Systematics of Haloniscus Chilton, 1920 (Isopoda: Oniscidea: Philosciidae), with description of four new species from threatened Great Artesian Basin springs in South Australia

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.

Development and evaluation of a custom bait design based on 469 single-copy protein-coding genes for exon capture of isopods (Philosciidae: Haloniscus)

“…Overall, the exon capture methods and bioinformatics data processing approach used here have been effective in obtaining a large set of single-copy orthologous groups, successful bait design that enriches targeted loci from diverse Haloniscus and other more distantly related isopod species, and generating a large and informative phylogenomic dataset. While the final alignments employed for ML tree inference contained differing levels of missing data, the phylogenies revealed identical topologies and were largely consistent with previous taxonomic and phylogenetic research [28,30,66]. In contrast to previous studies, however, most of the phylogenetic relationships inferred here were fully resolved, showing maximal bootstrap support, particularly for internal branches, which provides further confidence in this approach.…”

Time capsules of biodiversity: Future research directions for groundwater-dependent ecosystems of the Great Artesian Basin

“…For eDNA metabarcoding to be an effective tool for biomonitoring, an accurate barcode reference library is required: a database containing DNA sequences annotated with taxonomic information such that new sequences may be referenced against it to determine the identity of the organism they originated from. For GAB spring taxa, much of existing publically available DNA sequence data corresponds to the mitochondrial cytochrome c oxidase subunit 1 (CO1) mitochondrial gene, limiting the ease of taxonomic identification of eDNA data represented by other genes or loci (i.e., nuclear or other mitochondrial genes, commonly 12S, 16S, or 18S rRNA) or for organisms lacking a mitochondrion such as bacteria (Page et al, 2007;King, 2009;Murphy et al, 2009;Guzik et al, 2012;Murphy et al, 2013;King et al, 2014;Murphy et al, 2015a;Guzik et al, 2019;Stringer et al, 2019). If eDNA metabarcoding were to be implemented as a biomonitoring tool in GAB springs, DNA sequencing for other barcoding genes would be required to establish robust and taxonomically accurate barcode reference libraries (Saccò et al, 2022).…”

A comprehensive review of South Australia’s Great Artesian Basin spring and discharge wetlands biota

“…Metrics calculated from only confident records are available in Supplementary File S2. We use the term "taxon richness" over "species richness" here as several taxa in the dataset are putative species based on morphological and/or molecular divergences per their respective taxonomic authorities (Greenslade, 1985;Murphy et al, 2009;Guzik et al, 2012Guzik et al, , 2019DeBoo et al, 2019;Stringer et al, 2019).…”

“…(Rossini et al, 2018) subsequently increased this number to 52 across 154 SA spring groups in a synthesis on GAB spring endemics. These checklists have been supplemented by genetic studies of the taxa found in SA GAB springs such as crustaceans (Murphy et al, 2009, 2013, 2015; Guzik et al, 2012, 2019; Guzik & Murphy, 2013; Stringer et al, 2019), snails (Ponder et al, 1995; Murphy et al, 2012), beetles (DeBoo et al, 2019), spiders (Gotch et al, 2008), and microbes (Byers et al, 1998). Collating fundamental biodiversity information such as this and ensuring the data are accessible and usable is a first step towards future science-based decision making (i.e., FAIR).…”