Ana Cristina Prado Veiga-Menoncello

A phylogenetic analysis of Pseudopaludicola (Anura) providing evidence of progressive chromosome reduction

Here, we present a molecular phylogenetic analysis of the Neotropical genus Pseudopaludicola focusing on species relationships including 11 of the 17 known species of Pseudopaludicola; several samples of Pseudopaludicola are not assigned to any species; and 34 terminal species as an outgroup. The study was based on the analysis of approximately 2.3 kb of the sequence of the mitochondrial 12S rRNA, tRNAval and 16S rRNA genes through maximum parsimony and Bayesian phylogenetic reconstruction approaches. Our results showed that Pseudopaludicola is a well‐supported monophyletic group organized into four major clades and confirmed that the assemblage of species that lack T‐shaped terminal phalanges is paraphyletic with respect to the P. pusilla Group. Chromosomal data mapped on the cladogram showed a direct correlation among the four clades and observed chromosome numbers (2n = 22, 20, 18 and 16) with a progressive reduction in the chromosome number. Overall, our findings suggest that some taxonomic changes are necessary and reinforce the need for a revision of the genus Pseudopaludicola.

Two New Species of Pseudopaludicola Miranda-Ribeiro, 1926 (Anura: Leptodactylidae: Leiuperinae) from Eastern Bolivia and Western Brazil

Abstract:  Two new species of Pseudopaludicola from midwestern Brazil are described. One of them, distributed in Bolivian and Brazilian areas within the Upper Paraguay and Upper Guaporé river basins, is characterized by the presence of a conspicuous conical tubercle on each heel, by T-shaped terminal phalanges, and so belongs to the formally recognized Pseudopaludicola pusilla group. The advertisement call is composed of a series of 14–720 notes with concatenated pulses—each lasting for 5–25 ms—and mean dominant frequency of 5071 ± 242 Hz. The second species, restricted to the southeastern-most region of the Brazilian state of Mato Grosso, is characterized mainly by a 2n = 18 karyotype, an advertisement call composed of series of 12–287 notes with concatenated pulses and mean dominant frequency of 4167.7 ± 287.5 Hz. A detailed description of the karyotype of this latter species is also provided.

Ultrastructure variation in the spermatozoa of Pseudopaludicola frogs (Amphibia, Anura, Leptodactylidae), with brief comments on its phylogenetic relevance.

The taxonomic history of the small frogs of the genus Pseudopaludicola from South America has been controversial. Phylogenetic inferences based on molecular data have identified four Pseudopaludicola clades, correlating with the known variation in karyotypes (2n = 22, 20, 18, and 16). In this study, the ultrastructure of the spermatozoa was analyzed in 12 species of the Pseudopaludicola, with the aim of describing their morphology and identifying characters that may contribute to a better understanding of the phylogenetic relationships. The spermatozoa presented marked differences in tail structures. The tails of the spermatozoa of the species with 2n = 22 chromosomes (Pseudopaludicola sp. 1 [P. pusilla group], Pseudopaludicola falcipes, P. mineira, and Pseudopaludicola saltica), as well as Pseudopaludicola ameghini and Pseudopaludicola ternetzi (2n=20), have juxta‐axonemal fibers, undulating membranes and axial fibers. In contrast, in the species with 2n = 18 (P. facureae, P. giarettai, Pseudopaludicola canga, P. atragula, and Pseudopaludicola sp. 2) and 2n = 16 (Pseudopaludicola mystacalis), there are no evident axial or juxta‐axonemal fibers, but a paraxonemal rod with a thick undulating membrane, which is shorter than that found among Pseudopaludicola species. The ultrastructural morphological differences observed in the spermatozoa of these species may be phylogenetically informative, given that they coincide with the consensus phylogeny of the group and appear to represent a progressive simplification of the spermatozoon. J. Morphol. 276:1495–1504, 2015.

Comparative sperm ultrastructure of twelve leptodactylid frog species with insights into their phylogenetic relationships

The spermatozoa of representatives of three Neotropical frog subfamilies, Leiuperinae, Leptodactylinae and Paratelmatobiinae, were observed using Transmission Electron Microscopy, with the aim of identifying ultrastructural traits that provide insights into the phylogenetic relationships among these anurans, which are currently unclear. In the leiuperines, spermatozoa of Physalaemus albifrons, P. cicada, P. deimaticus and P. feioi were characterized by an acrosomal vesicle covering the subacrosomal cone that was not observed in the spermatozoa of Physalaemus centralis and P. cuvieri. The tail of the spermatozoa of P. albifrons, P. centralis, P. cicada, P. cuvieri, P. deimaticus, and P. feioi presented a long undulating membrane, whereas Engystomops petersi and E. freibergi, which form a sister clade to Physalaemus, had an axial fiber, which were absent in Physalaemus. Other leiuperine, E. puyango had an abaxonemal bulb-like swelling distally to the paraxonemal rod, which were also absent in Physalaemus. These differences support the revalidation of Engystomops as a true taxon, distinct from Physalaemus. The tail of the spermatozoa of E. petersi and E. freibergi was similar to that of Paratelmatobius poecilogaster (Paratelmatobiinae). The spermatozoa of Leptodactylus natalenis (Leptodactylinae) had undulating membrane and axial fiber, in contrast with Adenomera marmorata, which lacked these structures. Morphological differences between A. marmorata and L. natalensis sperm cells appeared to validate the allocation of A. marmorata into a genus distinct from Leptodactylus. Overall, dissimilarities in the spermatozoa of the leptodactylids provided an important phylogenetic signal for the understanding of their taxonomic relationships.