Natural hybrids between the frogs Rana cascadae and Rana pretiosa (Anura: Ranidae)

Publication Type:

Journal Article

Authors:

Green, David M.

Source:

Herpetologica, The Herpetologists' League, Volume 43, Issue 3, p.262-267 (1985)

Call Number:

A85GRE01IDUS

URL:

http://www.jstor.org/stable/3892272

Keywords:

allozymes, chromosomes, electrophoresis, hybridization, Oregon, Rana cascadae, Rana pretiosa

Abstract:

The western North American frogs Rana cascadae and Rana pretiosa are usually allopatric, but natural hybrids between them have been found at Gold Lake near Willamette Pass, Oregon. Hybrids can be identified by diagnostic allozymes, particularly of the isozymes SOD, GOT-2 and LDH-1, and by the relative positions of secondary constrictions in their karyotypes. The secondary constriction is subterminal on chromosome No. 12 in the karyotype of R. cascadae, but it is median on chromosome No. 10 in R. pretiosa. Two hybrids, both adult males, showed no pairing of homologous chromosomes in meiosis, indicating a considerable degree of genetic divergence between the two species.