Abstract Taxonomic and cytogenetic aspects of Proceratophrys have not been thoroughly clarified in the literature; thus, objective present study was to provide unprecedent karyotype data regarding P. schirchi, laticeps melanopogon. Additionally, boiei (2n = 22) its ZZ / ZW sex chromosome system analyzed for different populations southeastern southern Brazil. All species a diploid number 2n 22 c...

Sex identification is linked to sexual dimorphism and an important study issue in fish biology aquaculture. However, owing the unmarked heteromorphism between adult Hemibarbus labeo, it often difficult distinguish their sex by visual observation. This aimed find a simple reliable morphometric criterion for of H. labeo using discriminant models. Forty-two traits sixty-eight individuals collected...

Pseudoryzomys simplex, the false rice rat, is a monotypic genus of the Oryzomyini tribe (Sigmodontinae) distributed in part of Bolivia, Paraguay, Argentina and Brazil. Its diploid number has been described as 56 acrocentric chromosomes decreasing in size and no karyotype figure has been depicted. Herein, we present karyotypic data on P. simplex, including chromosome banding and molecular fluore...

The production of two or more seed types by a single plant is known as seed heteromorphism. There have been many comparisons of seed traits or growth between plants grown from heteromorphic seeds. However, information is scarce regarding the mineral contents of adult plants from heteromorphic seeds. We herein present biomass and mineral profiles of adult plants grown from dimorphic seeds (non-d...

Cytogenetic analyses were carried out in a populational sample of Iheringichthys labrosus from the Guaraúna River (Upper Tibagi River; Paraná State, Brazil) in order to provide a karyotypic comparison with another previously studied population from the Lower Tibagi River, characterized by the presence of 32m + 8sm + 6st + 10a (2n = 56, FN = 102) and occurrence of supernumerary chromosomes (80% ...

Chromosomal pairing and recombination were analyzed in male specimens of Sceloporus grammicus heterozygous for a large pericentric inversion of macrochromosome 4. Analysis of silver-stained synaptonemal complexes (SCs) in surface-spread nuclei revealed that homologously paired inversion loops were not formed. Synapsis of the inverted segments proceeded directly to nonhomologous straight pairing...

There is uncertainty regarding the validity of Myxobolus heterosporus Baker, 1963. The present study revises the taxonomy, using specimens isolated from plasmodia situated in the infected cornea of Oreochromis aureus, O. niloticus or Tilapia zillii inhabiting the River Nile, Egypt. In addition, histological effects of the parasite on the infected tissue were examined. The spores of M. heterospo...

Hoplias malabaricus is a common fish species occurring in white, black and clear water rivers of the Amazon basin. Its large distribution across distinct aquatic environments can pose stressful conditions for dispersal and creates possibilities for the emergence of local adaptive profiles. We investigated the chromosomal localization of repetitive DNA markers (constitutive heterochromatin, rDNA...