Integrating Genetic and Cytogenetic Data: A Diversity Study of and (Characidae) Species from the Paraná River Basin.

is one of the most specious fish groups in the Neotropical region, with many cryptic species, which represents a challenge for correct identification through traditional taxonomic methods. is a recently resurrected genus group of species previously belonging to , specifically those with extensive chromosomal variation of the and s complexes. In the present study, the mitochondrial genes cytochrome oxidase subunit 1 (COI), mitochondrial ATP synthase 6 and 8 (ATPase 6/8), and NADH dehydrogenase subunit 2 (ND2) were used in conjunction with chromosomal data to characterize molecularly and cytogenetically populations of and from rivers and streams of the Ivaí River Basin (Paraná Basin).

Cytogenetic and Molecular Characterization of aff. (Gymnotiformes: Sternopygidae): A First Report of System of Sex Chromosomes ZWW/ZZ in Gymnotiformes.

Gymnotiformes a monophyletic group of fish endemic to the Neotropics, represent an important component of the freshwater ichthyofauna that presents relevant taxonomic problems. Thus, in view of the morphological complexity involving (Gymnotiformes) fish species, this study aimed to characterize aff. of the upper Paraguay River basin through cytogenetic and molecular analyses, to help in the correct identification and delimitation of species.

Molecular Markers Reveal a New and Possibly Threatened Species of (Poeciliidae, Cnesterodontini) from the Upper Paraná River Basin, Brazil.

comprises 10 valid species occurring in the major river basins of South America. Recent ichthyofaunistic studies in the Ivaí River basin, upper Paraná River system, suggested the existence of a possible new species, which was identified as sp. based on morphological characters.

Identification and molecular characterization of digenean trematode parasites of Aylacostoma chloroticum (Gastropoda: Thiaridae) from a Neotropical Basin.

Thiarids are pantropical gastropods distributed from South America to Australia and found in lentic and lotic freshwater environments. These gastropods act as intermediate hosts for several species of digeneans. There are difficulties in the correct identification of these digeneans in certain stages of the life cycle as the larvae have a reduced size and few morphological characteristics for diagnosis.

Morphological and molecular characterization of Austrodiplostomum compactum metacercariae in the eyes and brains of fishes from the Ivaí River, Brazil.

Austrodiplostomum spp. (Platyhelminthes: Digenea) are endoparasites with a broad geographic distribution in South America. During the larval stage, they parasitize the eyes, brains, muscles, gill, kidneys and swim bladder of a wide variety of fishes.

Cytogenetic and Molecular Characterization of (Characidae): A New Record of Supernumerary Chromosome in this Species.

The genus currently comprises 24 valid species distributed in the major river basins of South America. In this group, nine species were cytogenetically investigated, and found to share a diploid number of 50 chromosomes. Despite the conservation of the diploid number, variations in the karyotypic formula, number and position of the nucleolar organizer regions, and longitudinal bands have been described between both species and populations.

Integrative taxonomy reveals the historically poorly defined armoured catfish Hypostomus variipictus (Ihering 1911), from the upper rio Paraná basin, Brazil (Siluriformes, Loricariidae).

In a recent expedition to the rio Grande basin, a tributary of the rio Paraná in southern Brazil, individuals of the armoured catfish genus Hypostomus with a peculiar and beautiful colour pattern composed of pale vermiculations on the head and four to five horizontal stripes on the flanks were collected. Initially, the specimens were identified as a colour morph of the pale-spotted H. margaritifer.

Molecular evidence of new freshwater turtle blood flukes (Digenea: Spirorchiidae) in the intermediate snail host Biomphalaria occidentalis Paraense, 1981 in an urban aquatic ecosystem in Brazil.

In this study, two potentially new species of turtle blood flukes (TBFs) (Digenea: Spirorchiidae) have been recorded from South Brazil. The spirorchiid parasites infect the vascular system of turtles, thereby compromising their health. The life cycle of these parasites is not well studied.