Congruence among Character Sets in Phylogenetic Studies of the Frog Genus Leptodactylus

Miyamoto, M. M. (Department of Biological Sciences, Allan Hancock Foundation, University of Southern California, University Park, Los Angeles, California 90007) 1981. Congruence among character sets in phylogenetic studies of the frog genus Leptodactylus. Syst. Zool., 30:281-290.-Four species groups of the neotropical frog genus Leptodactylus are currently recognized on the bases of morphological arnd life history characteristics. The fuscus and pentadactylus groups are related as a monophyletic cluster, whereas the phylogenetic relationships of the melanonotus and ocellatus groups remain unknown. Five species representing all four species groups occur in Costa Rica. This study examined protein variability among four Costa Rican species as ascertained by electrophoretic and histochemical techniques. The presumptive genetic data were analyzed cladistically with the Wagner method. This procedure constructed a cladogram for the Costa Rican species which was congruent with the phylogenetic relationships proposed for their species groups from morphological and life history characteristics. This congruence among phylogenetic inferences based on different character sets argues for the continued recognition of species group relationships as currently viewed within the genus. [Leptodactylus; Costa Rica; phylogenetic relationships; electrophoresis, Wagner analysis; congruence.] The genus Leptodactylus (Leptodactylidae) contains approximately 30 nominal species of primarily neotropical frogs (Heyer, 1969a). Four species groups (fuscus, melanonotus, ocellatus, and pentadactylus) are currently recognized within the genus on the bases of morphological and life history characteristics (Heyer, 1969b, 1970a, 1974, 1978, 1979). Phylogenetic relationships among the species groups are represented in Figure 1 as ascertained by Heyer (1969c) from cladistic analysis of the morphological and life history data. The fuscus and pentadactylus groups are related as a monophyletic cluster, whereas the relationships of the melanonotus and ocellatus groups remain in question as reflected by the unresolved trichotomy at the base of the phylogeny. His patristic distances suggest that the melanonotus and ocellatus groups are relatively primitive and that the fuscus and pentadactylus groups are intermediate and derived, respectively, with respect to morphological and life history characteristics. Five species representing all four species groups of Leptodactylus occur in Costa Rica (Taylor, 1952; Heyer, 1970b; Savage, 1980). Leptodactylus bolivianus, L. melanonotus, and L. pentadactylus are the sole Costa Rican representatives of the ocellatus, melanonotus, and pentadactylus groups, respectively. The fuscus group is represented in Costa Rica by two species, L. fragilis and L. poecilochilus. The occurrence of taxonomically diverse species in Costa Rica provides an opportunity to test the phylogenetic relationships among the species groups of Leptodactylus. Phylogenetic relationships among the Costa Rican species must be congruent with the phylogeny recognized for their species groups if the latter are to be considered a stable and useful representation of evolutionary history within the genus. This study examines protein variability among the Costa Rican Leptodactylus (excluding L. fragilis) as ascertained by electrophoretic and histochemical techniques (Case et al., 1975; Case, 1978a, 1978b). Presumptive genetic data are analyzed with cladistic methods and these results are compared against the