Adrian Antonio Garda

A CRITICALLY ENDANGERED NEW SPECIES OF CNEMIDOPHORUS (SQUAMATA, TEIIDAE) FROM A CERRADO ENCLAVE IN SOUTHWESTERN AMAZONIA, BRAZIL

We describe a new species of Cnemidophorus from a Cerrado enclave in southwestern Amazonia, Rondônia state, Brazil. This species is apparently endemic to Cerrado enclaves in the vicinity of the city of Vilhena, a region under intensive anthropic pressure due to the expansion of soybean plantations. A discriminant analysis indicated that femoral pores and scales around the tail are the best discriminators among Brazilian species of Cnemidophorus. A naïve Bayesian network constructed with categorical (mostly coloration) variables indicated that the new species had high conditional probabilities of dorsolateral fields absent, vertebral field spotted, and paravertebral lines absent. The analyses revealed clear distinctions between species of Cnemidophorus that range north and south of the the Amazon River. The new species may have evolved as a result of vicariance, following the isolation of peripheral enclaves of Cerrado in southwestern Amazonia after the late Pleniglacial. The restricted range in small areas, under extreme human pressure around Vilhena, makes this species one of the most critically endangered elements of the Brazilian herpetofauna.

Detecting Variation in Microhabitat Use in Low-Diversity Lizard Assemblages across Small-Scale Habitat Gradients

Abstract If community structure is influenced by habitat structure at a local level, then it should be possible to tie species occurrence to key habitat variables. We used a pitfall-trap system to determine the relationship of species composition, species diversity (relative abundance), and community structure to habitat structure along a transect through a habitat gradient in the Brazilian Cerrado. A total of 531 individuals of 12 lizard species were sampled. A species accumulation curve based on EstimateS and a curve-fitting protocol predicted 12 species at day 22 and all species by about day 40. We registered 12 species at day 11. Trapping success declined through time, likely because of a combination of removal along the transect and seasonal environmental change (wet to dry). The more open end of our transect experienced higher temperatures in all microhabitats sampled, suggesting thermal structure associated with vegetative structure. A Canonical Correspondence Analysis showed that lizard species composition and relative abundance respond to variation in vegetative and physical structure of the habitat at small scales. Consequently, maintenance of habitat gradients should be considered in programs aimed at maintaining local biodiversity.

The ultrastructure of the spermatozoa of Epipedobates flavopictus (Amphibia, Anura, Dendrobatidae), with comments on its evolutionary significance.

We describe, for the first time, the spermatozoon ultrastructure of a dendrobatid frog, Epipedobates flavopictus. Mature spermatozoa of E. flavopictus are filiform, with a moderately curved head and a proportionally short tail. The acrosomal vesicle is a conical structure that covers the nucleus for a considerable distance. A homogeneous subacrosomal cone lies between the acrosome vesicle and the nucleus. The nucleus contains a nuclear space at its anterior end, and electron-lucent spaces and inclusions. No perforatorium is present. In the midpiece, the proximal centriole is housed inside a deep nuclear fossa. Mitochondria are scattered around the posterior end of the nucleus and inside the undulating membrane in the anterior portion of the tail. In transverse section the tail is formed by an U-shaped axial fiber connected to the axoneme through an axial sheath, which supports the undulating membrane. The juxta-axonemal fiber is absent. The spermatozoon of E. flavopictus has several characteristics not observed before in any anurans, such as a curved axial fiber, absence of a juxta-axonemal fiber, and presence of mitochondria in the typical undulating membrane. Our results endorse the view that, in anurans, the conical perforatorium and subacrosomal cone are homologous and that Dendrobatidae should be grouped within Bufonoidea rather than Ranoidea.

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.

Herpetofauna of protected areas in the Caatinga I: Raso da Catarina Ecological Station (Bahia, Brazil)

We provide a list of amphibian and squamate species collected in the Raso da Catarina Ecological Station, Bahia state, Brazil, during two distinct periods. An initial visual inventory of amphibians was conducted monthly from March 2010 to February 2011, using transects in a forest and temporary ponds. The second inventory was conducted over a 30-day period between March and April, 2012, when 37 pitfall trap arrays, each consisting of four buckets and supplementary glue traps, were set in low scrub and forest, complemented by opportunistic searches. A total of 19 lizard species, two amphisbaenians, 21 frogs, and 11 snakes were recorded during the study. New records for the protected area include 10 lizards, one amphisbaenian, 15 amphibians, and 11 snakes (36 species in total). Several species typical of the Atlantic Forest were collected, reflecting the potential influence of this biome, especially in the sampled forest habitats (Mata da Pororoca).

Speciation with gene flow in whiptail lizards from a Neotropical xeric biome

Two main hypotheses have been proposed to explain the diversification of the Caatinga biota. The riverine barrier hypothesis (RBH) claims that the São Francisco River (SFR) is a major biogeographic barrier to gene flow. The Pleistocene climatic fluctuation hypothesis (PCH) states that gene flow, geographic genetic structure and demographic signatures on endemic Caatinga taxa were influenced by Quaternary climate fluctuation cycles. Herein, we analyse genetic diversity and structure, phylogeographic history, and diversification of a widespread Caatinga lizard (Cnemidophorus ocellifer) based on large geographical sampling for multiple loci to test the predictions derived from the RBH and PCH. We inferred two well‐delimited lineages (Northeast and Southwest) that have diverged along the Cerrado–Caatinga border during the Mid‐Late Miocene (6–14 Ma) despite the presence of gene flow. We reject both major hypotheses proposed to explain diversification in the Caatinga. Surprisingly, our results revealed a striking complex diversification pattern where the Northeast lineage originated as a founder effect from a few individuals located along the edge of the Southwest lineage that eventually expanded throughout the Caatinga. The Southwest lineage is more diverse, older and associated with the Cerrado–Caatinga boundaries. Finally, we suggest that C. ocellifer from the Caatinga is composed of two distinct species. Our data support speciation in the presence of gene flow and highlight the role of environmental gradients in the diversification process.

Biodiversity conservation and sustainable development in the Amazon

The Amazon Forest is the most biodiverse region on earth and is central in the struggle to conserve biodiversity and control global warming. Biodiversity is not homogeneously distributed in the region, but concentrated within areas of endemism (AOE) that vary in size, degree of deforestation and human pressure. Unfortunately, these differences have not been used to guide governmental policies, land occupation and conservation. Instead, a violent occupation process started 40 years ago and marked by a frontier economy pattern is still under way. To change this course and truly promote a sustainable development mode in the Amazon region, we argue that an ambitious plan that includes completely halting illegal deforestation is needed. This plan should start by resolving land tenure issues and correctly assigning specific land uses. The three major land-use types in the region include protected areas (49% of the region), unprotected forests (39%) and altered lands (12–17%). Changing the current model of development implies shifting future uses and increasing support for these areas. This translates into three major goals: (1) adequately maintaining the integrity of the current protected areas, (2) protecting unprotected forests and (3) promoting higher productivity in deforested areas. The proportion of land-use types directed to each of these goals will depend on local socio-economic needs and conservation status, but must consider the AOE where it is present. Regional biodiversity corridors for each AOE should be planned and integrated into a large, Pan-Amazon biodiversity corridor to maintain the equilibrium of climatic and hydrological cycles. Politically, this corridor should aim at the integration of development and conservation plans beyond each countrys boundary, minimizing impacts of infrastructure development and maximizing social and environmental benefits.

At the water's edge : Ecology of semiaquatic teiids in Brazilian Amazon

Abstract We describe activity patterns, diet, reproduction, sexual dimorphism, and thermal ecology of the semiaquatic teiids Crocodilurus amazonicus and Dracaena guianensis, from two localities in the Brazilian Amazon. Most C. amazonicus were first sighted in water or on open ground, were active during the hottest hours of the day, and usually had low body temperatures associated with substrate temperatures. Dracaena guianensis were found mainly perching on shrubs and used higher perches located closer to the center of lakes compared to C. amazonicus. Both species appear to rely primarily on crypsis to escape detection by predators but will dive into water as a final means of escape. Crocodilurus amazonicus has a broad diet which includes terrestrial and aquatic prey, particularly spiders and hemipterans, whereas D. guianensis feeds primarily on aquatic snails. No association between body dimensions and prey dimensions was evident. Sexual size dimorphism was not significant in either species, contrary to results reported for other teiids elsewhere, but males of C. amazonicus had relatively longer bodies and tails than females. Clutch size of both species was small relative to their body size and relative to other Amazon teiids, apparently influenced by their semiaquatic habits and by locomotor constraints. We found reproductive females during March (wet season) and July (dry season), suggesting an extended reproductive season.

A New Species of Pseudopaludicola (Anura: Leptodactylidae: Leiuperinae) from Northeastern Brazil

Abstract:  We describe a new species of Pseudopaludicola endemic to the Caatinga ecoregion of northeastern Brazil. The new species is characterized morphologically by small size, lack of T-shape terminal phalanges, smooth upper eyelids, presence of abdominal and vocal sac folds, light cream-colored vocal sac, and short hind limbs with tibia–tarsal articulation reaching the eye. The tadpole has a globular body shape, low tail fins, and a ventral oral disc bordered by a single row of marginal papillae with a wide anterior gap and two ventrolateral gaps; oral formula: 2(2)/2(1). The advertisement call consists of a well-defined sequence of notes comprising three nonconcatenated pulses, each with long interpulse intervals (111 ± 21 ms) and average note duration of 238 ± 31 ms. The mean dominant frequency is 5636 ± 300 Hz, and increases from the first to the last pulse in each note. The advertisement call easily distinguishes the new species from all other congeners for which calls are known.

Herpetofauna of protected areas in the Caatinga II: Serra da Capivara National Park, Piauí, Brazil

We provide a list of amphibians, lizards, chelonians, and snakes collected during a 30-day expedition to the Serra da Capivara National Park, Piaui State, Brazil. Thirty-seven pitfall trap arrays composed of 4 buckets each, along with glue traps, funnel traps, and haphazard searches, were used to sample the herpetofaunal diversity. We recorded 17 species of lizards, 1 caecilian, 1 chelonian, 7 frogs, and 11 snakes. Rarefaction curves suggest that local biodiversity is still underestimated. An atypical drought during the period of study may have contributed to lower captures of certain groups, especially amphibians and snakes. The presence of water-dependent and forest-dependent species within local canyons (“Boqueiroes”) suggests that these areas harbor faunas associated with relictual rainforest fragments and need to be better studied and managed accordingly.