The role of peripheral endemism and habitat associations in the evolution of the Indo-West Pacific tuskfishes (Labridae: Choerodon).

The unrivalled level of biodiversity across the tropical Indo-Australian Archipelago (IAA) has been the subject of wide debate. Attempts to understand its origins have focussed on the timing of speciation, rates of diversification and the directionality of colonisation across geographical and climatic gradients in an array of marine groups. We investigate origins and evolution in the Choerodon tuskfishes, a group of labrids whose centre of diversity coincides with this region. Mitochondrial (COI, 16S) and nuclear (RAG2, Tmo4c4) molecular phylogenies and biogeographic analyses, coupled with molecular clock dating, were inferred from 19 of the 23 valid Choerodon species. Two additional, undescribed Choerodon species were also included, showing reciprocal monophyly in both genomes, confirming their species level status. Choerodon diverged from their ancestral sister group, the Odacines, at the onset of the Miocene, coinciding with the collision of the Australian and Eurasian Plates when extensive areas of shallow-water habitat formed. Despite subsequent evolutionary patterns being partially obscured by overlapping distribution ranges between many species and a lack of clear evidence for climatically driven lineage divergences, our data support an evolutionary scenario of peripheral endemics budding from once widespread populations across this biodiversity hotspot. Interestingly, these peripheral endemics tend to occupy more specialised reef or non-reef habitats whereas widespread groups appear to generally take advantage of both reef and non-reef environments. Our results are discussed in light of the most accredited hypotheses proposed to explain species richness in the IAA, with some support for processes such as centrifugal speciation.

Dipturus amphispinus sp. nov., a new longsnout skate (Rajoidei: Rajidae) from the Philippines.

A new long-snouted skate, Dipturus amphispinus sp. nov., is formally described based on material caught in the Sulu Sea and later acquired from fish markets of the central and southern Philippines. It differs from its congeners in the western North Pacific, apart from D. wuhanlingi (East and South China Seas), in having a variably-defined, parallel row of posterolaterally directed lumbar thorns, and well-developed scapular thorns on each side of the disc. However, the paired rows of lumbar thorns are better defined in Dipturus amphispinus sp. nov. than in D. wuhanlingi, and these species also differ in some aspects of their morphometrics, meristics and squamation. Dipturus amphispinus sp. nov. displays marked sexual dimorphism with adult males having a relatively broader mouth, much longer teeth, a relatively shorter snout, head and disc, a taller first dorsal fin, and a proportionally longer posterior pelvic-fin lobe and tail, than adult-sized females.

Notes on shark and ray types at the South China Sea Fisheries Research Institute (SCSFRI) in Guangzhou, China.

Most of the shark and ray type material at the South China Sea Fisheries Research Institute (SCSFRI) in Guangzhou, China was examined during a museum visit by the senior author in 2009. The status of the shark and ray species described from the South China Sea in the 1980s and deposited in this collection is discussed. Squalus acutirostris is considered a junior synonym of Squalus mitsukurii from the western North Pacific. Centrophorus ferrugineus is considered a junior synonym of Centrophorus squamosus. Centroscymnus macrops is confirmed as a junior synonym of Centroscymnus coelolepis. Scymnodon niger is confirmed as a junior synonym of Zameus squamulosus. Isistius labialis is considered a synonym of Isistius brasiliensis. Halaelurus immaculatus is confirmed as a valid species of the genus Bythaelurus. Urolophus marmoratus is considered a junior synonym of the widespread Plesiobatis daviesi. Springeria nanhaiensis is a questionable synonym of Sinobatis borneensis, following previous researchers. Springeria stenosoma is considered as questionably valid but with further investigation into generic placement required. The validity of species with SCSFRI type specimens not examined in this study are also briefly discussed.

Two new species of the coffinfish genus Chaunax (Lophiiformes: Chaunacidae) from the Indian Ocean.

Two new coffinfishes, Chaunax nebulosus n. sp. and Chaunax africanus n. sp., are described from the Indian Ocean. Both species belong to the C.fimbriatus-species group which is characterised by having filaments on the dorsal head and a complex color pattern on the dorsal surface. They are morphometrically and meristically conservative but differ in coloration. Chaunax nebulosus can be distinguished from its closest relatives by its dense covering of very small, irregular grayish green spots and having 5 small blackish markings on its dorsal surface. Chaunax africanus can be distinguished from other members in having a colour pattern of long narrow brown bars on the dorsal-fin base and head (forming a radiate pattern around the eye), and a complex white reticulate pattern (often double-lined) over the entire dorsal surface. Comments on species occurring in Indian Ocean and the status of members of C. fimbriatus-species group are also provided.

Two new stingrays (Chondrichthyes: Dasyatidae) from the eastern Indonesian Archipelago.

Two new stingrays, Dasyatis longicauda sp. nov. and Himanturajavaensis sp. nov., are described from material collected in the eastern Indonesian Archipelago. These species, which are both relatively small stingrays (both probably smaller than 40 cm DW), have been confused with closest relatives in the region. Dasyatis longicauda sp. nov., known from West Papua, differs from its congener, the Australian endemic D. fluviorum, in having a slightly lower vertebral count, lower pectoral-radial count, a longer tail, larger and less numerous thorns along the mid-disc and tail, as well as a different CO1 Barcode. Himantura javaensis sp. nov., known only from southern Java (near Cilacap), belongs to a complex of small whiprays which also includes another Indonesian species, H. walga. Apart from major differences in squamation and a different CO1 Barcode, Himantura javaensis is more brownish in coloration, has more vertebrae, a longer tail, smaller eye and orbit, more posteriorly positioned sting, shorter adult claspers, shorter pelvic fin, and differs in various measurements around the head.

A new species of wedgefish, Rhynchobatus immaculatus (Chondrichthyes, Rhynchobatidae), from Taiwan.

A new species of wedgefish, Rhynchobatus immaculatus sp. nov., is described from a small collection of specimens obtained from fish markets in northern Taiwan. It is probably a medium-sized species (probably attaining ca. 1.5 m TL) because the largest known specimen, an immature male (ca. I m TL), has prolongated dorsal and caudal fins typical of adult wedgefishes. Rhynchobatus immaculatus is unique within the family in having a very high vertebral count (within the range of 165-170 total free centra) and in lacking a dark pectoral marking. Other Rhynchobatus species occurring in Taiwanese seas appear to attain a larger adult size, possess a dark pectoral marking at least in young, and have lower vertebral counts (fewer than 161 total fee centra). Rhynchobatus yentinesis, which was described from a specimen taken nearby at Wenzhou, China, has not yet been attributed to a currently recognised species. However, based on the illustration of the holotype, which reveals a broad-snouted species with a dark pectoral spot, it is closest to either R. palpebratus or R. springeri.

A review of the rudderfish genus Tubbia (Stromateoidei: Centrolophidae) with the description of a new species from the Southern Hemisphere.

A combination of morphological and molecular techniques was used to confirm the existence of a second species of the monotypic centrolophid genus Tubbia. Adults of the seamount rudderfish, T. stewarti sp. nov., which reaches about 56 cm SL, is mesopelagic at depths of 525-1438 m in the temperate waters of the Southern Hemisphere. It has a confirmed distribution off Australia and New Zealand where it occurs sympatrically with the wider ranging T. tasmanica Whitley. Like most other members of the group, juveniles live in the epipelagic zone where they have been taken at 30-50 m depth. The new species has a more robust head, more slender body, more flattened interorbit, longer jaws, denser head pores, relatively larger eyes and nostrils, narrower caudal peduncle and more vertebral centra than T. tasmanica, and also differs subtly in some morphometric ratios. A rediagnosis of T. tasmanica is also provided.

An annotated checklist of the chondrichthyans of Taiwan.

An annotated checklist of chondrichthyan fishes (sharks, batoids, and chimaeras) occurring in Taiwanese waters is presented. The checklist is the result of a biodiversity workshop held in Mach 2012 as well as on-going systematic revisions by the authors. The chondrichthyan fauna of Taiwan is one of the richest in the world with the number of species totaling 181, comprising 52 families and 98 genera. It includes 31 families, 64 genera, and 119 species of sharks, 19 families, 31 genera, and 58 species of batoids, and 2 families, 3 genera, and 4 species of chimaeras. The most species-rich families are the Carcharhinidae with 22 species followed by the Scyliorhinidae with 17. The most species-rich batoid families are the Dasyatidae with 11 species and and the Rajidae with 10. Verified voucher material is provided for each species where available and potential taxonomic issues are high-lighted when applicable. This represents the first detailed, evidence-based checklist of chondrichthyans from Taiwanese waters in over 40 years.

Revision of the fish family Euclichthyidae (Pisces: Gadiformes) with the description of two new species from the Western Pacific.

Members of the benthopelagic fish family Euclichthyidae, also known as the Eucla cods, occur on the upper continental slopes off Australasia at 220-1040 m depths. Euclichthyids essentially differ from other gadiform fishes in a combination of two almost contiguous dorsal fins with the second much longer based, a deeply notched anal fin with its anterior portion greatly elevated, jugular pelvic fins consisting of 3 partly united filiform upper rays and 3 free filamentous lower rays, an asymmetrical caudal fin with 5 hypurals fused into two plates, and no chin barbel, or vomerine and palatine tooth patches. Additional characters attributed to the group by other published studies include: no horizontal diaphragm within the posterior chamber of the swim bladder, no swim bladder-auditory capsule connection, presence of a luminous organ, and cranial muscle adductor arcus palatini divided by a strong ligament running from the lateral ethmoid and palatine to the medial face of the hyomandibular. Widely considered to be monotypic since its erection in 1984, the group consists of a single genus and three allopatric species, Euclichthys polynemus McCulloch, 1926 (Western and southern Australia, New Zealand), and two new taxa, E. microdorsalis sp. nov. (northeastern Australia) and E. robertsi sp. nov. (eastern Australia and New Caledonia). Eucla cods are morphologically conservative with both new species superficially resembling the type species, E. polynemus. Euclichthys microdorsalis sp. nov. is the most anatomically and morphologically divergent member of the group in having a shorter first dorsal fin, longer snout, relatively small eye compared to its interorbital width, and fewer caudal-fin rays and primary rakers on the outer gill arch than its congeners. Euclichthys robersti sp. nov. differs from E. polynemus in being smaller with a more slender head, and having a smaller eye, longer anal-fin base and tail, smaller scales, fewer primary rakers on the outer gill arch, more elongate oval otoliths, and usually having a X and/or Y bone in the caudal skeleton (both absent in other Euclichthys). Little is known of their biology but available material suggest that early juveniles remain pelagic in the open ocean with adults benthopelagic near the sea floor. Diagnoses and a key are provided for the three species.

Hemitrygon yemenensis sp. nov., a new species of stingray (Myliobatoidea: Dasyatidae) from the northwestern Indian Ocean.

A new stingray, Hemitrygon yemenensis sp. nov., is described from old preserved material collected on the Arabian Sea coast of eastern Yemen. Consistent with other members of the genus, H. yemenensis sp. nov. is a small dasyatid (males mature at ~22 cm disc width), but it is the only Hemitrygon known to occur outside the western Pacific and eastern Indian Oceans. Hemitrygon yemenensis sp. nov. most closely resembles H. bennetti, but H. yemenensis is separable based on several characters including a longer and more narrowly pointed snout, shorter tail, and a longer disc and head. Hemitrygon yemenensis is unknown to science beyond the two type specimens collected nearly 120 years ago.

Description of Rhinobatos ranongensis sp. nov. (Rhinopristiformes: Rhinobatidae) from the Andaman Sea and Bay of Bengal with a review of its northern Indian Ocean congeners.

A new species of guitarfish, Rhinobatos ranongensis sp. nov., is described from 5 preserved specimens, and images and tissue samples of additional material, collected from the Andaman Sea and Bay of Bengal. This species co-occurs in the eastern sector of the northern Indian Ocean with two poorly defined congeners, R. annandalei Norman and R. lionotus Norman, which have been misidentified and confused with Indo-Pacific congeners since they were first described in 1926. Norman's species are rediagnosed based on limited new material and a re-examination of the types. In the western sector of the northern Indian Ocean, Rhinobatos annandalei has been confused in recent literature with the sympatric R. punctifer Compagno and Randall, which is represented by four primary colour morphs, including a white-spotted colour morph resembling R. annandalei. Rhinobatos punctifer also displays strong intraspecific variability and sexual dimorphism in some body dimensions. These four species of Rhinobatos have unique MtDna sequences and belong to a clade of Indo-West Pacific species that are morphologically similar. Despite the relatively small numbers of specimens available for investigation, these species exhibit some clear differences in body proportions, meristics and squamation. Rhinobatos ranongensis sp. nov. differs from its northern Indian Ocean congeners through a combination of a relatively narrow disc and mouth, high vertebral count, long snout, low dorsal fins, and being largely plain coloured. A new lectotype and a paralectotype are designated for the syntypes of R. annandalei, and the four primary colour forms of R. punctifer, the plain, white-spotted and ocellated morphs, are described and the three nominal species rediagnosed. A key is provided to the four known members of the genus in the northern Indian Ocean.

Review of the batfish genus Halicmetus Alcock, 1891 from Australian waters, with descriptions of two new species (Lophiiformes: Ogcocephalidae).

A taxonomic review of species of the Indo-Pacific batfish genus Halicmetus occurring in the Australian Exclusive Economic Zone is provided. Treatments of six species in the region, including diagnoses of the widespread Halicmetus niger Ho, Endo Sakamaki, 2008, H. reticulatus Smith Radcliffe, 1912 and H. ruber Alcock 1891, a reclassification of the poorly known H. marmoratus Weber, 1913, and descriptions of two new species, H. westraliensis n. sp. (an Australian endemic) and H. drypus n. sp. (from the northern sector of the Australian Exclusive Economic Zone off Norfolk Island). The Australian species can be distinguished from each other and regional congeners by a combination of morphometrics, meristics and colouration. A key is provided for all known species of the genus.

A new species of velvet skate, Notoraja sereti n.sp. (Rajiformes: Arhynchobatidae) from Papua New Guinea.

A new arhynchobatin skate, Notoraja sereti n. sp., is described based on three specimens collected from off Madang (Papua New Guinea) at depths of 800-980 m. This medium-size Notoraja skate shares with other velcro skates from the Western Pacific, N. alisae, N. fijiensis, N. inusitata and N. longiventralis, a ventral surface covering of fine denticles giving the skin a velvety feel. Notoraja sereti differs from all of these species in having a shorter snout (preorbital length 10.1-11.1 vs. 11.5-14.5% TL, prenasal length 8.2-8.9 vs, 9.8-12.1% TL), shorter head (dorsal head length 15.2-16.2 vs. 17.1-19.3% TL, ventral head length 21.6-22.9 vs. 22.9-25.9% TL), fewer pectoral-fin radials (total radials 58-60 vs. 61-74), and fewer vertebrae (predorsal diplospondylous centra 66-71 vs. 72-82, predorsal centra 90-95 vs. 98-107, total centra 126-131 vs. 135-152).

A new legskate, Sinobatis andamanensis (Rajiformes: Anacanthobatidae), from the Andaman Sea (northeastern Indian Ocean).

A new legskate, Sinobatis andamanensis sp. nov. is described from a small collection of specimens taken off Phuket (Thailand) during an exploratory survey of the Andaman Sea. It is the first species of Sinobatis and the only legskate known from the northern Indian Ocean. Sinobatis andamanensis sp. nov. has an especially long and narrowly pointed snout (preorbital length exceeding 23% TL) with an interorbital distance 7-9.5 in snout length (up to 6.7 in other Sinobatis species). Molecular data are unavailable for most members of the genus, but based on morphology it shares with S. caerulea bluish dorsal and ventral surfaces when fresh and a long ventral head (length 36-42% TL). As well as differing in several morphometric differences, Sinobatis andamanensis sp. nov. seems to be a much smaller legskate (males adult from 186 mm DW vs. still immature at 540 mm DW in S. caerulea). Sinobatis bulbicauda also has an expanded posterior tail, but S. andamanensis sp. nov. differs from that species in having a narrower disc (width at anterior orbit 3.7-4.9 vs. 5.2-7.8 times mouth width) and anterior pelvic-fin lobes (base width 2.7-5.0 vs. 1.7-3.2 in distance between pelvic-fin origins), and shorter and less-conical tooth cusps and fewer vertebrae (total centra 126-133 vs. 148-171).

Platyrhina psomadakisi sp. nov., a new species of fanray (Batoidea: Platyrhinidae) from the Andaman Sea, the first record of this family in the Indian Ocean.

A new species of fanray (Platyrhina) is described based on four specimens collected in 2015 from the Andaman Sea, off Myanmar. These represent the first records of the family Platyrhinidae from the Indian Ocean with the three other members of the genus being restricted to the North-West Pacific. The new species differs from its congeners in having a series of faint dark bands on the body and tail, more pectoral-fin radials, and much more widely separated dorsal fins.

A new Eastern Central Atlantic skate Raja parva sp. nov. (Rajoidei: Rajidae) belonging to the Raja miraletus species complex.

An investigation of combined CO1 and NADH2 data for rajid skates referable to Raja miraletus provided evidence that populations ranging from southern Africa to the North-East Atlantic and Mediterranean Sea, once considered to represent a cline, belong to a species complex consisting of at least four valid species. Raja miraletus appears to be confined to the Mediterranean Sea, and the North-East Atlantic from the Bay of Biscay south to Morocco and Madeira. The southernmost species, referable to the resurrected Raja ocellifera, occurs off southern Africa, off Namibia and from False Bay to Durban (South Africa). Two species occur off tropical West Africa, including Raja parva sp. nov. (Senegal, Liberia and Angola but is probably more widespread within the region), and another unidentified species needing further investigation. Raja cf. miraletus, confirmed from Mauritania and Senegal, appears to be a larger skate with a broader disc, more broadly pointed snout, larger spiracles, and a slightly longer and broader tail. Raja parva sp. nov. differs from nominal members of the complex in having an unusually long procaudal tail (exceeding 22% TL), as well as a combination of other external characters. Past investigators observed morphological and anatomical differences between these forms but these were thought to be due to intraspecific variability. They postulated that an upwelling at Cape Blanco (21°N) may have isolated the Mediterranean form (R. miraletus) from Mauritania-Senegal form (now known to be two species). Similarly, the Benguela Current and upwelling off Cape Frio (18°S) were thought to be responsible for separating the Angolan form (R. parva) and South African form (R. ocellifera).

A new skate genus Orbiraja (Rajiformes: Rajidae) from the Indo-West Pacific.

Molecular analyses and information gleaned from an examination of the newly available adult male of the North-West Pacific skate, Okamejei jensenae Last & Lim, supported earlier concerns that the species might be mis-assigned. Morphological data based on this specimen supported its placement in a new genus Orbiraja that is assigned to the recently named Rostrorajini based on molecular evidence. This subgroup of the family Rajidae also includes Malacoraja, Neoraja, Rostroraja and an unresolved 'amphi-American Assemblage' (sensu McEachran & Dunn, 1998). Orbiraja is unique within the rajids in having the combination of three, very closely spaced median thorn rows on the tail, no dark-edged ventral pores, and a clasper skeleton with a prominent accessory terminal 3 cartilage formed by a medio-distal extension of the accessory terminal 2 cartilage. Its spiracle appears to be situated posteriorly with respect to the orbit. The group contains two other nominal species, Orbiraja powelli (Alcock) and O. philipi (Lloyd), and an un-named species from Indonesia that needs further investigation. Orbiraja jensenae is rediagnosed based on characteristics of the adult male.

Taxonomic status of maskrays of the Neotrygon kuhlii species complex (Myliobatoidei: Dasyatidae) with the description of three new species from the Indo-West Pacific.

The bluespotted maskray, Neotrygon kuhlii (Müller & Henle, 1841), once thought to be widely distributed in the Indo-West Pacific, consists of a complex of several species and the type series consists of multiple species; its nomenclature is discussed. A lectotype and paralectotype are designated and the species rediagnosed based on the types and a fresh specimen from Honiara (Solomon Islands), near to the collection locality of the lectotype (Vanikoro, Solomon Islands). Molecular and morphological data provide confirmatory evidence that this maskray is distinct from some other regional forms. Three members of the complex from the Western Pacific identified in earlier studies are confirmed to be new species; Neotrygon australiae sp. nov. (Australia, New Guinea and eastern Indonesia), N. caeruleopunctata sp. nov. (Indian Ocean), and N. orientale sp. nov. (North-West Pacific). These species differ from each other and N. kuhlii in their adult size, anterior angle of the disc, number and distribution of blue spots on the dorsal disc, and other more subtle morphometric and meristic characters. Another largely plain-coloured Neotrygon, also currently misidentified as N. kuhlii, is sympatric with N. orientale sp. nov. in the South China Sea and off Taiwan. Neotrygon varidens (Garman) is resurrected as the valid name for this ray. A key is provided to species of the genus.

Maculabatis ambigua sp. nov., a new whipray (Myliobatiformes: Dasyatidae) from the Western Indian Ocean.

A new whipray, Maculabatis ambigua sp. nov., described from material collected from the Red Sea and off Zanzibar (Tanzania), is probably more widespread in the northwestern Indian Ocean. It has been confused with other Indian Ocean whiprays of the genus Maculabatis (formerly Himantura in part) i.e. M. gerrardi and M. randalli. Maculabatis ambigua sp. nov. was first distinguished from these species by molecular analysis, and subsequently by a combination of morphological characters, i.e. disc shape, coloration, morphometrics and squamation. Molecular data suggest that it is most closely related to the morphologically similar M. gerrardi, which occurs further east in the Indian Ocean (Oman to Indonesia) and North-West Pacific (north to Taiwan). The dorsal disc of M. gerrardi typically has a full or partial coverage of white spots (usually present at least on the posterior disc), whereas M. ambigua sp. nov. is plain coloured. Maculabatis randalli, which occurs in the Persian and Arabian Gulfs, is plain coloured, but has a longer disc relative to its width, more acute and longer snout, longer head and larger intergill width, wider internasal distance, and a narrower secondary denticle band in adults. Maculabatis ambigua sp. nov. is relatively common in the shallow, soft-sedimentary habitats of the southern Red Sea from where it is taken as low-value or discarded bycatch of trawl fisheries. It is a medium-sized whipray with a maximum confirmed size of 840 mm disc width.

Two new whiprays, Maculabatis arabica sp. nov. and M. bineeshi sp. nov. (Myliobatiformes: Dasyatidae), from the northern Indian Ocean.

Two new medium-sized whiprays, Maculabatis arabica sp. nov. and M. bineeshi sp. nov., are described from specimens collected in coastal habitats of the northern Indian Ocean, off India and Pakistan. Both species superficially resemble M. randalli (Last, Manjaji-Matsumoto & Moore), and appear to have been confused with a more widely distributed whipray M. gerrardi Gray, and another undescribed species from the Indian Ocean. Maculabatis arabica sp. nov. (attains at least 63 cm DW) is diagnosed by a combination of external characters, i.e. morphometrics (e.g. relatively short disc, narrow interspaces between paired structures on the head), squamation (relatively slow denticle development and a characteristic denticle band shape), plain dorsal disc coloration (rather than spotted), and tail light brown and banded beyond the caudal sting in juveniles but almost plain in adults. Maculabatis bineeshi sp. nov. (attains at least 66 cm DW) is diagnosed by a combination of characters, i.e. morphometrics (e.g. suboval to weakly rhombic disc in young), squamation (rapid denticle development and broad denticle band with margins truncate near pectoral-fin insertions), plain dorsal disc coloration (no white spots), and a dark blackish tail (especially in young) with weakly mottled banding on its dorsal surface beyond the caudal sting. Maculabatis arabica sp. nov. appears to be confined to the Arabian Sea (from Pakistan to western India), whereas M. bineeshi sp. nov. occurs in the Arabian Sea (off Pakistan and northwestern India) and in the Bay of Bengal (confirmed off Odisha, eastern India).