Development of an Index of Biotic Integrity Based on Fish Communities to Assess the Effects of Rural and Urban Land Use on a Stream in Southeastern Brazil

A fish‐based Index of Biotic Integrity (IBI) was adapted for use in a stream of the heavily impacted Piracicaba River basin in southeastern Brazil. The influences of land use (mainly sugar‐cane crops) and an urban area on the fish community were investigated at ten sites along a 17 km‐long stream during the dry and rainy season. The IBI varied with the season and location along the stream, reflecting differences between the agricultural and urban sites, which were more pronounced during the dry season. The final index was positively correlated with a Habitat Quality Index (dry season) but not with a Water Quality Index. The results can be viewed as a tool for assessing and monitoring the ecological health of streams in this watershed. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Detection Dogs: An Effective Technique for Bush Dog Surveys

ABSTRACT Detailed ecological data on the bush dog (Speothos venaticus) have been lacking, since standard field techniques, such as camera traps, have had little success recording their presence. This study eliminates dependence on visitation rate and switches the focus to locating evidence (e.g., olfactory) associated with the species’ natural behavior and movement patterns. Over a 3-month period, a detection dog located multiple (n = 11, 4 confirmed and 7 potential) bush dog areas in Upper Paraná Atlantic Forest of Misiones Argentina. These positive results demonstrate that detection dogs can provide species-specific data on the bush dog despite the rugged terrain and dense forest vegetation they may occupy. The ecological data collected using this technique allow effective conservation strategies to be developed, wildlife corridors and biological crossings to be designed, and species distributions to be examined.     

Atractiellomycetes belonging to the ‘rust’ lineage (Pucciniomycotina) form mycorrhizae with terrestrial and epiphytic neotropical orchids

Distinctive groups of fungi are involved in the diverse mycorrhizal associations of land plants. All previously known mycorrhiza-forming Basidiomycota associated with trees, ericads, liverworts or orchids are hosted in Agaricomycetes, Agaricomycotina. Here we demonstrate for the first time that Atractiellomycetes, members of the ‘rust’ lineage (Pucciniomycotina), are mycobionts of orchids. The mycobionts of 103 terrestrial and epiphytic orchid individuals, sampled in the tropical mountain rainforest of Southern Ecuador, were identified by sequencing the whole ITS1-5.8S-ITS2 region and part of 28S rDNA. Mycorrhizae of 13 orchid individuals were investigated by transmission electron microscopy. Simple septal pores and symplechosomes in the hyphal coils of mycorrhizae from four orchid individuals indicated members of Atractiellomycetes. Molecular phylogeny of sequences from mycobionts of 32 orchid individuals out of 103 samples confirmed Atractiellomycetes and the placement in Pucciniomycotina, previously known to comprise only parasitic and saprophytic fungi. Thus, our finding reveals these fungi, frequently associated to neotropical orchids, as the most basal living basidiomycetes involved in mycorrhizal associations of land plants.     

DNA barcoding reveals taxonomic uncertainty in Salminus (Characiformes)

Salminus is a genus composed of four species of migratory fishes and top predators. Although this group has great economic and ecological importance, the species level diversity of Salminus is not yet completely clarified. Our goal was to detect if this taxonomic problem is the consequence of lineage divergence within species, and, if so, whether these divergences are sufficient to flag potentially undescribed taxa. We employed the standard DNA barcoding analyses and a generalized mixed Yule-coalescent model (GMYC) using one mitochondrial (COI) marker and Bayesian Inference (BI) reconstruction for one nuclear (RAG2) marker for all currently recognized species of Salminus, sampled across different hydrographic basins. Eight MOTUs (Molecular Operational Taxonomic Units) were determined by distance and model-based analyses, and recovered with BI analyses for COI. Only Salminus affinis and Salminus franciscanus formed monophyletic haplogroups. Salminus brasiliensis and Salminus hilarii had two and four distinct mitochondrial lineages, respectively, and higher intraspecific K2P distances than the adopted optimum threshold. The RAG2 gene tree supported two lineages of S. hilarii (S. hilarii Amazon and S. hilarii Araguaia), while the other mitochondrial lineages of S. hilarii and S. brasiliensis were not supported. All lineages of both species, corresponded to morphological variation described in previous studies. We suggest, based on the DNA barcoding analysis, a new taxonomic scenario and conservation polices for Salminus in the Brazilian territory.     

Molecular phylogeny of Moenkhausia (Characidae) inferred from mitochondrial and nuclear DNA evidence

Moenkhausia is one of the most speciose genera in Characidae, currently composed of 75 nominal species of small fishes distributed across South American hydrographic basins, primarily the Amazon and Guyanas. Despite the large number of described species, studies involving a substantial number of its species designed to better understand their relationships and putative monophyly are still lacking. In this study, we analysed a large number of species of Moenkhausia to test the monophyly of the genus based on the phylogenetic analysis of DNA sequences of two mitochondrial and three nuclear genes. The in‐group included 29 species of Moenkhausia, and the out‐group was composed of representatives of Characidae and other members of Characiformes. All species of Moenkhausia belong to the same clade (Clade C); however, they appear distributed in five monophyletic groups along with other different genera, which means that Moenkhausia is polyphyletic and indicates the necessity of an extensive revision of the group.     

Variation in spectral reflectance among populations of Dendrobates pumilio, the strawberry poison frog, in the Bocas del Toro Archipelago, Panama

Aim The goal of this study was to quantify levels of variation in spectral reflectance within and among populations of Dendrobates pumilio, the strawberry poison frog from the Bocas del Toro Archipelago. Location This study was carried out in the Bocas del Toro Archipelago, in the Republic of Panama, Central America. Methods Spectral reflectance was measured for samples of individuals from fifteen distinct island and mainland populations, using an Ocean Optics 2000 spectrometer and a BiLink portable computer. Results Our results provide quantitative evidence for extreme polymorphism among populations, and more limited levels of polymorphism within some populations. No obvious signs of sexual dimorphism were found. All the colour morphs appear to have relatively little reflectance in the ultraviolet part of the spectrum. There is some evidence for clinal variation in colour and pattern across some mainland populations. There is also at least one area where distinctly different morphs occur in sympatry, suggesting the possibility of incipient reproductive isolation. We argue that variation in coloration may have been enhanced by sexual selection.     

An asymmetry in niche conservatism contributes to the latitudinal species diversity gradient in New World vertebrates

The Tropical Niche Conservatism hypothesis is a leading explanation for why biodiversity increases towards the equator. The model suggests that most lineages have tropical origins, with few dispersing into temperate regions. However, biotas are comprised of lineages with differing geographical origins, thus it is unclear whether lineages that originated on different continents will exhibit similar patterns of niche conservatism. Here, we summarised biogeographical patterns of New World vertebrates and compared species diversity patterns between families that originated in North and South America. Overall, families with southern origins exhibit niche conservatism with many lineages restricted to the Neotropics, whereas many northern‐origin families are distributed across the Neotropics and the Nearctic. Consequently, northern lineages have contributed to high tropical biodiversity, but southern lineages have contributed relatively little to temperate biodiversity in North America. The asymmetry in niche conservatism between northern and southern lineages is an important contributor to the biodiversity gradient.     

Genetic diversity and population structure of bocachico Prochilodus magdalenae (Pisces,Prochilodontidae) in the Magdalena River basin and its tributaries,Colombia

Prochilodus magdalenae is an endemic freshwater fish that occurs in the Magdalena, Sinú and Atrato hydrographic basins. It has an important economic role and is a food resource for the artisanal fishing communities. Its socioeconomic importance contrasts with the current status of its fisheries, where stocks are being depleted. Considering its importance and lack of information on its genetic structure, we used seven microsatellite markers to assess the genetic structure of wild populations of P. magdalenae. The genetic diversity was assessed and the population genetic structure was estimated through Fst, analysis of molecular variance and Bayesian analysis. A total of 290 alleles were found in all loci throughout all population. The high polymorphism contrasts with the levels of observed heterozygosity (Ho = 0.276), which are the lowest values recorded for the family. We found three populations of bocachico coexisting throughout the studied system, contradicting the hypothesis that freshwater migratory fish form panmictic populations. These results on the genetic structure of P. magdalenae constitute tools for a better understanding of the behavior and biology of this species, contributing to fish management and conservation programs.