Isoenzimatic analysis of four Anopheles (Kerteszia) cruzii (Diptera: Culicidae) populations of Brazil

Anopheles cruzii is a small sylvatic mosquito and primary human Plasmodium vector in Southern Brazil. The distribution of this bromeliad-breeding mosquito follows the Atlantic forest coastal distribution, where bromeliads are abundant. Morphological, genetic, and molecular polymorphisms among different populations have been reported and it has recently been suggested that An. cruzii is a complex of cryptic species. The aim of this work is to analyze the gene flow between different populations of An. cruzii collected in four localities within the geographic distribution range of the species, and to examine if An. cruzii is a complex of cryptic species. The genetic distances show that populations of the states of Santa Catarina, Sao Paulo, and Rio de Janeiro are genetically closer (0.032 to 0.083) than populations of Bahia (0.364 to 0.853) based on profiles from 10 distinct isoenzyme loci. The Fst was lower (0.077) when the Bahia population was excluded than when it was included (0.300) in the analyses. The inferred number of migrants per generation was 2.99 individuals among populations from the states of Santa Catarina, Sao Paulo, and Rio de Janeiro and 0.58 migrants per generation among all populations. Results suggest that An. cruzii is a complex of species and that the specimens of state of Bahia can be considered as belonging to a species that is distinct from other three closely-related populations studied.     

The Barred Antshrike (Thamnophilus doliatus) on Trinidad and Tobago: habitat niche expansion of a generalist forager

Summary The Barred Antshrike (Thamnophilus doliatus) is the most abundant insectivorous foliage-gleaning vertebrate in both closed rain forest and second growth on the island of Tobago. However, it occurs only in second growth on the larger neighbor island of Trinidad and on the neotropical mainland.Habitat niche expansion into Tobago forest has been facilitated by several behavioral traits which set the antshrike apart from other foliage-gleaners of forest and second growth on Tobago. The antshrike captures a higher diversity of foliage, branch & trunk, and terrestrial arthropods. It forages over a wider range of heights and under a wider variety of crown cover situations than any of its closest ecological counterparts on Tobago. The antshrike also takes a wider range of prey sizes and regularly uses additional food sources, including fruit and ants, not taken by other guild members. The broad foraging niche of the antshrike enables it to breed during many times of the year when other narrower-niched foliage-gleaners do not.On Trinidad, although the most common foliagegleaner in second growth, the antshrike was not observed in adjacent closed rain forest. Several facts suggest that diffuse competition may be excluding antshrikes from Trinidad forest: 1) a general pattern of rarity or absence in other parts of its range where there are more guild members; 2) more species and individuals of foliagegleaners with an overall higher biomass in Trinidad forest than in Tobago forest; 3) foliage arthropod resources are significantly (1.7x) lower in Trinidad forest than Tobago forest, suggesting that Trinidad forest guild members may be depressing the quantity of important resources for antshrikes; and 4) Trinidad forest species with the highest foraging similarity to antshrikes have a greater precentage of prey captures comprised of relatively specialized attack behaviors than do Tobago forest antshrikes.Foraging generalists like the Barred Antshrike appear to expand or contract their habitat niches depending upon the number of ecologically similar species in a given habitat. They may occur in high densities in habitats typically foreign to them provided competitors are few and there is sufficient food to supply their catholic requirements.     

First records of Synoeca septentrionalis Richards, 1978 (Hymenoptera, Vespidae, Epiponini) in the Brazilian Atlantic Rain Forest

Nests of Synoeca septentrionalis were collected in two Brazilian Atlantic Rain Forest localities (Itabuna and Santa Terezinha, in the state of Bahia and Alfredo Chaves in the state of Espírito Santo). Synoeca septentrionalis was previously recorded only from Central America and northwestern South America. This findingextends its geographical distribution to Northeast and Southeast regions of Brazil, and represents the first record for Synoeca septentrionalis in the Brazilian Atlantic Rain forest, raising to three the number of Synoeca species known from Bahia State.     

RAPD and mitochondrial DNA analysis of the soybean stalk weevil, Sternechus subsignatus (Coleoptera: Curculionidae)

Sternechus subsignatus Boheman (Curculionidae: Sternechini) is one of the primary Curculionidae species that reduces soybean yield in Brazil. Initially, outbreaks were reported in southern Brazil in 1973; but, more recent, outbreaks were reported in Bahia (summer 1997-1998) and Maranh?o (summer 2003-2004), two states in northeastern Brazil. A putative related species, S. pinguis (Fabricius), was first detected in Salta Province, Argentina. The objective of this study was to evaluate intraspecific molecular polymorphisms of geographically distinct Sternechus populations. Randomly amplified polymorphic DNA (RAPD) profiles and partial mitochondrial cytochrome B (CytB) gene sequences were used to determine whether individual soybean stalk weevils were one of two different species and to infer pest invasion pattern. Putative S. pinguis and S. subsignatus populations were collected in San Agustin (Cruz Alta, Tucumán Province, Argentina) and different sampling sites in the Brazilian states of Paraná, Bahia and Maranh?o. Polymorphic bands were obtained by RAPD and analyzed by Dice coefficients. Populations from southern Brazil were more closely related genetically to an Argentinean group than the populations sampled in northeastern Brazil. The Londrina Co., Brazil population displayed the highest intra-population genetic similarity. Most of the soybean stalk weevils collected from San Agustin, Tucumán, Argentina were divergent from those collected in Brazil. Sequencing and parsimony analysis of CytB did not differentiate specimens collected in Argentina and Brazil. Thus, our data show that soybean stalk weevil outbreaks and population increases in northeastern Brazil involved local genotypes.     

Diversity of mud-dauber wasps (Hymenoptera: Crabronidae: Trypoxylon Latreille) in a secondary forest of Trinidad,West Indies

Over a two-year period we operated two intercept traps for flying insects near and within a well-developed secondary forest in the Arima Valley of Trinidad. These yielded 368 Trypoxylon, representing 30 species. The sample’s Shannon–Wiener diversity of H′ = 2.61 is higher than that from a comparable study of Trypoxylon on the smaller island of Tobago (15 species, H′ = 2.09) and the even smaller Little Tobago (six species, H′ = 1.41). Analysis of the samples by the Chao1 method suggests that the species numbers recorded on the two smaller islands are complete, while there is at least one additional species at the Trinidad locality. The four most abundant species in our samples show no evident bias in numbers of females between the wet and dry seasons, consistent with the hypothesis that at least these species nest throughout the year.     

Insular avian adaptations on two Neotropical continental islands

Aim Most studies of avian insular adaptations have focused on oceanic islands, which may not allow characters that are insular adaptations to be teased apart from those that benefit dispersal and colonization. Using birds on continental islands, we investigated characters that evolved in situ in response to insular environments created by late Pleistocene sea level rise. Location Trinidad and Tobago and continental South America. Methods We weighed fresh flight muscles and measured museum skeletal specimens of seven species of birds common to the continental islands of Trinidad and Tobago. Results When corrected for body size, study species exhibited significantly smaller flight muscles, sterna and sternal keels on Tobago than on larger Trinidad and continental South America. Tobago populations were more ‘insular’ in their morphologies than conspecifics on Trinidad or the continent in other ways as well, including having longer bills, longer wings, longer tails and longer legs. Main conclusions We hypothesize that the longer bills enhance foraging diversity, the longer wings and tails compensate for the smaller pectoral assemblage (allowing for retention of volancy, but with a probable reduction in flight power and speed), and the longer legs expand perching ability. Each of these differences is likely to be related to the lower diversity and fewer potential predators and competitors on Tobago compared with Trinidad. These patterns of smaller flight muscles and larger bills, legs, wings and tails in island birds are not the results of selection for island dispersal and colonization, but probably arose from selection pressures acting on populations already inhabiting these islands.     

Atherinella blackburni (Schultz, 1949) at Itamambuca Beach, Ubatuba, SP: ecological characterization and distribution on the Brazilian coast (Teleostei: Atheriniformes: Atherinopsidae)

Atherinella blackburni is a silverside species whose occurrence on the Brazilian coast was not properly registered until recently. So far, records of its distribution along the Brazilian shore were limited to Itaparica Island, Bahia State, and Porto Inhaúma, Rio de Janeiro State. In a recent survey of the ichthyofauna of Itamambuca Beach, Ubatuba, S?o Paulo State, 100 specimens of this species were collected, yielding a considerable source of information regarding its ecology and a new southern limit of its distribution. A detailed survey of an ichthyological collection revealed lots of this species from regions of the Brazilian Northeast, resulting in a northward expansion of the occurrence of A. blackburni in Brazilian waters. Besides the populations found on the Brazilian coast, the species also occurs discontinuously in the Atlantic coasts of Costa Rica, Panama and Venezuela. Meristic and morphometric analysis showed overlapped values between Brazilian populations and the ones closer to the Caribbean. An ecological study of A. blackburni at Itamambuca Beach revealed that it is a predominantly diurnal species with preference for warm and salty waters, often occurring in sandy-bottom environments. It was more abundant in Summer and Winter, when individuals with smaller values of length and weight also occurred.     

Presence of the Chytrid Fungus Batrachochytrium dendrobatidis in Populations of the Critically Endangered Frog Mannophryne olmonae in Tobago, West Indies

The emerging infectious disease chytridiomycosis is prevalent in Central and South America, and has caused catastrophic declines of amphibian populations in the Neotropics. The responsible organism, Batrachochytrium dendrobatidis, has been recorded on three West Indian islands, but the whole of the Caribbean region is predicted to offer a suitable environment for the disease. Monitoring the spread of chytridiomycosis is thus a priority in this region, which has exceptionally high levels of amphibian endemism. PCR analysis of 124 amphibian skin swabs in Tobago (Republic of Trinidad and Tobago) demonstrated the presence of B. dendrobatidis in three widely separated populations of the frog Mannophryne olmonae, which is listed as Critically Endangered on the basis of recent population declines. Chytridiomycosis is presently endemic in this species, with a prevalence of about 20% and no associated clinical disease. Increased susceptibility to chytridiomycosis from climate change is unlikely in amphibian populations in Tobago, as this island does not have high montane environments, but remains a possibility in the sister island of Trinidad. Preventing the spread of chytridiomycosis within and between these and other Caribbean islands should be a major goal of practical conservation measures for amphibians in the region.     

Diversity and distribution of Collembola (Arthropoda: Hexapoda) of Brazil

Objectives of this study are to summarize the current state of knowledge of the diversity and distribution of Collembola in Brazil; to identify areas of most importance, interest, and need of additional research; and to enable development of experimental hypotheses for future research on Collembola in this region. The total number of collembolan species currently known from Brazil is 199, distributed among 19 families and 80 genera. The greatest numbers of species have been recorded from the states of Rio de Janeiro and Amazonas (with 69 and 56 species, respectively). Few or no species are known from most Brazilian states. Most of the species for which specific Brazilian environmental habitat information is available (93, 66%) are known only from forest environments. Most of the species (127, 64%) are known only from Brazil (most likely being endemic); 33 species (17%) are known only from Brazil and other neotropical areas; and 39 species (20%) have a distribution beyond the neotropical region. Results of this study indicate that much remains to be learned about the Brazilian collembolan fauna. This is especially true for areas of the northeastern, central-western, and southern regions. Studies to determine the species composition of collembolan communities in specific environments in Brazil are needed. The great diversity of Collembola species in Brazil is largely unknown and there are many opportunities for additional research on these environmentally important organisms in this area. Such additional research on the Collembola in Brazil is also essential for a better understanding of the neotropical (and world) collembolan fauna.     

Ecology,conservation status,and phylogenetic placement of endemic Pristimantis frogs (Anura: Craugastoridae) in Trinidad and Tobago and genetic affinities to northern Venezuela

Trinidad and Tobago are home to three endemic species in the anuran genus Pristimantis, of which two (Pristimantis charlottevillensis and Pristimantis turpinorum) occur in Tobago alone and the third (Pristimantis urichi) is present on both islands. Earlier, the IUCN assessed the conservation status of these species as: P. urichi, Endangered (EN); P. charlottevillensis, Least Concern (LC); P. turpinorum, Vulnerable (VU). However, these assessments were based on very little field-based evidence. Here, we present survey results which contributed to reassessments as LC, VU and Data Deficient for these three species, respectively. Despite the close proximity of Trinidad to northern Venezuela, the islands do not share any Pristimantis species with the mainland, which holds a rich endemicity of Pristimantis regionally. In this study, we used genetic sequencing from several island populations and compared them to northern Venezuelan endemics to assess genetic divergence for the first time. The time tree analyses found that only the northern Tobago species P. turpinorum is closely related to mainland Pristimantis, with a genetic split dating to the Late Miocene, suggesting a vicariant event of mainland and island species. Pristimantis urichi, although identical between the two islands, remains highly divergent from the mainland species. Similar results were found for P. charlottevillensis. In addition, there was a high level of divergence between P. urichi and P. charlottevillensis. These findings indicate different island colonization events by different lineages. Sequencing other Venezuelan species remains pivotal to unravel the complexity of the colonization episodes in the region, likely influenced by the changing topography and multiple connection and isolation episodes of the islands by eustatic sea-level changes.     

Two new species of Huberia (Melastomataceae: Merianieae) from Brazil

Two new Brazilian species of the genusHuberia,H. carvalhoi andH. consimilis, are described, discussed, and illustrated.Huberia carvalhoi is endemic to Bahia;H. consimilis has a wider distribution, with disjunct populations in Pernambuco, Bahia, and Rio de Janeiro. A key is provided to the three Bahia taxa with some comments on the taxonomic affinities of the two new species.     

MITOCHONDRIAL DNA SEQUENCE VARIATION AMONG NATURAL POPULATIONS OF THE TRINIDAD GUPPY,POECILIA RETICULATA

Guppies were sampled from eight populations representing four river drainage basins in northern Trinidad, and from one population on the nearby island of Tobago. For each individual, a 465 base pair (bp) segment of the control region of the mitochondrial genome was sequenced. The resulting DNA sequences were subjected to sequence divergence calculations and the populations were linked by maximum parsimony analysis to determine their phylogenetic relationships. Mitochondrial DNA (mtDNA) sequence variation was found both within and between river drainages, correlated with the geographic features of northern Trinidad. The variation observed exists primarily between drainages, particularly between the Oropuche drainage and all other Trinidad drainages examined. Estimates of time of divergence between guppy populations of different drainages, based on mtDNA sequence variation, ranged from 100,000 to 200,000 for the most recently separated populations and from 600,000 to 1.2 million years between the Oropuche populations and all others examined. Examination of fish from northeastern South America will be required to determine whether these populations differentiated in their present locations or were the result of separate invasions of Trinidad from different Venezuelan sources. However, genetic isolation of these populations appears to predate the current physical separation of the island of Trinidad from the Venezuelan mainland.     

A new species of Hybanthus (Violaceae) from north-eastern Brazil

A new species of Hybanthus (Violaceae) from north-eastern Brazil is described and illustrated. Hybanthus verrucosus Paula-Souza is endemic to 'caatingas' of Bahia and Alagoas states and is very distinct from all other Brazilian species of the genus, for its anterior petal, which is covered with small wart-like outgrowths. Other distinctive characteristics of the new species and its relationship with a closely related species ( H. atropurpureus (A.St.-Hil.) Taub.) are discussed.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 503–506.     

A hot-point within a hot-spot: a high diversity site in Brazil’s Atlantic Forest

The Brazilian Atlantic Forest is considered one of the world’s most important sites for biodiversity conservation, and within this biome there are regions with differing levels of species richness, species composition, and endemism. The present study was undertaken in southern Bahia, Brazil, and employed a standardized sampling method to compare the density of arboreal species in this region with other areas throughout the world known for their high tree species density. A total of 144 tree species with DBH > 4.8 cm were sampled within a 0.1 ha plot of old-growth forest (OGF), and these data were then compared with 22 other world sites that had been sampled using the same methodology and likewise demonstrated high densities of arboreal species. Only one site of ombrophilous forest in Colombia demonstrated a higher tree species density (148 spp. in 0.1 ha) than was encountered in southern Bahia. Other areas of Brazil, including other Atlantic Forest sites, showed significantly inferior tree species densities. These results indicate that this region of southern Bahia has one of the greatest numbers of tree species in Brazil and in the world. These results, associated with the high levels of endemism there, indicate the high biological importance of this region. It is therefore fundamental that efforts aimed at halting the degradation of these forests be linked to programs that will increase our knowledge of the species found there as well as the ecological and evolutionary processes that originated these unique forests.     

Chloroplast microsatellite primers for cacao (Theobroma cacao) and other Malvaceae

? Premise of the study: Chloroplast microsatellites were developed in Theobroma cacao to examine the genetic diversity of cacao cultivars in Trinidad and Tobago. ? Methods and Results: Nine polymorphic microsatellites were designed from the chloroplast genomes of two T. cacao accessions. These microsatellites were tested in 95 hybrid accessions from Trinidad and Tobago. An average of 2.9 alleles per locus was found. ? Conclusions: These chloroplast microsatellites, particularly the highly polymorphic pentameric repeat, were useful in assessing genetic variation in T. cacao. In addition, these markers should also prove to be useful for population genetic studies in other species of Malvaceae.     

A preliminary study of genetic variation in populations of Monstera adansonii var. klotzschiana (Araceae) from North-East Brazil, estimated with AFLP molecular markers

BACKGROUND AND AIMS: This study sought genetic evidence of long-term isolation in populations of Monstera adansonii var. klotzschiana (Araceae), a herbaceous, probably outbreeding, humid forest hemi-epiphyte, in the brejo forests of Ceará (north-east Brazil), and clarification of their relationships with populations in Amazonia and the Atlantic forest of Brazil. METHODS: Within-population genetic diversity and between-population dissimilarity were estimated using AFLP molecular markers in 75 individuals from eight populations located in Ceará, the Brazilian Atlantic Forest and Amazonia. KEY RESULTS: The populations showed a clinal pattern of weak genetic differentiation over a large geographical region (F(ST) = 0.1896). A strong correlation between genetic and geographical distance (Mantel test: r = 0.6903, P = 0.002) suggests a historical pattern of isolation by distance. Genetic structure analysis revealed at least two distinct gene pools in the data. The two isolated Ceará populations are significantly different from each other (pairwise Phi(PT) = 0.137, P = 0.003) and as diverse (Nei's gene diversity, average H(e) = 0.1832, 0.1706) as those in the Atlantic and Amazon forest regions. The population in southern Brazil is less diverse (Nei's gene diversity, average H(e) = 0.127) than the rest. The Ceará populations are related to those of the Atlantic forest rather than those from Amazonia (AMOVA, among-groups variation = 11.95 %, P = 0.037). CONCLUSIONS: The gene pools detected within an overall pattern of clinal variation suggest distinct episodes of gene flow, possibly correlated with past humid forest expansions. The Ceará populations show no evidence of erosion of genetic diversity, although this was expected because of their isolation. Their genetic differentiation and relatively high diversity reinforce the importance of conserving the endangered brejo forests.     

Phylogenetic patterns of diversification in a clade of Neotropical frogs (Anura: Aromobatidae: Mannophryne)

We used partial sequences of mitochondrial 16S and cytochrome oxidase I genes to perform a phylogenetic study of collared frogs (Anura: Aromobatidae: Mannophryne ), a genus endemic to Venezuela and the islands of Trinidad and Tobago. We analysed 1.2 kb from 13 of the 15 described species of Mannophryne . Maximum parsimony, maximum likelihood and Bayesian analyses support the monophyly of Mannophryne . Mannophryne consists of three deeply differentiated clades that split from each other in a relatively short period of time. The diversification of Mannophryne occurred well before the glacial-interglacial periods of the Quaternary. Our data support the taxonomic validity of M. olmonae , a species endemic to Tobago Island. Mannophryne olmonae is more closely related to the continental species Mannophryne riveroi than to the Trinidad island endemic Mannophryne trinitatis . As in most tropical clades of frogs, molecular evidence indicates that species richness in Mannophryne is largely underestimated and, consequently, current priorities for conservation are inadequate.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 185–199.     

Genetic variability in mitochondrial and nuclear genes of Larus dominicanus (Charadriiformes,Laridae) from the Brazilian coast

Several phylogeographic studies of seabirds have documented low genetic diversity that has been attributed to bottleneck events or individual capacity for dispersal. Few studies have been done in seabirds on the Brazilian coast and all have shown low genetic differentiation on a wide geographic scale. The Kelp Gull is a common species with a wide distribution in the Southern Hemisphere. In this study, we used mitochondrial and nuclear markers to examine the genetic variability of Kelp Gull populations on the Brazilian coast and compared this variability with that of sub-Antarctic island populations of this species. Kelp Gulls showed extremely low genetic variability for mitochondrial markers (cytb and ATPase) and high diversity for a nuclear locus (intron 7 of the β-fibrinogen). The intraspecific evolutionary history of Kelp Gulls showed that the variability found in intron 7 of the β-fibrinogen gene was compatible with the variability expected under neutral evolution but suggested an increase in population size during the last 10,000 years. However, none of the markers revealed evidence of a bottleneck population. These findings indicate that the recent origin of Kelp Gulls is the main explanation for their nuclear diversity, although selective pressure on the mtDNA of this species cannot be discarded.     

Restoration Strategies to Improve Connectivity for Golden-Headed Lion Tamarins (<Emphasis Type="Italic">Leontopithecus chrysomelas</Emphasis>) in the Bahian Atlantic Forest,Brazil

Habitat loss and fragmentation are the leading causes of biodiversity decline world-wide. Animals sensitive to fragmentation experience reduced dispersal, breeding opportunities, and genetic diversity, making them vulnerable to local extinction. Over the last few decades the Atlantic Forest of Brazil has been extremely fragmented, with only 11–16% of forest remaining. The Brazilian government and nongovernmental organizations have taken actions through legislation and conservation initiatives to restore forest. Using computer modeling, we compared how alternative forest restoration strategies could improve functional connectivity for golden-headed lion tamarins (Leontopithecus chrysomelas) in Southern Bahia, Brazil. Strategies differed by restoration configuration, including Within- and Across-Property approaches, and restoration amount (0–20% restoration). Increasing restoration amounts resulted in greater species functional connectivity, and Within-Property and Across-Property strategies both had significantly more connectivity than the Random strategy. We suggest restoration management consider the size and placement of restored forest, and that riparian forest be restored first to create dispersal corridors and reestablish essential ecosystem services. We further suggest the importance of forming canopy bridges across narrow sections of rivers during the early stages of the restoration process to promote increased connectivity of these newly restored areas. Our findings can aid managers and landowners in understanding the implications of different restoration strategies for highly arboreal, matrix-sensitive species.