TY - JOUR
AU - Austin, Andrew, D
AB - Abstract Recent surveys of Australian arid-zone groundwater ecosystems have uncovered considerable species diversity and extreme endemism for the oniscidean isopod genus Haloniscus Chilton, 1920. Phylogenetic and species delimitation analyses have recognised several distinct species from the Great Artesian Basin springs in South Australia, inspiring a morphological reassessment of the genus and examination of specimens from the iconic Lake Eyre and Dalhousie Springs. We present a revised diagnosis of Haloniscus, transfer the genus from the family Scyphacidae to Philosciidae and describe four new species, H. fontanus Stringer, King & Taiti n. sp., H. microphthalmus Stringer, King & Taiti n. sp., H. rotundus Stringer, King & Taiti n. sp., and H. yardiyaensis Stringer, King & Taiti n. sp., based on combined morphological and molecular evidence. We compare the results of molecular-based species delimitation analyses with morphological data, provide distribution information, and present a key to the described species of Haloniscus. Two species presently included in Andricophiloscia Vandel, 1973, A. stepheni (Nicholls & Barnes, 1926) and A. pedisetosa Taiti & Humphreys, 2001, from Western Australia are also transferred to Haloniscus. INTRODUCTION Exceptionally diverse invertebrate communities are known to inhabit the unique groundwater-dependent springs of the Great Artesian Basin (GAB) in South Australia (SA), with molecular studies uncovering numerous undescribed species and high levels of isolation and short-range endemism (Murphy et al., 2009, 2012, 2013, 2015a; Guzik et al., 2012). These desert springs represent the most reliable source of freshwater in this arid region, and are now regarded as significant areas for biodiversity (Ponder et al., 1995; Ponder, 2003). The springs, nonetheless, are one of Australia’s most threatened ecosystems due to aquifer drawdown from extensive water extraction from the GAB for mining and pastoral activities, and are, therefore, listed as an “endangered ecological community” under the Australian Environmental Protection and Biodiversity Act (Harris, 1992; Fensham & Price, 2004). A comprehensive understanding of the taxonomy, distribution, composition, and number of species is, consequently, vital to the conservation of important desert spring invertebrates for potential listing as threatened species (Taylor et al., 2018). The oniscidean isopod genus Haloniscus Chilton, 1920, in particular, was recently discovered from the GAB springs, with broad sampling, a multi-gene phylogeny, and species delimitation analyses revealing significant genetic diversity across taxa (Fig. 1) (Guzik et al., 2019). The study estimated between three and eight new putative Haloniscus species using the delineation methods, Automatic Barcode Gap Discovery (ABGD) (Puillandre et al., 2012) and Bayesian Poisson Tree Processes (bPTP) (Zhang et al., 2013), respectively. This evidence, together with the discovery of new Haloniscus lineages from two further arid-zone groundwater ecosystems (Cooper et al., 2008; Guzik et al., 2019), has encouraged a morphological reassessment of the genus and formal descriptions of new species. Figure 1. Open in new tabDownload slide Molecular phylogenetic trees modified from Guzik et al. (2019) with colour-coded lineages corresponding to the new species of Haloniscus. Bayesian Inference COI phylogeny with Haloniscus microphthalmus n. sp. from Francis Swamp (green), Haloniscus rotundus n. sp. from Dalhousie Springs (red), Haloniscus yardiyaensis n. sp. from Freeling South Springs (blue), and Haloniscus fontanus n. sp. from (α) southern Lake Eyre and (β) northern Lake Eyre (Neales Complex) (purple) (A). The orange lineage corresponds to Haloniscus stepheni. Delineated species are indicated to the right of the phylogeny represented by outlined bars for the ABGD and bPTP methods, respectively. Subset (corresponding to the clade in the COI phylogeny denoted by * of the Bayesian Inference combined COI and 18S phylogeny with colour codes as above (B). Lineages not examined in this study are in grey. This figure is available in colour at Journal of Crustacean Biology online. Figure 1. Open in new tabDownload slide Molecular phylogenetic trees modified from Guzik et al. (2019) with colour-coded lineages corresponding to the new species of Haloniscus. Bayesian Inference COI phylogeny with Haloniscus microphthalmus n. sp. from Francis Swamp (green), Haloniscus rotundus n. sp. from Dalhousie Springs (red), Haloniscus yardiyaensis n. sp. from Freeling South Springs (blue), and Haloniscus fontanus n. sp. from (α) southern Lake Eyre and (β) northern Lake Eyre (Neales Complex) (purple) (A). The orange lineage corresponds to Haloniscus stepheni. Delineated species are indicated to the right of the phylogeny represented by outlined bars for the ABGD and bPTP methods, respectively. Subset (corresponding to the clade in the COI phylogeny denoted by * of the Bayesian Inference combined COI and 18S phylogeny with colour codes as above (B). Lineages not examined in this study are in grey. This figure is available in colour at Journal of Crustacean Biology online. Haloniscus so far consists of five described species, with four from Australia and one from New Caledonia: H. searlei Chilton, 1920, with a wide distribution in salt lakes across Western Australia (WA), Victoria, Tasmania, and SA; H. longiantennatus Taiti & Humphreys, 2001, H. stilifer Taiti & Humphreys, 2001, and H. tomentosus Taiti & Humphreys, 2001 from subterranean calcrete aquifers in WA; and H. anophthalmus Taiti, Ferrara & Iliffe, 1995 found in anchialine limestone cave waters in the Isle of Pines, New Caledonia. We describe four new species of Haloniscus from SA GAB springs and compare the results of species delimitation analyses with morphological data. In light of the molecular phylogenetic results of Guzik et al. (2019) and our morphological study, we also reassess the family level placement of Haloniscus as well as the generic status of Andricophiloscia stepheni (Nicholls & Barnes, 1926) and A. pedisetosa Taiti & Humphreys, 2001 from WA. MATERIALS AND METHODS Researchers from The University of Adelaide and the South Australian Museum undertook extensive sampling across the South Australian spring supergroups, Dalhousie and Lake Eyre (Fig. 2). The GAB springs fall naturally into geographic hierarchical clusters where proximate springs form ‘groups’ and, at broader scales, ‘complexes’ that are hydrochemically and hydrogeologically similar (Habermehl, 1980). The springs have been grouped further into 13 major clusters, called ‘supergroups’, in SA, Queensland, and New South Wales (Ponder, 2002). Specimens of Haloniscus were collected opportunistically by hand from the wet margins of springs and stored in 100% ethanol. Type specimens were dissected along the left side (where possible) and appendages were slide-mounted and illustrated with a camera lucida attachment to a Nikon Eclipse 80i (Nikon, Tokyo, Japan) compound microscope. Total body length was measured through the mid-line of the specimen, from the head to the telson. All type material of the new spring species is lodged at the South Australian Museum (SAMA). We also re-examined the type material for H. stepheni and H. pedisetosus, deposited in the Western Australian Museum (WAM). Figure 2. Open in new tabDownload slide Map of sampled SA GAB spring locations where red represents the distribution of Haloniscus rotundus n. sp. across Dalhousie Springs (Main Pool, Kingfisher and Meeting Place), Haloniscus yardiyaensis n. sp. in Freeling South Springs (blue), Haloniscus microphthalmus n. sp. in Francis Swamp (green), and Haloniscus fontanus n. sp. across the Neales (Hawker and Fanny Springs), Strangways, McKewin and Coward (Bubbler Spring) Complexes (purple). This figure is available in colour at Journal of Crustacean Biology online. Figure 2. Open in new tabDownload slide Map of sampled SA GAB spring locations where red represents the distribution of Haloniscus rotundus n. sp. across Dalhousie Springs (Main Pool, Kingfisher and Meeting Place), Haloniscus yardiyaensis n. sp. in Freeling South Springs (blue), Haloniscus microphthalmus n. sp. in Francis Swamp (green), and Haloniscus fontanus n. sp. across the Neales (Hawker and Fanny Springs), Strangways, McKewin and Coward (Bubbler Spring) Complexes (purple). This figure is available in colour at Journal of Crustacean Biology online. Species were delineated using an integrated approach along with the general lineage species concept (de Queiroz, 1998, 2007); i.e. with fixed morphological differences (analysis carried out here) and phylogenetic analyses of molecular data (all sequencing and associated molecular analyses conducted by Guzik et al. (2019) (Fig. 1)), providing the operational criteria to delimit species. Guzik et al. (2019) generated sequences from the mitochondrial cytochrome c oxidase subunit I (COI) gene and the 18S rRNA gene, and further calculated COI nucleotide divergences using the Kimura 2-parameter (K2P) model (Kimura, 1980), as implemented in MEGA 6.0 (Tamura et al., 2013), with pertinent results included here (see below). Guzik et al. (2019) provided a detailed outline of the DNA extraction and sequencing techniques, as well as the molecular phylogenetic, COI divergence, and species delimitation (ABGD and bPTP) analyses undertaken. SYSTEMATICS Family Philosciidae Kinahan, 1857 Genus Haloniscus Chilton, 1920 Type species Haloniscus searlei Chilton, 1920 by monotypy. Species included Haloniscus anophthalmus Taiti, Ferrara & Iliffe, 1995,, H. fontanus Stringer, King & Taiti n. sp., H. longiantennatus Taiti & Humphreys, 2001, H. microphthalmus Stringer, King & Taiti n. sp., H. pedisetosus (Taiti & Humphreys, 2001) n. comb., H. rotundus Stringer, King & Taiti n. sp., H. searlei Chilton, 1920, H. stepheni Nicholls & Barnes, 1926, H. stilifer Taiti & Humphreys, 2001, H. tomentosus Taiti & Humphreys, 2001, and H. yardiyaensis Stringer, King & Taiti n. sp. Amended diagnosis Body elongated with pleon distinctly narrower than pereon. Noduli laterales on pereonites present in epigean and some subterranean species, secondarily absent in most subterranean species; when present, noduli laterales inserted at similar distance from lateral margins of pereonites. Cephalon with small, rounded lateral lobes not protruding frontward; supra-antennal line usually present (absent in H. anophthalmus); no frontal line. Pleon epimera with posterior points slightly reduced. Antennule of 3 articles with some aesthetascs at apex. Antennal flagellum of 3 articles, with short apical organ. Molar penicil of mandible dichotomised, consisting of tuft of plumose setae. Outer branch of maxillule with 10 or 11 teeth all with simple apex, flagelliform seta among outer group of teeth; inner branch with 2 subequal penicils, no posterior point. Endite of maxilliped setose with large penicil on medial corner. Pereopods with flagelliform dactylar, ungual seta. Pereopod 1 with cleaning device (or tuft of setae) for antennae slightly developed. Exopods of pleopods with marginal fringe of long, thin setae overlapping medially in aquatic forms (epigean and subterranean), no fringe of setae, not overlapping in epigean terrestrial forms; no respiratory structures. Uropod with protopod, exopod grooved on outer margin in some species, flattened in others; insertion of endopod slightly proximal to that of exopod. Remarks Despite sharing some characters with the family Philosciidae, Haloniscus was tentatively included in Scyphacidae by Taiti & Humphreys (2001), primarily based on the characters for the known, aquatic species: noduli laterales absent; uropods with protopods often enlarged, protopods and exopods with lateral margins not grooved. Haloniscus stepheni, described by Nicholls & Barnes (1926) from Kockatea Gully, Tenindewa, WA, was further transferred to Andricophiloscia Vandel, 1973 (type species: A. melanesiensis Vandel, 1973) from Haloniscus by Taiti & Humphreys (2001) and A. pedisetosa was described. These two Australian species were principally included in Andricophiloscia as they possessed characters listed in the generic diagnosis of Vandel (1973a), particularly in the presence of noduli laterales, and uropods with protopods and exopods grooved on the outer margin. These species are members of Philosciidae, but, according to molecular evidence from Guzik et al. (2019) (Fig. 1A), they do fall within Haloniscus and are transferred herein. Haloniscus stepheni is grouped with an undescribed Haloniscus species from Lake Goorly in WA with strong support (posterior probability of 99%) and is, furthermore, clustered in a larger clade of subterranean Haloniscus (containing H. stilifer) from calcrete aquifers in the Yilgarn region of WA (posterior probability of 95%) (Fig. 1A). It appears that the absence of noduli laterales and grooved lateral margins on the uropods, along with the occurrence of a marginal fringe of setae on the exopods of pleopods, are adaptations to an aquatic lifestyle and, as such, Haloniscus should be accommodated in the family Philosciidae rather than Scyphacidae. Haloniscus now includes 11 species with some solely aquatic forms (H. searlei, H. anophthalmus, H. longiantennatus, H. stilifer, and H. tomentosus), whereas others are terrestrial or semi-terrestrial. The new SA GAB associated species (H. fontanus Stringer, King & Taiti n. sp., H. microphthalmus Stringer, King & Taiti n. sp., H. rotundus Stringer, King & Taiti n. sp., and H. yardiyaensis Stringer, King & Taiti n. sp.) occur along the wet margins of springs, whereas H. stepheni is found beneath logs by creek banks. Haloniscus pedisetosus was collected within the same calcrete system in the Yilgarn (WA) as H. longiantennatus, but, according to Taiti & Humphreys (2001), it is unclear whether this species is equally aquatic. These semi-terrestrial species are all morphologically comparable (noduli laterales present on pereonites, uropods grooved on the lateral margins, and marginal fringe of setae on exopods of pleopods absent, characters in opposition to those in aquatic species as mentioned above), which again further seems to suggest that variation in morphological characters across Haloniscus species is likely associated with adaptations to different environments. Haloniscus fontanus Stringer, King & Taiti n. sp. (Figs. 3–5) Material examined Holotype, male SAMA C13220 (GAB00765), Bubbler Spring, Coward Complex, South Australia, 29°26′46.9ʺS 136°51′28.8ʺE, coll. M. Guzik and N. Murphy, 3 November 2007. Paratypes: 4 males, 3 females SAMA C13221 (GAB00765), same collection data as holotype; 1 female SAMA C13222 (GAB00765.5; Genbank COI: KT236011, Genbank 18S: MK286387), same collection data as holotype; 3 males, 2 females SAMA C13223 (GAB00738), Strangways Springs, South Australia, 29°09′31.4ʺS 136°32’37.6”E, coll. M. Guzik and N. Murphy, 1 November 2007. Figure 3. Open in new tabDownload slide Haloniscus fontanus n. sp. holotype male (A, G–I), paratype female (B–F). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and uropods (G); antennule (H); antenna (I). Figure 3. Open in new tabDownload slide Haloniscus fontanus n. sp. holotype male (A, G–I), paratype female (B–F). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and uropods (G); antennule (H); antenna (I). Figure 4. Open in new tabDownload slide Haloniscus fontanus n. sp. holotype male. Left mandible (A); right mandible (B); maxillule (C); maxilla (D); maxilliped (E); uropod (F). Figure 4. Open in new tabDownload slide Haloniscus fontanus n. sp. holotype male. Left mandible (A); right mandible (B); maxillule (C); maxilla (D); maxilliped (E); uropod (F). Figure 5. Open in new tabDownload slide Haloniscus fontanus n. sp. holotype male. Pereopod 1 (A); pereopod 7 (B); pleopod 1 (C); pleopod 2 (D); pleopod 3 exopod (E); pleopod 4 exopod (F); pleopod 5 exopod (G). Figure 5. Open in new tabDownload slide Haloniscus fontanus n. sp. holotype male. Pereopod 1 (A); pereopod 7 (B); pleopod 1 (C); pleopod 2 (D); pleopod 3 exopod (E); pleopod 4 exopod (F); pleopod 5 exopod (G). Additional material 1 female SAMA C13224 (GAB00744.4; Genbank COI: KT236007), Strangways Springs, South Australia, 29°09′35.0ʺS 136°33′04.2ʺE, coll. M. Guzik and N. Murphy, 1 November 2007; 2 males, 1 female SAMA C13225 (GAB00669), McKewin Spring, South Australia, 29°23′10.3ʺS 136°32′48.8ʺE, coll. M. Guzik and N. Murphy, 3 November 2007; 1 female SAMA C13226 (GAB00669.4; Genbank COI: KT235998), McKewin Spring, South Australia, 29°23′10.3ʺS 136°32′48.8ʺE, coll. M. Guzik and N. Murphy, 3 November 2007; 1 male and 1 female SAMA C13228 (GAB01007), Hawker Springs, Neales Complex, South Australia, 28°25′30.2ʺS 136°11′09.9ʺE, coll. M. Guzik and N. Murphy, 27 August 2008; 1 male SAMA C13227 (GAB01007.4; Genbank COI: KT236017), Hawker Springs, Neales Complex, South Australia, 28°25′30.2ʺS 136°11′09.9ʺE, coll. M. Guzik and N. Murphy, 27 August 2008; 1 male SAMA C13230 (GAB01008.3; Genbank COI: KT236020), 1 female SAMA C13229 (GAB01008.1; Genbank COI: KT236018), Hawker Springs, Neales Complex, South Australia, 28°23′04.1ʺS 136°09′03.7ʺE, coll. M. Guzik and N. Murphy, 27 August 2008; 1 male SAMA C13232 (GAB01011.5; Genbank COI: KT236024, Genbank 18S: MK286387), 1 female SAMA C13231 (GAB01011.1; Genbank COI: KT236024), Fanny Springs, Neales Complex, South Australia, 28°19′22.2ʺS 136°14′16.1ʺE, coll. M. Guzik and N. Murphy, 29 August 2008. Diagnosis Antennae reaching past pereonite 2. Male pereopods 1–3 with carpus, merus bearing thick brush of long setae on sternal margin. Male pleopod 2 exopod with around 10 robust setae on outer margin. Description Maximum body length: male 4.5 mm, female 5 mm. Colour in alcohol pale, speckled with brown on anterior parts of pereonites, pleonites, more evident in medial area of the body. Body (Fig. 3A) moderately convex, elongated, about 3× as long as wide, with pleon distinctly narrower than pereon. Dorsum smooth with triangular scale-setae (Fig. 3A, B); noduli laterales present on pereonites with one per side on each segment, inserted at similar distance from lateral margins of pereonites; b/c and d/c co-ordinates as in Fig. 3C. Cephalon (Fig. 3D–F) with small, rounded lateral lobes; supra-antennal line present, slightly sinuous. Eyes with 10–12 ommatidia. Pereonites 1–4 with straight posterior margins, right-angled posterior corners; pereonites 5–7 with posterior corners progressively more acute. Pleonites 3–5 with posterior points reduced (Fig. 3A, G). Telson (Fig. 3A, G) almost twice as wide as long, distal part with straight sides, rounded apex. Antennule (Fig. 3H) with first, third articles longer than second, 2 aesthetascs at apex, tuft of 3 aesthetascs subapically. Antenna (Fig. 3I) short, reaching past pereonite 2; fifth article of peduncle slightly shorter than flagellum; flagellum with first, second articles subequal in length, third longer; second, third articles with 1, 2 aesthetascs, respectively. Mandibles (Fig. 4A, B) with molar penicil consisting of 4 plumose setae, 2 + 1 free penicils on the left, 1 + 1 on the right mandible. Maxillule (Fig. 4C) inner branch apically rounded, with 2 large subequal penicils; outer branch with 4 + 6 simple large teeth, small tooth, flagelliform seta among outer group of teeth. Maxilla (Fig. 4D) with outer lobe about 1.5× wider than inner lobe, both covered with fine setae on distal ends. Maxilliped (Fig. 4E) with distal part of palp without visible transverse suture; proximal article of palp with 2 robust setae. Uropod (Fig. 4F) protopod, exopod grooved on outer margin, insertion of endopod proximal to that of exopod, exopod about twice as long as endopod. Male: Pereopods 1 (Fig. 5A)–3 with carpus, merus bearing brush of long setae on sternal margin. Pereopod 7 (Fig. 5B) ischium with sternal margin straight to slightly concave in proximal half. Pleopod 1 (Fig. 5C) exopod apically rounded, with no setae along margin; endopod significantly longer than exopod, with pointed apical part bent outwards. Pleopod 2 (Fig. 5D) exopod triangular with 10 robust setae on outer margin, endopod distinctly longer than exopod, with flagelliform distal end. Pleopods 3, 4 (Fig. 5E, F) exopods triangular with outer margin comprising 9, 10 robust setae. Pleopod 5 (Fig. 5G) exopod triangular with 6 or 7 robust setae on outer margin. Pleopods 2–5 exopods with short setae on medial margin. Etymology The species name, fontanus, refers to the Latin word for ‘related to spring’, and is a reference to the Great Artesian Basin springs in South Australia where the species occurs. Remarks Haloniscus fontanus n. sp. is morphologically similar to H. yardiyaensis n. sp. and H. stepheni, but differs predominantly in antenna length (reaching past pereonite 2) and in the male characters where pereopods 1–3 consist of longer, thicker brushes of setae on the carpus and merus, and the exopods of pleopods 2–5 comprise a larger number of robust setae on the outer margin. As well as being the most alike morphologically, the combined phylogeny (Fig. 1B) suggests that H. fontanus is most closely related to H. yardiyaensis, with a 10–12% COI divergence (Guzik et al., 2019), of the newly described GAB species. Haloniscus stepheni presumably displays similar characters to the SA GAB species, in particular H. fontanus and H. yardiyaensis, because they occur in similar habitats. The specimens from the northern Lake Eyre region (Neales Complex) also appear to be morphologically identical to the H. fontanus specimens from the southern Lake Eyre Springs (Bubbler, Strangways, and McKewin Springs), despite the apparent phylogenetic structuring (COI divergence estimates of 8–9%; Guzik et al., 2019) evident in Fig. 1 as well as the geographic isolation between the spring complexes. There was also very little COI genetic divergence (2–3%; Guzik et al., 2019) between the Bubbler, Strangways, and McKewin spring group populations. Nomenclatural statement A life science identifier (LSID) number was obtained for the new species: urn:lsid:zoobank.org:pub:71C7FCDD-FEB8-4F1D-A709-CE4E0F27A7DD. Haloniscus microphthalmus Stringer, King & Taiti n. sp. (Figs. 6, 7) Material examined Holotype, male SAMA C13233 (GAB0764.5; Genbank COI: KT236009, Genbank 18S: MK286391), Francis Swamp Springs, South Australia, 29°04′46.9ʺS 136°16′36.7ʺE, coll. M. Guzik and N. Murphy, 3 November 2007. Paratypes: 6 males SAMA C13234–C13239 (GAB0764.2–4 and GAB0764.6–8; Genbank COI: KT236009, Genbank 18S: MK286391), same collection data as holotype. Figure 6. Open in new tabDownload slide Haloniscus microphthalmus n. sp. holotype male (A, G–J), paratype male (B–F). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and uropods (G); antennule (H); antenna (I); uropod (J). Figure 6. Open in new tabDownload slide Haloniscus microphthalmus n. sp. holotype male (A, G–J), paratype male (B–F). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and uropods (G); antennule (H); antenna (I); uropod (J). Figure 7. Open in new tabDownload slide Haloniscus microphthalmus n. sp. holotype male. Pereopod 1 (A); pereopod 7 (B); pleopod 1 (C); pleopod 2 (D); pleopod 3 exopod (E); pleopod 4 exopod (F); pleopod 5 exopod (G). Figure 7. Open in new tabDownload slide Haloniscus microphthalmus n. sp. holotype male. Pereopod 1 (A); pereopod 7 (B); pleopod 1 (C); pleopod 2 (D); pleopod 3 exopod (E); pleopod 4 exopod (F); pleopod 5 exopod (G). Diagnosis Dorsum equipped with numerous broad based, apically frayed triangular scale setae. Eyes reduced to single spot of black pigment. Antennule with first, third articles longer than second; aesthetascs grooved longitudinally. Description Maximum body length 3.5 mm. Colour in alcohol pale with few traces of pigment. Body (Fig. 6A) moderately convex, elongated, about 3.5× as long as wide, with pleon distinctly narrower than pereon. Dorsum smooth with numerous frayed, triangular scale-setae (Fig. 6A, B); noduli laterales present, inserted at similar distance from lateral margins of pereonites; b/c, d/c co-ordinates as in Fig. 6C. Cephalon (Fig. 6D–F) with small, rounded lateral lobes; supra-antennal line present, slightly sinuous. Eyes reduced to spot of black pigment. Pereonites 1–4 with straight posterior margins, right-angled posterior corners; pereonites 5–7 with posterior corners progressively more acute. Pleonites 3–5 with posterior points reduced (Fig. 6A, G). Telson (Fig. 6A, G) almost twice as wide as long, distal part with straight sides, rounded apex. Antennule (Fig. 6H) with first, third articles longer than second, 2 aesthetascs at apex, tuft of 4 aesthetascs subapically; all aesthetascs grooved longitudinally. Antenna (Fig. 6I) short, reaching to, but not past, pereonite 2; fifth article of peduncle slightly shorter than flagellum; flagellum with first, second articles subequal in length, third article longer; second, third articles with 1, 2 aesthetascs, respectively. Mouth appendages as in H. fontanus. Uropod (Fig. 6J) protopod, exopod grooved on outer margin, insertion of endopod proximal to that of exopod, exopod less than twice as long as endopod. Pereopods 1 (Fig. 7A), 2 with carpus, merus bearing some long setae on sternal margin; pereopod 7 (Fig. 7B) ischium with sternal margin straight to slightly concave in proximal half. Pleopod 1 (Fig. 7C) exopod apically rounded, with no setae along margin; endopod significantly longer than exopod, with pointed apical part bent outwards. Pleopod 2 (Fig. 7D) exopod triangular with 6 or 7 robust setae on outer margin; endopod distinctly longer than exopod, with flagelliform distal end. Pleopods 3, 4 exopods (Fig. 7E, F) triangular with rounded apex, 6, 7 robust setae on outer margin. Pleopod 5 (Fig. 7G) exopod triangular with 6 robust setae on outer margin. Pleopods 2–5 exopods with short setae on medial margin. Etymology The species name is composed of the Greek micros for ‘small’ and ophthalmos for ‘eye’ referring to the reduced eye visible as a spot of dark pigment. Remarks Haloniscus microphthalmus n. sp. is readily distinguished from the other SA GAB spring species described here by the reduced eyes, body setation, and shortened uropods. The new species is highly divergent genetically, showing approximately 20% COI divergence from the additional Lake Eyre and Dalhousie spring species and is, remarkably, more closely related to Haloniscus from subterranean calcrete aquifers in the Yilgarn, WA than to the other SA GAB species (Fig. 1A; Guzik et al., 2019). Haloniscus microphthalmus is restricted to one spring group, Francis Swamp. No female specimens were collected at this location and, as such, potential female-only characters could not be recorded. Nomenclatural statement A life science identifier (LSID) number was obtained for the new species: urn:lsid:zoobank.org:pub:71C7FCDD-FEB8-4F1D-A709-CE4E0F27A7DD. Haloniscus pedisetosus (Taiti & Humphreys, 2001) n. comb. Andricophiloscia pedisetosa Taiti & Humphreys, 2001: 147, fig. 10; Cooper et al., 2008: 197. Material examined Holotype, male WAM C25015 (BES 7207), Murchison Region, Lake Way, site 286, Western Australia, 26°41.256′S 120°17.868′E, coll. W.F. Humphreys and H.J. Hahn, 21 May 1999. Remarks Haloniscus pedisetosus n. comb. was only tentatively included in Andricophiloscia by Taiti & Humphreys (2001) as it possesses all the major characters of the generic diagnosis and is similar in morphology to H. stepheni, particularly in the occurrence of noduli laterales on the pereonites, uropods grooved on the lateral margin, and the exopod of male pleopods not fringed with fine setae. Taiti & Humphreys (2001) nevertheless also noted that it displayed a number of unusual characters, such as the petaliform aesthetascs of the antennule and a brush of setae on the carpus and merus of the male pereopods. These characters, as described above, are now all known in species of Haloniscus and, therefore, A. pedisetosa is transferred here to the genus Haloniscus. Haloniscus rotundus Stringer, King & Taiti n. sp. (Figs. 8, 9) Material examined Holotype, male SAMA C13240 (GAB01459), Main Pool, Dalhousie Springs, South Australia, 26°25′16.3ʺS 135°30′11.6ʺE, coll. M. Guzik, R. King and L. Harsche, 6 July 2009. Paratypes: 6 males, 6 females SAMA C13241 (GAB01459), same collection data as holotype; 1 female C13242 (GAB01459.1; Genbank COI: KT236034, Genbank 18S: MK286388), same collection data as holotype; 5 males, 4 females SAMA C13243 (GAB01472), Meeting Place, Dalhousie Springs, South Australia, 26°29′18.3ʺS 135°29′15.6ʺE, coll. M. Guzik, R. King and L. Harsche, 9 July 2009. Figure 8. Open in new tabDownload slide Haloniscus rotundus n. sp. holotype male (A, G–I), paratype female (B–F). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and uropods (G); antennule (H); antenna (I). Figure 8. Open in new tabDownload slide Haloniscus rotundus n. sp. holotype male (A, G–I), paratype female (B–F). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and uropods (G); antennule (H); antenna (I). Figure 9. Open in new tabDownload slide Haloniscus rotundus n. sp. holotype male (A, C), paratype male (B, D–H). Uropod (A); pereopod 1 (B); pereopod 7 (C); pleopod 1 (D); pleopod 2 (E); pleopod 3 exopod (F); pleopod 4 exopod (G); pleopod 5 exopod (H). Figure 9. Open in new tabDownload slide Haloniscus rotundus n. sp. holotype male (A, C), paratype male (B, D–H). Uropod (A); pereopod 1 (B); pereopod 7 (C); pleopod 1 (D); pleopod 2 (E); pleopod 3 exopod (F); pleopod 4 exopod (G); pleopod 5 exopod (H). Additional material 1 male, 4 females, SAMA C13244 (GAB01433), Kingfisher, Dalhousie Springs, South Australia, 26°24′29.9ʺS 135°31′17.9ʺE, coll. M. Guzik, R. King and L. Harsche, 7 July 2009; 1 male SAMA C13245 (GAB01433.2; Genbank COI: KT236027, Genbank 18S: MK286388), Kingfisher, Dalhousie Springs, South Australia, 26°24′29.9ʺS 135°31′17.9ʺE, coll. M. Guzik, R. King and L. Harsche, 7 July 2009; 5 males, 5 females, SAMA C13246 (GAB01525), Kingfisher, Dalhousie Springs, South Australia, 26°24′31.4ʺS 135°31′12.1ʺE, coll. M. Guzik, R. King and L. Harsche, 8 July 2009. Diagnosis Telson with broadly rounded apex. Male pleopod 1 exopod with outer margin slightly sinuous. Male pleopod 2 exopod triangular, distinctly concave towards the apex. Description Maximum body length: male, female 3 mm. Colour in alcohol light brown, with large pale muscle spots. Body (Fig. 8A) moderately convex, elongated, about 3× as long as wide, with pleon distinctly narrower than pereon. Dorsum smooth with some triangular scale-setae with narrow base (Fig. 8A, B); noduli laterales present, inserted at similar distance from lateral margins of pereonites; b/c, d/c co-ordinates as in Fig. 8C. Cephalon (Fig. 8D–F) with small, rounded lateral lobes; supra-antennal line present, distinctly sinuous. Eyes with 13, 14 ommatidia. Pereonites 1–4 with straight posterior margins, right-angled posterior corners; pereonites 5–7 with posterior corners progressively more acute. Pleonites 3–5 with posterior points reduced (Fig. 8A, G). Telson (Fig. 8A, G) twice as wide as long with broadly rounded apex. Antennule (Fig. 8H) with first, third articles longer than second, 2 long aesthetascs at apex, 2 in centre of third article. Antenna (Fig. 8I) short, reaching to, but not past, pereonite 2; fifth article of peduncle slightly shorter than flagellum; flagellum with first, second articles subequal in length, third longer. Mouth appendages as in H. fontanus. Uropod (Fig. 9A) protopod, exopod grooved on outer margin, insertion of endopod proximal to that of exopod, exopod less than twice as long as endopod. Male: Pereopods 1 (Fig. 9B), 2 with merus bearing some long setae, a fringe of scales on sternal margin; carpus with several long setae on sternal margin, half frontal surface covered with fine setae or scales. Pereopod 7 (Fig. 9C) ischium with sternal margin straight. Pleopod 1 (Fig. 9D) exopod with rounded apex, outer margin slightly sinuous, no setae along margin; endopod much longer than exopod, with short pointed apical part bent outwards. Pleopod 2 (Fig. 9E) exopod triangular, distinctly concave towards apex with 8 robust setae on outer margin; endopod distinctly longer than exopod, with flagelliform distal end. Pleopods 3, 4 (Fig. 9F, G) exopods triangular with outer margin bearing 6, 7 robust setae. Pleopod 5 (Fig. 9H) exopod triangular with 4 or 5 robust setae on outer margin. Pleopods 2–5 exopods with short setae on medial margin. Etymology Name composed of the Latin rotundus for “round” referring to the broadly rounded distal margin of the telson. Remarks Haloniscus rotundus n. sp. is primarily characterised by its broadly rounded telson. This new species is endemic to the Dalhousie Springs supergroup and is genetically distinct, showing COI divergences between 23–26%, from the more geographically distant Lake Eyre supergroup species: H. fontanus n. sp., H. microphthalmus n. sp., and H. yardiyaensis n. sp. (Guzik et al., 2019). Nomenclatural statement A life science identifier (LSID) number was obtained for the new species: urn:lsid:zoobank.org:pub:71C7FCDD-FEB8-4F1D-A709-CE4E0F27A7DD. Haloniscus stepheni Nicholls & Barnes, 1926 Haloniscus stepheni Nicholls & Barnes, 1926: 89, figs. 1–6, pl. 10, figs. 1–14; Vandel, 1973b: 101; Green, 1974: 245; Taiti et al., 1995: 321. Andricophiloscia stepheni - Taiti & Humphreys, 2001: 147; Cooper et al., 2008: 197. Material examined Syntypes 10 males, 8 females WAM C25012, Kokatea Creek, Tenindewa, Western Australia, 8 January 1926. Additional material 3 males, 1 female WAM C74280 (BES 9888) (BES 9888.1; GenBank COI: EU364622), Martinjinni Nature Reserve Lake, Western Australia, 30.302°S 116.454°E, CALM Salinity Action Plan SPS155, 20 September 1999. Remarks Haloniscus stepheni was described by Nicholls & Barnes (1926) from specimens collected under logs by the banks of Kokatea Creek [= Kockatea Gully] near Tenindewa, WA, and later re-examined by Taiti & Humphreys (2001), with additional material from the type locality, and transferred to Andricophiloscia. Specimens subsequently collected from Martinjinni Nature Reserve (WA) (BES 9888) were found to be morphologically identical to H. stepheni, and were incorporated into the sequencing work of Guzik et al. (2019), revealing that this species does in fact belong to Haloniscus as originally described (Fig. 1A). The phylogeny suggests that H. stepheni is closely related to subterranean Haloniscus species from WA calcrete aquifers and, despite the similar morphology, is genetically distinct (COI divergence 18–23%; unpublished data) from the GAB species. With the exclusion of H. stepheni and H. pedisetosus from Andricophiloscia, this genus now comprises only the type species, A. melanesiensis Vandel, 1973, from Japen Island, New Guinea. The type material recorded by Vandel (1973a) should be re-examined to confirm the validity of the genus Andricophiloscia. Haloniscus yardiyaensis Stringer, King & Taiti n. sp. (Figs. 10, 11) Material examined Holotype, male SAMA C13247 (GAB01571), Freeling South Springs, Mount Dennison Complex, South Australia, 28°04′34.3ʺS 135°54′14.5ʺE, coll. M. Guzik, R. King and L. Harsche, 3 July 2009. Paratypes: 1 male, 3 females SAMA C13248 (GAB01571), same collection data as holotype; 1 female SAMA C13249 (GAB01571.1; GenBank COI: KT236029, GenBank 18S: MK286387), same collection data as holotype; 3 males, 2 females SAMA C13250 (GAB01614), Freeling South Springs, Mount Dennison Complex, South Australia, 28°04′17.7ʺS 135°54′14.3ʺE, coll. M. Guzik, R. King and L. Harsche, 3 July 2009; 2 males, 3 females SAMA C13251 (GAB01613), Freeling South Springs, Mount Dennison Complex, South Australia, 28°04′45.9ʺS 135°54′17.7ʺE, coll. M. Guzik, R. King and L. Harsche, 3 July 2009; 1 female SAMA C13252 (GAB01613.2; Genbank COI: KT236031, Genbank 18S: MK286387), Freeling South Springs, Mount Dennison Complex, South Australia, 28°04′45.9ʺS 135°54′17.7ʺE, coll. M. Guzik, R. King and L. Harsche, 3 July 2009. Figure 10. Open in new tabDownload slide Haloniscus yardiyaensis n. sp. holotype male (A, G, H, J), paratype female (B–F), paratype male (I). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and left uropod (G); antennule (H); antenna (I); uropod (J). Figure 10. Open in new tabDownload slide Haloniscus yardiyaensis n. sp. holotype male (A, G, H, J), paratype female (B–F), paratype male (I). Whole specimen, dorsal view (A); dorsal scale-seta (B); coordinates of the noduli laterales (C); cephalon, frontal view (D); cephalon, dorsal view (E); cephalon and pereonite 1, lateral view (F); telson and left uropod (G); antennule (H); antenna (I); uropod (J). Figure 11. Open in new tabDownload slide Haloniscus yardiyaensis n. sp. holotype male. Pereopod 1 (A); pereopod 7 (B); pleopod 1 (C); pleopod 2 (D); pleopod 3 exopod (E); pleopod 4 exopod (F); pleopod 5 exopod (G). Figure 11. Open in new tabDownload slide Haloniscus yardiyaensis n. sp. holotype male. Pereopod 1 (A); pereopod 7 (B); pleopod 1 (C); pleopod 2 (D); pleopod 3 exopod (E); pleopod 4 exopod (F); pleopod 5 exopod (G). Diagnosis Antenna with fifth article of peduncle slightly swollen; flagellum with first, second articles subequal in length, third slightly longer. Male pereopod 1 carpus with several long setae on sternal margin, lines of short setae near sternal margin. Description Maximum body length: male 4.2 mm, female 5 mm. Colour in alcohol light brown with large pale muscle spots. Body (Fig. 10A) moderately convex, elongated, about 3.2× as long as wide, with pleon distinctly narrower than pereon. Dorsum smooth with triangular scale-setae (Fig. 10A, B); noduli laterales present on pereonites with one per side on each segment, inserted at similar distance from lateral margins of pereonites; b/c, d/c co-ordinates as in Fig. 10C. Cephalon (Fig. 10D–F) with small, rounded lateral lobes; supra-antennal line present, distinctly sinuous. Eyes with 9, 10 ommatidia. Pereonites 1–4 with straight posterior margins, right-angled posterior corners; pereonites 5–7 with posterior corners progressively more acute. Pleonites 3–5 with posterior points reduced (Fig. 10A, G). Telson (Fig. 10A, G) almost twice as wide as long, distal part with straight sides, rounded apex. Antennule (Fig. 10H) with third article slightly longer than first, second, 2 long aesthetascs subapically, tuft of 3 aesthetascs in central part of third article. Antenna (Fig. 10I) short, reaching to, but not past, pereonite 2; fifth article of peduncle slightly swollen, shorter than flagellum; flagellum with first, second articles subequal in length, third slightly longer; second, third articles with 1, 2 aesthetascs, respectively. Mouth appendages as in H. fontanus. Uropod (Fig. 10J) with protopod, exopod grooved on outer margin, insertion of endopod proximal to that of exopod, exopod about twice as long as endopod. Male: Pereopod 1 (Fig. 11A) with merus bearing some long setae on sternal margin; carpus with several long setae on sternal margin, lines of short setae. Pereopod 7 (Fig. 11B) ischium with sternal margin straight to slightly concave in proximal half. Pleopod 1 (Fig. 11C) exopod apically rounded, with no setae along margin; endopod much longer than exopod, with pointed apical part bent outwards. Pleopod 2 (Fig. 11D) exopod triangular with outer margin slightly concave, bearing 5 robust setae. Pleopods 3, 4 (Fig. 11E, F) exopods triangular with outer margin comprising 6–8 robust setae. Pleopod 5 (Fig. 11G) exopod triangular with 5 robust setae on outer margin. Pleopods 2–5 exopods with short setae on medial margin. Etymology The species name refers to Yardiya, an Arabana language name for Freeling Springs. Remarks As discussed above, H. yardiyaensis n. sp. from Freeling South is morphologically similar to both H. fontanus n. sp. (southern Lake Eyre and Neales Complex), where it largely differs in antenna length, setation of the carpus and merus of male pereopod 1, and the length and number of robust setae on the exopods of male pleopods, and H. stepheni (WA), where it contrasts in the length of antennal flagellum articles. Haloniscus yardiyaensis and H. stepheni are nevertheless almost identical morphologically, but the phylogeny in Fig. 1A reveals that the two species are likely genetically distinct, with H. yardiyaensis more closely related to the GAB spring Haloniscus (excluding H. microphthalmus n. sp.) and H. stepheni grouping with a Yilgarn (WA) calcrete aquifer lineage. This morphology may, as mentioned previously, be convergent and an adaptation to their semi-terrestrial habitat. Nomenclatural statement A life science identifier (LSID) number was obtained for the new species: urn:lsid:zoobank.org:pub:71C7FCDD-FEB8-4F1D-A709-CE4E0F27A7DD. DISCUSSION The four newly described species are endemic to the SA GAB springs and thus not found elsewhere in Australia. The addition of these species, as well as H. stepheni and H. pedisetosus n. comb., to the genus elevates the total number of described Haloniscus from five to 11. Prior to the present study, Haloniscus species had never been described from GAB springs and, therefore, the inclusion of four new species to a slowly increasing list of endemic taxa living in this unique ecosystem is significant. The descriptions presented here are based on traditional, rigorous morphological comparison in conjunction with the molecular species delimitation results of Guzik et al. (2019). The molecular analyses proposed between three (ABGD) and eight (bPTP) putative species from the GAB springs. The ABGD analysis (Fig. 1A) suggested that the Francis Swamp, Dalhousie, and the larger Lake Eyre clade represent three distinct species, whereas bPTP (Fig. 1A) proposed one Francis and two Dalhousie species and further split the Lake Eyre lineages into five species, with two Neales, one Hermit Hills, one Freeling, and one combined Bubbler, Strangways, and McKewin species. A potential problem with these multi-species coalescent methods is that they cannot differentiate phylogeographic structure, resulting from isolation of populations, from species exhibiting long-term isolation (Sukumaran & Knowles, 2017) and, consequently, these estimates should ideally be used in combination with morphological assessment. Our morphological analysis largely supported the estimate of between three and eight new SA spring species, but the final species number presented here is nevertheless more comparable to the conservative estimate of the ABGD analysis. The use of molecular systematics to help delineate putative species for taxonomic description is a widely accepted and successful practice (King, 2009; King et al., 2012; Rix et al., 2018). We combined evidence from a multi-gene phylogeny, species delimitation analyses (Fig. 1; Guzik et al., 2019) and morphological assessment to identify four new species from the SA GAB springs. Overall, each of the new species was associated with a distinct geographic range: Haloniscus fontanus corresponded to the southern Lake Eyre (Strangways, McKewin, and Bubbler spring groups) and Neales populations, H. yardiyaensis is a seemingly closely related species from the proximate Freeling South Springs, H. rotundus occurs in the Dalhousie Springs supergroup, and H. microphthalmus is endemic to the Francis Swamp southern Lake Eyre region (see Fig. 1). Specimens from the geographically distant northern Lake Eyre Neales region are morphologically identical to the specimens from Bubbler, McKewin, and Strangways Springs, which are within the southern region of the Lake Eyre Basin. This is a surprising result considering the evident isolation of the springs and some phylogeographic structuring of the Neales populations (Fig. 1), which may imply a cryptic species (Murphy et al., 2015b). The COI-only phylogeny (Fig. 1A) furthermore suggested (although with low posterior support) that the Neales population forms a monophyletic grouping with the Freeling population rather than the morphologically identical southern Lake Eyre Springs populations. These relationships were nevertheless not reinforced by adding the more conserved 18S locus (Fig. 1B). The relationships amongst each of the reciprocally monophyletic southern Lake Eyre, Freeling, and Neales spring populations remain unresolved, and this may be due to relatively recent divergences between populations. Future next-generation sequencing work could help increase understanding of these complex species relationships. We have chosen a somewhat conservative approach and include the Neales population (with the Strangways, McKewin and Bubbler group) in H. fontanus. Our decision is based on this phylogenetic evidence along with COI-divergence estimates among the populations calculated below the 16% molecular threshold for species delimitation as proposed by Lefébure et al. (2006) as well as the apparent lack of morphological differences. The molecular study by Guzik et al. (2019) reveals that the current taxonomic position of Haloniscus greatly underestimates the true species diversity within Australia, particularly across important groundwater-dependent ecosystems within the arid zone, with additional descriptions of species from subterranean aquifers in WA and the Northern Territory to be published at a later date. The description of four new species here has important implications for GAB springs conservation management and the protection of species in this unique and threatened system. Taylor et al. (2018) suggest Phreatomerus latipes (Chilton, 1922), an isopod species complex endemic to the SA GAB springs with similarly restricted distributions (Guzik et al., 2012), as a flagship species of high scientific and social value, which should be listed under the EPBC Act. These newly described Haloniscus species are similarly diverse, short-range endemics, and potential relicts, and, as such, conservation management to maximise their genetic diversity is vital to avoid the extinction of these species. Key to species of Haloniscus (after Taiti & Humphreys (2001)) 1. Eyes present ........................................................................................................................................................................................ 2 — Eyes absent ......................................................................................................................................................................................... 7 2. Uropod with protopod flattened, outer margin of protopod and exopod not grooved; pereopods 1–4 subchelate; male pereopod 1 merus wider than long; male pereopods 2–7 ischium with a brush of long setae on sternal margin; all pleopods with exopods bearing a fringe of fine setae; endopod and exopod of male pleopod 1 subequal in length; endopod of male pleopod 2 about ¾ that of exopod .................................................................................................................................................................... Haloniscus searlei — Uropod with protopod not flattened, outer margin of protopod and exopod grooved (Fig. 4G, F); pereopods not subchelate; male pereopod 1 merus longer than wide (Fig. 5A); male pereopods 2–7 ischium with none or some long setae on sternal margin (Fig. 5B); exopod of male pleopod 1 without setae on outer margin (Fig. 5C), exopods of male pleopods 2–5 fringed only on medial margin (Fig. 5D–G); endopod of male pleopods 1 and 2 distinctly longer than exopod (Fig. 5C, D) ............................................................ 3 3. Dorsum smooth with numerous broad based, apically frayed triangular scale-setae (Fig. 6B); eyes reduced to single spot of pigment (Fig. 6A, D–F); antennule with aesthetascs grooved longitudinally (Fig. 6H) ....................................... Haloniscus microphthalmus n. sp. — Dorsum smooth with triangular scale-setae, not broad based and apically frayed (Figs. 3B, 8B); eyes with at least 9 ommatidia; antennule with aesthetascs not grooved longitudinally (Fig. 3H) ............................................................................................................ 4 4. Telson with broadly rounded apex (Fig. 8G) ................................................................................................. Haloniscus rotundus n. sp. — Telson with apex not broadly rounded (Figs. 3G, 10G) ...................................................................................................................... 5 5. Antennae reaching past pereonite 2 (Fig. 3A); male pleopod 2 exopod with around 10 robust setae on outer margin (Fig. 5D) ..................................................................................................................................................................................Haloniscus fontanus n. sp. — Antennae not reaching past pereonite 2; male pleopod 2 exopod with fewer than 8 robust setae on outer margin (Fig. 11D) .......... 6 6. Antenna with fifth article of peduncle slightly swollen; flagellum with first and second articles subequal in length, third slightly longer (Fig. 10I); endemic to Freeling South Springs (SA) ......................................................................... Haloniscus yardiyaensis n. sp. — Antenna with fifth article of peduncle not swollen; flagellum with first and third articles subequal in length, second shorter; known only from WA ............................................................................................................................................................ Haloniscus stepheni 7. Cephalon with no supra-antennal line; male pleopod 1 endopod with stout, spoon-like apical part directed outwards, equipped with fine setae and a terminal acute spine .................................................................................................................. Haloniscus anophthalmus — Cephalon with distinct supra-antennal line; male pleopod 1 endopod without spoon-like apical part and terminal acute spine ...... 8 8. Noduli laterales distinct, one per side on each pereonite; antennule with petaliform shaped aesthetascs; uropod with protopod and exopod deeply grooved on outer margin; male pleopod 1 exopod without a marginal fringe of fine setae ........................................................................................................................................................................................................... Haloniscus pedisetosus n. comb. — Noduli laterales absent, antennule without petaliform shaped aesthetascs; uropod with protopod flattened and not grooved on outer margin; male pleopod 1 exopod with a marginal fringe of fine setae ...................................................................................................9 9. Antennae very long, reaching posterior margin of pereonite 6; anterior male pereopods without brush of scales on merus sternal margin; male pleopod 1 endopod with stout apical part ................................................................................. Haloniscus longiantennatus — Antennae shorter, reaching posterior margin of pereonite 2 or 3; anterior male pereopods with a brush of scales on merus sternal margin; male pleopod 1 endopod with styliform apical part ............................................................................................................ 10 10. Antennule with third article much shorter than second; exopods of male pleopods cordiform ............................ Haloniscus tomentosus — Antennule with third article as long as second; exopods of male pleopods ovoid ....................................................... Haloniscus stilifer ACKNOWLEDGEMENTS The authors thank Nick Murphy (LaTrobe University) and Travis Gotch (Department for Environment and Water) for their invaluable advice at the GAB springs; Steve Delean (The University of Adelaide) and Lewis Harsche for field assistance; Bill Humphreys (Western Australian Museum) for his support with aspects of the manuscript; and Steven Stringer for his help with figure design. Field work at the springs was completed under South Australian Permit No: Z25519 to Dr Nick Murphy. We appreciate the access provided to us by the traditional owners of the GAB spring country, particularly Reg Dodd and Dean Ah Chee, and would like to thank Greg Campbell (Chief Executive Officer of S. Kidman & Co Ltd.) as well as station managers, Randall Crozier, Peter Paisley, and Bobby Hunter, for permission to sample on private property. This work was funded by the Australian Biological Resources Study (ABRS) National Taxonomy Research Grant Program (NTRGP) (Capacity-Building grant: CT214-11) to DNS, Australian Research Council Linkage Grants (LP0669062 and LP140100555) to ADA and SJBC with industry partners the South Australian Museum, the South Australian Department for Environment and Water (DEW), BHP Billiton and the Nature Foundation, SA (LP0669062), and the South Australian Museum, Western Australian Museum, WA Department of Biodiversity, Conservation and Attractions, Bennelongia Pty Ltd. and Biota Environmental Sciences Pty Ltd. (LP140100555), and the Nature Conservancy, generously supported by The Thomas Foundation to DNS. DNS also wishes to acknowledge the support of an Australian Government Research Training Program Scholarship through The University of Adelaide. Lastly, we thank two anonymous reviewers for providing constructive feedback on an earlier version of the manuscript. 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TI - Systematics of Haloniscus Chilton, 1920 (Isopoda: Oniscidea: Philosciidae), with description of four new species from threatened Great Artesian Basin springs in South Australia
JO - The Journal of Crustacean Biology
DO - 10.1093/jcbiol/ruz044
DA - 2019-09-18
UR - https://www.deepdyve.com/lp/oxford-university-press/systematics-of-haloniscus-chilton-1920-isopoda-oniscidea-philosciidae-cxLX0Bn2lT
SP - 651
VL - 39
IS - 5
DP - DeepDyve
ER -