Boomeranging around Australia: Historical biogeography and population genomics of the anti-equatorial fish Microcanthus strigatus (Teleostei: Microcanthidae).

The geographic distributions of marine fishes have been shaped by ancient vicariance and ongoing dispersal events. Some species exhibit anti-equatorial distributions, inhabiting temperate regions on both sides of the tropics while being absent from equatorial latitudes. The perciform fish Microcanthus strigatus (the stripey) exhibits such a distribution with disjunct populations occurring in East Asia, Hawaii, Western Australia, and the southwest Pacific. Here, we examine the historical biogeography and evolutionary history of M. strigatus, based on more than 80 specimens sampled from the four major populations. We analysed 36 morphological characters, three mitochondrial markers, and two sets of 7,120 and 12,771 single-nucleotide polymorphisms from the nuclear genome. Our results suggest that M. strigatus represents a cryptic species complex comprising at least two genetically distinct populations worthy of species-level recognition, with one population exhibiting strong genetic structuring but with intermittent, historical gene flow. We provide evidence for a southwest Pacific origin for the ancestral Microcanthus and explain how past connectivity between these regions might have given rise to the relationships observed in present-day marine fauna. Our ancestral range reconstructions and molecular-clock analyses support a southwest Pacific centre of origin for Microcanthus, with subsequent colonization of Western Australia through the Bass Strait followed by transequatorial dispersals to the Northern Hemisphere during the Pleistocene. Our results detail an anti-tropical dispersal pattern that is highly unusual and previously undocumented, thereby emphasizing the importance of integrative systematics in the evaluation of widespread species.

Does counting species count as taxonomy? On misrepresenting systematics, yet again.

Recent commentary by Costello and collaborators on the current state of the global taxonomic enterprise attempts to demonstrate that taxonomy is not in decline as feared by taxonomists, but rather is increasing by virtue of the rate at which new species are formally named. Having supported their views with data that clearly indicate as much, Costello et al. make recommendations to increase the rate of new species descriptions even more. However, their views appear to rely on the perception of species as static and numerically if not historically equivalent entities whose value lie in their roles as "metrics". As such, their one-dimensional portrayal of the discipline, as concerned solely with the creation of new species names, fails to take into account both the conceptual and epistemological foundations of systematics. We refute the end-user view that taxonomy is on the rise simply because more new species are being described compared with earlier decades, and that, by implication, taxonomic practice is a formality whose pace can be streamlined without considerable resources, intellectual or otherwise. Rather, we defend the opposite viewpoint that professional taxonomy is in decline relative to the immediacy of the extinction crisis, and that this decline threatens not just the empirical science of phylogenetic systematics, but also the foundations of comparative biology on which other fields rely. The allocation of space in top-ranked journals to propagate views such as those of Costello et al. lends superficial credence to the unsupportive mindset of many of those in charge of the institutional fate of taxonomy. We emphasize that taxonomy and the description of new species are dependent upon, and only make sense in light of, empirically based classifications that reflect evolutionary history; homology assessments are at the centre of these endeavours, such that the biological sciences cannot afford to have professional taxonomists sacrifice the comparative and historical depth of their hypotheses in order to accelerate new species descriptions.

Gymnoxenisthmus tigrellus, new genus and species of gobioid fish from the Red Sea (Gobioidei: Xenisthmidae).

Gymnoxenisthmus tigrellus is described from the 15.2 mm SL holotype collected from the Farasan Archipelago, southern Red Sea. It is distinguished from other xenisthmid genera in having the following combination of characters: head pores absent; no scales; first dorsal fin with five spines; at least some dorsal-, anal- and pectoral-fin rays branched; pelvic fin with a spine and five unbranched rays. Evaluation of available (mostly external) characters suggests the new genus is the sister group of a clade consisting of Rotuma, Tyson and Allomicrodesmus.

Classification and relationships of Assiculus and Assiculoides (Teleostei: Pseudochromidae).

The monotypic Australian pseudochromid fish genera Assiculus and Assiculoides had been previously included in the subfamily Pseudochrominae on the basis of symplesiomorphic characters. Osteological synapomorphies are identified in support of a closer relationship to the remaining pseudochromid subfamilies. Two synapomorphies (five or fewer infraorbital bones, haemal spine of preural vertebra 2 attached to centrum) diagnose a clade consisting of Assiculoides, Pseudoplesiopinae, Anisochrominae and Congrogadinae. Two additional synapomorphies (parhypural not separate from hypurals 1+2, total caudalfin rays modally 27 or fewer) diagnose a more inclusive clade that also includes Assiculus. Two new subfamilies are erected to reflect these relationships.

Acanthoplesiops cappuccino, a new species of acanthoclinine fish from the Red Sea (Teleostei: Plesiopidae) .

Acanthoplesiops cappuccino is described from the 16.4 mm SL holotype collected from Jeddah, Saudi Arabia, Red Sea. The following combination of characters distinguishes it from congeners: dorsal-fin rays XVIII,4; anal-fin rays VII,4; pectoral-fin rays 18; caudal fin not connected to last rays of dorsal and anal fins by membrane; and caudal peduncle with a pale yellowish brown bar, which extends broadly on to caudal fin. An underwater photo of the anaesthetised holotype is provided, as well as one of the freshly dead holotype and only known specimen of the similar species A. naka. Tables summarizing diagnostic characters of the six known species of Acanthoplesiops are included. congeners by possessing both rostral and maxillary barbels; having the last simple dorsal-fin ray weak and smooth; the lateral line complete, with 40-42+1 pored scales; ½7-½8/1/3½ scales in transverse line from dorsal-fin origin to pelvic-fin origin; 4½ scales between lateral line and anal-fin origin. Hypselobarbus kolus is considered a synonym of H. curmuca, which is redescribed: it is distinguished from all congeners by possessing maxillary barbels only; the last simple dorsal-fin ray weak and smooth; 41-43+1 lateral-line scales; 9-10/1/4½-5 scales in transverse line between origins of dorsal and pelvic fins; and 5½-6 scales between lateral line and anal-fin origin.  

Taxonomic identity of the enigmatic Western Australian fish species Stigmatonotus australis Peters, 1877 (Teleostei).

The familial classification and specific identity of Stigmatonotus australis Peters, 1877 has been unresolved ever since its original description. Examination of a photograph and X-radiograph of the holotype confirms placement in the serranid subfamily Anthiadinae. It is further identified to the genus Hypoplectrodes Gill, 1862 and shown to represent a juvenile specimen of the species currently called H. cardinalis Allen & Randall, 1990. Character and other evidence supporting this conclusion are summarised, including discussion of apparently contradictory characters. Consequently, the following synonymisations are proposed: the family-group name Stigmatonotidae Whitley, 1954 with Anthiadides Poey, 1861, the generic name Stigmatonotus Peters, 1877 with Hypoplectrodes Gill, 1862, and the species name H. cardinalis Allen & Randall, 1990 with S. australis Peters, 1877.

Revised definitions of the anthiadine fish genera Mirolabrichthys Herre and Nemanthias Smith, with description of a new genus (Teleostei: Serranidae).

Previously regarded as a subgenus of Pseudanthias Bleeker, Mirolabrichthys is rediagnosed and restricted to three species, the type species, M. tuka Herre Montalban, along with M. pascalus (Jordan Tanaka) and M. evansi (Smith). Five other species previously classified in Mirolabrichthys are reallocated to Nemanthias Smith, which beforehand had included only the type species, N. carberryi Smith: N. bartlettorum (Randall Lubbock), N. bicolor (Randall), N. dispar (Herre), N. ignitus (Randall Lubbock), and N. regalis (Randall Lubbock). The remaining nine species previously placed in Mirolabrichthys are classified in a new genus, Pyronotanthias: P. lori (Lubbock Randall), P. aurulentus (Randall McCosker), P. bimarginatus (Randall), P. flavoguttatus (Katayama Masuda), P. parvirostris (Randall Lubbock), P. privitera (Randall Pyle), P. smithvanizi (Randall Lubbock), P. timanoa (Victor, Teitelbaum Randall) and P. unimarginatus (Randall). Synapomorphies supporting monophyly of each genus are provided, along with generic descriptions and character summaries for included species. Characters supporting relationships of the three genera to each other and to other anthiadines are discussed.

Odontanthias grahami Randall & Heemstra, a junior synonym of Anthias xanthomaculatus Fourmanoir & Rivaton (Teleostei: Serranidae: Anthiadinae).

Although previously classified in the genus Pseudanthias Bleeker, 1871, the holotype of Anthias xanthomaculatus Fourmanoir & Rivaton, 1979 from New Caledonia was recently shown to be a juvenile specimen of the genus Odontanthias Bleeker, 1873, and possibly conspecific with Odontanthias grahami Randall & Heemstra, 2006 from eastern Australia. Meaningful comparison with the latter species was problematic as it was known only from four adult specimens. Recent collection of a size series of six specimens from the Lord Howe Rise confirms that the two nominal species are conspecific. Odontanthias grahami is therefore placed in the synonymy of A. xanthomaculatus.

Mammal type specimens in the Macleay Collections, University of Sydney.

Type material of 12 mammal taxa originally proposed as species or subspecies are housed in the former Macleay Museum (now Macleay Collections, Chau Chak Wing Museum), University of Sydney and consist of seven holotypes and 12 syntypes. These were published from 1875 to 1887, five by N.N. Miklouho-Maclay and seven by E.P. Ramsay, of which six are currently considered valid taxa. Six type specimens are identified in the Collection for the first time. This includes rediscovery of the holotype skull of the New Guinean forest wallaby Dorcopsis chalmersii Miklouho-Maclay not reported since its description in 1884, a likely syntype of the bandicoot Perameles macroura torosa Ramsay, and three additional syntypes of the flying fox Pteropus (Epomops?) epularius Ramsay. The holotype of the dasyurid Antechinus (Podabrus) froggatti Ramsay, housed at the Australian Museum since before 1959, is also discussed. Limited specimen data currently prevents validation of an additional six specimens identified here as suspected syntypes of four further names: the macropodoids Halmaturus mastersii Krefft, Halmaturus crassipes Ramsay and Hypsiprymnodon moschatus Ramsay, and the bandicoot Perameles moresbyensis Ramsay. Individual accounts are given for a total of 21 proposed names. Type material of four of these remain unlocated in world collections and it is not known if they were ever in the Macleay Collections: the bandicoot Brachymelis garagassi Miklouho-Maclay, 1884; the wallaby Macropus tibol Miklouho-Maclay, 1885; the cuscus Cuscus chrysorrhous var. goldiei Ramsay and the giant rat Hapalotis papuanus Ramsay. The nomenclatural status of the possum Phalangista pinnata Ramsay, 1877, a possible nomen nudum, is also discussed. No nomenclatural actions are taken in this paper.

Taxonomy of the genus Dactylanthias Bleeker (Teleostei: Serranidae: Anthiadinae).

The anthiadine genus Dactylanthias is reviewed. Two species, Dactylanthias aplodactylus (Bleeker, 1858) and Dactylanthias baccheti Randall, 2007 are currently recognised, each known only from their holotypes. A specimen of Dactylanthias matching D. baccheti in coloration was recently collected from Nauru in the West Pacific Ocean. It was retained by a recreational fisher and deposited into the CSIRO Australian National Fish Collection, Hobart. Data collected from this specimen and comparison to images of and data from the holotypes of both nominal species indicate that Dactylanthias baccheti Randall, 2007 is a junior synonym of Dactylanthias aplodactylus (Bleeker, 1858). Additional records of specimens from Ambon, Indonesia (type locality of D. apolodactylus) and the Maldives Islands, Indian Ocean are reported. The genus is briefly compared with other anthiadine genera.

Review of Australian species of Plectranthias Bleeker and Selenanthias Tanaka (Teleostei: Serranidae: Anthiadinae), with descriptions of four new species.

Australian species of the anthiadine genera Plectranthias and Selenanthias are reviewed. Twenty-two species of Plectranthias and two species of Selenanthias are recorded from Australian waters: Plectranthias sp. 1 from a seamount north of Middleton Reef and Norfolk Ridge, Tasman Sea; P. alleni Randall from off southwest Western Australia; P. azumanus (Jordan Richardson) from off southwest Western Australia; P. bennetti Allen Walsh from Holmes Reef, Coral Sea; P. cruentus Gill Roberts from Lord Howe Island, and possibly off Stradbroke Island, Queensland; P. ferrugineus n. sp. from the North West Shelf and Arafura Sea; P. fourmanoiri Randall from Christmas Island and Holmes Reef, Coral Sea; P. grahami n. sp. from off central New South Wales, Tasman Sea; P. inermis Randall from Christmas Island; P. japonicus (Steindachner) from the Arafura Sea and North West Shelf; P. kamii Randall from the Coral Sea, Lord Howe Island and Christmas Island; P. lasti Randall Hoese from the North West Shelf and off Marion Reef, Queensland; P. longimanus (Weber) from the Timor Sea, Great Barrier Reef, Coral Sea and southern Queensland; P. maculicauda (Regan) from southeastern Australia; P. mcgroutheri n. sp. from the North West Shelf; P. megalophthalmus Fourmanoir Randall from northeast of the Whitsunday Islands, Queensland; P. melanesius Randall from southeastern Queensland and a seamount north of Middleton Reef; P. moretonensis n. sp. from off Stradbroke Island, Queensland; P. nanus Randall from the Cocos (Keeling) Islands, Christmas Island, Great Barrier Reef and Coral Sea; P. retrofasciatus Fourmanoir Randall from the Great Barrier Reef; P. robertsi Randall Hoese from off Queensland, Coral Sea; P. winniensis (Tyler) from the Great Barrier Reef and Coral Sea; Selenanthias analis Tanaka from the North West Shelf and Arafura Sea; and S. barroi (Fourmanoir) from west of Lihou Reef, Coral Sea. Five of the species represent new records for Australia: P. azumanus, P. kamii, P. megalophthalmus, P. melanesius and S. barroi. Previous records of P. megalophthalmus from the North West Shelf are based on misidentified specimens of P. lasti. Records of P. wheeleri from the North West Shelf are based on specimens here identified as P. mcgroutheri n. sp. A record of P. yamakawai Yoshino from Christmas Island is based on a misidentified specimen of P. kamii. Plectranthias retrofasciatus was previously recorded from the Great Barrier Reef as P. pallidus Randall Hoese, here shown to be a junior synonym of P. retrofasciatus. Video-based records of P. kelloggi from the Great Barrier Reef appear to be based on P. retrofasciatus. Identification keys, diagnoses, character summaries, photographs and Australian distribution information are presented for all species. Full descriptions are provided for the new species and for those newly recorded from Australia.

Three new species of Australian anthiadine fishes, with comments on the monophyly of Pseudanthias Bleeker (Teleostei: Serranidae).

Three new species of anthiadine species are described from specimens trawled from Australian waters. Pseudanthias paralourgus n. sp. is described from five specimens collected off southeastern Queensland. It resembles P. elongatus (Franz, 1910) from Japan to the South China Sea, but differs in male live coloration. The remaining two species are assigned to the genus Tosana Smith Pope, 1906, which is newly diagnosed to include the two new species and the type species from southern Japan to the South China Sea, T. niwae Smith Pope, 1906. The two new species, T. dampieriensis n. sp. described from three specimens from off Western Australia and T. longipinnis n. sp. described from 42 specimens from off eastern Australia, differ from each other and from T. niwae in various meristic and morphometric details. Pseudanthias paralourgus co-occurs with T. longipinnis. Molecular phylogenetic analysis of mitochondrial COI yielded a tree with the three Tosana species forming the sister group of a clade consisting of P. paralourgus n. sp., P. elongatus and the type species of Pseudanthias Bleeker, 1871, P. pleurotaenia (Bleeker, 1857). Our preliminary phylogenetic analyses suggest that Pseudanthias comprises a polyphyletic assemblage of species that also includes Nemanthias Smith, 1954, Luzonichthys Herre, 1936, Tosanoides Kamohara, 1953, Odontanthias Bleeker, 1873, and Serranocirrhitus Watanabe, 1949, thus highlighting the need for a revised generic classification of species currently assigned to Pseudanthias.

Redescription of Conniella apterygia Allen and its reassignment in the genus Cirrhilabrus Temminck and Schlegel (Teleostei: Labridae), with comments on cirrhilabrin pelvic morphology.

Conniella apterygia is redescribed from re-examination of the holotype, two paratypes, and six additional specimens. The genus is closely allied to Cirrhilabrus, sharing similarities in general morphological and meristic details, but is separated from Cirrhilabrus and most other labrid fishes in lacking pelvic fins and a pelvic girdle. Recent molecular phylogenetic studies have provided strong evidence for the deep nesting of Conniella within Cirrhilabrus, contradicting its generic validity and suggesting that the loss of pelvic elements is autapomorphic. Consequently, the species is redescribed and assigned to the genus Cirrhilabrus, as Cirrhilabrus apterygia new combination. The pelvic morphologies of related cirrhilabrin labrids are discussed, and a new synapomorphy is identified for Paracheilinus.

Osteological evidence for monophyly of the Leiognathidae (Teleostei: Acanthomorpha: Acanthuriformes).

Osteological characters supporting monophyly and identification of extant Leiognathidae are reviewed. Ten osteological synapomorphies support monophyly of the Leiognathidae, involving modification of the ribs, gill arches, palatoquadrate, median fins and branchiostegals. Fourteen additional characters are noted that nest the Leiognathidae within the Acanthuriformes (sensu Gill Leis). Nine further characters are noted as useful for identification of leiognathids, though each occurs more widely among acanthuriforms and other fishes. Three fossil genera that have been assigned to the Leiognathidae are briefly reviewed for the various leiognathid characters. Only one fossil genus, †Euleiognathus Yabumoto Uyeno, appears correctly placed in the family.

Systematic reappraisal of the anti-equatorial fish genus Microcanthus Swainson (Teleostei: Microcanthidae), with redescription and resurrection of Microcanthus joyceae Whitley.

The taxonomy and classification of the microcanthid fish genus Microcanthus Swainson has been a subject of contention dating back to the 19th century. Its allopatric, disjunct anti-equatorial distribution across the Indo-West Pacific has resulted in the recognition of several nominal taxa, though these have been widely regarded as synonyms of Microcanthus strigatus (Cuvier). Following the results published in a companion study elsewhere by the authors, the taxonomy of Microcanthus and the validity of these nominal synonyms are herewith revised. Microcanthus strigatus is redescribed on the basis of 66 specimens from East Asia, Hawaii and Western Australia, and M. joyceae is resurrected and redescribed on the basis of 25 specimens from eastern Australia and the southwest Pacific. Microcanthus differs from other microcanthid genera in having the following combination of characters: dorsal-fin rays XI,15-17 (usually XI,16); anal-fin rays III,13-15 (usually III,14); pectoral-fin rays 15-17 (usually 16); scales ctenoid with ctenial bases present; lateral-line scales partially or heavily obscured by adjacent scales; and body pale in preservation with five horizontal dark stripes reaching the posterior edges of dorsal and anal fins, and base of caudal fin. The review is accompanied by a key to the genera of Microcanthidae.

Plectranthias cruentus, a new species of anthiadine perchlet (Teleostei: Serranidae) from the Lord Howe Rise, Tasman Sea.

Plectranthias cruentus new species is described from the holotype and two paratypes collected off Ball's Pyramid and a paratype from Lord Howe Island. It resembles P. pelicieri Randall Shimizu 1994 in live coloration and most morphological details, including absence of predorsal scales anterior to the supratemporal commissure, but differs in having the fifth or sixth (versus third) dorsal-fin spine longest, at least some pectoral-fin rays branched (versus all unbranched), and inconspicuous (versus distinct) serrations on the interopercle. It also differs in live coloration details.

Redescription of Anthias xanthomaculatus Fourmanoir and Rivaton, and its reassignment in the genus Odontanthias Bleeker (Teleostei: Serranidae: Anthiadinae).

Anthias xanthomaculatus is redescribed from re-examination of the holotype. On the basis of fin shape, meristic details and presence of two closely spaced supraneural bones, it is assigned to the genus Odontanthias Bleeker. It is compared with known Odontanthias species, and shown to be a valid species of the genus and a possible senior synonym of O. grahami Randall Heemstra. Comparative data for the holotype and three non-type specimens of O. grahami are provided.

Phylogenetic position of the fish genera Lobotes, Datnioides and Hapalogenys, with a reappraisal of acanthuriform composition and relationships based on adult and larval morphology.

Lobotes, Datnioides and Hapalogenys are assigned to a newly defined Acanthuriformes on the basis of their pattern of tooth replacement (termed posterolateral tooth replacement), where new teeth form at the posterolateral ends of series. Posterolateral tooth replacement is shown to be a synamorphy of the order. The order is expanded to include Chaetodontidae, Pomacanthidae, Drepaneidae, Ephippidae, Leiognathidae, Antigonia, Scatophagidae and Capros, along with the more traditional members, Siganidae, Luvaridae, Zanclidae and Acanthuridae. Three-item analysis of 63 adult and larval morphological characters yields two optimal trees that differ only in the relative positions of Capros and Siganidae. The intersection tree of the two optimal trees is: (((Hapalogenys (Datnioides, Lobotidae)) (Pomacanthidae (Drepaneidae (Chaetodontidae (Ephippidae (Leiognathidae (Scatophagidae (Antigonia (Siganidae, Capros (Luvaridae (Zanclidae, Acanthuridae)))))))))))). This cladogram is compared with recent phylogenies based on analyses of sequence data, and few differences are found once the weakly-supported interior nodes of the latter are collapsed. Aside from expansion of the Acanthuriformes, the following classification changes are proposed in order to reflect the phylogenetic relationships: redefinition of the Lobotidae to include Lobotes, Datnioides and Hapalogenys; separate families for Antigonia and Capros (Antigoniidae and Caproidae, respectively); continued recognition of Drepaneidae (often considered a synonym of Ephippidae). The larvae of Capros aper are illustrated to show features overlooked in earlier descriptions.

Description of a second species of Gymnoxenisthmus from the Red Sea (Teleostei: Gobioidei: Xenisthmidae).

Gymnoxenisthmus flavicinctus n. sp. is described from the 20.2 mm SL holotype collected from Sharm Obhur, Jeddah, Saudi Arabia, central Red Sea. It differs from the holotype and only known specimen of its congener G. tigrellus in having entirely unbranched pectoral-fin rays (versus only upper two rays and lowermost ray unbranched), 17 (versus 15) pectoral-fin rays and 13 (versus 12) segmented anal-fin rays. It also differs in live and preserved coloration. The new species brings the total number of xenisthmids known from the Red Sea to five.

Chromis tingting, a new species of damselfish from mesophotic coral ecosystems of southern Japan, with notes on C. mirationis Tanaka (Teleostei: Pomacentridae).

Chromis tingting sp. nov., is described on the basis of the holotype and three paratypes from Sagami Bay, Japan. The new species likely belongs to a complex consisting of C. mirationis, C. okamurai and C. struhsakeri, with which it shares the following character combination: dorsal rays XIV,13-14; anal rays II,12; pectoral rays 19-20; tubed lateral-line scales 15-17; two spinous procurrent rays dorsally and ventrally in the caudal fin; and a generally silvery white adult coloration. The new species differs from the other members of its complex in coloration details (particularly in juvenile coloration), and in having fewer gill rakers (5-6 + 17-20 = 22-26), and a larger eye -(13.7-19.4 % SL). The new species has previously been confused with Chromis mirationis, and the contention is herewith briefly discussed.