Lilian G. Giugliano

Phylogeny, biogeography and evolution of clutch size in South American lizards of the genus Kentropyx (Squamata: Teiidae)

The lizard genus Kentropyx (Squamata: Teiidae) comprises nine species, which have been placed in three species groups (calcarata group, associated to forests ecosystems; paulensis and striata groups, associated to open ecosystems). We reconstructed phylogenetic relationships of Kentropyx based on morphology (pholidosis and coloration) and mitochondrial DNA data (12S and 16S), using maximum parsimony and Bayesian methods, and evaluated biogeographic scenarios based on ancestral areas analyses and molecular dating by Bayesian methods. Additionally, we tested the life‐history hypothesis that species of Kentropyx inhabiting open ecosystems (under seasonal environments) produce larger clutches with smaller eggs and that species inhabiting forest ecosystems (under aseasonal conditions) produce clutches with fewer and larger eggs, using Stearns’ phylogenetic‐subtraction method and canonical phylogenetic ordination to take in to account the effects of phylogeny. Our results showed that Kentropyx comprises three monophyletic groups, with K. striata occupying a basal position in opposition to previous suggestions of relationships. Additionally, Bayesian analysis of divergence time showed that Kentropyx may have originated at the Tertiary (Eocene/Oligocene) and the ‘Pleistocene Refuge Hypothesis’ may not explain the species diversification. Based on ancestral reconstruction and molecular dating, we argued that a savanna ancestor is more likely and that historical events during the Tertiary of South America promoted the differentiation of the genus, coupled with recent Quaternary events that were important as dispersion routes and for the diversification at populational levels. Clutch size and egg volume were not significantly different between major clades and ecosystems of occurrence, even accounting for the phylogenetic effects. Finally, we argue that phylogenetic constraints and phylogenetic inertia might be playing essential roles in life history evolution of Kentropyx.

Reproduction, Body Size, and Diet of Polychrus acutirostris (Squamata: Polychrotidae) in Two Contrasting Environments in Brazil

Abstract We compared reproduction, diet, and body size of Polychrus acutirostris (Squamata: Polychrotidae) from the Cerrado and Caatinga biomes in Brazil. Because these two biomes have widely different climates, we predicted that lizards in Caatinga would produce smaller clutches in response to rainfall unpredictability. We also expected reproductive timing to differ between biomes, with lizards occurring in the Cerrado producing a single clutch in association with the predictable rains of October–November. Contrary to expectations, clutches had fewer (although larger) eggs in Cerrado. Reproductive period was remarkably similar (peak of female reproductive activity in November), but female reproduction started 1 month earlier in Cerrado. Diet composition was also similar, with the exception of spiders, that exhibited a high index of relative importance in Cerrado but were nearly absent in Caatinga lizard diets. Lizards from both biomes ingested a large proportion of plant material, as well as soft-bodied arboreal arthropods, such as orthopterans, and mostly slow-moving, large arboreal insects. Rainfall predictability in the Cerrado therefore did not influence Polychrus reproduction or diet in the same manner as in other lizard species. The large number of small eggs in the Caatinga suggests that the competitive environment for offspring is either unpredictable or that mortality is high but random. Rain forest Polychrus lizards produce few large eggs, suggesting that the competitive environment for offspring is predictably intense and mortality is non-random. Cerrado Polychrus lizards seem intermediate between Caatinga and rain forest Polychrus lizards, producing fewer and larger eggs than their conspecifics in the Caatinga but relatively more and smaller eggs than rain forest Polychrus species.

Cryptic lineages and diversification of an endemic anole lizard (Squamata, Dactyloidae) of the Cerrado hotspot ☆ ☆☆

The Cerrado is a wide Neotropical savanna with tremendously high endemic diversity. Yet, it is not clear what the prevalent processes leading to such diversification are. We used the Cerrado-endemic lizard Norops meridionalis to investigate the main abiotic factors that promoted genetic divergence, the timings of these divergence events, and how these relate to cryptic diversity in the group. We sequenced mitochondrial and nuclear genes from 21 sites of N. meridionalis to generate species tree, divergence time estimations, and estimate species limits. We also performed population-level analysis and estimated distribution models to test the roles of niche conservatism and divergence in the group diversification. We found that N. meridionalis is composed by at least five cryptic species. Divergence time estimations suggest that the deepest branches split back into the early-mid Miocene, when most of the geophysical activity of the Cerrado took place. The deep divergences found in N. meridionalis suggest that beta anoles invaded South America much earlier than previously thought. Recent published evidence supports this view, indicating that the Panama gap closed as early as 15 mya, allowing for an early invasion of Norops into South America. The spatial pattern of diversification within N. meridionalis follows a northwest-southeast direction, which is consistent across several species of vertebrates endemic to the Cerrado. Also, we found evidence for non-stationary isolation by distance, which occurs when genetic differentiation depends on space. Our preliminary data in two out of five lineages suggest that niche conservatism is an important mechanism that promoted geographic fragmentation in the group.

Structural and ultrastructural studies of Anticarsia gemmatalis midgut cells infected with the baculovirus A. gemmatalis nucleopolyhedrovirus

Anticarsia gemmatalis is a lepidopteran insect susceptible to A. gemmatalis nucleopolyhedrovirus (AgNPV), which is being used in a large scale, in Brazil, as a biological control agent against this serious soybean pest. Baculovirus usually infects its insect host through the midgut epithelium. In the midgut, it replicates in the nuclei of epithelial cells, producing progeny virus and establishing systemic infection. The AgNPV infection of A. gemmatalis midgut was studied using light and electron microscopy. It was observed that AgNPV enters the midgut mainly through columnar cells. Although the virus was not found in the nuclei of columnar cells until late on infection, it is believed that these cells are the primary sites of infection and replication. This fact can be explained by the continuous regeneration of the midgut epithelium. Besides, the infection may be occurring in isolated cells, making it more difficult to be visualized by electron microscopy. At 48 h post infection, hemocytes and tracheoblasts are infected and polyhedra are formed later in these cells, which are the secondary sites of infection.

Cryptic diversity in South American Teiinae (Squamata, Teiidae) lizards

Based on phylogenetic and molecular dating analyses of several species of Cnemidophorus and Ameiva, representing major groups of species of these two genera, we uncover a previously unrecognized Ameiva lineage, which includes described Cnemidophorus parecis from south‐western Amazonia. We discuss the diagnosis of Ameiva and Cnemidophorus and the implications of the new taxonomic rearrangement of genera from Teiidae for the monophyly of Ameiva. Based on the conclusion of our analyses, we provide description of a new species named Ameiva jacuba from the central Brazilian Cerrado and a detailed diagnosis for the relocation of C. parecis to Ameiva. We do not adopt here recent taxonomic changes proposed for Teiidae and provide a discussion about them. Finally, based on molecular dating and the distribution of living species, we propose an evolutionary scenario for the origins of South American cis‐Andean Ameiva lineages, associated with the topographic subdivision of the Cerrado region during Miocene marine introgressions.

Cytogenetic studies in Hasemania crenuchoides (Characiformes: Characidae) and molecular investigations into kinship relationships of the genus

ABSTRACT The genus Hasemania is considered incertae sedis from the family Characidae which possesses nine fish species. Hasemania crenuchoides is endemic to the Federal District of Brazil and is under threat of extinction. The objective of this work was to characterize the Hasemania crenuchoides karyotype and investigate phylogenetic relationships using the 5ʹ region of the COI gene. Our results showed a chromosome number of 2n = 50, with a fundamental number equal to 82 and a karyotype formula of 32m/sm+ 18st/a. C banding evidenced that constitutive heterochromatin is not only present in pericentromeric regions, but also in telomeric and interstitial regions. Ag-NOR marking occurred in the short arm of pair 6. DAPI staining revealed that few bands were rich in A/T. The diploid number observed is in accordance with previous findings in Characidae, including the presence of a long metacentric pair, and is considered a plesiomorphic character. Based on the literature, together with cytogenetic and molecular data, it is suggested that Hasemania is possibly not monophyletic, composed of two groups: (1) a basal group with H. hanseni and H. nana; and (2) a derived group with H. crenuchoides, H. kalunga, and H. uberaba. Therefore, the molecular and cytogenetic data presented may contribute to understanding phylogenetic relationships within the family.