Paralimnadia queenslandicus, Timms, Brian V., 2016

Timms, Brian V., 2016, A review of the Australian endemic clam shrimp, Paralimnadia Sars 1896 (Crustacea: Branchiopoda: Spinicaudata), Zootaxa 4161 (4), pp. 451-508 : 490-493

Paralimnadia queenslandicus n. sp.

( Figs. 4 , 20 , 21 )

Paralimnadia sp. A.— Schwentner et al. 2015: 369 –370.

Etymology. This species occurs throughout inland Queensland so the epithet ‘ queenslandicus ’ seems appropriate, even though this species penetrates a little into adjacent western NSW.

Type material. Holotype: AM P99025, male, length 8.0 mm, height 5.00 mm, Queensland, beach pool on old NW shoreline of Lake Buchanan , 21°32’15”S, 145°47’05”E, 26 February 2008, BVT . Allotype: AM P99026, female, length 9.0 mm, height 6.2 mm, collected with holotype. Paratypes: AM P99027, 2 males, 8.2 × 5.2 mm, 7.9 × 5.0 mm, 2 females, 8.8 × 6.0 mm, 9.7 × 6.0 mm, collected with holotype.

Other material examined. Queensland: Yarromere Station , pool besides Mogga Creek near Lake Buchanan, 21°27’22”S, 145°48’38”E, 25 February, 2008, BVT, 20 specimens, AM P99028 ; beach pool on old NW shoreline of Lake Buchanan , 21°32’15”S, 145°47’05”E, 26 February, 2008, BVT, 18 specimens, AM P99029 ; 135 km SW of Boulia, Craven Peak Station , Nardoo-sundew-canegrass swamp, 23°17’21.9”S, 138°33’ 4.5”E, 16 April, 2007, Joan Powling, 10 specimens, AM P99030 ; 29.2 km W of Alpha on Capricornia Highway , burrow pit, 23°37’35”S, 146°21’12”E, 14 February 2010, BVT, 98 specimens, AM P99031 ; 72 km NW of Bollon on Linden-Nebine Rd , roadside swamp, 27°42’18”S, 146°50’12’E, 18 February 2010, BVT, 76 specimens, AM P99032 ; 1.5 km S of The Gums , roadside pool, 27°21’27”S, 150°11’29”E, 9 June 2009, BVT, 26 specimens, AM P99033 . New South Wales: 44 km ENE of Enngonia, Council gravel pit, 29°12’03”S, 146°16’50”E, 21 January 2010, BVT, 22 specimens, AM P99034 ; 115 km NW of Bourke, Muella Station , Carters Swamp, 29°26’00”S, 144°58’58”E, 19 Januray 2010, BVT, 109 specimens, AM P99035 ; 117 km NW of Bourke, Bloodwood Station , The Freshwater Lake, 29°29’12”S, 144°50’06”E, 9 February 2010, BVT, 17 specimens, AM P99036 ; 117 km NW of Bourke, Bloodwood Station , Beverleys Pool, 29°32’11”S, 144°51’15”E, 24 May 2000, BVT, 12 specimens, AM P99037 ; 117 km NW of Bourke, Bloodwood Station , Marsilea Pool, 29°32’13”S, 144°52’26”E, 21 January 2011, BVT, 52 specimens, AM P99038 .

Diagnosis. Spherical egg with about 36 elongated depressions containing shallow grooves. Trunk 16 or 17 segments, claspers with both long palps bearing three palpomeres with inerm junctions. Telson with about 22 pairs of spines and cercopod basal section 66% of total length and with 18 setae serially from long to short.

Description. Male. Head ( Fig. 21 B) with ocular tubercle prominent, compound eye occupying about 80%. Rostrum protruding little more than ocular tubercle and at about 110° from frons, triangular, apex rounded. Ocellus slightly smaller than compound eye and lying at base of rostrum. Dorsal organ posterior to eye by about half its height, pedunculate and asymmetrical and about three quarters as high as ocular tubercle.

First antennae ( Fig. 21 B) almost twice length of peduncle of second antennae; with 8 lobes, each with numerous short sensory setae. Second antennae with spinose peduncle and dorsal flagellum with 12 antennomeres and ventral flagellum with 13 antennomeres, and dorsally with 0–3 short spines and ventrally with 0–7 longer setae, commonly with 2 or 3 spines and 5 or 6 setae. Distal antennomeres with minimal spines and maximal setae.

Carapace ( Fig. 21 A) elongated oval, pellucid, with little indication of growth lines. Adductor muscle scar at about 45° to carapace long axis, only visible when animal removed from carapace.

Thoarcopods. Seventeen pairs of thoracopods. Claspers ( Fig. 21 D) with palm trapezoidal with distinct rounded projection distomedially. Apical club spherical with many stout spines pointing medially. Small palp with many short aciculate spines apically. Finger arcuate with blunt apex bearing many rounded pits ventrally. Both long palps of claspers inserted on apical edge of palm and with 3 palpomeres, palpomere junctions inerm but many limp filiform setae on flattened palaform apical area. Long palp of first clasper about 1.5 × length of palm and 2.25× length in second clasper. Other thoracopods of typical structure for Paralimnadia , decreasing is size and complexity posteriorly. Last 10 segments dorsally with short spine medially.

Telson ( Fig. 21 C) spine ridges with about 22 pairs of spines, with anteriormost spine about same size as next few; penultimate spines little longer than most spines. Spines with spinules. Telsonic filaments originating from mound little higher than floor of telson positioned between 4th and 5th spine. Floor of telson posterior to mound sharply declivious then slightly convex to base of cercopod. Cercopods almost as long as dorsum of telson, basal twothirds narrowing slightly to small spine then tapering to acute apex. About 18 setae on basal twothirds and many tiny denticles dorsolaterally on apical third. Setae gradually shortening from being about 3 × cercopod basal diameter at cercopod base to subequal to this diameter at spine, geniculate and plumose. Ventroposterior corner of telson rounded and hardly protruding.

Female. Head ( Fig. 21 F) with ocular tubercle prominent, with compound eye occupying about 80%. Rostrum a rounded bulge protruding about half ocular tubercle and with ocellus about half size of compound eye basodorsally. Dorsal organ posterior to ocular tubercle by about half its height, pedunculate and asymmetrical and three quarters as high as ocular tubercle.

First antennae ( Fig. 21 F) a little shorter than peduncle of second antennae, with 6 small lobes each with many short sensory setae. Second antennae largely as in male.

Carapace ( Fig. 21 E) as in male, though more vaulted dorsally.

Thoracopods. Seventeen pairs of thoracopods of typical Paralimnadia structure. Trunk dorsum with segments 1–9 naked, segments 10–14 with 3–5 spines distomedially; segments 15–17 with spine distomedially. Thoracopods 9 and 10 with long flabellum dorsally.

Telson ( Fig. 21 G) as in male, though posterior row spines smaller.

Egg ( Fig. 11 K, L). Diameter 136 µm, range 125 to 154 µm, n = 24. Spherical with randomly arranged elongated depressions each with a shallow groove and approximately 50 µm by 20 µm wide and less than 10 µm deep. Small pores in some grooves and most eggs with two larger pores, one each side of a groove. Walls of depressions rounded and sometimes form small elevations where adjacent walls meet. Grooves number about 36, range 32–42.

Variability. This species is particularly variable across its wide distribution. The male rostrum, though basically triangular, can be asymmetrical and 100–115° to the frons. The dorsal organ can be subequal to the ocular tubercle in height. Antennal lobes vary from 7–10 in males and from 5–7 in females and antennomeres number from 10–13. Many individuals of both sexes have 16 trunk segments and clasper palps sometimes have only two palpomeres due to incomplete division of the distal segment. Telsonic spines range from 16–25 pairs and of various configurations and cercopod setae from 15–20 with less variation in length along the row.

Differential diagnosis. The P. queenslandicus n. sp. egg with its wide shallow depressions and two pores on either side of one groove is distinctive. Otherwise the male rostrum, antennae, claspers and telsonic spines are variable and encompass the range seen in many other species of Paralimnadia . The cercopod however is distinctive by its division by a spine into a basal two-thirds with setae and a distal one third with denticles —the division is usually 50:50. Setae are numerous (15–20) as in P. flavia n. sp. and most P. westraliensis n. sp., but the variation in length serially from long to short is unique to P. queenslandicus n. sp.

Distribution and ecology. Paralimnadia queenslandicus n. sp. occurs in temporary ponds, roadside ditches, and artificial sites, often with clear waters, across inland Queensland and adjacent New South Wales. It probably penetrates further south in New South Wales but there has been little searching beyond the Paroo. The single species of Paralimandia in the northern inland contrasts with the numerous species of the related Eulimnadia in the same area ( Schwentner et al. 2015).

Figures

FIGURE 4. Map of Australia showing distributions of all species with insert of details of Sydney region, especially for sites of P. stanyleyana.

FIGURE 11. Scanning electron micrographs of eggs. A-B, Paralimnadia ammolophos n. sp., C, P. bishopi n. sp., D-F, P. flavia n. sp., G-H, P. hyposalina n. sp., I-J, P. monaro n. sp., K-L, P. montana n. sp. A from Brooms Head, NSW, AM P 99008; B from Shelly Beach, NSW, AM P 99007; C from Cape Bedford, Qld, AM P 99359; D from Radom Springs, NT, AM P 98911; E from Larrimah, NT, AM P 98999; F from near Kununurra, WA, WAM C 61749; G from Coomberdale, WA, WAM C 61751; H from Watheroo, WA, WAM C 61753; I from near Berridale, NSW, AM P 99011; J from Manderley Pool, NSW, AM P 47129; K from Glencoe Lagoon, NSW, AMP 99014; L from Emu Rk Tarn, NSW, AM P 47132. Scale bars 0.1 mm.

FIGURE 20. Scanning electron micrographs of eggs. A, Paralimnadia multispinosa n. sp.; B – F, P. queenslandicus n sp.; G – H, P. saxitalis n. sp.; I – L, P. westraliensis n. sp. A, near Paynes Find, WA, WAM C 61755; B, near Lake Buchanan, Qld AM P 99026; C, near Lake Buchanan, Qld showing details of the paired pits; D, Craven Peak Station, Qld, AM P 99030; E, near Emerald, Qld, AM P 99031; F, Bloodwood Station, Paroo, NSW, AM P 99036; G, Mt Kaputar, NSW, AM P 99021; H, Uluru NT, AM P 98561; I, Sieda Farm, near Grass Patch, WA, WAM C 61758; J, Guest Rd Lake, near Grass Patch, WA, WAM C 61762; K, Wanarra Station, near Perenjori, WA, WAM C 61763; L, Austin Downs Station, near Cue, WA, WAM C 61764. Scale bars: A, B, D – I 0.1 mm; C 0.01 mm.

FIGURE 21. Paralimnadia queenslandicus n. sp.: A – D, male, AM P 99025; E – G, female, AM P 99026. A, carapace; B, head; C, telson; D, 1 st clasper with long palp of 2 nd clasper beside it; E, carapace; F, head; G, telson. Scale bars 1 mm.