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1.
Xavier, R., Santos, A. M., Harris, D. J., Sezgin, M., Machado, M., Branco, M. (2012). Phylogenetic analysis of the north‐east Atlantic and Mediterranean species of the genus Stenosoma (Isopoda, Valvifera, Idoteidae). —Zoologica Scripta, 41, 386–399. The marine isopod genus Stenosoma is widespread in the northern hemisphere. However, 12 of its 14 known species are found within the Mediterranean basin and adjacent regions of the north‐east Atlantic and the Black Sea. Such a high level of diversity confined to a limited region of a much larger circumglobal distribution suggests that the Mediterranean region may have played a crucial role in the evolutionary history of this genus. In the present work, the phylogeny of the genus Stenosoma was investigated on the basis of DNA sequencing data from one nuclear (28SrRNA) and two mitochondrial (COI, ND4) gene fragments obtained for nine of 12 Atlantic–Mediterranean species. Divergence time estimates point to a Tethyan origin of Stenosoma and suggest that the speciation events from which stem most of the extant species took place well before the Messinian Salinity Crisis. Stenosoma spinosum and Stenosoma appendiculatum are the only exceptions, as they apparently arose within the Mediterranean during the Pleistocene. Phylogenetic reconstruction agrees with current taxonomic status of most species. However, Stenosoma capito clustered in two distinct and well‐supported clades, one composed of eastern Mediterranean and Black Sea specimens and the other by western Mediterranean and Atlantic ones. Such polyphyly suggests the existence of a previously unrecognized species, Stenosoma sp., which so far has been confounded with S. capito.  相似文献   

2.
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   

3.
4.
The Ayu, Plecoglossus altivelis, comprising three subspecies, is the only species in the genus Plecoglossus in the family Osmeridae. Here, we describe for the first time the discovery of fossil specimens of P. altivelis from the Upper Miocene sediment of Matsue, Shimane Prefecture, Japan. The fossil individuals are subadult and have comb teeth in the second and third generations. These fossil specimens are clearly similar to the recent P. altivelis, the former’s meristic characters being included in the three recent subspecies. In terms of numbers of pectoral fin rays and vertebrae, the fossil specimens are more similar to the subspecies Plecoglossus altivelis ryukyuensis than the other subspecies, but they also show different dorsal fin shapes and anal fin ray counts. This discovery of fossil P. altivelis indicates the persistence of the species for at least 10 million years, from the Late Miocene to the present.  相似文献   

5.
Aim To reconstruct the phylogenetic relationships of the four species of the genus Sarda (Sarda sarda, Sarda orientalis, Sarda australis and Sarda chilensis) and their phylogeographic history in the context of historical and ecological biogeography. Also, to reconstruct within‐species phylogenetic relationships to test whether the North Atlantic and Mediterranean populations of Atlantic bonito (S. sarda) warrant subspecies status, and the validity of the allopatric northern and southern populations of eastern Pacific bonito (S. chiliensis), recognized as S. chiliensis lineolata and S. chiliensis chiliensis. Location Representative samples of all four Sarda species collected world‐wide were analysed. Methods Phylogenetic inference was carried out with neighbour‐joining, maximum parsimony and maximum likelihood, employing nucleotide sequences of the mitochondrial DNA (mtDNA) control region I (CR‐I) and of the single‐copy nuclear DNA (nDNA) Tmo‐4c4 gene. Analysis of molecular variance was used on the mtDNA data to estimate the extent of geographic population structuring. Results Gene trees derived from mtDNA and nDNA data yielded concordant phylogenies that support the monophyly of the genus Sarda. The following sibling pairs received strong statistical support: striped bonito (S. orientalis) with Australian bonito (S. australis), and Atlantic bonito (S. sarda) with eastern Pacific bonito (S. chiliensis). Furthermore, the origin of S. sarda mtDNA is paraphyletic with respect to S. chiliensis, and these results are indicative of introgression. The analysis of Tmo‐4c4 sequences corroborates the ancestral hybridization between these allopatric species. Comparisons of north‐west Atlantic and Mediterranean populations of S. sarda using mtDNA CR‐I data revealed substantial genetic differentiation. By contrast, no differences between the putative northern and southern allopatric subspecies of S. chiliensis were detected. Main conclusions The monophyly of the genus Sarda as indicated by morphology is corroborated using both molecular markers. However, molecular phylogenies depicted a paraphyletic relationship between S. sarda and S. chiliensis. This phylogeographical relationship is better explained by an ancestral introgression facilitated by trans‐Arctic contact during the Pleistocene. The pronounced genetic differentiation between S. sarda samples from the north‐west Atlantic and the Mediterranean is consistent with the differentiation of these two regions, but not with the amphi‐Atlantic speciation hypothesis. Finally, the S. chiliensis lineolata and S. chiliensis chiliensis subspecies status is not supported by the molecular data.  相似文献   

6.
We propose the new genus Melyvonnea to accommodate species previously included in Mesophyllum having: a) perithallial protuberances that may branch and dominate over the encrusting base, b) monoecious gametophytes with gametangial conceptacles occasionally developed in superimposition, c) spheroid carposporangial chambers (lacking a central pedestal), and d) filaments lining canals of multiporate roofs composed of 3 to 5 cells with distinctively elongate basal cells. The new genus shares with Mesophyllum the development of a predominantly coaxial hypothallium. Melyvonnea presently accommodates three species in the Central Atlantic, viz. the generitype Melyvonnea canariensis (Foslie) comb. nov. from the Canary Islands, Melyvonnea erubescens (Foslie) comb. nov. ( = Mesophyllum incertum; type locality: Bermuda) from the western Atlantic, Melyvonnea aemulans (Foslie & Howe) comb. nov. from Puerto Rico, and one Indo‐Pacific species, Melyvonnea madagascariensis (Foslie) comb. nov. We also emend Mesophyllum Lemoine to encompass Northern Hemisphere species that lack the above apomorphies of Melyvonnea and in addition develop a central pedestal in carposporangial conceptacles (via dissolution of the surrounding cells) with gonimoblasts bending down to fill the empty space. Mesophyllum sensu stricto currently includes six species in the northeast Pacific (M. aleuticum, M. conchatum, M. crassiusculum, M. lamellatum, M. megagastri, M. vancouveriense), two species in the western Atlantic (M. mesomorphum and M. syntrophicum), and three species in the northeast Atlantic and the Mediterranean Sea (M. expansum, M. lichenoides, M. philippii). Gametophytic species of each genus show a mainly disjunct distribution being restricted to the tropics–subtropics (Melyvonnea) and the temperate waters of the Northern Hemisphere (Mesophyllum s.s.). This classification is supported by a consensus of studies of all well‐known species of Mesophyllum sensu Adey (1970), and is based on a phylogenetic analysis of morphological and anatomical characters in addition to molecular evidence.  相似文献   

7.
The first three zoeal stages of the portunid crab Macropipus tuberculatus (Roux, 1830) are described and illustrated from laboratory-reared material obtained from one ovigerous crab captured in the western Mediterranean Sea. Zoeae of M.tuberculatus can be distinguished from other known polybiinid species from the northeastern Atlantic and Mediterranean waters by a combination of meristic and morphometric features, especially by the number of setae in the outer lobe of the maxilla endopod. Larval morphology presents additional evidence supporting the split of the genus Macropipus into the genera Liocarcinus and Macropipus sensu stricto based on adult characters.   相似文献   

8.
9.
A new subspecies, Kailasius autocrator murun Korb, ssp. n., of the species Kailasius autocrator (Avinov, 1913) from the eastern part of the Alai Mountain Ridge is described. This subspecies differs from the other known ones in the smaller size (the fore-wing length is less than 23 mm) and in the presence of 5 black rounded spots in the submarginal area of the hind-wing upper side (4 spots in the nominotypical subspecies and K. a. pshartanus). The new subspecies is shown to be the most archaic one among the subspecies of the genus Kailasius by the wing pattern. Possible ways for the origin of local and small populations of morphologically different subspecies of the genus are discussed.  相似文献   

10.
The low representativeness of the dog‐faced bats (genus Cynomops Thomas, 1920 ) in collections has constrained the study of the diversity and the evolutionary relationships within this genus. Taxonomic revisions of some taxa, in particular the large‐sized Cynomops abrasus (Temminck, 1827 ), are crucial for understanding the phylogeny of Cynomops. A total of four subspecies of C. abrasus have been described to date, all widespread in South America: C. a. mastivus (Thomas, 1911 ), C. a. brachymeles (Peters, 1865), C. a. cerastes (Thomas, 1901 ) and C. a. abrasus (Temminck, 1827 ). Here, we evaluated the phylogenetic relationships within Cynomops, and the status of the four C. abrasus subspecies using complete sequences of two mitochondrial genes (Cyt b and COI) and 39 morphological characters. Maximum‐parsimony, maximum‐likelihood and Bayesian phylogenetic reconstructions recovered a novel hypothesis for Cynomops, supported the recognition of C. a. mastivus as a distinct species, separated from C. abrasus, and two hypotheses of lineages previously unrecognized for Cynomops. The use of mitochondrial genes combined with morphological characters revealed again to be a powerful tool to recover the phylogenetic relationships within Cynomops and demonstrated that the genus is more diverse than previously thought.  相似文献   

11.
Two new species of the kinorhynch genus Pycnophyes are described from the Atlantic Ocean, Northwest Spain, and the Mediterranean Sea, East of Spain, using differential interference contrast microscopy and scanning electron microscopy (SEM): Pycnophyes dolichurus sp. nov. and P. aulacodes sp. nov. Taxonomic characters from cuticular structures in homalorhagids are discussed and reevaluated. The longitudinal positions of cuticular structures along the trunk are furthermore defined, and the positional terminology is standardized. The distribution of the genus Pycnophyes in European waters is revised, revealing a poor knowledge of kinorhynch biogeography, probably due to incomplete sampling.  相似文献   

12.
《Ostrich》2013,84(1-2):26-35
The generic and specific relationships of the Malagasy rock-thrushes, variously placed in the genus Monticola or as an endemic genus Pseudocossyphus, are examined using morphological and molecular characters. On the basis of mitochondrial DNA cytochrome b sequence data it was concluded that all Malagasy rock-thrushes fall between Asian Monticola and a species group of Monticola occurring in numerous Old World areas. It is recommended that all Malagasy species be placed in the genus Monticola. Relationships between various named forms of Malagasy rock-thrushes indicate: M. imerinus is a distinct species, M. bensoni is a synonym of M. sharpei, the subspecies M. sharpei erythronotus should be elevated to a full species, and that no geographic forms of M. sharpei (including interioris and salomonseni) should be recognized on the basis of current evidence. These taxonomic conclusions have important implications for conservation projects currently underway on Madagascar.  相似文献   

13.
Melanoscirtes gen.n. is established within Karniellina. The members of this subtribe are small conocephaline bush crickets, confined to Africa. Melanoscirtes is erected on Phlesirtes kibonotensis, a species restricted to forest clearings and forest edge in the submontane and montane zones of Mt. Kilimanjaro. A subspecies, M. kibonotensis uguenoensis, is described from the North Pare mountains, a mountain range of the Eastern Arc adjacent to Mt. Kilimanjaro. Further species of Melanoscirtes occur on other mountain ranges of the northern branch of the Eastern Arc mountains of northern Tanzania and southern Kenya. The South Pare mountains harbour M. shengenae; the West Usambaras, M. usambarensis, and the Taita Hills, M. taitensis. All species and subspecies of Melanoscirtes exhibit a similar morphology and occupy analogous habitats on the respective mountains. The song patterns for all species found within this genus are very similar, and this, together with evidence from molecular data, suggests that allopatric speciation is the reason for the biogeographic pattern found in this genus. A key for the subspecies and species of Melanoscirtes is provided.  相似文献   

14.
Bottlenose dolphins (Tursiops spp.) are cosmopolitan animals widely distributed in waters of both hemispheres. The taxonomy of Tursiops has long been controversial, with over 20 specific names being published, and subspecies and inshore/offshore forms being proposed. In the southwestern South Atlantic, subspecies T. truncatus truncatus and T. truncatus gephyreus were proposed for specimens along the coasts of Brazil, Uruguay, and Argentina. Sightings of bottlenose dolphins are common along the coast of Argentina as far south as the Province of Chubut (ca. 46°S). Here, we summarize and discuss the southernmost records of bottlenose dolphins. We cannot make inferences about the species or subspecies to which these animals belong given the small number of specimens. Future studies of external measurements, pigmentation, DNA, and isotopes from both sides of the continent should help clarify the situation off southern South America. Furthermore, research is needed to explore a possible link between an effect of general global warming and the Tursiops specimens found this far south. The sighting and specimens described here, at 53°S–nearly 55°S, are the southernmost records for the genus and extend the range of the species in the southern South Atlantic.  相似文献   

15.
GILL  Ayesha E. 《Genetica》1984,52(1):105-117
Summary A partial reproductive barrier found between subspecies of the California vole indicates that there may be obstacles to free interbreeding within this species in nature. Both the reduced fertility between subspecies and the sterility of hybrid males found in laboratory crosses would be obstacles to gene exchange between contiguous subspecies populations. Combative behavior engaged in by approximately half of the mixed subspecies pairs in the laboratory indicate that there might also be behavioral constraints to their breeding. Substantial differentiation has already occurred between M.c. californicus and stephensi in some of the faster evolving structural gene loci coding for enzymes not involved in glucose metabolism. Due to significant differences in body size, skull characteristics, and organ weights, the two subspecies are clearly distinguishable on the basis of these morphophysiological characters at this stage of reproductive isolation. Thus, there is good reason to believe that these populations of the California vole are diverging to the species level. I am continuing the investigation of the intraspecific divergence with a comparative study of the geographically intervening subspecies M.c. sanctidiegi, to determine its interfertility with californicus and stephensi. The speciation process has been studied extensively in drosophilids (Ayala, 1975) and there have been many studies of geographical variation and speciation in the genus Peromyscus (Dice, 1940, 1968), but it is not likely that the same model of speciation will apply equally to all organisms (White, 1973; Dobzhansky, 1972). The California vole promises to provide another important case study of the speciation process and of the nature of genetic changes involved in it.  相似文献   

16.
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   

17.
Abstract. We investigated genetic divergence and phylogenetic relationships amongst all known species of Palaearctic butterflies of the genus Melanargia using sequence information from three genes [mitochondrial cox1 barcode region (658 bp), ribosomal 16S rRNA (c. 518 bp), and nuclear wg (404 bp)]. Results show a lack of DNA divergence among several poorly characterized taxa, as well as deep divergences within and between others. We corroborated the molecular information with morphological and genitalic characters as well as with geographic data. We revise the taxonomy of Melanargia, and propose a new systematic scheme for the group. We revive some previous synonymies (M. lucasi meadwaldoi stat. rev. , M. ines fathme stat. rev. , M. ines jahandiezi stat. rev. , M. meridionalis tapaishanensis stat. rev. ), revise the status of some subspecies into species (M. transcaspica stat. nov. , M. lucida stat. nov. , M. wiskotti stat. nov. ) and of several species into subspecies of other taxa (M. evartianae sadjadii stat. nov. , M. larissa hylata stat. nov. , M. larissa grumi stat. nov. , M. larissa syriaca stat. nov. , M. larissa titea stat. nov. , M. lugens montana stat. nov. , M. epimede ganymedes stat. nov. ), revise the status of subspecies and transfer them to other species (M. larissa lorestanensis stat. nov. , M. larissa iranica stat. nov. , M. larissa karabagi stat. rev. , M. larissa kocaki stat. nov. , M. transcaspica eberti stat. nov. ), and propose new synonymies (M. larissa titea = M. titea standfussi syn. nov. = M. titea titania syn. nov. , M. leda leda = M. leda yunnana syn. nov. , M. lugens lugens = M. lugens ahyoui syn. nov. , M. lugens hengshanensis = M. lugens hoenei syn. nov. , M. halimede halimede = M. halimede gratiani syn. nov. , M. asiatica asiatica = M. asiatica dejeani syn. nov. , = M. asiatica elisa syn. nov. , = M. asiatica sigberti syn. nov. ).  相似文献   

18.
Morphological and cytological characters were analysed among thirty populations of the genus Dactylis L. from Algeria, to understand its infraspecific diversity. Principal Component Analysis using quantitative characters allowed discriminating the tetraploid populations into two subspecies, marina (Borrill) Greuter, localised on sea cliffs, and hispanica (Roth) Nyman, very widespread. Some individuals of these latest populations formed a distinct group, identified as subsp. glomerata Hayek. Three diploid taxa are described in the literature: subspecies santai Stebbins & Zohary, castellata Parker & Borrill and mairei Stebbins & Zohary that are considered as prevalent in Algeria, distributed in Tellian Atlas, in forest ecosystems within mesophytic habitats. Canonical Discriminant Analysis on natural populations and on experimental cultures showed two main groups: the first group corresponds to subspecies mairei, with a narrow distribution; the second one exhibits a wide morphological variability and belongs to santai type. Based on this study, a key to aid in identification of the subspecies is presented.  相似文献   

19.
The family Ischyroceridae is analysed herein by cladistic methods based on morphological characters, using both PAUP 4.0b and TNT. The data matrix of 41 characters × 32 terminal taxa was constructed using DELTA. Based on the results, we comment on the phylogenetic relationships of certain genera and their synapomorphic characters, also discussing the phylogenetic position of M yersius gen. nov. , which appeared as the sister group of Bathyphotis. In addition, Pseudischyrocerus crenatipes is removed to Bathyphotis, for which a new diagnosis is provided. A taxonomic study with the Ischyroceridae collected on the continental slope (depth, 700–2000 m) in the Campos Basin (20.5–24°S, 40–41°W) was also performed. Samples were collected in November–December 2002 and July–August 2003 using a box core device. As a result, a new genus and eight new species are described: B onnierella campensis sp. nov. , B onnierella laurensi sp. nov. , M yersius denticaudatus gen. et sp. nov. , N otopoma lowryi sp. nov. , N otopoma teresae sp. nov. , P seudericthonius bousfieldi sp. nov. , P seudericthonius concavus sp. nov. , and P seudischyrocerus caecus sp. nov. The genus Bonnierella is recorded for the first time from Brazilian waters, and the subspecies Bonnierella linearis linearis and Bonnierella linearis californica are elevated to species rank. Keys to the genera of Ischyroceridae used in the cladistic analysis and the world species of Notopoma are given. © 2014 The Linnean Society of London  相似文献   

20.
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