Lynceus magdaleanae, Timms, 2013

TIMMS, BRIAN V, 2013, A Revision of the Australian species of Lynceus Müller, 1776 (Crustacea: Branchiopoda: Laevicaudata, Lynceidae), Zootaxa 3702 (6), pp. 501-533 : 521-524

L. magdaleanae sp. nov.

( Figs. 3E , 4E , 12 )

Etymology. This species is named for Magdaleana Davis (nee Zofkova) to honour molecular her work in identifying the presence of at least three species of Lynceus in Western Australia.

Type locality. Australia, Western Australia, 18 km NE of Goomalling, East Oak Park pit gnamma, 31 o 08’ 20”S, 116 o 52’ 49”E, 19 October 2011, collector BVT .

Holotype. Male deposited in the Western Australian Museum (Perth). Length 5.5 mm. Registration number WAM 51624.

Allotype. Female deposited in the Western Australian Museum (Perth). Length 5.0 mm. Registration number, WAM 51625.

Paratypes. 8 altogether; 2 males and 2 females deposited in Australian Museum (Sydney) Registration number, AM P89077 , and 2 males and two females deposited in Western Australian Museum (Perth), WAM 51626 .

Other Material. Northern Territory: Papunya, 4 km E, gnamma on Warumpi Hill , 23 o 15’S, 131 o 54’E), 14 May 1998, IAEB, AM P90069 ; Macdonnell Ranges, Palm Creek in PalmValley , 24 o 03’ 25”S, 132 o 44’ 47”E, 13 September 1958, D.F. McMichael, AM P55727 & P88376 ; Kata Tjuta (= Mt. Olga ), 25 o 17’ 22”E, 130 o 44’ 18”E, 11 August 1966, A Frecker & P. Keane, AM P55684 & P88157 .

Queensland: 105 km N of Hughenden , L. Louisa, 19 o 53’ 36”S, 144 o 15’10”E, 7 April 2009, BVT & MS, AM P89078 ; 7 km E of Boulia , burrow pit, 22 o 54’ 44”S, 139 o 58’24”E, 4 March 2011; BVT & MS, AM P89079 ; 2 km E of Boulia , swamp, 22 o 54’ 41”S, 139 o 55’ 30”E, 4 March 2011, BVT & MS, AM P90067 ; 76 km NE of Aramac , L Galilee Hazelmere Inlet, 22 o 26’ 00”S, 145 o 42’30”E, 15 February, 2010, BVT & MS, AM P90068 .

South Australia: Musgrave Ranges, Erliwunyawunya Rockhole , 29 May 1961, H.G. Cogger, AM P15286, P55685, P88143, P88380 ; Musgrave Ranges, 7 km S of Mt. Woodroffe, waterhole in Currie Creek tributary, 9 May 1983, 26 o 19.134’E. 131 o 44.715’E, W. Zeidler, SAM C7631 ; Everard Ranges, Carmeena Rockhole , 27 o 06.51’S, 132 o 33.011’E, 14 August 1914, Capt S. A. White, SAM C7632 ; Everard Homestead, Victoria Springs , 27 o 0.368’S, 132 o 42.565’E, 31 October 1970, E Matthews SAM C7646 ; Gawler Ranges, pool near Hiltaba Homestead , 32 o 09.422’S, 135 o 04.084’E, P. Aerfeldt & P. Cokerham, 14 October 1984, SAM 7633 ; Gawler Ranges, pool near Yarna Homestead , 32 o 03.213’S, 135 o 07.751’E, P. Aerfeldt & P. Cokerham, 15 October 1984, SAM C7634 ; Gawler Ranges, pool near Paney Homestead , 32 o 35.240’S, 135 o 25.803’E, P. Aerfeldt & P. Cokerham, 16 October 1984, SAM C7635 ; Gawler Ranges National Park, 40 km NE of Wudinna, Policemans Point , 32 o 35’ 17”S, 135 o 26’ 30”E, 5 October 2009, BVT, SAM C7636 ; 13.5 km NE of Minnipa, Pildappa Rock , western pit gnamma, 32 o 45’ 05”S, 135 o 13’ 48”E, 23 November 2003, BVT, SAM P7637 ; 25 km ENE of Wudinna, Peela Rock , northernmost pit gnamma, 33 o 00’ 09”S, 135 o 43’ 28”E, 26 October 2011, BVT, SAM C7638 ; Frances, Lake Cadnite , 36deg 42.685’S, 140deg 56.559’E, 6 May 1979, W. Zeidler, SAM C7639 .

Western Australia: Little Sandy Desert, Hutton Range , 16 km N, ca 24 o 46’S, 123 o 48’E, 4 September 1971,no collector recorded, WAM 51322 ; 83 km N of Northhampton, Euardy Station , roadside ditch, 27 o 36’ 31”S, 114 o 41’ 43”E, 5 July 2011, Koen Martens, WAM 51591 ; 50 km NW of Cue, pit gnamma on Walloo Hill , 27 o 14’ 47”S, 117 o 25’ 44”E, 23 August 2009, BVT, WAM 51592 ; Gibson Desert, Gunbarrel Highway, Mt Samuel , pool (probably one of the Mangi gnammas) 1.6 km WSW, 1 June 1966, 25 o 45’ 50”S, 125 o 55’ 50”E (for Mt Samuel ), K. Davey. AM P55668, P88159 ; Great Victoria Desert, Knight Gnamma Holes , 28 o 12.795’S, 124 o 39.993’S, 25 August 2010, IAEB, WAM 51593 ; Great Victoria Desert, Sunday Surprise Rocks , 27 o 57.379’S, 125 o 00.350’E, 27 August 2009, IAEB, WAM 51594 ; 60 road km SE of Giles, Kutjurritari Gnammas , ca 25 o 17’S, 127 o 49’E, 23 September 2009, BVT, WAM 51595 ; Great Victoria Desert, Connie Sue Highway , gnammas 10 km W of Lake Serpentine, 26 August 1980, J.A. Forrest, WAM 51596 ; Warburton, Windaroo Rockhole , 21 June 1979, J. Blyth, WAM 51597 ; 71 km WSW of Menzies, pit gnamma on Scorpion Rocks , 29 o 51’ 10”S, 120 o 19’ 36”E, 10 October 2011, Bindy Datson, WAM 51598 ; Paynes Find area , 2 September 1991, no date or collector recorded, WAM 51317 ; 11 km NNW of Paynes Find, south pit gnamma on Bullamanya Rocks , 29 o 09’ 53”S, 117 o 39’ 36”E, 5 October 2010, BVT, WAM 51599 ; 15 km SW of Wubin, pit gnamma on Miamoon Rocks , 30 o 09’ 07”S, 116 o 20’ 45”E, 14 September 2003, BVT, WAM 51600 ; 25 km E of Wongan Hills, Dingo Rock , 30 o 50’ 41”S, 116 o 58’ 30”E, 27 September 2012, BVT, WAM 51601 ; 43 km NNW of Hyden, rock pool at base of Mt Walker ; 32 o 04’ 11”S, 118 o 45’ 21”E, 31 August 2009, BVT, WAM 51602 ; 17 km NE of Hyden, northern pit gnamma at The Humps , 32 o 18’ 41”S, 118 o 57’ 37”E, 4 August 2005, BVT, WAM 51603 ; near Buncubbin, Dajoing, soak at Yalburnunging Rock , no date, E. Simpson, WAM 51318 ; 40 km NE of Mukinbudin, pit gnamma on Yanneymooning Rock , 30 o 43’ 04”S, 118 o 33’ 24”E, 24 October 2010, BVT, WAM 51604 ; 44 km S of Coolgardie , pit gnamma on Victoria Rock , 31 o 17’ 37”S, 120 o 55’ 32”E, 14 September 2002, IAEB & BVT, WAM 51605 ; 40 km E of Lake King Township, pit gnamma on Lilian Stokes Rock , 33 o 04’ 06”S, 120 o 05’ 49”E, 1 September 2009, BVT, WAM 51606 ; 95 km SW of Norseman, near Metcalf Lake , creek crossing, permanent water under rock tunnel, 32 o 28’ 30”S, 120 o 49’E, no date or collector recorded; WAM 51323 ; Dundas , rockhole, ca 32 o 27’S, 121 o 46’E, no date or collector, WAM 6735 ; 27.5 km NE of Norseman, Buldania Rocks , western pit gnamma, 4 December 1959, D.H. Edwards, AM P55661 & P88381 ; 89.6 road kms E of Norseman off Eyre Highway, Smithania Rock , June 1964, Lee, AM P55656 & P88153 ; 196 km E of Norseman, a pit gnamma on Balladonia Rock , 32 o 27’ 41”S, 123 o 51’ 48”E, 18 March 2007, BVT, WAM 51607 .

Diagnosis. Thoracopod I of male with endite VI with a broad almost rectangular base because of a distinct angular hump of about 110–120 o on the distal surface, and a short somewhat triangular process medially, much shorter than the base and reaching only about a third of the medial length of endite III, and not covering all the teeth on the distomedial surface of endite III.

Description of male. Head ( Fig 12B,C ) subequal to body size, finely punctuate. Fornices broad, angulated and arcuate over second antennal base. Small mound centroposteriorly the site of the dorsal organ. Compound eyes close together about midway along central ridge and just posterior to the frontal pore and two small lateral setal fields. Ocellus deeply embedded beneath the setal fields. Rostral dorsal surface lower than surface posterior to compound eye, the junction marked by the lateral suture from the eye to the nearby fornix. Rostrum about as long as wide with upper surface significantly expanded terminally (by about 30% each side). Central carina bold and bifurcated distally associated with terminal truncation to form a broadly based triangular terminal facet. This facet ciliated on the ventral edge and almost at right angles to head alignment and with anterior margin of base straight.

First antenna ( Fig 12D ) small, a little shorter than rostrum, and with two antennomeres. Proximal antennomere cylindrical with concave face terminally and supporting second antennomere. This antennomere subequal in length to the first, clavate and with a few short setae terminally and on dorsal distal surface.

Second antenna ( Fig 12E ) biramous, well developed, twice as long as rostrum. Peduncle of three segments, proximal segment with 3–4 plumose setae, middle segment with 1–2 spines and the distal peduncular segment with about 8 short spines mainly at the base of the anterior ramus. Anterior ramus with about 25 antennomeres and ventral ramus with a few more antennomeres. Both rami with long plumose ventral setae, one per antennomere, while anterior ramus with short dorsal setae also.

Labrum large, well developed, clothed in small setae. Mandible broadly spatulate. First maxilla typical for genus and second maxilla absent.

Carapace ( Fig 12A ) with hinge line slightly arcuate, umbo lacking and no growth lines. Anterior margin broadly arcuate, curving evenly to ventral margin and back to the posterior, though posterior is slightly narrower so that deepest part of carapace a little before midway along its length. Dorsally carapace slightly arcuate, thus hiding the hinge line. Valves roundly inflated laterally. Carapace surface finely punctate. Abductor muscle scar in an anteriolateral position about twice its diameter from the margin and associated with oval imprint of maxillary glands lying at about 40 o to the hinge line.

Thorax. Ten thoracic segments, each with paired thoracopods. Anal plate partly divided centroposteriorly, each half bearing a long seta. Somite below enlarged, even more divided centroposteriorly and each half bearing a small denticle apically.

Thoracopod I ( Fig 3E , 12F ) modified as a clasping appendage, the right and left claspers equal in shape and size. Endite VI with a broad almost rectangular base because of a distinct angular hump of about 110–120 o on the distal surface, and a short somewhat triangular medial process, much shorter than the base and reaching only about a third of the medial length of endite III and not covering all the spines row on the distiomedial surface of endite III. Endite V cylindrical and straight, and about two and a half times longer than broad and four to five times larger than endite IV. Endite V with a vertical row of about 13 larger stout setae from about one third of the endite’s length to its apex and also with an oval field of numerous lithe setae centred about 90 o around the palp but spreading close to the distinct setal row and covering the distal two-thirds of the palp. Endite IV oval in profile and margined with numerous setae mainly on the side distal to Endite V. Endite III rectangular but distinctly narrowing distally and with major axis at right angles to thoracopod axis. A row of about nine triangular spines distiomedially and a large field of stout setae mediolaterally clumped distally.

Thoracopod II of general form for Lynceus (Martin & Belk, 1988) and depicted for L. baylyi ( Fig.11) with two significant differences: 1) it lacks serrated anterior setae, all anterior setae being naked and 2) the distal lobe of the exopod narrows evenly along its length instead of having a distinctly wider area near its base.

Thoracopods III to XI similar to thoracopod II, though the last three much reduced in size and lacking epipodites and proximal lobe of the exopodites.

Description of female: Head ( Fig. 12G,H ): general structure similar to male. Compound eyes, ocellus, frontal pore and setal fields as in male. However anterior dorsal carina not bifurcated and rostrum not truncated, so that rostrum a little longer than wide. Rostrum increases in width anteriorly by about 30% on each side. Central carinae bold and lateral suture marking boundary between higher posterior surface and lower rostral dorsal surface as in male. Anterior margin of rostrum arcuate, but with a small notch at each anteriolateral corner.

Carapace as in male, umbo lacking, no growth lines, same size and shape. Egg mass, if present, visible through the carapace.

Thorax. Twelve thoracic segments, the last three with a lamina abdominalis laterally ( Fig 12J ). This lamina with an obtuse process anteriorly, two subequal triangular lateral lobes and a larger triangular lateral lobe posteriorly. A thin digital process arising dorsolaterally from a broad swollen base between the clavate process and the first triangular lobe. Anal plate as in the male, but last somite more rounded than in male.

Thoracopods. 12 pairs of thoracopods, diminishing in size posteriorly, and thoracopods IX and X with exopod dorsal lobes cylindrical and extending dorsally beyond thoracic dorsum. These, plus the lamina abdominalis, help to anchor the egg mass.

Resting egg. ( Fig 4E ) Round, irregular low wide ridges enclosing enlongated irregular depressions. Size 111.5 ± 4.6 ųm (n = 5).

Size. Length holotype 5.5 mm, paratypes (n=4) 5.2 – 5.8 (x = 5.5 ± 0.35 mm); height holotype 5.0 mm, paratypes 4.2 – 5.1 (x = 4.75 ± 0.36 mm), width holotype 4.4 mm. Length allotype 5.0 mm, paratypes 4.9 – 5.4 (x = 5.15 ± 0.21 mm), height allotype 4.7 mm, paratypes 4.2 – 5.2 (x = 4.6 ± 0.42 mm), width allotype 3.9 mm.

Variability. In males the truncated terminal facet of the rostrum is not always at 90 o to the rostral axis, but may be as low as 75 o. The rostrum may be expanded terminally by about 20–25%, rather than 30%, and the dorsal carina is not always bold, hardly standing expressed beyond the rostral dorsal surface. On the clasper, the hump on the basal part of endite VI is not always so distinct as in the type, the endites V and IV are variable in shape and setation, and the spines on the distomedial corner of endite III vary from six to nine. Interestingly the sites in the distributional outlier of north Queensland, mostly have 22–26 large setae in the setal row on endite V and only five to seven teeth on the distomedial corner of endite III, whereas the average is about 15 setae and seven to nine teeth over most of the range in WA and SA.

In females, the rostrum may not be as wide terminally as in the type and on the posteriolateral plate the size and shape of the lateral lobes are variable, but there is always only one dorsal digitiform process anteriorly.

Distribution. L. magdaleanae sp. nov. occurs ubiquitously in deeper gnammas throughout the Wheatbelt (e.g. Fig. 9C ) and adjacent Goldfields of Western Australia (except the strip from Beacon to Trayning occupied by L. baylyi sp.nov. ― see above). It also occurs in pit gnammas throughout the northern Eyre Peninsula, Gawler Ranges and northwestern half of South Australia and the southwestern Northern Terrritory, and sporadically in gnammas in the central deserts of Western Australia. L. magdaleanae sp. nov. is also established in northern Queensland but not in gnammas; these occurrences and habitat choice seem incongruous considering its widespread occurrence in gnammas in WA and western SA. Perhaps these northern Queensland records are of a separate species, but so far they are only distinguishable by a slightly different count of setae of endite V and of spines on the distomedial corner of endite III. Specimens from the Wheatbelt and Goldfields of Western Australia were previously misidentified by MZ and the author as L. macleayanus (see Bayly et al 2012; Passaq et al. 2011; Timms 2006, 2012; Zofkova 2007).

Figures

FIGURE 3. Digital Images of claspers of Lynceus. A, L. tatei (from Serpentine, WA, WAM 51609); B, L. tatei (from Armadale WA, MZ Collection); C, L. macleayanus (from Brooms Head, NSW, AM P89072); D, L. baylyi sp.nov. (from Washington Rocks, WA, WAM 51581); E.L. magdaleanae sp.nov. (from Yanneymooning Rock, WA, WAM 51604); F, L. susanneae sp. nov. (from Cocklebiddy, WA, WAM C51326)

FIGURE 4. Resting eggs of Lynceus. A. L. macleayanus; B, L. tatei; C, L. argillaphilus sp. nov.; D, L. baylyi sp. nov.; E, L. magdaleanae sp. nov.; F, L. susanneae sp. nov. Scale bars 50 ųm.

FIGURE 9. Images of sites where new species have been found. A, Peewah Ck, Pilbara, L. argillaphilus sp. nov., image courtesy A. Pinder, DEC, WA; B, middle gnamma in row of five,14.6 km N of Trayning, L. baylyi sp. nov., image by author; C, East Oak Park gnamma, via Goomalling, L. magdaleanae sp. nov., image by author; D. Gnamma in limestone, 12 km south of Cocklebiddy, Nullarbor Plain, L. susanneae sp. nov., image courtesy A. Clarke, DEC, WA. Gnammas B, C and D are the type localities for their respective species.

FIGURE 12. L. magdaleanae sp. nov. A–F male: A, carapace; B, dorsal view of head; C, lateral view of head; D, first antenna; E, second antenna; F, clasper (endites III to VI of thoracopod). G–I female: G, dorsal view of head; H, lateral view of head; J, posteriolateral process, anal plate and last somite. Scale bars 1 mm.