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Batrochoglanis labrosus new species, is described from the Capim River Basin, State of Pará, Brazil. The new species differs from congeners by the stout, inferior mandible, hypertrophied lips on the lateral of the mouth, a broad dark brown band extending dorsoventrally from the beginning of the trunk to the posterior third of the adipose fin followed by a second dark brown band on the caudal peduncle, dark brown pelvic fin, and caudal fin hyaline with a concentration of dark brown spots on the posterior margin, sometimes forming an irregular band. The morphometric variables of B. labrosus are similar in B. villosus and B. castaneus, forming a B. villosus species group. The B. villosus group is distinct from other group formed by B. acanthochiroides and B. transmontanus in the third axis of the Principal Components Analysis. The variables with higher positive loadings in the B. villosus group, representing larger measurements, were adipose-fin base length, eye diameter, maxillary barbel length, head depth, and mouth width; the higher negative loadings representing shorter measurements were pelvic fin to anal fin distance and pectoral-fin spine length. The species is known only from the Capim River basin, where it is possibly endemic.

A new species, Batrochoglanis castaneus, is described from the Aripuanã River basin, Brazil. It differs from congeners, except B. raninus and B. transmontanus, by the dark brown color of the body and a dark brown stripe on the caudal fin. The new species differs from B. raninus by the longer maxillary barbel, longer prepelvic length, greater prepectoral length, smaller anal-fin base length, and smaller head depth. The new species differs from B. transmontanus by the longer caudal-fin dorsal lobe, presence of a hyaline spot or stripe on pelvic, dorsal, and anal fins, longer maxillary barbel, longer pectoral-fin, and dorsal-fin spines, greater eye diameter, smaller head depth, and larger mouth width. A metapterygoid anteriorly bifurcated and the lateral line reaching the adipose fin present in the new species are interpreted as synapomorphies of Batrochoglanis. On the other hand, the distribution of pore and neuromasts of the laterosensory system of the head seems to be very conservative in the family. The new species is known only from the Aripuanã River basin, reinforcing its characteristics as an area of endemism for fishes in the Amazon basin.

Environmental heterogeneity is a factor which can help explain the higher local species richness. The objective of this study was to test if richness and composition of anurans species are related to available microhabitats and landscape type of sampled sites. We assume that a higher number of microhabitats increase environmental heterogeneity and this, in turn, affects species richness of amphibians. We performed the study in the Mesophytic Semideciduous Forest, a vegetation type within Atlantic Forest Domain. Between October 2010 and February 2011, we sampled 23 water bodies located in the agricultural, forest, and urban landscapes. The species richness was determined using survey at breeding sites methodology, and the availability of microhabitats was estimated visually. Thirty-four anuran species belonging to 12 families were recorded. The species richness in water bodies ranged from two to 13 species. The highest species richness was recorded in environments with a higher number of microhabitats, while the species composition in water bodies was partially grouped according to the predominant landscape type that is agricultural, forest, forest edge or urban. Our results suggest that species use specific environments (e.g. landscapes, habitat and microhabitat) for their reproductive activities.

The southern region of Brazil is characterized by high species diversity and endemism of freshwater fishes distributed across geographically isolated river basins. Microglanis cottoides has a widespread range across these river basins and occurs in sympatry with other endemic species of the genus (e.g. M. cibelae, M. eurystoma, and M. malabarbai). Herein we tested the monophyly of M. cottoides and presented for the first time information about the molecular phylogeny of species in the genus. The results suggest that M. cottoides currently forms a non-monophyletic group which includes populations endemic to the Uruguay River basin that are more closely related to M. malabarbai, and excludes M. cibelae, found to be nested within M. cottoides. Based on an integrative approach using morphological and molecular data, we propose M. cibelae as a junior synonym of M. cottoides, and the populations of the Uruguay River basin previously assigned to M. cottoides in fact belong to M. malabarbai. Our molecular phylogeny shows that M. cottoides is sister to M. parahybae, which is also a coastal species, and M. malabarbai is sister of M. garavelloi, both endemic to inland river basins. The time-calibrated phylogeny indicates that the separation between inland and the coastal clades occurred in the Tertiary period, and that the species within the coastal basins diverged in the Pliocene, which overlaps with the diversification times estimated for the two inland species as well. This pattern of diversification corroborates some previous studies with other fishes from the same region., Competing Interests: The authors have declared that no competing interests exist.

Cytogenetic and morphometric analyses were carried out in Hoplias aff. malabaricus specimens from six distinct populations from the lower Paranapanema River basin, located between the states of Paraná and São Paulo, Brazil. Measurements were also taken from a specimen collected in Surinam. In a population from a fish farm station at Universidade do Norte do Parana (EPUNOPAR), two sympatric cytotypes (2n = 40 and 2n = 42 chromosomes) are found. A population from a fish farm station at Universidade Estadual de Londrina (EPUEL) shows 2n = 42 meta-submetacentric chromosomes for males and females with a simple sex chromosome system of XX/XY type. Populations from the Vermelho and Rancho Alegre Rivers, Três Bocas Stream and Paranapanema River have 2n = 39 chromosomes in males and 2n = 40 chromosomes in females, showing a multiple sex chromosome system of X(1)X(1)X(2)X(2)/X(1)X(2)Y type. Twenty morphological variables were studied. These measurements were used for an analysis of the canonical variables and standard analysis of proportional measurements. The most variable measurements among the specimens are the maxilla length (MXL) and the pre-dorsal distance (PDD). Analysis of canonical variables indicates three distinct groups in the first canonical axis formed by: (1) Três Bocas Stream, (2) Rancho Alegre + Vermelho River + EPUNOPAR and (3) EPUEL + Paranapanema River. This axis retained 79.4% of information from the original matrix. Analysis of morphometrics reveals differences among populations from the Paranapanema River basin and between these and the specimen from Surinam. The morphometric and cytogenetic differences among the studied populations suggest a species complex.