMAG G6450, 3 ♂♂ (30–33 mm), 3 juv. ♂♂ (16–22 mm), 6 ♀♀ (26–40 mm), 4 juv. ♀♀ (18–23 mm), St. Crispins Well, Mt Wellington , 42°55.76'S 147°12.57'E, 640 m asl, coll. R. Swain, 14 Feb 1971; ZSRO CR177, 1 juv.♂ (25 mm), 1 juv.♀ (16 mm), 3 indet juv.(7–10 mm), St. Crispins Well , 42°55'39.73"S 147°12'42.48"E, 750 m asl, coll. S. Ahyong, M. Grams, C. HÖpel & S. Richter, 19 Feb 2019; AM P106560, 1 juv. ♂ (24 mm), 2 juv. ♀♀ (13–20 mm), 1 indet juv. (7 mm), St. Crispins Well , 42°55'39.73"S 147°12'42.48"E, 750 m asl, coll. S.Ahyong,M. Grams, C. HÖpel & S. Richter, 19 Feb 2019; ZSRO CR176, 1 juv. ♀ (12 mm), 3 indet juv.(7–9 mm), Levert Rivulet , 42°56'45.33"S 147°13'49.08"E, 524 m asl, coll. S. Ahyong, M. Grams, C. HÖpel & S. Richter, 19 Feb 2019; AM P106561, 1 juv.♀ (26 mm), Levert Rivulet , 42°56'45.33"S 147°13'49.08"E, 524 m asl, coll. S.Ahyong, M. Grams, C. HÖpel & S. Richter, 19 Feb 2019; ZSRO CR175, 2 juv. ♂♂ (10–13 mm), 1 juv. ♀ (13 mm), 2 indet juv. (9 mm), unnamed creek on Pipeline track, 42°57'05.2"S 147°13'49.7"E, 716 m asl, coll. S. Ahyong, M. Grams, C. HÖpel & S. Richter, 19 Feb 2019; AM P106562, 1 juv. ♀ (12 mm), 1 indet juv. (7 mm), unnamed creek on Pipeline track, 42°57'05.2"S 147°13'49.7"E, 716 m asl, coll. S. Ahyong, M. Grams, C. HÖpel & S. Richter, 19 Feb 2019; SAMA C8445, 1 juv. ♂ (21 mm), 1 ♀ (28 mm), 1 juv. ♀ (22 mm), Huonville, creeks, coll. R.T.T.

Description. Eyes with well-developed cornea, pigmented, wider than and longer than half length of stalk; stalk with subparallel margins. Rostrum narrow in adults, apex blunt.

Pleonites with pleura sparsely setose, rounded; pleura 1–3 unarmed; pleuron 4 usually unarmed (rarely with 1 small spine on one side); pleuron 5 with 0–3 small spines (usually unarmed or with 1 spine). Pleonite 5 posterior tergal margin setose, unarmed or with 1–4 small spines either side of midline. Pleonite 6 tergal posterior margin with 0–11 spines in juveniles and 0–15 in adults, setose; posterolateral margin setose, rounded, with or without minute denticles. Pleonal sternites 3–4 with distinctly bilobed median processes between pleopod bases, widest on sternite 3; sternite 5 with narrow, weakly emarginate lobe.

Telson slightly wider than long to longer than wide (usually equal to slightly wider than long), pentagonal, widest proximally; lateral margins slightly sinuous to nearly parallel in dorsal outline, transition from lateral to posterior margin obtusely angular; posterior margin slightly angular, apex bluntly rounded medially; posterior spine row with 14–53 (juveniles) or 24–54 (adults) slender, evenly graded, closely spaced spines, longest medially.

Antennule inner flagellum about 0.2× body length (22–23 annulations in holotype); in adult males articles 1–5 wider than long, articles 6–7 as wide as long, article 8 wider than long, articles 1–6 densely setose on lateral inner margin, articles 1–8 with small spines on the outer lateral margin, longest on article 1, article 4–7 obtusely angled inner margin, article 7 usually with 2 small, clasping spines proximally (rarely 3 or 4 clasping spines on one site), directed distally, distal clasping spines equal to slightly longer than width of article 7, proximal clasping spine equal to slightly shorter than width of article 7; outer flagellum 0.5–0.9× body length (usually 0.5–0.7) (77–85 annulations in holotype).

Antennal flagellum 0.3–0.4× body length (55–58 annulations in holotype); scaphocerite elongate, ovate, lateral spine slightly distal to midlength; apex reaching as far as midlength of distal peduncular article.

Right mandibular incisor process with proximal tooth distally bifid to quadrifid, usually trifid.

Pleopods 1–4 (rarely on pleopod 5 on one side) each with endopod in adults. Adult male pleopod 1 distally widened, scoop-like, lateral margins expanded, obscuring retinacular lobe in lateral view.

Uropodal protopod dorsally unarmed or with 1–3 small spines; exopod with 2–5 movable spines on outer margin near position of partial diaeresis; exopod length about 2.5–3.0× width, slightly wider than endopod, apex rounded, narrow to relatively broad.

Measurements. Adult male (n = 62) 24–40 mm, juvenile male (n = 165) 9–29 mm, adult female (n = 187) 23–41 mm, juvenile female (n = 214) 8–27 mm, sex indeterminate (n = 24) 5–11 mm.

Distribution. South-eastern Tasmania from the Arve Valley and Hartz Mountains area over the Mt Picton area and Snowy Mountains to the Wellington Range and western to northwestern Mt Wellington (Collinsvale and North West Bay River catchment); Southern-Derwent and Huon drainage system ( Figs 7–10 ); 390–1260 m asl.

Etymology. Named in honour of Michael Driessen PhD, for his many contributions to the conservation of Tasmanian Wildlife, especially of our knowledge of Allanaspides , and for his facilitation of our research in Tasmania.

Remarks. Of the three morphological forms of Anaspides swaini recognized by Ahyong (2016), A. driesseni sp. nov. corresponds to form 3. Anaspides driesseni sp. nov. differs from form 1 through the reduced pleonal spination (except for some specimens from the Arthurs Range and Frankland Range), the less narrowed lateral margins of the telson, which are more parallel and narrows just to the end, the shape of the antennule inner flagellum with the highly setose lateral inner margins on article 1–6, the proportions of article 5–6 (in A. swaini form 1, article 5 is as wide as long to slightly longer than wide and article 6 is always longer than wide), the obtusely angled inner margin of article 4–7 and the presence of two short clasping spines, with the distal clasping spine being equal to slightly longer than the width of article 7 and the proximal clasping spine being equal to slightly shorter than the width of article 7 ( Figs 2G , 4E,H,M , 5 ). In contrast, both clasping spines of A. swaini form 1 are always longer than the width of article 7 (1.3–2.0× longer than the width) ( Fig. 11A,B ). Anaspides swaini form 2 has reduced pleonal spination as in A. driesseni , but differs in the shape of the telson, resembling that of form 1, the presence of pleopodal endopod 1–5 and the shape of the antennule inner flagellum. As in A. swaini form 1, both clasping spines are longer than the width of article 7 (1.1–1.8× longer than the width of article 7), only article 6 is obtusely angled and articles 5–6 are longer than wide ( Fig. 11C ). Also A. swaini form 2 shows less setation on articles 1–6, similar to that of A. swaini form 1.

Anaspides driesseni sp. nov. is distinguished from other congeners by the combination of the angular posterior margin of the telson, the presence of pleopodal endopod 1–4, the greater size at maturity (23–29 mm, usually 26–28 mm), the shape of the antennule inner flagellum in adult males ( Figs 2G , 4E,H,J , 5 ) and the presence of two small clasping spines ( Figs 2G , 4E,J , 5 ).

Sexual maturation at a larger body size (indicated by the full development of secondary sexual features) is noticeable and separates A. driesseni from all other species of the genus. In A. driesseni , sexual maturity is reached by 23–29 mm, usually at 26–28 mm body length, while other species reach maturity at 18–23 mm (usually 20–21 mm), respectively 14–15 mm in A. spinulae (Ahyong, 2016) . In A. driesseni , the endopod of pleopod 4 is not developed (occasionally on one side) before reaching a size of about 11 mm.

Overall, A. driesseni is morphologically rather consistent, with only slight variation evident. The specimens from the Snowy Range region, except those from the unnamed creek crossing the road off Waterfall Creek Road (tributary of Styx River) (ZSRO CR183, AM P106559), some specimens from Lake Skinner and one specimen from Lake Picton (TMAG G6424), lack the denticle on the uropodal protopod and show no pleural spination of the pleon. Furthermore, the antennular outer flagellum is elongated, ranging from 0.7–0.9× of the body length in comparison to specimens from the Wellington Range and the tributary of Styx River (0.4–0.8× of the body length, usually 0.4–0.6). The Arve-Valley-Hartz populations similarly lack the denticle on the uropodal protopod, but in the remaining characters, resemble the populations from the Wellington Range. Only in three aberrant specimens from Snowy North (ZSRO CR183) and one specimen from a nameless tarn near the summit of Snowy South, an abnormal number of clasping spines on one side was observed. Three specimens had 3 clasping spines (2x Snowy North, 1x Snowy South) on one side rather than the usual 2, and one specimen had 4 clasping spines ( Fig. 5B ). In these specimens the additional spines were not in a row as in “normal” males, but instead they stand disorderly in a second row, forming a kind of cluster. These cases appear to be the result of abnormal development of the clasping spines, which typically develop in a single row along the article axis.

Anaspides driesseni the species with the largest known males, with two males from an unnamed tarn near the summit of Snowy South reaching 40 mm total length. The largest known male so far is one male of A. richardsoni from Honeycomb Cave in the Mole Creek karst system reaching 37 mm. The largest epigean males apart A. driesseni are recorded with 33 mm in A. richardsoni and A. tasmaniae (Ahyong, 2016) .

Why epigean A. driesseni attains such a large maximum body size compared to congeners might be related to the onset of maturity at a larger body size.

To date, there are no known subterranean occurrences of A. driesseni .

Molecular data. Maximum intraspecific uncorrected p-distances for A. driesseni were 2.2% in COI, 0.6% in 16S and 0.3% in 28S, while interspecific distances to other congeners of the genus Anaspides were 8.4–14.2% in COI, 1.2–7.1% in 16S and 0.6–3.5% in 28S ( Table 2 ). In COI we uncovered 11 different haplotypes in 4 distinct haplotype clusters for Anaspides driesseni ( Fig. 6 ). The first cluster comprises specimens from an unnamed creek crossing the road off Waterfall Creek Road, the tributary of South Styx River, a nameless tarn near Snowy South, Billy Brown River, Glen Dhu Creek and a roadside ditch near the East-West track. The second cluster comprises specimens from Lake Skinner, while the third cluster comprises specimens from St. Crispins Well and an unnamed creek crossing the Pipeline Track. The fourth cluster comprises specimens from Myrtle Forest Creek, Sorell Creek, Trestle Creek and Levert Rivulet. In 16S, three haplotypes were found each separated by one mutation. One haplotype comprises specimens from Myrtle Forest Creek and Sorell Creek, one comprises specimens from Trestle Creek and Knights Creek and the last one comprises specimens from Billy Brown River, a tributary of the South Styx River and a nameless tarn near the summit of Snowy South. In 28S, we found 4 haplotypes, each separated by one mutation respectively one indel (compared with 6 nucleotide positions in the other two haplotypes). The first haplotype comprises specimens from Billy Brown River, Levert Rivulet, Glen Dhu Creek and the roadside ditch at the East-West track. The second haplotype comprises specimens from Trestle Creek, Billy Brown River, St. Crispins Well, an unnamed creek crossing the Pipeline Track, the tributary to South Styx River, an unnamed creek crossing the road off Waterfall Creek Road, Lake Skinner and a nameless tarn near the summit of Snowy South. The third haplotype comprises specimens from Lake Skinner, while the fourth haplotypes comprises specimens from Myrtle Forest Creek ( Fig. 6 ).

Figures

Figure 1. Anaspides driesseni sp. nov., male holotype, 32 mm, Myrtle Forest Creek, Wellington Range, TMAG G9228. Habitus, right lateral view. Scale = 2.0 mm.

Figure 2. Anaspides driesseni sp. nov., male holotype, 32 mm, Myrtle Forest Creek, Wellington Range, TMAG G9228. (A) anterior cephalothorax, dorsal view; (B) pleonite 6, telson and right uropod; (C) pleonite 6 and telson; (D–F) pleonites 4–6 pleura, right lateral view; (G) right antennule; (H) right antenna; (I) labrum, anterior view; (J) right mandible; (K) right mandible incisor process; (L) left mandible incisor process; (M) paragnaths, anterior view; (N) right maxillule; (O) right maxilla; (P) pleopods 1–2, in-situ, ventral view; (Q–R) right pleopod 1 endopod, lateral view and dorsal view, respectively; (S) right pleopod 2 endopod, lateral view. Scale:A, B, D–H, P–S = 2.0 mm, C, I–O = 1.0 mm.

Figure 3. Anaspides driesseni sp. nov., (A–L) male holotype, 32 mm, Myrtle Forest Creek, Wellington Range, TMAG G6403; (M–N), female, 34 mm, Mount Wellington, AM P9218. (A) right thoracopod 1 (maxilliped); (B–H) right thoracopods 2–8, respectively; (I) right pleopod 4, anterior view; (J–L) pleonites 3–5 median sternal processes, respectively; (M, N) female gonopore, right lateral and ventral views, respectively. Scale 2.0 mm.

Figure 4. Anaspides driesseni sp. nov. selected features. (A–E) juv. male, 28 mm, Myrtle Forest,AM P106558; (F–H) juv.male, 29 mm, Myrtle Forest, AM P106558 (I–J) male, 28 mm, Mt Fenton, TMAG G6407. (A, F) anterior cephalothorax. (B) telson with uropods. (C) scaphocerite. (G, I) telson. (D) pleonal pleura. (E) right antennule with clasping spines. (H, J) left antennule with clasping spines. Scale: A–D, F, G, I = 2.0 mm, E, H, J = 1.0 mm.

Figure 5. Dorsal view on the antenna of male A. driesseni sp. nov. (A–C) Snowy North, unnamed tributary of Styx River crossing the road off Waterfall Creek Road, ZSRO CR183; (A) 35 mm, right antenna; (B) Ana 560, 35 mm, right antenna, with 4 abnormal clasping spines, highlighted with white outlines; (C) Ana 560, 35 mm, left antenna; (D) right antenna, 29 mm, Knights Creek, Wellington Range, ZSRO CR179. Scale bars: 1 mm.

Figure 6. COI, 16S and 28S median joining haplotype networks of Anaspides driesseni. Colours correspond to figure legend. The size of each haplotype corresponds to the number of individuals sharing that specific haplotype (see scale). Each dash corresponds to one mutation respectively indel.

Figure 7. Distribution map of A. swaini and A. driesseni with important drainage divides (1) Franklin-Gordon; (2) Derwent; (3) Huon; (4) Port Davey; and (5) North West Bay River. Light brownish background colour indicates National Parks. (A) detailed view of Snowy Range, see Fig. 8; (B) detailed view of Wellington Park, see Fig. 9. Modified after the Tasmania catchments map. https://dpipwe.tas.gov. au/Documents/Tasmania-Catchment-Map.pdf

Figure 8. Topographical map of Snowy Range with major drainage systems,aswell ascollectionsites withgenetically analysedindividuals from this study. 1 corresponds to the Derwent River drainage system, while 2 corresponds to the Huon River drainage systems. Base image by TASMAP© (www.tasmap.tas.gov.au) State of Tasmania.

Figure 9. Topographical map of Wellington Park with drainage and sub-drainage systems, as well as collection sites with genetically analysed individuals from this study. Subdrainage systems 1–7 drain into the Derwent River drainage system: (1) Lachlan River/Myrtle Falls Creek; (2) Glen Dhu Creek; (3) Myrtle Forest Creek/Sorell Creek; (4) Knights Creek; (5) New Town Rivulet; (6) Guy Fawkes; (7) Browns River; (8) corresponds to the Noth West Bay River drainage system; whereas subdrainage system 9–10 drain into the Huon River drainage system; (9) Mountain River; (10) Judds Creek. Base image by TASMAP© (www.tasmap.tas.gov.au). State of Tasmania.

Figure 10. Typical habitats and colour-in-life of A. driesseni: (A) Glen Dhu Creek (B) Knights Creek at Knights Creek Track (C) small trickle fed road side ditch, next to Collins Cap Trail (D) unnamed creek, tributary of Styx River, crossing the road off Waterfall Creek Road (E) adult male, 35 mm,Ana560, unnamed creek, tributary of Styx River, crossing the road off Waterfall Creek Road. (F) adult male, 29 mm, AM P106559, unnamed creek, tributary of Styx River, crossing the road off Waterfall Creek Road.

Figure 11. Dorsal view on the antenna of male A. swaini form 1 and 2: (A) A. swaini form 1, 28 mm, tributary of Weld River, Mueller Road, 5.1 km behind west gate, ZSRO CR76,Ana329, right antenna; (B) A. swaini form 1, 23 mm, tributary of Weld River, Mueller Road, 4.4 km behind west gate, ZSRO CR75, Ana 655, right antenna; (C) A. swaini form 2, 29 mm, Lake Oenone, ZSRO CR206, Ana621, left antenna (mirrored view). Scale bars: 1 mm.