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1.
The conservation of humpback dolphins, distributed in coastal waters of the Indo‐West Pacific and eastern Atlantic Oceans, has been hindered by a lack of understanding about the number of species in the genus (Sousa) and their population structure. To address this issue, we present a combined analysis of genetic and morphologic data collected from beach‐cast, remote‐biopsied and museum specimens from throughout the known Sousa range. We extracted genetic sequence data from 235 samples from extant populations and explored the mitochondrial control region and four nuclear introns through phylogenetic, population‐level and population aggregation frameworks. In addition, 180 cranial specimens from the same geographical regions allowed comparisons of 24 morphological characters through multivariate analyses. The genetic and morphological data showed significant and concordant patterns of geographical segregation, which are typical for the kind of demographic isolation displayed by species units, across the Sousa genus distribution range. Based on our combined genetic and morphological analyses, there is convincing evidence for at least four species within the genus (S. teuszii in the Atlantic off West Africa, S. plumbea in the central and western Indian Ocean, S. chinensis in the eastern Indian and West Pacific Oceans, and a new as‐yet‐unnamed species off northern Australia).  相似文献   

2.
The clingfish Apletodon barbatus sp. nov. is described on the basis of 22 specimens and color photos from Santiago and Sal Islands, Cape Verde Islands, eastern central Atlantic Ocean. The species is very small, apparently not exceeding 18 mm total length; it is characterized by having a conspicuous maxillary barbel in males, 4–5 incisors in the upper jaw, numerous brown spots on the head and body in males, and a double white spot near the anus. The new species is compared with other species of the genus; a key to the males of the 5 known species of the eastern Atlantic genus Apletodon is presented. A checklist is provided for the species of Apletodon and their synonyms. Several new records are included in the present paper: Apletodon dentatus and A. incognitus are recorded from the Canary Islands, and A. wirtzi is recorded from Cameroon.  相似文献   

3.
Bathycongrus parviporus sp. nova is described from specimens collected in the South China Sea, in the coastal waters of central Vietnam. By its characters (short snout, elongate-oval vomerine tooth patch with numerous small teeth of approximately the same size, slender relatively short tail, and residual leptocephalic pigmentation as a series of small melanophores just below lateral line in adults), the species belongs to the group of species of this genus represented by B. bleekeri, B. trimaculatus, and B. unimaculatus in the western part of the Pacific Ocean and B. dubius in the western Atlantic Ocean but differs in small infraorbital pores which are enlarged in all known species of the genus Bathycongrus. By the number of preanal pores, the new species is similar to B. bleekeri from Philippine waters but differs from it in a higher number of vertebrae (120–122), in more numerous rows of teeth on the premaxilloethmoid, in more number of branchiostegal rays (9–10), a shorter head, and in some other proportions of head and body. Topography of canals and pores of the cephalic seismosensory system of B. parviporus sp. nova is described. Morphometric and osteological characters for placing this species in the genus Bathycongrus are noted.  相似文献   

4.
38 halacarid species from the coasts of the boreal West Atlantic Ocean have been recorded. In a wide-spread net of stations, samples were taken from different substrata in marine and brackish waters in order to obtain information on the biology and ecology of halacarid species. Several habitats with their flora, fauna and halacarid species are described. In intertidal areas on the coasts of boreal North America fewer species were found than known from European coasts. Similar habitats on the west and east coasts of the North Atlantic Ocean are compared with respect to their halacarid population. In the rhombognathine and the genusHalacarellus, most species found in the West Atlantic Ocean are known in the East Atlantic too, living in similar habitats. The generaAnomalohalacarus andCopidognathus are common both in North American and European waters, but comparable biotopes are inhabited by different species, though often related or very similar in their appearance. 45 % of the halacarid species found in the boreal West Atlantic Ocean are also known in the East Atlantic. Hypotheses as to the dispersal and geographical distribution of halacarid genera and species are discussed. It is supposed, that many of the amphiatlantic species invaded biotopes on the American and European coasts, shortly after these continental plates drifted apart.  相似文献   

5.
Over the last few decades, advances in molecular techniques have led to the detection of strong geographic population structure and cryptic speciation in many benthic marine taxa, even those with long‐lived pelagic larval stages. Polychaete annelids, in particular, generally show a high degree of population divergence, especially in mitochondrial genes. Rarely have molecular studies confirmed the presence of ‘cosmopolitan’ species. The amphinomid polychaete Hermodice carunculata was long considered the sole species within its genus, with a reported distribution throughout the Atlantic and adjacent basins. However, recent studies have indicated morphological differences, primarily in the number of branchial filaments, between the East and West Atlantic populations; these differences were invoked to re‐instate Hermodice nigrolineata, formerly considered a junior synonym of H. carunculata. We utilized sequence data from two mitochondrial (cytochrome c oxidase subunit I, 16S rDNA) markers and one nuclear (internal transcribed spacer) marker to examine the genetic diversity of Hermodice throughout its distribution range in the Atlantic Ocean, including the Mediterranean Sea, the Caribbean Sea, the Gulf of Mexico and the Gulf of Guinea. Our analyses revealed generally low genetic divergences among collecting localities and between the East and West Atlantic, although phylogenetic trees based on mitochondrial data indicate the presence of a private lineage in the Mediterranean Sea. A re‐evaluation of the number of branchial filaments confirmed differences between East and West Atlantic populations; however, the differences were not diagnostic and did not reflect the observed genetic population structure. Rather, we suspect that the number of branchial filaments is a function of oxygen saturation in the environment. Our results do not support the distinction between Hcarunculata in the West Atlantic and H. nigrolineata in the East Atlantic. Instead, they re‐affirm the older notion that H. carunculata is a cohesive species with a broad distribution across the Atlantic Ocean.  相似文献   

6.
Colossendeis megalonyx Hoek, 1881 is a widespread and abundant pycnogonid in the Southern Ocean which has also been reported from the South Atlantic and South Pacific Oceans. Its strictly benthic lifestyle is expected to promote genetic differentiation among populations and ultimately facilitate speciation. On the other hand, the reported eurybathy and unknown larval stages of this species may allow Colossendeis megalonyx to maintain genetic continuity between isolated shallow-water habitats by active dispersal through the deep sea or by passive rafting on floating substrates. Thus, it remains unknown whether and to which extent geographically separated populations of Colossendeis megalonyx maintain gene flow in the Southern Ocean. We sampled 96 specimens of Colossendeis megalonyx from three stations in the Atlantic Sector of the Southern Ocean and one station from the South American continental shelf (Burdwood Bank). The genetic structure of nominal Colossendeis megalonyx as well as its phylogenetic position within the genus Colossendeis were assessed using a fragment of the cytochrome c oxidase subunit 1 gene. Our data strongly support that nominal Colossendeis megalonyx consists of at least five cryptic and one pseudocryptic mitochondrial lineages, four of which appear to be geographically restricted. Two lineages occurred at locations separated by more than 1,000 km in the Antarctic, thus indicating high levels of gene flow or recent colonization. No haplotype sharing across the Polar Frontal Zone was observed. Our results strongly suggest that cryptic speciation occurred within the genus Colossendeis. The wide biogeographic distribution range of Colossendeis megalonyx and perhaps that of other Antarctic pycnogonids should therefore be regarded with caution.  相似文献   

7.
Deep‐sea octopuses of the genus Muusoctopus are thought to have originated in the Pacific Northern Hemisphere and then diversified throughout the Pacific and into the rest of the World Ocean. However, this hypothesis was inferred only from molecular divergence times. Here, the ancestral distribution and dispersal routes are estimated by Bayesian analysis based on a new phylogeny including 38 specimens from the south‐eastern Pacific Ocean. Morphological data and molecular sequences of three mitochondrial genes (16S rRNA, COI and COIII) are presented. The morphological data confirm that specimens newly acquired from off the coast of Chile comprise two species: Muusoctopus longibrachus and the poorly described species, Muusoctopus eicomar. The latter is here redescribed and is clearly distinguished from M. longibrachus and other closely related species in the region. A gene tree was built using Bayesian analysis to infer the phylogenetic position of these species within the species group, revealing that a large genetic distance separates the two sympatric Chilean species. M. longibrachus is confirmed as the sister species of Muusooctopus eureka from the Falkland Islands; while M. eicomar is a sister species of Muusoctopus yaquinae from the North Pacific, most closely related to the amphi‐Atlantic species Muusoctopus januarii. Molecular divergence times and ancestral distribution analyses suggest that genus Muusoctopus may have originated in the North Atlantic: one lineage dispersed directly southward to the Magellan region and another dispersed southward along the Eastern Pacific to the Southern Ocean and Antarctica. The Muusoctopus species in the Southern Hemisphere have different phylogenetic origins and represent independent invasions of this region.  相似文献   

8.
Despite Springer’s (1964) revision of the sharpnose sharks (genus Rhizoprionodon), the taxonomic definition and ranges of Rhizoprionodon in the western Atlantic Ocean remains problematic. In particular, the distinction between Rhizoprionodon terraenovae and R. porosus, and the occurrence of R. terraenovae in South American waters are unresolved issues involving common and ecologically important species in need of fishery management in Caribbean and southwest Atlantic waters. In recent years, molecular markers have been used as efficient tools for the detection of cryptic species and to address controversial taxonomic issues. In this study 415 samples of the genus Rhizoprionodon captured in the western Atlantic Ocean from Florida to southern Brazil were examined for sequences of the COI gene and the D-loop and evaluated for nucleotide differences. The results on nucleotide composition, AMOVA tests, and relationship distances using Bayesian-likelihood method and haplotypes network, corroborates Springer’s (1964) morphometric and meristic finding and provide strong evidence that supports consideration of R. terraenovae and R. porosus as distinct species.  相似文献   

9.
10.
Three new species of digenean are described from demersal fishes taken in deep waters of the northwestern and northeastern Atlantic Ocean: Podocotyle schistotesticulata n. sp. from Antimora rostrata; P. harrisae n. sp. from Coryphaenoides (Lionurus) carapinus; and Gaevskajatrema halosauropsi n. sp. from Halosauropsis macrochir. The status of the nominal species of the genus Podocotyle Dujardin, 1845 is presented in annotated summary, along with a tabulation of the distinctive characteristics of recognised species of the genus. Gaevskajatrema Gibson & Bray, 1982 is discussed and its diagnosis amended.  相似文献   

11.
Moura, C. J., Cunha, M. R., Porteiro, F. M., Yesson, C. & Rogers, A. D. (2011) Evolution of Nemertesia hydroids (Cnidaria: Hydrozoa, Plumulariidae) from the shallow and deep waters of the NE Atlantic and Western Mediterranean. —Zoologica Scripta, 41, 79–96. Hydroid species from the genus Nemertesia develop some of the largest and most complex hydrozoan colonies. These colonies are abundant and ecologically important in both shallow and deep waters worldwide. Here, we analyse the systematics of most Nemertesia species from the NE Atlantic and Mediterranean using morphology and phylogenetic inferences of 16S rRNA haplotype data. Phylogeographical analysis revealed multiple movements of taxa to and from the Mediterranean after the Messinian salinity crisis through shallow and deep waters. The nominal species Nemertesia belini and Nemertesia antennina revealed multiple genetic lineages representing cryptic species diversity. Molecular phylogenetic evidence was supported by consistent phenotypic differences between lineages, and three and seven putative species were resolved within the N. belini and N. antennina complexes, respectively. Three putative species of the N. antennina complex found at different seamounts of Azores grouped in a clade clustered amongst the other four cryptic species present at neighbouring bathyal localities of the Gulf of Cadiz. These cryptic species, mostly from the deep sea, form a clade distantly related to the typical N. antennina from European coastal waters. Depth or environmental correlates of depth seem to influence the reproductive strategies of Nemertesia colonies and ultimately speciation. In particular, speciation of these hydroids must have been influenced by hydrography, habitat heterogeneity, isolation by distance and larval dispersal capacity. The deep sea is shown as an important environment in the generation and accumulation of lineages that may occasionally invade coastal waters in the NE Atlantic. Glacial cycles of cooling, along with changes in sea level, and eradication of some coastal faunas likely facilitated speciation and evolutionary transitions from deep to shallow waters.  相似文献   

12.
  Misophrioid copepods are reported for the first time from Antarctic waters. A species of each of the genera Misophriopsis and Misophriella is described from hyperbenthic layers of the continental shelf of the eastern Weddell Sea. The genus Misophria is also reported from these waters. Misophriopsis australis sp. nov. is the fifth representative of this widely distributed genus, previously reported from the North Atlantic, the China Sea, and both NW and NE quadrants of the Pacific Ocean. Misophriella schminkei sp. nov. is the second representative of the genus, known to date only from a single female caught in North Atlantic bathyal depths. Traces of subdivisions on antennary exopodal segments of the latter species suggest that the first segment may be a triple segment, while the second and terminal segments may be double segments. In addition, the mandibular exopod of this taxon indicates that a six-segmented ramus with setal formula 0, 1, 1, 1, 1, 2 may represent the ground pattern in Copepoda. The presence of parts of a cyclopinid copepod in the gut of M. schminkei sp. nov. indicates that this species may be carnivorous. Received: 12 November 1998 / Received in revised form: 26 July 1999 / Accepted: 27 July 1999  相似文献   

13.
A systematic revision of flying fishes of the subgenus Hirundichthys s.str was carried out based on a study of meristic and morphometric traits and characteristics of pigmentation of fishes from the local populations of species belonging to the subgenus. It is found out that the subgenus includes four species: oceanic H. speculiger from the Atlantic, Pacific and Indian Oceans, oceanic H. indicus sp.n. from the waters of the Indian Ocean, nerito-oceanic H. oxycephalus from the waters of the Indo-West Pacific and nerito-oceanic H. affinis from the Atlantic Ocean. The first part of the review focuses on two oceanic species with a large “mirror” on the pectoral fins: H. speculiger and H. indicus. A comparison of local populations showed that the species H. indicus is polytypic and consists of two subspecies. One of the subspecies—nominative H. indicus indicus—is distributed in the western and the central parts of the Indian Ocean and the other—H. indicus orientalis ssp.n.—in the Eastern Indian Ocean. Maps showing a geographical distribution of the species and the subspecies in the World Ocean are drawn up.  相似文献   

14.
The carditid genus Cyclocardia is currently the most diverse genus of the family, including nearly 180 nominal species encompassing wide stratigraphical (Cretaceous–Recent) and geographical (Antarctica, South and North America, Europe, Africa, Alaska, Russia, Japan and New Zealand) ranges. Due to the lack of autapomorphies in the diagnosis of the genus and its large account of species, we re-evaluate the systematic and phylogenetic status of Cyclocardia. We applied three approaches: bibliographic revision, phylogenetic analysis and an exploration of morphological disparity. We used a shell–character matrix comprising 65 taxa (2 outgroups, 29 non-Cyclocardia carditids and 28 species of Cyclocardia) for phylogenetic and disparity analyses. Maximum Observable Rescaled Distances was used to construct a distance matrix to compare Cyclocardia species and other carditid groups. According to our results, Cyclocardia represents a non-monophyletic taxon and is thus a ‘wastebasket taxon’, chiefly because its diagnosis was based mainly on plesiomorphic characters. The European species C. kickxi and C. chameformis are placed within Scalaricardita, and the previously proposed genus Crassicardia is monophyletic (including C. crassidens, C. crebricostata, C. isaotakii and C. rjabininae). Three new genera are proposed for new groups identified by the phylogenetic analysis: South American Oesterheldia gen. nov. (including O. cannada and O. dalek), western North American Coanicardita gen. nov. (including C. ventricosa and C. occidentalis), and North Pacific Hippocampocardia gen. nov. (including H. barbarensis, H. hamiltonensis and H. yakatagensis). The newly defined monophyletic Cyclocardia is restricted to the Atlantic Ocean species C. borealis, C. novangliae and C. compressa.  相似文献   

15.
A new species,Paralepidapedon williamsi, is described from the fishCottunculus microps and an unidentified fish of the suborder Cottoidei in the NE Atlantic Ocean. This species is the first member of the genus to be recognized in the Atlantic Ocean. Its general morphology is similar to that of the other members of the genus, but it is distinguished by its large eggs and the relatively few gland-cells associated with the external seminal vesicle. The genusParalepidapedon, which differs fromNeolepidapedon in the possession of a uroproct, is reviewed and a key to the species given. The genus is considered to include five species.  相似文献   

16.
During the BENGAL cruises, an important collection of deep-sea benthic organisms was sampled. Among the pennatulacean colonies, a previously undescribed species of chunellid was collected. That material is here described as the type species of a new genus, Porcupinella gen. nov. The new genus and species are described based on material collected in the Porcupine Abyssal Plain (NE Atlantic), 4,839–4,847 m in depth. This is the first time that a chunellid is reported from the Atlantic Ocean. The new genus is compared with the other genera in the family, and some phylogenetic remarks about the families Chunellidae and Umbellulidae are also provided.  相似文献   

17.
In the fourth part of the revision of the genus Melamphaes (Melamphaidae) multi-raker species (20 and more rakers at the first gill arch, rarely 19??in M. ebelingi) with eight soft rays in the ventral fin are considered. In this species, temporal spine is absent, there are 15 rays in the pectoral fin, and there are 11 to 12 abdominal vertebrae. M. ebelingi inhabits tropical and subtropical waters of the Atlantic Ocean. A new catch of this rare species in the northeastern part of the ocean is reported. The new species M. occlusus is described from one specimen from the subtropical part of the southwestern part of the Indian Ocean. Still another new species, M. nikolayi, is described from one specimen from the northwestern part of the Pacific Ocean (subtropical waters). A table for identification of 15 multi-raker species of the genus Melamphaes is provided.  相似文献   

18.
The commercial deep‐sea penaeid shrimp genus Parapenaeus contains 15 species, three subspecies and two forms in the Indo‐West Pacific and the Atlantic. Novel nucleotide sequence data from five different genes (COI, 16S, 12S, NaK and PEPCK) were collected to estimate phylogenetic relationships and taxonomic status amongst all but one subspecies in this genus. The phylogenetic results only support two of the four species groups previously proposed for this genus and indicate an evolution direction of the genital organs from simple to complex. The present results suggest that Parapenaeus originated in the shallow waters of the West Pacific with subsequent migration to the deep sea and the Atlantic. The molecular data reveal that there was probably misidentification of females between Parapenaeus australiensis and Parapenaeus ruberoculatus, with females previously assigned as P. australiensis likely being the females of P. ruberoculatus, while material identified as P. australiensis forma nodosa being the true P. australiensis females. On the other hand, Parapenaeus longipes forma denticulata truly represents a variation of the same species, while the subspecies Parapenaeus fissuroides indicus warrants a specific rank.  相似文献   

19.
The fish belonging to Gerreidae are common representatives of the coastal ichthyofauna of the tropics and subtropics of the world. The genus Diapterus has a neotropical distribution and currently includes four species: two in the Atlantic Ocean [Irish mojarra D. auratus Ranzani 1842 and rhombic mojarra D. rhombeus (Cuvier 1829)] and two in the Pacific Ocean [short‐beaked mojarra D. brevirostris (Sauvage 1879) and golden mojarra D. aureolus (Jordan & Gilbert 1882)]. This genus has uncertain taxonomy based on the remarkable and dissimilar morphology of D. aureolus. We evaluated the taxonomy and phylogeny of Diapterus with statistical (canonical discriminant analysis) and phylogenetic analyses (maximum parsimony, maximum likelihood and Bayesian inference) of geometric morphometric data (relative warps) and molecular data (12Sr RNA, 16Sr RNA, COI and RAG1 sequences). Our results indicate that the genus Diapterus as we currently conceive it is a polyphyletic group: [(Gerres cinereusEucinostomus spp. (D. aureolus – (Eugerres spp. (D. auratus – (D. brevirostris – D. rhombeus)))))]. Therefore, a taxonomic rearrangement is needed. To preserve the monophyly of the group, our proposal is to remove D. aureolus and place it in a new monotypic genus. A neotype is designated for D. aureolus as well as an artificial identification key for the genera and the species treated in this article.  相似文献   

20.
Based upon COI‐5P, LSU rDNA, and rbcL sequence data and morphological characteristics, six new members of the noncalcified crustose genus of red algae Ethelia are described in a new family, Etheliaceae (Gigartinales), sister to the recently described Ptilocladiopsidaceae. The novel species are described from subtropical to tropical Atlantic and Indo‐Pacific Ocean basins; E. mucronata sp. nov. and E. denizotii sp. nov. from southern and northern Western Australia respectively, E. wilcei sp. nov. from the Cocos (Keeling) Islands of Australia, E. suluensis sp. nov. from the Philippines, E. umbricola sp. nov. from Bermuda and E. kraftii sp. nov. from Lord Howe Island, Australia. The generitype, Ethelia biradiata, originally reported from the Seychelles, Indian Ocean, is added to the Western Australian flora.  相似文献   

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