Anaspides tasmaniae ( Thomson, 1893 )

Ahyong, Shane T., 2016, The Tasmanian Mountain Shrimps, Anaspides Thomson, 1894 (Crustacea, Syncarida, Anaspididae), Records of the Australian Museum 68 (7), pp. 313-364 : 317-322

Anaspides tasmaniae ( Thomson, 1893)

Figs 1–4 , 35A , 36

Anaspis tasmaniae Thomson, 1893: 7–10 (type locality: near The Springs, Mt Wellington).

Anaspides tasmaniae . — Calman, 1897: 787–794, pl. 1, 2, fig. 12–14. — Thomson, 1897: 580; 1926: 161. — Manton, 1930: pl. 4. — Hickman, 1937: 2, tab. 1–3, pl. 1–13. — Hewer, 1967: 1–2. —Kauri & Lake, 1972: 432, figs. 1–17. — Williams, 1974: 80, fig. 4.6, tab. 4.1. —Silvey & Wilson, 1979: 122. —Jarman & Elliot, 2000: 624, tab. 1 (Mt Wellington). — Jarman, 2001: 201, tab. 1. — Jarman et al. 2000: 27, tab. 1 — Lake et al., 2002: 11–12. — Serov, 2002: 8, 15. — Camacho, 2006: 4.

Type material. LECTOTYPE: AM G2130 ,male (23 mm), Mt Wellington,“ 4000 ft ”, per G.M. Thomson . PARALECTOTYPES: AM P99315, 1 female (24 mm), 1 juv. ♀ (19 mm), collected with lectotype ; OM Iv.1396, 1♀ (22 mm), Mt Wellington, “ 4000 ft ” [1200 m], coll. G.M. Thomson.

Other material examined. TMAG 14370 /G114, 7♂♂ (14–26 mm), 1♀ (29 mm), New Town Rivulet, Mt Wellington, 42°52.5'S 147°15.8' E, 1000 ft asl [300 m], coll. J. Pearson, 20 Jun 1937 ; QVM 10 :8079, 1♂ (damaged, c. 27 mm), 2♀♀ (26–27 mm), New Town Creek, Mt Wellington, 42°52'S 147°16'E, coll. E. Guiler, 1956 ; TMAG G6433 , 2♂♂ (22–24 mm), 6♀♀ (22–26 mm), Lenah Valley, Newtown Rivulet , 42°51.6'S 147°16.9'E, 150 m asl,coll . R. Swain , Jul 1969 ; NMV J42438 , 1♂ (28 mm), 2♀♀ (21–25 mm), 2 juv. ♀♀ (13–14 mm), Organ Pipes, Mt Wellington, 42°53.8'S 147°14.5' S coll. 12 May 1912 , pres J. Searle , Feb 1936 ; TMAG G6383 , 5♀♀ (27–32 mm), Picnic Hut, Mt Wellington, 42°53.9'S 147°14.2'E, 1250 m asl, coll . R. Swain , 4 Nov 1969 ; TMAG G6404 , 3♂♂ (22–24 mm), 10 ♀♀ (22–27 mm), Picnic Hut, Mt Wellington, 42°53.9'S 147°14.2'E, 1250 m asl, coll . R. Swain , Apr 1969 ; TMAG G6365 , 2♂♂ (21–24 mm), 7♀♀ (24–30 mm), Picnic Hut, Mt Wellington, 42°53.9'S 147°14.2'E, 1250 m asl, coll . R. Swain , 14 Sep 1969 ; AM P14157, 2 specimens (slide preparations), Picnic Point, Mt Wellington, 42°54.9'S 147°14.7'E, stream, 800 m asl, coll. W.D. Williams 29 Jan 1963 ; AM P99314, 1♀ (28 mm), The Chalet, Mt Wellington, 42°53.43'S 147°14.04'E, stream, 970 m asl, coll. S. Jarman, Nov 1997 ; TMAG G6414 , 4♂♂ (27–33 mm), 7♀♀ (27–35 mm), Fern Tree, Mt Wellington, 42°55.5'S 147°15.6'E, 420 m asl, coll . R. Swain , 14 Feb 1971 ; AM P97847, 1 juv. ♀ (12 mm, Silver Falls, Mt Wellington, 42°55.3'S 147°14.9'E, 1500 ft asl [450 m], 28 Feb 1935 ; TMAG G6431 , 2♂♂ (26 mm), 3 juv. ♂♂ (19–21 mm), 5♀♀ (19–28 mm), Browns River, above Silver Falls , 42°55.1'S 147°14.7'E, 620 m asl, coll. I. Wilson & B. Knott, 20 Jan 1971 ; AM P98089, 1♂ (24 mm), 4 juv. ♂♂ (14–16 mm), 2♀♀ (23–28 mm), 4♀♀ (10–16 mm), Mt Wellington, creeks, coll . R. Swain & A. Richardson, Jul 1990 ; MZUSP 33665 , 1 juv. ♀ (16 mm), Mt Wellington, coll . R. Swain & A. Richardson, Jul 1990 ; UFMG, 1♀ (19 mm), Mt Wellington, coll . R. Swain & A. Richardson, Jul 1990 ; USNM 60111 , 1♂ (25 mm), 1 juv. ♂ (15 mm), 1♀ (23 mm), Silver Falls , Mt Wellington, coll. W.M. Tattersall, 1914 ; HMUS Cr (M) II/II/1–1(i), 18♂♂ (14–24 mm), 16♀♀ (14–28 mm), from creeks on Mt Wellington, 26 Aug 1965 ; USNM 291481 , 1♂ (24 mm), Mt Wellington, coll. F . R. Schram , 25 May 1980 ; NMV J42440 , 1♀ (28 mm), Mt Wellington, 4000 ft asl [1200 m], coll. A. Neboiss, 22 Feb 1967 ; TMAG, 5♂♂ (24–26 mm), no data ; USNM 30578 , 2 juv. ♂♂ (13–14 mm), 1♀ (22 mm), 2 juv. ♀♀ (13–14 mm), from G.M. Thomson, no data .

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

Pleonites with sparsely setose pleural margins, rounded; pleuron 1 unarmed; pleura 2–3 with 0–2 small spines; pleuron 4 with 1–4 small spines and scattered setae. Pleonite 5 pleuron with 1–4 spines and scattered setae; posterior tergal margin with 3–5 spines either side of midline, setose. Pleonite 6 posterior margin spinose, setose; posterolateral margin setose, rounded. Pleonal sternites 3–5 with low, weakly bilobed median processes between pleopod bases, widest on sternite 3, narrowest on sternite 5.

Telson longer than wide, linguiform, widest proximally; lateral margins sinuous in dorsal outline, distally convergent; transition from lateral to rounded posterior margin evenly curved, seamless; posterior spine row with 19–37 short, evenly graded, slender, closely spaced spines, generally longest medially.

Antennule inner flagellum about 0.2 × body length (19–20 articles in figured 28 mm male); article 7 inner margin obtusely angled in adult males, with 2 long, slender clasping spines proximally; outer flagellum 0.4–0.5 × body length (69 articles in figured 28 mm male). Antennal flagellum 0.3–0.4 × body length (47 articles in figured 28 mm male); scaphocerite elongate, ovate, lateral spine slightly distal to midlength; apex reaching almost to midlength of distal peduncular article.

Right mandibular incisor process with proximal tooth distally undivided to trifurcate, usually bifid.

Pleopods 1–4 with endopod in adults (rarely on one side on pleopod 5). Adult male pleopod 1 distally widened, scoop-like, lateral margins weakly expanded, not obscuring retinacular lobe in lateral view.

Uropodal protopod dorsally unarmed or with 1 or 2 small spines; exopod with 2–4 movable spines on outer margin near position of partial diaeresis; exopod length about 2.5–3 times width, as wide as endopod, apex rounded, relatively broad.

Measurements. Male (n = 55) 14–33 mm; female (n = 96) 10–35 mm.

Remarks. Anaspides tasmaniae is readily distinguished from other species of the genus by the combination of welldeveloped eyes, the presence of two antennular clasping spines in adult males ( Fig. 2D ), the elongated telson with an evenly rounded posterior margin lined with closely set spinules ( Fig. 2B ), and a male pleopod 1 in which the retinacular lobe is visible in lateral view ( Fig. 3I ). Anaspides tasmaniae shares the presence of two male antennular clasping spines with A. swaini and A. spinulae , but differs by the rounded versus triangular posterior margin of the telson. Although some specimens of A. swaini may also have a slightly rounded posterior margin of the telson ( Fig. 33L ), the transition between the lateral and posterior margins, marked by the beginning of the spine row, is seamless in A. tasmaniae rather than bluntly and obtusely angular.

Morphological variation in A. tasmaniae is not marked. The pleonite 4–5 pleura (sometimes also 2–3) are multidenticulate, with 1–4 (usually 2 or 3) small pleural spines on pleonites 4 and 5 ( Fig. 4 ). The posterior tergal margin of pleonite 5 is spinose (usually 2–4 small spines on either side of the midline) and that of pleonite 6 is spinose along the entire posterior margin. The extent of pleonal spination of A. tasmaniae , like A. swaini , may approach that of A. spinulae . In A. spinulae , however, the pleonal spines are always considerably more prominent, even in juveniles ( Fig. 28B,E ), and the posterolateral angle of somite 6 is produced to a prominent spine ( Fig. 25C ), rather than forming a blunt lobe ( Fig. 2B,C ). The proximal incisor tooth on the right mandible of A. tasmaniae is usually distally bifid or trifid (occasionally undivided) ( Fig. 2H ). As in other congeners, the rostrum of A. tasmaniae is proportionally broadest in juveniles, becoming proportionally narrower with increasing body size, and the proportional length of setae on the pleonal pleura and posterior margins decreases with increasing body size. The pleopod 5 endopod is absent in all specimens except for a male from Lenah Valley (24 mm; TMAG G6433) in which an endopod is present on the right side. Both sexes exhibit full secondary sexual characters by 20–21 mm body length. Anaspides tasmaniae was previously accorded a wide distribution throughout Tasmania, but is here restricted to southeastern Tasmania from surface localities on the eastern and southeastern face of Mt Wellington at altitudes of 150–1250 m above sea-level; it is not yet known from caves. Anaspides from elsewhere in Tasmania are referrable to other species ( Ahyong, 2015). The locality data accompanying a number of specimens of A. tasmaniae sensu stricto from Mt Wellington do not indicate the drainage or precise location, but those with more specific locality data are all from eastern drainages on Mt Wellington between the catchments of New Town Rivulet and Browns River. Previous records of A. tasmaniae from northern and western localities around Mt Wellington, such as Myrtle Forest (Collinsvale) and the catchment of the North West Bay River ( O’Brien, 1990) are referrable to A. swaini , having an angular rather than evenly rounded posterior margin of the telson and minimal pleonal spination (at most with scattered denticles on pleonite 6 and occasionally one or two denticles on the pleonite 5 pleuron) ( Fig. 33A–J ). A series from the Huonville area slightly west of Mt Wellington (presumably from the catchment of the Mountain River) is also referable to A. swaini . Specimens corresponding to A. swaini , but labelled only as coming from Mt Wellington, were presumably collected from a westerly locality in the North West Bay River catchment. Two anomalous lots with specific locality data, however, were collected in 1928 from Fern Tree Glen and Wishing Well on the southeastern face of Mt Wellington (AM P9217, 9218). The location of Wishing Well is well known but “Fern Tree Glen” is probably an error for Fern Tree Bower on the lower Browns River, well downstream of Silver Falls. Either way, the presence of A. swaini in the Browns River catchment, an eastern locale, is unexpected. Other specimens from the Browns River catchment (Silver Falls and Fern Tree) represent A. tasmaniae sensu stricto but those from “Fern Tree Glen” and Wishing Well agree with those from St Crispins Well ( Fig. 33A–F ), in the catchment of the North West Bay River. The North West Bay and Browns rivers, however, do not share catchments, making natural dispersal between these drainages unlikely. Fern Tree Bower and Wishing Well, however, are notable as two key points along the aqueduct that drew water from the western side of Mt Wellington (starting at St Crispins Well) to Hobart since at least 1881. As a result, the records of A. swaini in the lower Browns River from 1928 could be the result of accidental translocation from the western side of Mt Wellington; it remains to be determined whether A. swaini is still present there. The western and northern Mt Wellington specimens here referred to A. swaini differ slightly from topotypic material (see Remarks under account of A. swaini ).

Anaspides was previously recorded from the plateau near the summit of Mt Wellington in tarns and creeks, most of which drain into the North West Bay River ( Manton, 1930). It apparently no longer occurs there, however, probably as a result of major bushfires that swept across the top of Mt Wellington in 1930s (Swain pers. com. in O’Brien, 1990). Anaspides populations are now restricted to catchment creeks to the periphery of the summit— A. tasmaniae to the east and south-east, and A. swaini to the west and northwest. Material from the uppermost parts of Mt Wellington collected during or before the early decades of the 20th century includes both A. swaini and A. tasmaniae , so it is possible they were sympatric or lived in close proximity atop Mt Wellington prior to the 1930s bushfires. Manton (1930) observed two colour forms in Anaspides on Mt Wellington: a dark brown to olive-green form found on the Mt Wellington plateau, and a light brown form occurring on the slopes. Notwithstanding likely habitat related colour variation, the distribution of Anaspides on Mt Wellington as determined herein suggests that Manton’s dark form is referrable to A. swaini , and the light brown form, to A. tasmaniae ( Manton, 1930: pl. 2–3, 4). Nicholls’ (1947) remark that the “dark coloration prevails almost everywhere the species is taken (many quite remote from Mt Wellington)” is consistent with the much wider range of A. swaini relative to A. tasmaniae .

The type series of A. tasmaniae was collected from Mt Wellington on two occasions in 1892. Specimens were first collected in January 1892 by G.M. Thomson during a visit to Hobart for the Congress of the Australasian Association for the Advancement of Science ( Morton, 1893; Thomson, 1926) and by Leonard Rodway (Tasmanian Government botanist) on 24 May 1892 from the original locality ( Thomson, 1893, 1894). Thomson’s (1893, 1894) early accounts suggest that the specimens were collected near the summit of Mt Wellington at an elevation of “over 4,000 ft ” (= 1200 m). Thomson’s (1926: 161) more detailed account of events, however, indicates the specimens were collected “about three-fourths of the way to the summit, where the water issues from a few deep pools among the rocks” near “The Springs”. Thus, rather than the summit, the type series would have originated from the eastern face of Mt Wellington, nearer to 700 m asl. These specimens of A. tasmaniae are now in poor condition, having at one time been dried, but clearly preserve the primary diagnostic features —an elongated telson with rounded posterior margin, two male antennular clasping spines, spinose pleural margins of pleonites 2–5, spinose tergal margins of pleonites 5–6, and absence of the pleopod 5 endopod. The male ( Fig. 4A–D ) is herein designated as the lectotype to fix the identity of the species. Other type specimens become paralectotypes. The female paralectotype in the Otago Museum (OM Iv.1396) was collected by Thomson, corresponding to a January 1892 collection date.

Being confined to catchments on the eastern face of Mt Wellington, Anaspides tasmaniae as currently understood has a considerably narrower distribution than previously thought. Although A. tasmaniae resides within the relative protection of the Wellington Park reserve its conservation status requires reassessment along with detailed delimitation surveys to precisely determine its current distribution.

Distribution. Eastern Mt Wellington, from the catchments of the Newtown Rivulet to the Browns River; 150–1250 m asl.

Figures

Figure 1.Anaspides tasmaniae (Thomson, 1893), male, 28 mm, Fern Tree, TMAG 6414. Habitus, right lateral view. Scale 2.0 mm.

Figure 2. Anaspides tasmaniae (Thomson, 1893), male, 28 mm, Fern Tree, TMAG 6414. (A) cephalothorax, dorsal view; (B) pleonite 6, telson and right uropod; (C) pleonites 3–6 pleura, right lateral view; (D) right antennule; (E) right antenna; (F) labrum, anterior view; (G) right mandible; (H) right mandible incisor process; (I) left mandible incisor process; (J) paragnaths, anterior view; (K) right maxillule; (L) right maxilla; (M) pleopods 1–2, in-situ, ventral view. Scale: A–E, M = 1.0 mm; F–L = 0.7 mm.

Figure 3.Anaspides tasmaniae (Thomson, 1893), Fern Tree, TMAG 6414, male 28 mm(A–N), female 30 mm(O–P). (A) right thoracopod 1 (maxilliped); (B–H) right thoracopods 2–8; (I) right pleopod 1 endopod, lateral view (retinacular lobe indicated by arrow); (J) right pleopod 2 endopod, lateral view;(K) right pleopod 4, anterior view;(L–N) pleonites 3–5 median sternal processes;(O–P) female gonopore, right lateral and ventral views. Scale A–H = 1.0 mm; I–P = 0.7 mm.

Figure 4.Anaspides tasmaniae (Thomson, 1893).(A–D) lectotype male, 23 mm,AM G2130, Mt Wellington.(E) juv. male, 20 mm, Silver Falls, Browns River, TMAG G6431. (F–J) female, 28 mm, Silver Falls, Browns River, TMAG G6431. (K) female, 27 mm, Silver Falls, Browns River, TMAG G6431. (L–O) female, 32 mm, Picnic Hut, Mt Wellington, TMAG G6383. (P–R) female, 23 mm, Mt Wellington, AM P98089. A, G, M, P, telson. B, E, H, K, Q, N, right pleonal pleura. C, right antennular clasping spines. D, right pleopod 1 endopod, right lateral view. F, L, anterior cephalothorax. I, R, O, right scaphocerite. J, right uropodal endopod. Scale 1.0 mm.

Figure 25. Anaspides spinulae Williams, 1965, holotype female, 25 mm, Lake St Clair, AM P14146. (A) cephalothorax, dorsal view; (B) pleonite 6, telson and right uropod; (C) pleonites 1–6 pleura, right lateral view; (D) right antennule; (E) right antenna; (F) labrum, anterior view; (G) right mandible; (H) right mandible incisor process; (I) paragnaths, anterior view; (J) right maxillule; (K) right maxilla. Scale: A–E = 1.0 mm; F–K = 0.7 mm.

Figure 28. Anaspides spinulae Williams, 1965, selected features, Lake St. Clair. (A–C) juv. female, 10 mm, AM P99313; (D–F) paratype female, 21 mm, AM P14156; (G) paratype, sex indet, c. 10 mm, on slide, AM P14152; (H) paratype male, c. 13 mm, AM P14147; (I) paratype female, +20 mm, on slide, AM P14148. Scale:A–C, G–H= 0.5 mm; D–F, I = 1.0 mm.

Figure 33.Anaspides swaini Ahyong, 2015, selected features. (A–D) male, 33 mm, St. Crispins Well, North West Bay River, MtWellington, TMAG G6450; (E–F) juv. male (16 mm), juv. female (23 mm), St. Crispins Well, Mt Wellington, TMAG G6450; (G–J) male, 22 mm, Sorell Creek,Myrtle Forest,TMAG G983;(K–N) male, 24 mm, Butlers Gorge,YPM 9195;(O–P) indet juv, 8 mm, Mt Rufus,AM P72842; (Q–T) female, 30 mm, Mt Rufus, AM P72842. A, K, O, anterior cephalothorax. B, E–G, L, P, Q, telson. C, I, M, S, pleonal pleura. D, J, N, T, scaphocerite. H, R, rostrum. Scale: A–N, Q–T = 1.0 mm; O–P = 0.5 mm.

Figure 36. Distribution of Anaspides. Dubious Orford record of A. swaini indicated by “?”.

Figure35.(A) Anaspides tasmaniae (Thomson, 1893), female,Mt Wellington,specimen not preserved;(B) A.clarkeiAhyong, 2015, female, 24 mm, Eastern Passage streamway of Little Grunt Cave and Exit Cave, QVM 10:49168; (C) A. clarkeiAhyong, 2015, male, Lake Pluto, Wolf Hole, specimen not examined; (D) A. richardsoni sp. nov., female, Tarn Shelf, Mt Field, specimen not preserved; (E) A. richardsoni sp. nov., female, 32 mm, Kellys Pot, Mole Creek karst,TMAG G6463;(F) A. richardsoni sp.nov., female,35 mm, Marakoopa Cave, Mole Creek karst, specimen not preserved. Photo credits: A, Kristi Ellingsen, used under a Creative Commons Attribution-NonCommercial license (http://creativecommons.org/licenses/by-nc/2.0/); B, E, ©Stefan Eberhard; C, F, ©Arthur Clarke; D, ©Simon Grove, TMAG.