278 research outputs found
FIGURE 3 in A revision of the clam shrimp Australimnadia Timms and Schwentner, 2012 (Crustacea: Spinicaudata: Limnadiidae) with two new species from Western Australia
No full textFIGURE 3. SEMs of Australimnadia eggs. A–E: A. grobbeni (Daday, 1925). A, Knuckeys Lagoon, Darwin, NT; B, dune lake, Ussher Pt, Cape York, Qld; C, gilgai, Meandarra, Qld; D, pond, Taloumbi, NSW; E, swamp, Barmah Forest, Vic; F, Limnadia lenticularis Sars, North America. Scale bars 100 µm.Published as part of Timms, Brian V. & Schwentner, Martin, 2017, A revision of the clam shrimp Australimnadia Timms and Schwentner, 2012 (Crustacea: Spinicaudata: Limnadiidae) with two new species from Western Australia, pp. 81-98 in Zootaxa 4291 (1) on page 86, DOI: 10.11646/zootaxa.4291.1.5, http://zenodo.org/record/82938
Eulimnadia palustera Timms 2015
No full textSynonymy of <i>E. palustera</i> <p> This species was originally assigned to <i>Eulimnadia</i> on the sole criterion of an apparent spine beneath the cercopod base (Timms, 2015). However, this spine is not a typical subcercopod spine of most <i>Eulimnadia</i> but a rather sharp triangular ventroposterior corner of the telson. Hence, an assignment to <i>Paralimnadia</i> is necessary. Furthermore, three other features suggest placement in <i>Paralimnadia</i>: a cercopod with a spine approximately midlength and not at about 80% of its length, 13 antennomeres rather than about 8, and a sex ratio approximating 1:1, all generally (but not absolutely) indicating <i>Paralimnadia</i> (Timms, 2016a, 2016b).</p> <p> Given the placement of <i>P. palustera</i> within <i>Paralimnadia</i>, its eggs are identical with those of <i>P. rivolensis</i> being astroform with 14–20 projections subtended by 3–8 sharp-edged grooves (fig. 4). Egg morphology has proved to be the most reliable character separating species within <i>Eulimnadia</i> (Belk, 1998; Rabet, 2010; Rogers et al., 2012; Timms, 2016a) and <i>Paralimnadia</i> (Timms, 2016b). The next most reliable species indicator in both genera is the nature of the cercopod setae. Both <i>P. palustera</i> and <i>P. rivolensis</i> have about 8 medium length (i.e. 1–2× cercopod diameter) setae (cf. fig. 6 in Timms, 2015 and figs 1–3). Again, both species have about 21 telsonic spines, although spacing is different in the two species. In <i>P. rivolensis</i>, all are evenly sized and spaced, except for the first three, which are larger and more spaced. In <i>P. palustera</i>, the telsonic spines are mixed in size (cf. fig 6 in Timms 2015 and figs 1–3). Two characters generally of poor differentiating ability are the first antennae and rostrum, although in these two species, there are only minor differences (cf. fig 6 in Timms and figs 1–3).</p> <p> The claspers are somewhat different between the two species. <i>P. palustera</i> has a distinct hamulus medially on the hand (endite IV), while <i>P. rivolensis</i> has just a slight swelling there. The palps are variable, with 3 palpomeres in the paralectotype of <i>P. rivolensis</i>, but only 2 indistinct ones in most other specimens examined. <i>P. palustera</i> generally has 3 palpomeres but may have the second division indistinct or incomplete. Sometimes there are spines at palpomere junction 1–2 in <i>P. rivolensis.</i> Similar variability has sometimes been observed in a few other <i>Paralimnadia</i> species (Timms 2016b).</p> <p> <i>Distribution.</i> South-western Western Australia, south-eastern South Australia, southern Victoria and Tasmania. There is a single record from central Australia, which is difficult to accept considering the prominent maritime distribution across southern Australia. It has not been collected in Victoria since 1910, its habitat in the swamps of eastern Port Philip Bay being drained and urbanised in the early 1900s. Widespread drainage in the south-east of South Australia seems to have denied it habitat there. The most recent collection from near the type locality is dated 1975, and my expeditions there in the spring of 2010 and winter of 2016 were unsuccessful. Sites in central Tasmania seem (as of March 2018) also to be drained, so that perhaps it now only occurs in refuges of Flinders Island, Kangaroo Island and south-western Western Australia.</p>Published as part of <i>Timms, Brian V., 2019, A redescription of Eulimnadia rivolensis (Brady, 1886) (Branchiopoda: Spinicaudata: Limnadiiidae), and its transfer to Paralimnadia, pp. 57-64 in Memoirs of Museum Victoria 78</i> on page 63, DOI: 10.24199/j.mmv.2019.78.03, <a href="http://zenodo.org/record/8065279">http://zenodo.org/record/8065279</a>
Three new species of spinicaudatan clam shrimps from Australia, all from gnammas (rock pools)
No full textBrian V Timms (2018): Three new species of spinicaudatan clam shrimps from Australia, all from gnammas (rock pools). Zootaxa 4418 (2): 136-148, DOI: 10.11646/zootaxa.4418.2.
A partial revision of the Australian Eulimnadia Packard, 1874 (Branchiopoda: Spinicaudata: Limnadiidae)
No full textBrian V Timms (2016): A partial revision of the Australian Eulimnadia Packard, 1874 (Branchiopoda: Spinicaudata: Limnadiidae). Zootaxa 4066 (4): 351-389, DOI: 10.11646/zootaxa.4066.4.
Hall (Crustacea: Branchiopoda: Spinicaudata: Limnadiidae)
No full textTimms, Brian V. (2009): A Revision of the Australian Endemic Clam Shrimp Genus Limnadopsis Spencer & Hall (Crustacea: Branchiopoda: Spinicaudata: Limnadiidae). Records of the Australian Museum 61 (1): 49-72, DOI: 10.3853/j.0067-1975.61.2009.1498, URL: http://dx.doi.org/10.3853/j.0067-1975.61.2009.149
Eulimnadia kimberleyensis Timms, 2018, sp. nov.
No full textEulimnadia kimberleyensis sp. nov. (Figs 1, 2). Etymology. This species is named for the area of Australia in which it occurs. Type material. Holotype. Female. Rock pool. Western Australia, Kimberley, Gardner Plateau, from 14o 47’ 2.1”S, 126o 31’ 18.9”E. Length 4 mm, height 3.1 mm (WAM C72086), coll A. Cross, March 2012. Paratypes. Two females. Lengths 4.0 and 3.9 mm (WAM C72087) from the same locality. Diagnosis. Egg spherical with about 36 grooves arranged randomly and about 30 µm long; walls of grooves thick and rounded with surface usually crenulated at right angles to groove axis. Female first antennae with about three lobes; second antennae with 7 antennomeres and generally 4–5 spines dorsally. Telson with about 19 dorsal spines and cercopod with about 8 long setae. Description. Egg (Fig 1A, B, C). Spherical, mean diameter 128 µm, range 122 to 134 µm, n = 10. Surface with about 36 (range 33–42, n = 10) grooves each about 30 µm long and arranged randomly. Tertiary layer represented by the apparent groove walls spongiform and thick and rounded, though surface usually crenulated at right angles to the major axis; sometimes a minor elevated area where walls of adjacent grooves confluent. In cross section, each groove—wall system consists of 80–90% wall and only 10–20% flat-floored groove with a distinct demarcation between the two. Female. Head (Fig. 2B) with ocular tubercle prominent, the compound eye occupying most (ca 80%) of it. Rostrum broadly rounded and protruding a little less than the ocular tubercle. Ocellus about as large as the compound eye and located in the middle base of the rostrum. Frons-rostrum angle about 150o. Dorsal organ posterior to the eye by about its height, pedunculated, asymmetrical and about half as high as the ocular tubercle. First antenna (Fig 2B) short, about 40% the length of the peduncle of the second antenna, and with three lobes, each with short sensory fine setae. Second antenna (Fig 2C) with 7 antennomeres, most (II to VI) with 4–5 short spines dorsally and 3–5 long setae ventrally. Basal antennomere with just 3 spines and a seta while distal antennomere with 2 spines and about seven setae. Carapace (Fig 2A) elongated oval with a vaulted dorsal and ventral edge and weak anterodorsal and posterodorsal angles. Abductor muscle scar at about 45o to carapace long axis. Carapace pellucid and without markings except for five growth lines, generally well spaced except near the ventral edge. Trunk of 18 segments. Dorsal surface of posteriormost 9–10 segments with many long two-segmented setae and sometimes shorter spines. Thoracopods of trunk segments IX and X with long epipods for retaining eggs. Telson (Fig 2D) with 9 dorsal spines followed by a large spiniform projection, the first spine about 20% larger than the next few followed by some variation in size and spacing along the row. Spines smooth. Telsonic filaments inserted on a mound between 2nd and 3rd spine. A moderate declivity posterior to the mound, remainder of telsonic floor sloping evenly and gently to cercopod base. Cercopod a little shorter than telson length and with a short spine about 80% along its length separating a thicker basal area supporting setae from a thinning distal area with a weak cirrus of small denticles. Short laminate spine with about 7 serrations on anterior surface and two small spines near the base. (see Fig. 2D insert). Eight long cercopod setae, their length about twice the basal diameter of the cercopod. Prominent spiniform projection on ventroposterior corner of telson. Variability. There are only three specimens available, so little can be added on variability of the above characters. Sometimes there are only six antennomeres though whether this is natural or damaged is not certain. Telsonic spines may number 8–10 and and cercopod setae 7–10. Differential diagnosis. There is no doubt this species belongs to the genus Eulimnadia. The diagnostic character is a spiniform projection on the ventroposterior corner of the telson (Rogers et al., 2012). In addition most Eulimnadia, including this species, have a spine on the cercopod at about 4/5ths its length and the antenna has about 7–8 antennomeres on each flagellum (Timms, 2016a). However, because of the limited number of specimens and lack of males the description of this species is minimal. Nevertheless species specific egg morphology in this genus (Belk, 1989; Rabet, 2010; Timms, 2016a) provides characters to separate species and in some cases is about the only distinguishing character, e.g. E. graniticola Rogers et al. 2010). However, for Australian species species specific egg morphology has been supported by features of the cercopods and sometimes a few other characters as well from the telson, claspers, antenna and head (Timms, 2016a). This dictum applies to this species. In this case the egg morphology is certainly the most distinguishing feature, though a combination of less important characters (a cercopod with 8 uniform setae, just nine unevenly spaced telsonic spines and a first antenna of just three lobes) help to define it. The most similar eggs are of E. beverleyae Timms, 2016 and E. uluruensis Timms, 2016. Eggs of E. beverleyae (Fig. 3F, Timms 2016a) have about 30 grooves, each about 40 µm long, and of the same tertiary material as their walls, whereas in E. kimberleyensis sp. nov. there are but 40 grooves, 40 µm long and of different tertiary material to that of the walls. In addition E. beverleyae has 11–13 cercopod setae whereas E. kimberleyensis sp. nov. has only about 8 cercopod setae. In E. uluruensis (Fig.9 H. Timms, 2016a) the grooves number about 28, lie within distinct polygons with low lateral ridges and a knobbly surface, a situation quite different to that in E. kimberleyensis sp. nov. (see above). Though E. uluruensis has telsonic spines reminiscent of E. kimberleyenesis sp. nov., the cercopod setae of E. uluruensis are shorter than those of E. kimberleyensis sp. nov. Given E. kimberleyensis sp. nov. lies within the distribution of the widespread and variable E. dahli Sars 1896, it is appropriate to detail their distinctiveness. Firstly, habitat choice is not distinctive— E. dahli occurs in gnammas in limestone in northwest Queensland (Timms, 2016a) and also in granite in the Pilbara (author unpublished data) while E. kimberleyensis sp. nov. occurs in sandstone gnammas in between these areas. However, their eggs are entirely different, those of E. dahli have ca. 20 surface polygons, while those of E. kimberleyensis sp. nov. have ca.36 grooves. Eulimnadia dahli typically (but not always) has 20 trunk segments, and E. kimberleyensis sp. nov. the standard 18. Furthermore E. dahli has ca. 15 telsonic spines and ca 18 cercopod setae, whereas E. kimberleyensis sp. nov. has ca 9 and 8 respectively, a difference wide enough to be certain of identity. Distribution. Known only from gnammas on the Gardner Plateau, Kimberley. These pools fill during the wet season, November to April, and the deeper pools (averaging 46 mm) support aquatic plants (Cross et al., 2015a, 2015b). No information is available on their fauna, except that a few pools support the new species of clam shrimp described here plus Limnadopsis multilineata Timms 2009.Published as part of Brian V Timms, 2018, Three new species of spinicaudatan clam shrimps from Australia, all from gnammas (rock pools), pp. 136-148 in Zootaxa 4418 (2) on pages 137-139, DOI: 10.11646/zootaxa.4418.2.3, http://zenodo.org/record/124533
A Revision of the Australian species of Lynceus Müller, 1776 (Crustacea: Branchiopoda: Laevicaudata, Lynceidae)
No full textTIMMS, BRIAN V (2013): A Revision of the Australian species of Lynceus Müller, 1776 (Crustacea: Branchiopoda: Laevicaudata, Lynceidae). Zootaxa 3702 (6): 501-533, DOI: 10.11646/zootaxa.3702.6.1, URL: http://dx.doi.org/10.11646/zootaxa.3702.6.
Eocyzicus parooensis Richter & Timms 2005, n.sp.
No full textEocyzicus parooensis n.sp. Figs. 1–3 Eocyzicus sp. a, Timms & Richter, 2002. Limnadia sp. b, Timms, 1993. Type material. HOLOTYPE 3, formalin-fixed AM P68156, carapace 7.8 × 4.5 mm. PARATYPES formalin-fixed: 13 slide AM P68157, 1♀ slide AM P68158; 833, 9♀♀, AM P68159, all collected by B. V. Timms from Gidgee Lake, 17 November 1999. Type locality. Gidgee Lake on Bells Creek, Bloodwood Station, 130 km NW of Bourke, NSW, Australia, 29°33'S 144°52'E. Etymology. This species is named after the Paroo area where it occurs commonly in hyposaline waters. Description. Male carapace 7.2 to 7.8 mm length, 4.2 to 4.5 mm height (n = 10). Female carapace 6.4 to 6.7 mm length, 3.9. to 4.1 mm height, smallest and largest female both ovigerous (n = 10). Carapace in both sexes oval, with 10 to 11 growth lines in males, and 9 to 10 in females. Dorsal margin of carapace with prominent umbo, posterior of umbo straight. Male head region with prominent rectangular (hatchet-like) rostrum in lateral view (Fig. 2A), including bilateral anterior margins, a ventral margin and a posterior margin. Anterior margins together form a V-shape in the dorsal view, continuing into the fornices of both sides (Fig. 2B). Nauplius eye triangular shaped, with sharp end pointing to the compound eye. Central dorsal part of the head defined anteriorly by prominent compound eye chamber and posteriorly by rounded occipital condylus. Compound eye chamber opening via a small pore anteriorly, slightly above anterior margins of rostrum (Fig. 2A, arrowhead). Central head region filled by mid-gut diverticula. Dorsal organ located close to posterior margin of occipital condyle (Fig. 2B, arrowhead). Female head region differing in particular by shape of rostrum which is more triangular because of less distinct posterior margin (Fig. 3A). Antennule extending to about fourth (females) or sixth (males) segment of posterior antennal flagellum, and distinctly lobate with each lobe bearing short sensilla (Fig. 2C). Antenna with peduncle of about eight segments, anterior densely covered with setae (Fig. 3C), and with about 11 to 14 segments on both anterior and posterior flagellum. Each flagellum segment bearing about six short spines on anterior side, and a number of longer natatory setae at the posterior side. Trunk consisting of 22 (in a few cases 23) leg-bearing segments, the last (two) segments not entirely separated from telson (Figs. 2G, 3B). More posterior trunk segments (between 10 and 15) carrying single dorsal spine at posterior end of segment (Fig. 2F). First and second thoracopod of male modified as claspers, not differing general characters from each other. Movable finger smoothly curving to the apical club (i.e. expanded apex). Surface of movable finger adjacent to apical club covered with scales; apical club with stout flat-tipped spines opposite to scales of movable finger (Fig. 2D). Tip of movable finger with about six (specimen studied might be broken in this area) more elongated “hairy” scales, directed away from apical club (Fig. 2E). Two palps originating from palm, the larger (threesegmented) palp behind movable finger, smaller (onesegmented) palp at apical club base. In females, eggs carried by projections of exopod of the ninth and tenth pairs of thoracopods (Fig. 3D). Telson covered dorsally by numerous spines, with caudal furcae originating at its posterior end. Dorsal part of telson formed like a “U”, with connecting part anteriorly and the two parallel margins ending in strong, upwards curved apexes (Fig. 2G,H,K). Margins carrying about 10 to 13 spines each in males and about 15 to 20 in females, excluding the apex (Figs. 2G, 3B). Two telsonal setae originating from a common plate at anterior end, at inner side of “U” (Fig. 2K). Caudal furcae articulated with telson; each carrying many (about 15) long plumose setae on inner margin (Fig. 2G,K). Tips of caudal furcae covered by very small spinules (Fig. 2 I). Eggs round and smooth, not showing any specialized surface structures (Fig. 3D). Remarks. This species has been recorded from several other localities in the Paroo area (Timms & Richter, 2002). Some of the characters differ from those described herein, e.g., the number of growth lines, number of telson spines, and the carapace length and height. Nevertheless, we believe that all these records (referred to in Timms & Richter, 2002 as Eocyzicus sp. a) are of E. parooensis n.sp. Most remarkable from an ecological point of view is that all these records are from hyposaline water bodies (see Timms & Richter, 2002 for more details). There is probably a second undescribed Eocyzicus species common in the Paroo area, which prefers turbid fresh water habitats (referred to Eocyzicus sp. b by Timms & Richter, 2002).Published as part of Richter, Stefan & Timms, Brian V., 2005, A List of the Recent Clam Shrimps (Crustacea: Laevicaudata, Spinicaudata, Cyclestherida) of Australia, Including a Description of a New Species of Eocyzicus, pp. 341-354 in Records of the Australian Museum 57 (3) on page 343, DOI: 10.3853/j.0067-1975.57.2005.1454, http://zenodo.org/record/468562
FIGURE 8 in A review of the Australian endemic clam shrimp, Paralimnadia Sars 1896 (Crustacea: Branchiopoda: Spinicaudata)
No full textFIGURE 8. Paralimnadia sordida (King). Swamp at Elwood (NMV J207). A, male carapace; B, male head; C, male telson, D, male clasper with long palp of clasper I and then of clasper II; E, female carapace; F, female head. Scale bars 1 mm.Published as part of Timms, Brian V., 2016, A review of the Australian endemic clam shrimp, Paralimnadia Sars 1896 (Crustacea: Branchiopoda: Spinicaudata), pp. 451-508 in Zootaxa 4161 (4) on page 464, DOI: 10.11646/zootaxa.4161.4.1, http://zenodo.org/record/26644
Limnadopsis paradoxa Timms 2009, n.sp.
No full textLimnadopsis paradoxa n.sp. Figs. 2G, 4D, 5K,L, 13 Types. Holotype 3 WAM C39341, allotype ♀ WAM C39342, paratypes 23, 2♀, WAM C39343, 33, 2♀, AM P76808. Type locality: Western Australia, E of Grass Patch, Sieda Farm, Fitzgerald Paddock 81, temporary pool, 33°13'S 121°47'E, 2.ii.2007, B. V. Timms. Other material. Western Australia: 43, S of Newdegate, Lake Bryde, 33°21'S 118°49'E, 21.iii.2006, D. Cale, WAM C39344; c. 20 individuals, S of Newdegate, Lake Bryde East, 33°22'S 118°54'E, 21.iii.2006, D. Cale, WAM C39345; c. 20 individuals, SE of Salmon Gums, along Guest Rd, temporary pool in paddock, 33°06'S 121°46'E, 25.i.2007, B. V. Timms, WAM C39346;> 50 individuals, E of Grass Patch, Sieda Farm, Fitzgerald Paddock 81, temporary pool, 33°13'S 121°47'E, 2.ii.2007, B. V. Timms, WAM C39347;>50 individuals, SE of Scaddan, Truslove Nature Reserve, a paperbark swamp, 33°20'50"S 121°46'5"E, 27.i.2007, B. V. Timms, WAM C39348. South Australia: 13, N of Woomera, Olympic Dam, 30°28'S 136°44'E, 12.ii.1981, M.J. Tyler, SAM C6351. New South Wales: 13, near Wilcannia, roadside ditch 19.5 km east of town, 31°41'S 143°427'E, 14.i.2007, B. V. Timms. Habitat and distribution. Limnadopsis paradoxa lives in freshwater intermittent ponds and lakes, that are somewhat turbid or humic. More is known about the habitat of this new species than the others, because the author is personally familiar with the area. The ponds and lakes fill every few years and may take two or more years to dry (e.g., Lake Bryde, Cale et al., 2004) or dry within months (e.g., pools on Sieda Farm, A. Longbottom, pers. comm.). In all sites it was found only in the early period of inundation. It is known mainly from the southeastern wheatbelt of Western Australia, specifically south of Newdegate and north of Esperance. Two outlier populations were found much further east, in central South Australia and in southwestern NSW. In Lake Bryde, it was collected in March, 2006, six weeks after a major filling, and at the time the lake was fresh (EC 549 µS/cm), alkaline (pH 7.8), warm (21.8°C), well oxygenated (88% saturation), and only slightly coloured (D. Cale, pers. comm.) This lake fills to overflowing only occasionally (every few years in the 1990s to 2000s, S. Halse, pers. comm.); normally the episodic fillings result in a shallow, fresh to slightly saline lake that takes 12–24 months to dry. At such times it holds the clam shrimps Caenestheria sp. and Caenestheriella sp., but apparently not Limnadopsis paradoxa (Cale et al., 2004). In seven sites at Grass Patch it appeared as adults within three weeks of filling in late January, 2007. These ponds are c. 20–50 m in diameter, saucer-shaped and up to 2 m deep. They were once Melaleuca swamps, but many are now usually farmed for cereals. They fill partially, or deeply as in 2007, in wet summers, generally about once every 5–10 years (A. Longbottom, pers. comm.). Their water is humic (40–150 NTU), fresh (conductivity 260–440 µS/cm), warm (21–28°C), and acid to slightly alkaline (pH 5.8–7.4). By early March 2007, all of the ponds sampled had declining senescent populations, or none at all. Etymology. The species name derives from the paradox presented upon first examination: it has a carapace resembling L. birchii and a body-form superficially resembling L. tatei, but it differs from these two species on detailed examination. Male. Carapace (Fig. 13A) 14.6 mm long by 9.9 mm deep, L:D ratio c. 1.5. Dorsal margin doubly curved so lowest point at anterior umbo area and highest point about two-thirds of way along the hinge line. Hinge line uneven with growth lines protruding as small carinae, these generally more prominent posteriorly. Umbo humped dorsoanteriorly. Growth lines 12, expressed, crowded anteriorly, but more spaced spaced posteriorly. Carapace coloured dark humic brown. Head (Fig. 13B) with a pear-shaped pyriform frontal organ posteriorly, preceded by rounded prominence containing eye, then by large rostrum at right angles to head. Length of rostrum similar to length of anterior surface of head and about twice its own basal width. Rostrum curved downwards apically and containing triangular naupliar eye dipping at angle to rostrum axis and occupying much of its basal area. First antenna with 11 subequal lobes, slightly longer than peduncle of second antenna. Two flagella each bearing 15–18 beaded flagellomeres, each of latter with up to 6–7 spines evenly spaced along dorsal surface. Trunk segments 26. Dorsally, posteriormost segment with spineless protuberance, preceding 7–8 segments each with 3–5 spines on protuberance, then further anteriorly another 7 segments with 5–9 long setae each. Hand of claspers with blunt narrow outgrowth near inner basal corner. Third thoracopod (Fig. 4D) similar in structure to that of L. birchii. Proportions of endites, endopod, exopod and epipodite slightly different, and significantly palp of fifth endite slightly shorter than fifth endite and epipodite proportionally smaller. Other thoracopods of same basic structure, but without palp and with larger epipodite. Telson (Fig. 13C) with two rows of 13 to 14 strong, subequal spines, although the first spine slightly larger than next few spines and curving slightly posteriorly, middle spines slightly smaller and posterior spines more widely spaced, and sharper last spine near apex of claw. Two telsonic setae inserted on protuberance about one quarter of way along dorsal side of telson. Caudal claws well developed, at least twice as large as telsonic claws, curved concavely dorsally, with basal two-thirds bearing about 20 setae mesodorsally and terminating in a spine. Apical third of claw with many fine denticles dorsally. Female. Carapace (Fig. 13E) 13.5 mm by 9.7 mm. Similar to that of male, but anterior concavity less pronounced and highest point of carapace at about midlength. Carinae of growthlines prominent, but blunt compared with those of male. Head (Fig. 13F) similar to that of male, but rostrum short, about as long as deep, and blunt. Naupliar eye of about same size and position as in male, thus occupying much of rostrum. First antenna shorter than in male, with about 8 lobes. Second antenna as in male. Number of body segments, and details of telson (Fig. 13G) similar to those in male. Eggs (Figs. 4L,M) top-shaped, with prominences dorsal and ventral and about 5 prominences around equator. Typically about 16 grooves between equator and dorsal and ventral prominences, and about 3–4 grooves between each equatorial prominence. Ridges between grooves may be straightish or Y-shaped, the latter generally in the fields between equatorial and dorsal or ventral grooves. Sometimes only 4 equatorial prominences present and grooves somewhat randomly distributed. Maximum dimensions about 250 µm (range 241–254 µm, n = 20). Variability. The carapace size varies from c. 13 to16 mm, growth lines from 10 to 14, first antennal lobes 9 to 11, telsonic spines 15 to 18, and caudal claw setae from 16 to 21. There is no significant variation in the characteristic carapace shape, and all specimens have just one spine on the caudal claws. Comments. Limnadopsis paradoxa resembles small specimens of L. birchii, on account of its size, general shape, development of the carinae, and perhaps colouration. However, the body inside bears absolutely no resemblance to that of L. birchii. For instance there are 26 body segments, not 32, and there are only c. 14 telsonic spines on a almost straight edge compared to c. 50 spines on a doubly curved edge. The new species is most like L. tatei but has more growth lines, more lobes on the first antenna, more telsonic spines and more setae on the caudal claws. Perhaps it could be regarded as a bigger form of L. tatei, but the shape of the carapace is distinctive, particularly the concave dorsal surface and the lateral development of the umbo. The smaller first:second telsonic spine size ratio in L. paradoxa, and more numerous caudal claw setae are also distinctive. Limnadopsis pilbarensis n.sp. (see below) differs by having a convex edge in the umbo area, much less pronounced development of the dorsal outgrowths of the growth lines, and fewer telsonic denticles and setae on the caudal claws. The eggs of L. paradoxa and the three other abovementioned species are distinctive among themselves. At 40× magnification, eggs of L. birchii and L. tatei are smoothly round with groups of parallel grooves, more of the latter in L. birchii than in L. tatei. Eggs of L. paradoxa and L. pilbarensis both have rough surfaces, but those of L. pilbarensis have many (> 20) spines and those of L. paradoxa have just a few (<8) rounded prominences. These distinctions are even more pronounced as observed by SEM (Fig. 4).Published as part of Timms, Brian V., 2009, A Revision of the Australian Endemic Clam Shrimp Genus Limnadopsis Spencer & Hall (Crustacea: Branchiopoda: Spinicaudata: Limnadiidae), pp. 49-72 in Records of the Australian Museum 61 (1) on pages 65-66, DOI: 10.3853/j.0067-1975.61.2009.1498, http://zenodo.org/record/524026
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