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Hypseleotris galii, female neotype and male voucher specimen. (a) AMS I.49481-001, 28.6 mm female, neotype; (b) AMS I.49482-001, 30.3 mm male voucher specimen. This species is distinguished from H. acropinna and H. moolooboolaensis by the presence of dark pigment on and around the genital papilla in females.
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The rivers of southeastern Australia host a species complex within the carp gudgeon genus Hypseleotris that includes parental species and hemiclonal hybrid lineages. These hemiclones can be difficult to distinguish from their parent taxa, making delineation of species unusually difficult. We approach this historical taxonomic problem by using singl...
Citations
... In Indonesia, DNA barcoding with COI mitochondrial gene has been used to identify freshwater and marine fish species (Dahruddin et al. 2016;Fadli et al. 2020;Aji and Arisuryanti 2021;Rhaifa et al. 2021;). A hybrid technique of genetic and morphological characteristics has been widely employed and verified for the taxonomic categorization of various fish species, with special emphasis on Gobiiformes (Islam et al. 2021;Kovačić et al. 2022;Thacker et al. 2022). ...
Shabrina FN, Wibowo K, Arisuryanti T. 2024. Cryptic diversity of mudskipper genus Boleophthalmus (Gobiiformes: Oxudercidae) from the north coast of East Java, Indonesia. Biodiversitas 25: 412-420. Mudskippers of genus Boleophthalmus are commonly found in the Indo-Pacific area. This study aimed to examine the diversity of the genus Boleophthalmus from the north coast of East Java Province, Indonesia by employing the mitochondrial COI gene for DNA barcoding and morphological characterization. Ten individuals of this genus were analyzed. According to the similarity percentage evaluated using Basic Local Alignment Search Tool (BLAST) and Barcode of Life Data (BOLD) identification engines, all the individuals were identified as Boleophthalmus boddarti Pallas, 1770. However, phylogenetic analysis revealed that three of the individuals were identified as B. boddarti, and seven were identified as Boleophthalmus pectinirostris Linnaeus, 1758 originated from East Java, which is separated from the clade of B. pectinirostris from East Asia population. These results were supported by the genetic distance of 8.93%-13.81% and the morphological characteristics determined by principal component analysis (PCA). PCA revealed that B. boddarti and B. pectinirostris are primarily distinguished by the number of (longitudinal) scales (69-75 versus 113-123), length of second dorsal fin base (42.3-43.9 versus 38.1-49.0), and caudal fin length (18.1-22.4 versus 17.5-21.6). Further detailed studies are needed to clarify whether the seven individuals belonging to B. pectinirostris complex should be regarded as a new species or a new subspecies.
... As with many other Australian freshwater fishes, the taxonomy and distribution of H. klunzingeri has historically been equivocal, having first been mistaken by Klunzinger (1872Klunzinger ( , 1880 as H. cyprinoides (which does not occur in Australia), then described as Carrassiops klunzingeri by Ogilby (1898), to be later reassigned to the genus Hypseleotris. Its common name of western carp gudgeon relates to the early thought that the taxon primarily occurred west of the Great Dividing Range compared with the more easterly H. galii (e.g., Anderson et al., 1971), whereas today we know that representatives of both lineages naturally occur both east and west of the Great Dividing Range (Thacker, Geiger, & Unmack, 2022). While the current nomenclature suggests a robust taxonomic status, matrilineal phylogeographic data presented by Thacker et al. (2007) indicated several divergent lineages within H. klunzingeri that to date have not been closely re-assessed. ...
... lineages (Thacker et al., 2022b;Unmack et al., 2019). We hope that a recent taxonomic revision by Thacker, Geiger, and Unmack (2022) for this hemiclonal species complex, which includes five sexual species and multiple unisexual combinations, will help establish a more robust taxonomic framework for identifying individuals to their correct sexual group and hence facilitate the documentation of comparative biological information for all sexual forms of Hypseleotris, including those referable to the H. klunzingeri complex. Figure S5). ...
... This study has revealed that carp gudgeons are even more speciose than previously thought, adding several additional candidates to the existing six sexual species plus their various hemiclonal relatives (Thacker, Geiger, & Unmack, 2022, Thacker, Shelley, et al., 2022Unmack et al., 2019). Even ignoring the complication of sympatric hemiclones, many river basins contain at least three or more sexual species, with the geographically extensive MDB notably harboring six sexual taxa (plus multiple hemiclones). ...
Despite belonging to the most abundant and widespread genus of freshwater fishes in the region, the carp gudgeons of eastern Australia (genus Hypseleotris ) have proved taxonomically and ecologically problematic to science since the 19th century. Several molecular studies and a recent taxonomic revision have now shed light on the complex biology and evolutionary history that underlies this group. These studies have demonstrated that carp gudgeons include a sexual/unisexual complex (five sexual species plus an assortment of hemiclonal lineages), many members of which also co‐occur with an independent sexual relative, the western carp gudgeon ( H. klunzingeri ). Here, we fill yet another knowledge gap for this important group by presenting a detailed molecular phylogeographic assessment of the western carp gudgeon across its entire and extensive geographic range. We use a suite of nuclear genetic markers (SNPs and allozymes) plus a matrilineal genealogy (cyt b ) to demonstrate that H. klunzingeri s.l. also displays considerable taxonomic and phylogeographic complexity. All molecular datasets concur in recognizing the presence of multiple candidate species, two instances of historic between‐species admixture, and the existence of a natural hybrid zone between two of the three candidate species found in the Murray–Darling Basin. We also discuss the major phylogeographic patterns evident within each taxon. Together, these analyses provide a robust molecular, taxonomic, and distributional framework to underpin future morphological and ecological investigations on this prominent member of regional freshwater ecosystems in eastern Australia.
... Its common name of western carp gudgeon relates to the early thought that the taxon primarily occurred west of the Great Dividing Range compared with the more easterlyH. galii (e.g., Anderson, Lake & Mackay, 1971), whereas today we know that representatives of both lineages naturally occur both east and west of the Great Dividing Range (Thacker, Geiger & Unmack, 2022a). While the current nomenclature suggests a robust taxonomic status, matrilineal phylogeographic data presented by Thacker et al. (2007) indicated several divergent lineages within H. klunzingeri that to date have not been closely re-assessed. ...
... Unfortunately, observations relevant to this final step are largely unavailable in the literature, since many ecological studies ofHypseleotris in eastern Australia have not attempted to reliably distinguish H. klunzingeri from a suite of congeneric and often co-occurring taxa (e.g., Meredith, Matveev & Mayes, 2003;Lintermans, 2007), now known to comprise a complex of sexual species and 'unisexual' (hybridogenetic) lineages Thacker et al., 2022b). We hope that a recent taxonomic revision by Thacker et al. (2022a) for this hemiclonal species complex, which includes five sexual species and multiple unisexual combinations, will help establish a more robust taxonomic framework for identifying individuals to their correct sexual group and hence facilitate the documentation of comparative biological information for all sexual forms of Hypseleotris , including those referrable to the H. klunzingeri complex. Table 4 summarizes the outcomes of applying steps 3-5 to the primary taxa identified for H. klunzingeri using steps 1 and 2. As shown, there is strong evidence that KN, KE+, and KS are all valid candidate species, being unequivocally or effectively diagnosable from each other at hundreds of unlinked genes and displaying distributional patterns that are inconsistent with being phylogeographic lineages within a single species (Table 4, Fig. S5). ...
... Given their comparatively low number of diagnostic differences, the decision as to whether the allopatric taxa KS and KW+ are conspecific or represent distinct evolutionary species remains the only taxonomic question not fully resolved by our stand-alone genetic datasets. However, as the number of molecular characters that diagnose KS from KW+ greatly exceeds the nine partially-diagnostic morphological characters that delineate other co-occurring species of Hypseleotris (Thacker et al., 2022a), we have concluded that KW+ 'probably' represents a fourth candidate species. A full resolution of its taxonomic status will require additional targeted assessments of any morphological and other biological differences between KS and KW+, and must include exemplars of pure KS, pure KW, and KW m . ...
Despite belonging to the most abundant and widespread genus of freshwater fishes in the region, the carp gudgeons of eastern Australia (genus Hypseleotris) have proved taxonomically and ecologically problematic to science since the 19th century. Several molecular studies and a recent taxonomic revision have now shed light on the complex biology and evolutionary history that underlies this group. These studies have demonstrated that carp gudgeons include a sexual/unisexual complex (five sexual species plus an assortment of hemiclonal lineages), many members of which also co-occur with an independent sexual relative, the western carp gudgeon (H. klunzingeri). Here we fill yet another knowledge gap for this important group by presenting a detailed molecular phylogeographic assessment of the western carp gudgeon across its entire and extensive geographic range. We use a suite of nuclear genetic markers (SNPs and allozymes) plus a matrilineal genealogy (cytb) to demonstrate that H. klunzingeri s.l. also displays considerable taxonomic and phylogeographic complexity. All molecular datasets concur in recognizing the presence of multiple candidate species, two instances of historic between-species admixture, and the existence of a natural hybrid zone between two of the three candidate species found in the Murray Darling Basin. We also discuss the major phylogeographic patterns evident within each taxon. Together these analyses provide a robust molecular, taxonomic, and distributional framework to underpin future morphological and ecological investigations on this prominent member of regional freshwater ecosystems in eastern Australia.
... Although only surveying a small fraction of Australia's freshwater fish fauna, these studies have already added more than 50 candidate species to the national inventory. Of these, many are now formally recognised (Welsh et al. 2014(Welsh et al. , 2017Raadik 2014;Coleman et al. 2015;Shelley et al. 2017;Hammer et al. 2018Hammer et al. , 2019aLarson and Hammer 2021;Hoese and Hammer 2021;Thacker et al. 2022), some have become widely accepted as valid 'sp. nov.' (Raadik 2019a(Raadik , 2019b(Raadik , 2019c(Raadik , 2019dLintermans et al. 2020), and the rest occupy a 'twilight zone' of taxonomic anonymity, awaiting attention from the nation's small, over-stretched and underfunded ichthyological community (Leis et al. 2007). ...
Context. Galaxiids are a widespread, Southern Hemisphere radiation of mostly obligate freshwater fishes. Tasmania houses a diversity of endemic species of Galaxias and Paragalaxias. Of these, many are at risk of extinction, being landlocked, range restricted, and subject to anthropogenic threats, placing a high conservation priority on the region. Aim. Our aim was to synthesize historic and published molecular datasets to provide the sound systematic framework needed to underpin future conservation and taxonomic efforts for Tasmanian galaxiids. Methods. Novel and published nuclear (allozyme) and matrilineal (cytb) datasets were generated and integrated for every putative Tasmanian galaxiid species lacking a comparable multi-gene assessment. Key results. The Tasmanian galaxiids are phylogenetically diverse, with molecular data generally supporting the accepted taxonomy, but with potential species-level diversity noted within an alpine radiation of the Galaxias truttaceus complex and further support for synonymy of Galaxias niger within Galaxias brevipinnis. Conclusions. This study highlights the value of multi-locus studies in both validating species-level taxonomy and resolving taxonomic ambiguities and conservation priorities within Tasmania’s galaxiids. Implications. Our integrated genetic analyses provide a framework to underpin more in-depth genomic approaches to assess additional cryptic diversity and conservation planning, such as genetic rescue and ex situ population security.
... The gudgeon genus Hypseleotris is the most speciose eleotrid radiation in Australia with 13 described species (Thacker et al. 2022a;b). All but one of these species are restricted to Australian fresh waters, while H. compressa is found in estuaries and lower parts of rivers around much of the coastline of Australia and the southern coastline of the nearby island of New Guinea. ...
... This description combines our observations with those presented in Thacker et al. (2022a) and Keith and Mennesson (2023). ...
Species within the northwest Australian clade of Hypseleotris (six species) and the genus Kimberleyeleotris (two species) are reviewed following the recording of new populations in the region and a molecular study of the group that identified three undescribed candidate species. Based on the analysis of extensive morphological and nuclear and mitochondrial molecular datasets, Kimberleyeleotris is here formally synonymised with Hypseleotris. Furthermore, three species from the Kimberley region, Western Australia, are described to science: Hypseleotris maranda sp. nov., Hypseleotris wunduwala sp. nov., and Hypseleotris garawudjirri sp. nov. The presence of, or number of scales across the head and body, the pattern of sensory papillae on the head, fin ray counts, dorsal and anal fin colouration (particularly in breeding males), and body depth, can be used to distinguish the members of the northwest Australia lineage. Furthermore, the newly described species were genetically separated from all northwest Australian congeners by K2P distances ranging from 7.8–11.3% based on the CO1 gene, and 7.7–16.3 % based on the entire mitochondrial genome. Two of the new species, H. maranda sp. nov. and H. wunduwala sp. nov., have extremely narrow ranges being found in single sub-catchments of the Roe and King Edward Rivers respectively. On the other hand, H. garawudjirri sp. nov. is moderately widespread, being found across the Charnley, Calder, and Sale rivers. While the conservation risk to H. maranda sp. nov. and H. wunduwala sp. nov. is inherently high due to their small range, there are currently no obvious local threatening processes to either of these species given their remote locations that are little impacted by human activities.
