Cytological evidence of constant tetraploidy in the bisexual South American frog Odontophrynus americanus

@article{Beak1966CytologicalEO,
  title={Cytological evidence of constant tetraploidy in the bisexual South American frog Odontophrynus americanus},
  author={Maria Luiza Beçak and Willy Beçak and Maria Nazareth Rabello},
  journal={Chromosoma},
  year={1966},
  volume={19},
  pages={188-193}
}
Odontophrynus americanus has 2n=44 chromosomes in somatic and gonad cells which can be ordered in 11 groups of homologues. In spermatocytes I they form mostly ring quadrivalents. In metaphase II 22 dyads are present. There is no indication of abnormalities in ♂ and ♀ gonad development.