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1.
A hypothesis on the phylogenetic relationships of the neotropical catfish family Cetopsidae is proposed on the basis of the parsimony analysis of 127 morphological characters and most of the species currently recognized. The family and its two recognized subfamilies, the Cetopsinae and Helogeninae, are corroborated as monophyletic, in agreement with recent studies. Previously proposed classifications of the Cetopsinae, however, were found to be poorly representative of the phylogenetic relationships within the subfamily. Major generic rearrangements are implemented in order that the classification of the Cetopsinae reflects the phylogenetic hypothesis. Pseudocetopsis Bleeker (1862) was found to be polyphyletic and to include several disjunct lineages. One of these lineages, recently named as the genus Cetopsidium Vari, Ferraris, and de Pinna (2005), is the sister group to the rest of the Cetopsinae. Denticetopsis Ferraris (1996) is the next sister group to the remainder of the Cetopsinae. The remaining species of the Cetopsinae belong to one of two sister genera, Paracetopsis Bleeker (1862) and Cetopsis Spix and Agassiz (1829). The latter genus includes species formerly assigned to Hemicetopsis Bleeker (1862), Bathycetopsis Lundberg and Rapp Py‐Daniel (1994) and Pseudocetopsis Bleeker (1862). Continued recognition of Hemicetopsis and Bathycetopsis would have required the creation of several additional new genera for various species previously in Pseudocetopsis that form a series of sister groups to a clade composed of Cetopsis oliveirai (Lundberg and Rapp Py‐Daniel, 1994), C. coecutiens (Lichtenstein, 1819) and C. candiru (Spix and Agassiz, 1829). Cetopsis oliveirai is a highly paedomorphic species that displays surprising similarities with conditions in juvenile specimens of C. coecutiens, a species that attains a large body size. Such similarities are not evident in adult specimens of the latter species. A new classification is proposed, within which the subfamily Cetopsinae consists of three tribes, the Cetopsidiini, the Cetopsini and the Denticetopsini. The results of the study form the basis for a discussion of the phylogenetic position of the family within the Siluriformes, the phylogenetic biogeography of the Cetopsidae, paedomorphosis and gigantism in the family, and the effect of different semaphoronts on the intrafamilial phylogeny. Journal compilation © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150 , 755–813. No claim to original US government works.  相似文献   

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A new species of Megaleporinus is described from the Rio de Contas, a coastal drainage of eastern Brazil, and its phylogenetic relationships are studied using molecular data. The new species is unique among Anostomidae by possessing two exclusive features: an irregular dark longitudinal stripe from supracleithrum to second midlateral blotch and anterior cranial fontanel partially closed. In addition, the new species is diagnosed by having three premaxillary teeth, three dentary teeth, 37 or 38 scales in lateral line, 16 scale rows around caudal peduncle, three dark midlateral blotches on body, and red fins in life. The new species is closely related to M. obtusidens from the São Francisco basin, corroborating previous studies that indicated that the latter represents a species complex as currently defined. The new species exhibits the first rib enlarged in mature males, a feature described for some congeners. The new species is herein considered to be Endangered under the IUCN criteria.  相似文献   

4.
Reid  Janet W. 《Hydrobiologia》1988,167(1):429-434
Yansacyclops ferrarii, new genus, new species (Copepoda: Cyclopoida) is described from the plankton of Rios Guamá and Acará Grande near Belém, State of Pará, Brazil.  相似文献   

5.
An expedition to the middle Rio Purus basin uncovered a remarkable new species of the genus Spinipterus. The new species has a very distinct and conspicuous colour pattern resembling a jaguar and it is almost four times larger than Spinipterus acsi, a small specimen (32 mm LS) from Caño Santa Rita, a right bank tributary of Río Nanay in Peru and a second specimen was reported from Rio Juruá, Amazonas State, Brazil. Although the new species is more similar in size and colour pattern to Liosomadoras, it shares the synapomorphies for Spinipterus. The new species differs from the congener by the following characters: (a) colour pattern with large black rosette-like spots over a light yellow to brown background (v. brown background with small dark blotches over the body); (b) adult body size reaching 104.5 mm LS (v. maximum known size 37.1 mm LS); (c) posterior process of cleithrum short, never reaching vertical through the dorsal-fin origin (v. posterior process long, surpassing vertical through the dorsal-fin origin); (d) seven soft pectoral-fin rays (v. six); (e) caudal fin truncated (v. caudal fin rounded).  相似文献   

6.
A new subfamily, Delturinae, is described to accommodate the loricariid catfish genera Delturus Egenmann & Eigenmann, 1889 and Hemipsilichthys Eigenmann & Eigenmann, 1889, a clade recently demonstrated to be the sister group of all remaining loricariids except Lithogenes . The genus Hemipsilichthys is restricted to three species, H. gobio (Lütken, 1874), its sister species H. papillatus Pereira et al ., 2000, and H. nimius Pereira et al ., 2003. Relationships among species of Delturus were not resolved and a new species, D. brevis , is described from the Rio Jequitinhonha basin in eastern Brazil. The geographical distribution of Delturinae, exclusively on the south-eastern Brazilian Shield, indicates that south-eastern Brazil acts as either a refugium for basal loricariid taxa or a point of origin for the Loricariidae. Lectotypes are designated for D. parahybae Eigenmann & Eigenmann, 1889 and Plecostomus angulicauda Steindachner, 1877. Keys are presented for subfamilies of Loricariidae and for genera and species of Delturinae. Diagnoses are provided for all delturine clades and species.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 277–299.  相似文献   

7.
Hemibrycon iqueima sp. nov., is described from small streams in the Magdalena drainage at the foothills of the western slope of the Eastern Cordillera of the Colombian Andes, Suarez municipality, Tolima Department, Colombia. The new species is distinguished from its congeners in the Magdalena–Cauca River basin by a combination of characters related to snout–anal‐fin origin length, head length, dorsal–pectoral fin distance, dorsal‐fin–hypural distance, postorbital distance, orbital diameter, snout length, number of total vertebrae, pre‐dorsal scales, scale rows between anal‐fin origin and lateral line, number of branched rays of the anal fin, maxillary teeth number and number and arrangement of hooks on the branched rays of the pectoral and dorsal fins. In addition, the validity of this species is supported by previous molecular analyses that included specimens of the new species that had been erroneously identified. Phylogenetic relationships between the new species and congeners from Pacific coast basins are discussed.  相似文献   

8.
Rineloricaria isaaci is described from tributaries of the Uruguay River basin in Argentina, Brazil and Uruguay. The new species is distinguished by having a long and wide area of naked skin at the snout tip, surpassing the anteriormost pore of the infraorbital ramus of the sensory canal, approximately in the middle of the third postrostral plate, and by its particular sexual dimorphism characterized by the long pectoral and pelvic fins of mature males.  相似文献   

9.
The examination of material representing one of Lake Tanganyika's six previously recognized endemic catfish lineages, has revealed the presence of an additional genus of clariid, described here as Pseudotanganikallabes new genus. This genus is represented by a single species, Pseudotanganikallabes prognatha sp. nov., which is distinguished from all other clariids by its lack of an infraorbital series, the presence of multiple osseous connections between the swim bladder capsules and elements of the neurocranium, the absence of an ethmoid notch, the presence of a very large, egg‐shaped occipital fontanelle and the extension of the lower lip beyond the margin of the upper jaw. A combination of additional external and molecular characters serves to further distinguish this taxon from all currently recognized clariid species. Phylogenetic analysis of mitochondrial (cytb) and nuclear (18S‐ITS1‐5.8S‐ITS2‐28S) sequence data supports the creation of a new genus for this species, as it appears to represent an independent, monophyletic lineage within the family Clariidae.  相似文献   

10.
A new long-snouted Corydoras species is described from two tributaries of the río Manuripe and a tributary of the río Madre de Dios, rio Madeira basin, Peru. Corydoras fulleri can be distinguished from its congeners by having the following features: (a) branch of the temporal sensory canal at sphenotic, which gives rise to the supraorbital canal, with two pores; (b) upper tooth plate of branchial arch with three series of teeth; (c) area at the corner of the mouth, ventral to the maxillary barbel, with a small fleshy flap; (d) two moderate-sized dark-brown or black blotches on caudal-fin base, one on its lateral portion and another one on its dorsal portion, blotches variably diffuse and/or fused with each other; (e) absence of a dark-brown or black stripe transversally crossing the orbit; (f) a longitudinal dark-brown or black stripe on the postdorsal region of flank midline, variably fused with the lateral peduncular blotch, some specimens with slender, longitudinally elongated, dark-brown or black blotch on flank midline, forming a dash-like marking, stripe or dash-like blotch diffuse in some specimens; and (g) region around dorsal-fin origin generally lacking dark brown or black blotch, or displaying diffuse blotch.  相似文献   

11.
Loricaria cuffyi n. sp. is described based on 36 specimens from the Essequibo and upper Negro River drainages in western Guyana and the upper Orinoco River drainage in Venezuela. The new species can be distinguished from sympatric and geographically proximate congeners by a postorbital notch that is inconspicuous, shallow and rounded, odontode ridges on the dorsum of head and predorsal weakly developed, abdominal plates tightly joined and completely covering the median abdominal space and pectoral girdle, higher anterior lateral plate counts, and coloration characteristics. The distribution of the new species adds to an interesting and well-documented biogeographical pattern exhibited by other Guiana Shield loricariids influenced by the proto-Berbice during the Cenozoic and recent configuration of drainages in the Guiana Shield. We present an update on the taxonomy of Loricaria, and discuss the biogeography and conservation status of the new species.  相似文献   

12.
A new species of Parotocinclus is described from the Rio Mamanguape basin, in the State of Paraíba, north-eastern Brazil. The new species can be distinguished from all of its congeners, except for P. bahiensis, P. cesarpintoi, P. jumbo, P. nandae and P. spilosoma, by the presence of an abdomen covered by a few small and dispersed platelets (vs. an abdomen entirely covered by large plates in adult individuals or the absence of plates in that region). The new species differs from those mentioned above with respect to several features, such as an exposed pectoral girdle and supporting odontodes medially and laterally, the number of premaxillary and dentary teeth, odontodes covering only the lateral portion of the cleithrum and the absence of irregular golden lines on the head and body (colour in vivo). The new species was collected only in the upper and middle portions of the Rio Mamanguape basin, suggesting a geographic distribution restricted to the Caatinga biome.  相似文献   

13.
The gross morphology of the gas bladder is described and compared for representatives of all valid genera of Pseudopimelodidae (Siluriformes). Cephalosilurus albomarginatus and species of Batrochoglanis, and Microglanis have the most basic form: a large, cordiform gas bladder with a simple internal T‐shaped septum. Cephalosilurus apurensis, C. fowleri, and C. nigricauda also have a large, cordiform gas bladder, but they have well‐developed trabeculae associated with the internal T‐shaped septum, and a pair of well‐developed constrictor muscles inserted on the external wall; the latter feature is present in most species of Pimelodidae, but absent in all other catfishes. The monotypic Lophiosilurus alexandri also has well‐developed constrictor muscles, and its gas bladder is moderately sized. The species of Pseudopimelodus and Cruciglanis have a diminutive gas bladder partially divided into two lateral sacs without internal communication, and lack constrictor muscles. The parapophysis of the fourth vertebra is a wide and long shelf connected to the dorsal surface of the gas bladder in most pseudopimelodid genera. However, in the species of Pseudopimelodus and Cruciglanis the parapophysis of the fourth vertebra is shorter and has its anterior ramus folded back, partially covering the gas bladder anteroventrally; and the tympanic opening is smaller than in species of the other genera. Five phylogenetic characters are proposed based on the morphology of the gas bladder and associated structures in species of Pseudopimelodidae, and the evolution of those characters in the family is discussed. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.  相似文献   

14.
Ituglanis australis new species, is described from tributaries of the Laguna dos Patos and Río Uruguay, in Brazil and Uruguay. This represents the southernmost record of the genus and the first occurrence of a species of Ituglanis in those systems. It is distinguished from all its congeners, except Ituglanis parahybae and Ituglanis cahyensis, by its body pigmentation with three well‐defined dark brown stripes running along each flank. Ituglanis australis differs from I. parahybae and I. cahyensis in the pectoral‐ and pelvic‐fin ray counts, the pattern of the cephalic laterosensory system and the number of dorsal‐fin basal radials. The new species, as well as several other examined congeners, has the levator internus IV muscle attached to the dorsal face of the posttemporo‐supracleithrum; a condition that corroborates the inclusion of Ituglanis into a large trichomycterine clade that also includes Bullockia, Hatcheria, Scleronema and several species of Trichomycterus. Previous proposals of the affinities within Ituglanis are reviewed and, despite some advances, the phylogenetic relationships among species of the genus remain largely unknown.  相似文献   

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16.
A new species of Rhinopetitia is described from the Rio Teles Pires, a major tributary of the Rio Tapajós. The new taxon is distinguished from its only congener, Rhinopetitia myersi, by having all premaxillary teeth in both rows with seven to nine cusps, maxillary teeth with seven or eight cusps, a distinct dark midlateral stripe on the body and a round humeral blotch (v. outer series of premaxillary teeth with three cusps and inner series of premaxillary teeth with three to five cusps, maxillary teeth with three to five cusps, the absence of a dark midlateral stripe and humeral blotch). Putative characters suggesting a close relationship between Rhinopetitia, Bryconacidnus, Ceratobranchia, Monotocheirodon, Odontostoechus, Othonocheirodus and Rhinobrycon are presented. This putative clade is included in the Stevardiinae, a monophyletic group within the Characidae.  相似文献   

17.
Chaetostoma chimu sp. nov. is described from 119 specimens collected in the Andean foothills of the Orinoco River in Colombia. The new species can be distinguished from congeners by a combination of characters, including shape of cheek odontodes, presence of a supraoccipital excrescence, sexual dimorphism characters and colour pattern. In addition, this species can be distinguished from the sympatric and geographically close congeners of the Orinoco that have curved cheek odontodes (i.e., Chaetostoma anale, Chaetostoma formosae and Chaetostoma joropo), by presenting a generally larger orbital diameter and interorbital distance, details of sexual dimorphism and colour pattern. The type locality of specimens collected by Kjell von Sneidern in the mid-twentieth century in the Colombian Amazon is also clarified. Chaetostoma alternifasciatum and Chaetostoma vagum are proposed as junior synonyms of C. anale. An identification key for the species of Chaetostoma from cis-Andean drainages in Colombia is provided. The new species is herein categorized as Vulnerable (Vu) B1a (i, iii), following the IUCN criteria.  相似文献   

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19.
A new species of the sand-dwelling catfish genus Ammoglanis is described from a marginal habitat of the lower Atabapo River, a left-bank blackwater tributary of the upper Orinoco River in Amazonas, Venezuela, adjacent to the border with Colombia. Ammoglanis natgeorum is distinguished from all congeners by trunk pigmentation pattern consisting of scattered ventral chromatophores concentrated around the anal-fin base and numerous additional meristic and anatomical characteristics. A. natgeorum is the second species of Ammoglanis described from the Orinoco River basin after Ammoglanis pulex, and several shared character states (e.g., eight total dorsal-fin rays, overall coloration pattern and presence of two finger-like papillae posterior to chin) suggest that it is more closely related to Ammoglanis obliquus (from the central Amazon basin) and A. pulex than to other congeners.  相似文献   

20.
Three new species of Mitrephora (Blume) Hook. f. & Thomson, M. clemensiorum, M. vittata and M. woodii , are described from Sabah, Malaysia. Mitrephora clemensiorum is related to M. korthalsiana Miq., but is distinguished by having long inflorescences, long flowering and fruiting pedicels, and fruits with sessile monocarps. Mitrephora vittata is related to M. reflexa Merr., but has lanceolate, subcoriaceous leaves, and densely pubescent inflorescence rachides, flowering pedicels and bracts. Mitrephora woodii is similar to M. heyneana (Hook. f. & Thomson) Thwaites, but has smaller flowers and fruits with sessile monocarps  相似文献   

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