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1.
Zootaxa ; 4819(2): zootaxa.4819.2.8, 2020 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-33055664

RESUMEN

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.


Asunto(s)
Rajidae , Animales , Océano Índico , Masculino
2.
Zootaxa ; 4758(2): zootaxa.4758.2.2, 2020 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-32230141

RESUMEN

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.


Asunto(s)
Gadiformes , Perciformes , Animales , Peces
3.
Zootaxa ; 4576(2): zootaxa.4576.2.3, 2019 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-31715761

RESUMEN

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.


Asunto(s)
Rajidae , Animales , Bahías , Océano Índico , Océano Pacífico
4.
Zootaxa ; 4508(2): 179-196, 2018 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-30485972

RESUMEN

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.


Asunto(s)
Peces , Animales , Australia , Melanesia
5.
Zootaxa ; 4244(2): 219-230, 2017 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-28610121

RESUMEN

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).


Asunto(s)
Rajidae , Animales , Papúa Nueva Guinea
6.
Zootaxa ; 4184(1): 52-62, 2016 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-27811653

RESUMEN

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.


Asunto(s)
Rajidae/anatomía & histología , Rajidae/clasificación , Animales , Femenino , Masculino , Océano Pacífico , Especificidad de la Especie
7.
Zootaxa ; 4175(6): 588-600, 2016 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-27811742

RESUMEN

A new species of guitarfish (Rhinobatos) is described based on a single specimen collected in 2014 from off New Ireland in Papua New Guinea. This specimen represents the first record of the family Rhinobatidae in Papua New Guinean waters. Based on molecular data, the new species appears to be most similar to Rhinobatos whitei (Philippines) and Rhinobatos sainsburyi (northern Australia), but is distinguished based on its coloration, morphology and certain meristic characters.


Asunto(s)
Rajidae/anatomía & histología , Rajidae/clasificación , Animales , Femenino , Masculino , Papúa Nueva Guinea , Especificidad de la Especie
8.
Zootaxa ; 4168(1): 161-170, 2016 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-27701354

RESUMEN

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).


Asunto(s)
Rajidae/anatomía & histología , Rajidae/clasificación , Animales , Femenino , Océano Índico , Masculino , Especificidad de la Especie
9.
Zootaxa ; 4154(1): 66-78, 2016 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-27615825

RESUMEN

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.


Asunto(s)
Rajidae/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Ecosistema , Femenino , Océano Índico , Masculino , Tamaño de los Órganos , Filogenia , Rajidae/anatomía & histología , Rajidae/genética , Rajidae/crecimiento & desarrollo
10.
Zootaxa ; 4147(2): 162-76, 2016 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-27515613

RESUMEN

The Mumburarr Whipray, Urogymnus acanthobothrium sp. nov. is described from a single specimen taken from the Cambridge Gulf, Western Australia, and from images of 10 other specimens from northern Australia and Papua New Guinea (all observed but not collected). It is a very large ray that attains at least 161 cm disc width, making it amongst the largest of the whiprays. The ventral tail below the caudal sting has a low, short-based fold. A ventral tail fold (or a dorsal fold) has not been recorded for any other himanturin stingray in the Indo-West Pacific. Molecular data suggest it is most closely related to a similar but more widely distributed cognate, U. granulatus. Both of these species share a suboval disc shape, similar squamation patterns, and the tail posterior to the sting is entirely white (at least in small individuals). U. acanthobothrium sp. nov. differs from U. granulatus in having a longer and more angular snout, longer tail, more posteriorly inserted caudal sting, lacks white flecks on the dorsal surface, and the ventral disc is uniformly white (rather than white with a broad black margin). It co-occurs with two other morphologically distinct Urogymnus in the region (U. asperrimus and U. dalyensis). Like U. dalyensis it occurs in both brackish and marine waters. A key is proved to the members of the genus Urogymnus.


Asunto(s)
Rajidae/anatomía & histología , Rajidae/clasificación , Animales , Australia , Femenino , Masculino , Papúa Nueva Guinea , Especificidad de la Especie
11.
Zootaxa ; 4147(4): 377-402, 2016 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-27515624

RESUMEN

Three undescribed stingrays were discovered as part of a broader revision of the family Dasyatidae that formed part of the Chondrichthyan Tree of Life project. This research forms part of a sequence of papers on rays aimed at describing unnamed species for inclusion in a multi-authored guide to rays of the world. The first part of this series focused on a redefinition of genera of the family Dasyatidae. The new Indo-West Pacific taxa are represented by separate genera from three dasyatid subfamilies: Himantura australis sp. nov. (northern Australia and Papua New Guinea), Taeniura lessoni sp. nov. (Melanesia) and Telatrygon biasa sp. nov. (Indo-Malay Archipelago). Himantura australis sp. nov., which belongs to a complex of four closely related reticulate whiprays, differs subtly from its congeners in coloration, morphometrics and distribution. Taeniura lessoni sp. nov. is the second species in a genus containing the widely-distributed T. lymma, which is possibly the most abundant stingray in shallow coral-reef habitats of the Indo-Pacific, with the new species apparently restricted to Melanesia. Taeniura lessoni sp. nov. is distinguishable by the absence of a distinctive pair of vivid blue longitudinal stripes on the dorsolateral edges of the tail which is one of the most distinctive features of T. lymma. Telatrygon biasa sp. nov. belongs to a small, recently designated genus of stingrays represented by four species in the tropical Indo-West Pacific. Telatrygon biasa sp. nov. differs from these species in morphometrics. The new species differs markedly from T. zugei in its NADH2 sequence. Telatrygon crozieri is resurrected as a valid northern Indian Ocean representative of the T. zugei complex.


Asunto(s)
Elasmobranquios/anatomía & histología , Elasmobranquios/clasificación , Animales , Australia , Femenino , Masculino , Océano Pacífico , Papúa Nueva Guinea
12.
Zootaxa ; 4147(4): 477-89, 2016 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-27515630

RESUMEN

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).


Asunto(s)
Rajidae , África del Sur del Sahara , Distribución Animal , Animales , Océano Atlántico , Femenino , Masculino , Filogenia , Rajidae/anatomía & histología , Rajidae/clasificación , Rajidae/fisiología
13.
Zootaxa ; 4132(1): 107-17, 2016 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-27395656

RESUMEN

A single specimen of a new Bathyraja skate was collected by the authors in 2003 during a survey of the deepwater biota of the northern Tasman Sea by the New Zealand FRV Tangaroa. This skate, labelled the 'blonde skate' by voyage participants, is uniformly white on all surfaces of the body and the skin is partly translucent. It belongs to a subgroup of Bathyraja with a large, almost smooth, quadrangular disc and well-developed and equally spaced median tail thorns. Other similar and probably closely related Bathyraja specimens have been caught in seas to the south of New Zealand since the discovery of this species, but their identity is yet to be confirmed.


Asunto(s)
Rajidae/anatomía & histología , Rajidae/clasificación , Distribución Animal , Animales , Femenino , Masculino , Océano Pacífico , Especificidad de la Especie
14.
Zootaxa ; 4083(4): 533-61, 2016 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-27394245

RESUMEN

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.


Asunto(s)
Rajidae/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Femenino , Océano Índico , Masculino , Tamaño de los Órganos , Océano Pacífico , Rajidae/anatomía & histología , Rajidae/crecimiento & desarrollo
15.
Zootaxa ; 4139(2): 233-47, 2016 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-27470801

RESUMEN

A new dwarf wedgefish, Rhynchobatus cooki sp. nov. is described from a single female from a Jakarta fish market (Indonesia) and 11 specimens collected at Jurong fish market (Singapore). First collected in 1934, the broader ichthyological community have been aware of this distinctive but little known ray since the late 1990's. Rhynchobatus cooki is the smallest of the wedgefishes (to 81 cm TL) and has the lowest vertebral count (fewer than 107 centra). It is also distinguishable from its congeners based on its long, hastate snout, very strongly undulate anterior pectoral-fin margin, coloration and aspects of its squamation. The dorsal coloration is mainly dark and distinctively marked with white blotches, spots and streaks, and has a dark cruciate marking on the interorbit and a prominent white border around the body margin. Unlike most other wedgefish species, the snout tip lacks dark blotches and there is no black pectoral-fin marking. It shares well-developed rostral spines with a much larger Atlantic species (Rhynchobatus luebberti), but these spines are confined to the snout tip (rather than being more numerous and extending in paired rows along the rostral ridges nearly to the eyes). No additional specimens have been observed since 1996, despite an increased recent effort to survey the chondrichthyan fauna of South-East Asia and collect biological data for species, raising concerns over its conservation status.


Asunto(s)
Rajidae/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Femenino , Océano Índico , Masculino , Tamaño de los Órganos , Océano Pacífico , Rajidae/anatomía & histología , Rajidae/crecimiento & desarrollo
16.
Zootaxa ; 4139(3): 345-68, 2016 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-27470808

RESUMEN

The higher-level taxonomy of the stingrays (Dasyatidae) has never been comprehensively reviewed. Recent phylogenetic studies, supported by morphological data, have provided evidence that the group is monophyletic and consists of four major subgroups, the subfamilies Dasyatinae, Neotrygoninae, Urogymninae and Hypolophinae. A morphologically based review of 89 currently recognised species, undertaken for a guide to the world's rays, indicated that most of the currently recognised dasyatid genera are not monophyletic groups. These findings were supported by molecular analyses using the NADH2 gene for about 77 of these species, and this topology is supported by preliminary analyses base on whole mitochondrial genome comparisons. These molecular analyses, based on data generated from the Chondrichthyan Tree of Life project, are the most taxon-rich data available for this family. Material from all of the presently recognised genera (Dasyatis, Pteroplatytrygon and Taeniurops [Dasyatinae]; Neotrygon and Taeniura [Neotrygoninae]; Himantura and Urogymnus [Urogymninae]; and Makararaja and Pastinachus [Hypolophinae]), are included and their validity largely supported. Urogymnus and the two most species rich genera, Dasyatis and Himantura, are not considered to be monophyletic and were redefined based on external morphology. Seven new genus-level taxa are erected (Megatrygon and Telatrygon [Dasyatinae]; Brevitrygon, Fluvitrygon, Fontitrygon, Maculabatis and Pateobatis [Urogymninae], and an additional three (Bathytoshia, Hemitrygon and Hypanus [Dasyatinae]) are resurrected from the synonymy of Dasyatis. The monotypic genus Megatrygon clustered with 'amphi-American Himantura' outside the Dasyatidae, and instead as the sister group of the Potamotrygonidae and Urotrygonidae. Megatrygon is provisionally retained in the Dasyatinae pending further investigation of its internal anatomy. The morphologically divergent groups, Bathytoshia and Pteroplatytrygon, possibly form a single monophyletic group so further investigation is needed to confirm the validity of Pteroplatytrygon. A reclassification of the family Dasyatidae is provided and the above taxa are defined based on new morphological data.


Asunto(s)
Rajidae/clasificación , Distribución Animal , Animales , Tamaño Corporal , Ecosistema , Genoma Mitocondrial , Filogenia , Rajidae/genética , Rajidae/crecimiento & desarrollo
17.
Zootaxa ; 4144(2): 276-86, 2016 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-27470854

RESUMEN

The recently resurrected genus Acroteriobatus is represented in the western Indian Ocean by eight species, including a new guitarfish Acroteriobatus omanensis sp. nov. This small species (reaching ~60 cm TL) was discovered off Oman in an investigation of the chondrichthyan fauna of the Arabian in 2002 and 2003. Its distinctiveness from other members of the genus Acroteriobatus is strongly supported by molecular data. Acroteriobatus omanensis sp. nov. differs from all other members of the genus by its very narrowly pointed snout and having a dense pattern of small, symmetrically arranged ocelli each consisting of a white spot surrounded by a darker rim. Acroteriobatus annulatus and A. ocellatus have a       more-or-less ocellated dorsal colour pattern but the markings are larger and differ in form (ocelli consisting of a small dark central spot surrounded by a dark-edged pale ring in A. annulatus; larger, irregularly shaped ocelli with pale centres surrounded by a dark brown rim in A. ocellatus).


Asunto(s)
Rajidae/clasificación , Distribución Animal/fisiología , Animales , Femenino , Masculino , Rajidae/anatomía & histología , Rajidae/fisiología , Especificidad de la Especie
18.
Zootaxa ; 4144(3): 335-53, 2016 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-27470860

RESUMEN

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).


Asunto(s)
Rajidae/clasificación , Distribución Animal/fisiología , Animales , Femenino , Océano Índico , Masculino , Rajidae/anatomía & histología , Rajidae/fisiología , Especificidad de la Especie
19.
Zootaxa ; 4117(4): 451-75, 2016 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-27395187

RESUMEN

A new guitarfish, Rhinobatos borneensis sp. nov., is described from material collected at fish markets in Malaysian Borneo (South China Sea). This ray, which is almost plain coloured with faint orange blotches in adults, has a more colourful embryo marked with small pale ocelli with dark centres. Confused with R. schlegelii (Japan to Taiwan) and its junior synonym R. formosensis, new molecular data suggests it is more closely related to a subgroup of Rhinobatos from the Indo-Malay Archipelago that includes R. jimbaranensis, R. sainsburyi and R. whitei. Based on evidence from recent phylogenetic studies, the genus Rhinobatos is non-monophyletic, nor is the Rhinobatidae a monophyletic family-level group. Former subgenera of Rhinobatos, Acroteriobatus and Glaucostegus, are valid genus-level taxa supported by both morphological and molecular evidence. Moreover, amphi-American members of Rhinobatos, assigned herein to a new genus Pseudobatos, are not monophyletic with Rhinobatos, Acroteriobatus and Glaucostegus and its position within the newly erected order Rhinopristiformes needs to be reassessed. Several molecular studies have suggested that the family Rhinobatidae is polyphyletic and needs to be redefined. We propose a revised classification of the order Rhinopristiformes based on molecular analyses and supported by morphological data, making strong use of oronasal morphology. The group now contains 5 family-level taxa: three valid nominal taxa, Pristidae (2 genera, 5 species), Rhinidae (incorporating Rhynchobatidae, 2 genera, 9 species), Rhinobatidae (3 genera, 31 species); and two new taxa, Glaucostegidae (single genus, 6 species) and Trygonorrhinidae (3 genera, 8 species).


Asunto(s)
Rajidae/clasificación , Distribución Animal , Estructuras Animales/anatomía & histología , Estructuras Animales/crecimiento & desarrollo , Animales , Tamaño Corporal , Femenino , Indonesia , Masculino , Tamaño de los Órganos , Filogenia , Rajidae/anatomía & histología , Rajidae/genética , Rajidae/crecimiento & desarrollo
20.
Zootaxa ; 4121(5): 533-44, 2016 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-27395241

RESUMEN

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.


Asunto(s)
Rajidae/anatomía & histología , Rajidae/clasificación , Animales , Extremidades , Femenino , Geografía , Océano Índico , Masculino , Mianmar
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