Molecular and morphological diversity in species of Kronichthys (Teleostei,Loricariidae) from Atlantic coastal rivers of Brazil

The Neotropical catfish genus Kronichthys contains three species distributed along coastal rivers of southern and southeastern Brazil. Although phylogenetic hypotheses are available, the molecular and morphological diversity and species boundaries within the genus remain unexplored. In this study, the authors generated mitochondrial data for 90 specimens combined with morphometric and meristic data to investigate species diversity, species boundaries and putative morphological signatures in Kronichthys. Phylogenetic and species delimitation results clearly show the presence of four genetic lineages, three within Kronichthys heylandi along the coast from Rio de Janeiro to southern São Paulo and a single lineage encompassing both the nominal species Kronichthys lacerta and Kronichthys subteres from the Ribeira de Iguape basin to Santa Catarina in southern Brazil. Nonetheless, morphological data show overlapped ranges in morphometrics and a definition of only two morphotypes, with clear phenotypic differences in the teeth number: K. heylandi differs from K. subteres + K. lacerta by the higher number of premaxillary teeth (30–52 vs. 19–28) and higher number of dentary teeth (28–54 vs. 17–28). Headwater captures and connections of paleodrainages because of sea-level fluctuations represent the two major biogeographic processes promoting species diversification and lineage dispersal of Kronichthys in the Atlantic coastal range of Brazil.     

Karyotypic diversity of the armoured catfish genus Hypostomus (Siluriformes: Loricariidae) in the context of its occurrence and distribution

This study taxonomically reviewed the specimens studied by Artoni & Bertollo (1996) and assimilated species of Hypostomus into three groups according to their cytogenetic characteristics, vagility and occurrence environments.     

A new species of the leopard pleco genus Pseudacanthicus (Siluriformes: Loricariidae) from the Rio Xingu,Brazil

The genus Pseudacanthicus comprises six valid species distributed in the Amazon basin and Caribbean coastal drainages from Guyana to French Guiana: P. serratus, P. fordii, P. histrix, P. spinosus, P. leopardus and P. pitanga. A new species of Pseudacanthicus is described from the Rio Xingu Basin, distinguished from its congeners by the following combination of characters: presence of anastomose dark blotches forming continuous zigzag bands alongside longitudinal keels; presence of dark blotches on ventral surface of body and head; all fins with orange to red colour on unbranched rays and sometimes subsequent branched rays. Brief comments on ornamental fisheries and conservation of the new species are also provided.     

A new species of Astyanax Baird & Girard (Characiformes: Characidae) from the Rio Paraguaçu basin,Chapada Diamantina,Bahia, Brazil,with comments on bony hooks on all fins

A new species of Astyanax from the Rio Paraguaçu basin, Bahia, Brazil, is described. This new species is distinguished from its congeners known to occur in Brazilian drainages by the presence of small bony hooks on all fins of mature males. Furthermore, the new species can be diagnosed by its colour pattern, which consists of a unique vertically elongated humeral blotch, a conspicuous dark drop‐shaped horizontal blotch over the caudal peduncle, tapering anteriorly and not extending to the median caudal‐fin rays, and by the absence of a conspicuous broad dark midlateral stripe. The new species differs further by having the greatest body depth just anterior to the dorsal‐fin origin, 32–35 perforated scales in the lateral line and a reduced number of branched anal‐fin rays (16–20). Apparently, the new species does not fit into any species complex of Astyanax. The occurrence of bony hooks on all fins of Astyanax is discussed.     

Intra and intertribal genetic variation within a linguistic group: The Ge-speaking Indians of Brazil

A total of 562 individuals living in four villages of two Brazilian Indian tribes (Cayapo and Krahó) was studied in relation to blood groups ABO, MNSs, P, Rh, Lewis, Duffy, Kidd and Diego; haptoglobin, Gc, acid phosphatase and phosphoglucomutase types. These results were compared with those obtained previously among the Xavante, and the inhabitants of three other Cayapo villages, all of whom speak Ge languages; the ranges in gene frequencies observed in a representative series of South American Indians from all over the continent were also compiled. The Ge Indians are characterized by low frequencies ofR^z, medium frequencies ofR¹,R², R⁰, orr,Jk^a andPGM¹₁, and high frequencies ofGc² andACP^A when compared with other South American tribes. Genetic distance analyses based on six loci indicate that the intratribal variability observed among Cayapo is of the same order of magnitude as those obtained among the Xavante and Krahó, being much less pronounced than those observed among the Yanomama and Makiritare. The intertribal differences within this linguistic group are much less pronounced than those encountered among tribes that speak more differentiated languages.     

Two new species of Pseudancistrus (Siluriformes,Loricariidae) from the Amazon basin,northern Brazil

Two new species of Pseudancistrus, a genus diagnosed by non-evertible cheek plates and hypertrophied odontodes along the snout margin, are described from two drainages of the Brazilian Shield: Pseudancistrus kayabi from the rio Teles Pires (rio Tapajós basin) and Pseudancistrus asurini from the rio Xingu. The new species are distinguished from congeners (Pseudancistrus barbatus, Pseudancistrus corantijniensis, Pseudancistrus depressus, Pseudancistrus nigrescens, Pseudancistrus reus, and Pseudancistrus zawadzkii) by the coloration pattern. Pseudancistrus kayabi has dark bars on the dorsal and caudal fins which are similar to that of Pseudancistrus reus from the Caroní River, Venezuela. Pseudancistrus asurini is unique among Pseudancistrus in having whitish tips of the dorsal and caudal fins in juveniles to medium-sized adults.     

Parotocinclus jacksoni,a new hypoptopomatine catfish (Siluriformes: Loricariidae) from the Rio Mamanguape basin,north-eastern Brazil

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.     

A new species of Sturisoma (Loricariidae: Loricariinae) from the Madre de Dios River basin,Peru, with a key to all congeners and comments on the type series of Sturisoma rostratum

A new species of the genus Sturisoma from the Madre de Dios River, upper Madeira, Peru, is described. The new species can be differentiated from its congeners by the following characteristics: dorsolateral stripe reaching to less than half, or only half length of caudal peduncle (v. absence of dorsolateral stripe or, if present, spanning more than half caudal‐peduncle length); premaxillary teeth longer than dentary teeth (v. dentary teeth longer); sexually mature adult males having well‐developed odontodes on the sides of the head and a broader snout (v. adult males lacking well‐developed hypertrophied odontodes or, if present, rostrum is same width as females' or immature males'); by having the ventral portion of the rostrum conspicuously darker than ventral surface of the body (v. rostrum light, with same colour as ventral portion of body, except in Sturisoma barbatum); by lacking the lateral process of the sphenotic (v. lateral process of sphenotic well‐developed, except in Sturisoma tenuirostre); a dark spot on the first three branched pectoral‐fin rays (v. brown spot absent, except in S. barbatum); and the frontal bone contributing less than half of dorsal border of the orbital ridge (v. extensive participation of the frontal, except in Sturisoma guentheri). Furthermore, the new species has 18–20 plates in the median series, which differentiates it from Sturisoma rostratum (21–22), and Sturisoma monopelte (21); and 14–15 coalescent plates, which differentiates it from S. tenuirostre (16–17). It is further differentiated from Sturisoma brevirostre by presence of an enlarged rostrum (v. rostrum not enlarged). A discussion regarding status of the type series and geographic distribution of Sturisoma rostratum is offered, and an identification key for all Sturisoma species is presented.     

Morphological and molecular evidence for two new species of Tetragonopterus (Characiformes: Characidae) from central Brazil

The combination of morphological and molecular data of Tetragonopterus species collected in the Rio Araguaia basin allows the recognition of two undescribed species that are presented in this article. These species are distinguished from their congeners (Tetragonopterus anostomus, Tetragonopterus argenteus, Tetragonopterus carvalhoi, Tetragonopterus chalceus and Tetragonopterus rarus) by characters related to the number and morphology of the teeth, the numbers of gill rakers on the upper and lower limbs of the first gill arch, the number of predorsal scales and the overall colour pattern. In addition, the analysis of mitochondrial DNA sequences identified an accentuated genetic distance between these two new species and their congeners. A discussion of the phylogenetic relationships within Tetragonopterus is provided.     

Phylogeography and genetic differentiation along the distributional range of the orchid Epidendrum fulgens: a Neotropical coastal species not restricted to glacial refugia

Aim Phylogeographical studies in the Brazilian Atlantic Forest (BAF) have mostly included species associated with forest habitats, whereas taxa associated with grassland and sand‐dune plant communities have so far been largely overlooked. This study examines the phylogeography of the orchid Epidendrum fulgens, which occurs on coastal sand dunes and granitic outcrops, in order to identify major genetic divergences or disjunctions across the range of the species and to investigate the genetic signatures of past range contractions and expansions. Location Southern and south‐eastern seashore vegetation along the BAF biome, and granitic and arenitic outcrops that occur in the subtropical grassland plant communities located south of the BAF. Methods Nine nuclear and four plastid microsatellite loci were used to genotype 424 individuals from 16 populations across the distributional range of E. fulgens. For both sets of markers, we estimated genetic diversity and population differentiation, testing for a north–south gradient of genetic diversity. The plastid haplotype network and a Bayesian assignment analysis of nuclear markers were used to infer population structure. Past demographic changes were investigated using a coalescence approach. Results A deep disjunction was found between northern populations within the BAF and southern populations outside the BAF that occur on granitic and arenitic outcrops. Recent demographic reductions were detected in northern populations on coastal sands. Such demographic changes were not expected for those populations, as previous studies with forest species had found evidence of population expansion in the same areas. Higher genetic diversity was found in southern populations on granite, in contrast to patterns observed in previous studies of forest species. Main conclusions The results are consistent with the long‐term persistence of E. fulgens. Bottlenecks were detected in populations from areas where population expansion events have been detected in other plant (and animal) species, suggesting that forest expansion after the Last Glacial Maximum played a role in the population fragmentation and decrease in genetic diversity in E. fulgens. A substantial genetic division in E. fulgens corresponds to the ‘Portal de Torres’, a region that demarcates the northern limits of subtropical grassland plant communities and the southern limits of the BAF.     

Taxonomic revision of the genus Galictis (Carnivora: Mustelidae): species delimitation,morphological diagnosis,and refined mapping of geographical distribution

Although critical for enabling in‐depth evolutionary, ecological, or conservation‐orientated studies, taxonomic knowledge is still scarce for many groups of organisms, including mammals of the order Carnivora. For some of these taxa, even basic aspects such as species limits and geographical distribution are still uncertain. This is the case for the Neotropical mustelid genus Galictis, considered one of the least studied carnivoran genera in the Americas. To address this issue, we performed a comprehensive assessment of morphological and molecular characters to test the number of species within Galictis, and to characterize their distinctiveness and evolutionary history. In addition, we reviewed and consolidated the available information on the taxonomy of this genus, so as to provide a historical framework upon which we could interpret our data. Our analyses demonstrated that two Galictis species can be clearly delimited and diagnosed using metric and nonmetric morphological characters as well as DNA sequences from mitochondrial and nuclear gene segments. On the basis of this clarified species‐level delimitation, we reassessed the geographical range of each Galictis taxon, identifying possible areas of sympatry between them. These results provide a solid taxonomic framework for Galictis, enabling the development of additional studies focusing on this poorly known taxon. © 2013 The Linnean Society of London, Zoological Journal of the Linnean Society, 2013, 167 , 449–472.     

Species delimitation in the Acomys cahirinus–dimidiatus complex (Rodentia, Muridae) inferred from chromosomal and morphological analyses

Our earlier chromosome banding studies of Acomys cahirinus and Acomys dimidiatus (the latter long considered to be a subspecies of the former) revealed that, despite very close diploid numbers (36 vs. 38), these taxa possess sharply different karyotypes and undoubtedly belong to different species. In this context, the taxonomic status and the relationship between the two chromosomal forms in Sinai (2 n  = 36) and Israel (2 n  = 38), chromosomally homozygous across a vast range except for a very narrow hybrid zone, remain poorly documented. Neither of these forms have previously been studied by chromosome banding; thus, the exact nature of chromosomal differences as well as the species to which these forms should be assigned remain unknown. Here, we present the data on comparative G-banding analysis and morphometrics of Acomys from Israel, Sinai, and Saudi Arabia, and a hybrid obtained in laboratory crosses between latter two. The analysis revealed that karyotype of Acomys from Israel is identical to that of Acomys from Saudi Arabia and both are different from that of Acomys from Sinai by one Robertsonian fusion. Therefore, karyotypically, all three are very different from A. cahirinus . It follows from the study that Sinai and probably Arabian peninsula and Minor Asia must be excluded from geographical distribution of A. cahirinus , which is limited from West Sahara to Egypt along Nile river (except Sinai). Furthermore, the synthesis of chromosomal and recent molecular data suggests a phylogeographical scenario explaining the modern distribution of Acomys in the Sinai and Arabian peninsulas and permits the update of the taxonomic status of these populations.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 203–214.     

New Ecuadorian records of the eyeless banjo catfish Micromyzon akamai (Siluriformes: Aspredinidae) expand the species range and reveal intraspecific morphological variation

Two specimens of Micromyzon akamai, an eyeless and miniaturized species previously known only from the deep channels of the eastern Amazon basin in Brazil, are reported from the Curaray River, a tributary of the Napo River in Ecuador. The new specimens are the first records of Micromyzon in the headwaters of the Amazon River and the first records of M. akamai outside Brazil. External morphological characters and a phylogenetic analysis of cytochrome c oxidase I (coI) gene support the identification of the new specimens as M. akamai. Nevertheless, the new specimens also indicate that some features previously hypothesized to be apomorphic for M. akamai are intraspecifically variable.     

Chromosomes, RAPDs and evolutionary trends of the Neotropical fish Mimagoniates microlepis (Teleostei: Characidae: Glandulocaudinae) from coastal and continental regions of the Atlantic forest, Southern Brazil

Chromosome and random amplified polymorphic DNA (RAPD) markers of samples of Mimagoniates microlepis were studied to test the hypothesis that a vicariant event occurred as the result of the orogeny of the coastal mountain range (Serra do Mar; southeastern and southern Brazil). Conventional karyotypes and nucleolar organizer region (Ag-NOR) phenotypes of two samples of M. microlepis from the headwaters of the Iguaçu River (southern Brazil) were compared both with each other and with other local populations of the species in the coastal drainage of southeastern Brazil. Additional molecular data (RAPD markers and genetic diversity) were obtained from specimens from coastal and continental regions of southern Brazil. The same diploid number (52 chromosomes), karyotypic formula and Ag-NOR phenotype were found for both analysed samples from the Iguaçu River. A genetic discontinuity was discovered in the comparison of the karyotypical formula of the Iguaçu samples with those from coastal drainages of the region. Polymerase chain reaction-RAPD markers revealed strikingly different molecular profiles between coastal and continental samples and indications of a high degree of genetic variation. Based on these results, we provide some comments on the biogeographical patterns and evolutionary trends for M. microlepis from coastal and continental regions of southeastern/southern Brazil.     

New species and new records in Cerambycidae (Coleoptera) of the state of Bahia,Brazil

Two new species are described from Bahia (Brazil): Coleoxestia beckeri (Cerambycini), and Oncioderes obliqua (Onciderini). Nine species are recorded for the first time for Bahia (Brazil). Key to species of Oncioderes Martins & Galileo, 1990 is provided. Coleoxestia beckeri is included in a previous key.     

First report of Pseudococcus viburni (Hemiptera: Pseudococcidae) in Colombia: Morphometric and molecular analysis,with notes on morphological variation in specimens from Brazil and Colombia

The obscure mealybug Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) is recorded for the first time from Colombia based on specimens collected on Opuntia cylindrica (Lam.) DC., Mammillaria sp. (Cactaceae), Escallonia paniculata (Ruiz & Pav.), Roem. & Schult. (Escalloniaceae), Ficus carica L. (Moraceae), Coffea arabica L. (Rubiaceae), Citrus sp. (Rutaceae), Cestrum nocturnum L. and Solanum betaceum Cavanilles (Solanaceae). Multiple methods were used to identify P. viburni because it belongs to the “Pseudococcus maritimus” complex, a group composed of more than 60 species with high variation in morphological characteristics. The specimens were identified based on the morphology and morphometric analysis of third-instar nymphs and adult females. This morphological identification was corroborated by data on geographical distribution, plant hosts and a molecular identification using two different loci, CO1 (mtDNA) and the 28S ribosomal gene (nuclear genome). An updated list of species of Pseudococcus Westwood recorded from Colombia and information on morphological variation found in the studied specimens from Brazil and Colombia are provided.     

A new species of Odontostilbe cope (Characiformes: Cheirodontinae) from rio Madeira basin diagnosed based on morphological and molecular data

A new species of Odontostilbe is described from the rio Jaciparaná, rio Madeira basin, Rondônia, Brazil. Odontostilbe pacaasnovos differs from all its congeners, except O. pequira, by the colour pattern. Additionally, it differs from its congeners by the terminal mouth, number of cusps in the teeth of the premaxilla (5–7), number of branched rays in the anal fin (19–22), by the shape of dentary teeth (5–7 cusps with central cusp larger and longer than laterals cusps) and by the number of lamellae of the olfactory rosette (17–18 in male and 14 in female). Morphological and molecular comparisons corroborate the distinctiveness between O. pacaasnovos and its congeners, justifying its recognition as a new species.     

Among-populational genetic differentiation in the cyclical parthenogen Daphnia magna (Crustacea,Anomopoda) and its relation to geographic distance and clonal diversity

Using allozyme data based on four polymorphic enzymeloci, we present an analysis of geneticdifferentiation among eight Daphnia magnapopulations, separated by less than 100 m to more than500 km from each other. In spite of the large range ofgeographic distances, there was only a slight tendencyfor an increase in genetic differentiation withincreasing geographic distance between populations,and the relation was not significant. This was mainlydue to the fact that neighbouring populations werealready highly genetically differentiated. Our resultssuggest that in populations in which only a fewabundant clones are present after a period of strongclonal selection, among-populational geneticdifferentiation as revealed by allozyme markers isinflated as a result of stochasticity involving chanceassociations of alleles with specific abundantgenotypes. Indices quantifying genetic differentiationwere much higher among populations with a low clonaldiversity than among populations with a high clonaldiversity.