Tropidurus Itambere Research Articles

Thanatosis behavior during oviposition in Tropidurus itambere Rodrigues, 1987.

Thanatosis behavior during oviposition in Tropidurus itambere Rodrigues, 1987.

Communities and occurrences of Squamata reptiles in different vegetation types of the Serra de São José, Minas Gerais, Brazil

Abstract The objective of the present study was to learn which species of Squamata reptiles occur in Protected Area São José, in Tiradentes, Minas Gerais, Brazil. Between November 2009 and December 2010 reptiles were captured. In total 157 specimens were recorded of 29 species, 16 snakes, 12 lizards and one amphisbaena. Among the snakes, Dipsadidae showed the greatest richness, with a total of nine species. The group of snakes had the highest number of species present in the community, but 79% of sampled specimens were lizards, Enyalius bilineatus being the most abundant species, with 21% of occurrence. The area with the highest richness was the Cerradão. The lower abundance was found in the Gallery Forest area (n=14), but it was the vegetation type with the highest equitability. Areas of Cerradão and Cerrado sensu strictu showed the most similarity. In these areas five species were recorded in common, Bothrops neuwiedi (n=3) being the only species of snake, and the two species of lizards most abundant in both environments were Enyalius bilineatus (n=32) and Ameivula ocellifera (n=19). Ophiodes striatus and Xenodon merremii were common to Cerradão and Dirty Field areas. There was no species recorded that were common to the environments of Cerrado and Dirty Field but two species not sympatric were found of the same genus, Tropidurus torquatus, which was found only in the Cerrado sensu strictu and Tropidurus itambere exclusively in Dirty Field. Since none of the rarefaction curves reached full asymptote, this highlights the need for further study due to the high probability of new species being recorded for the studied area.

In the shadows: Phylogenomics and coalescent species delimitation unveil cryptic diversity in a Cerrado endemic lizard (Squamata: Tropidurus)

The recognition of cryptic diversity within geographically widespread species is gradually becoming a trend in the highly speciose Neotropical biomes. The statistical methods to recognise such cryptic lineages are rapidly advancing, but have rarely been applied to genomic-scale datasets. Herein, we used phylogenomic data to investigate phylogenetic history and cryptic diversity within Tropidurus itambere, a lizard endemic to the Cerrado biodiversity hotspot. We applied a series of phylogenetic methods to reconstruct evolutionary relationships and a coalescent Bayesian species delimitation approach (BPP) to clarify species limits. The BPP results suggest that the widespread nominal taxon comprises a complex of 5 highly supported and geographically structured cryptic species. We highlight and discuss the different topological patterns recovered by concatenated and coalescent species tree methods for these closely related lineages. Finally, we suggest that the existence of cryptic lineages in the Cerrado is much more common than traditionally thought, highlighting the value of using NGS data and coalescent techniques to investigate patterns of species diversity.

Simplified three-dimensional model provides anatomical insights in lizards' caudal autotomy as printed illustration.

Lizards' caudal autotomy is a complex and vastly employed antipredator mechanism, with thorough anatomic adaptations involved. Due to its diminished size and intricate structures, vertebral anatomy is hard to be clearly conveyed to students and researchers of other areas. Three-dimensional models are prodigious tools in unveiling anatomical nuances. Some of the techniques used to create them can produce irregular and complicated forms, which despite being very accurate, lack didactical uniformity and simplicity. Since both are considered fundamental characteristics for comprehension, a simplified model could be the key to improve learning. The model here presented depicts the caudal osteology of Tropidurus itambere, and was designed to be concise, in order to be easily assimilated, yet complete, not to compromise the informative aspect. The creation process requires only basic skills in manipulating polygons in 3D modeling softwares, in addition to the appropriate knowledge of the structure to be modeled. As reference for the modeling, we used microscopic observation and a photograph database of the caudal structures. This way, no advanced laboratory equipment was needed and all biological materials were preserved for future research. Therefore, we propose a wider usage of simplified 3D models both in the classroom and as illustrations for scientific publications.

Helminths from Lizards (Reptilia: Squamata) at the Cerrado of Goiás State, Brazil

Forty-three specimens representing 11 species of lizards (Ameiva ameiva, Anolis chrysolepis brasiliensis, Cnemidophorus cf. parecis, Hemidactylus mabouia, Mabuya dorsivittata, Mabuya nigropunctata, Ophiodes striatus, Philautus acutirostris, Tropidurus itambere, Tropidurus oreadicus, and Tupinambis merianae) collected in 6 localities of the Cerrado biome in the Brazilian state of Goiás were examined for helminths. Thirteen species of nematodes (Cruzia travassosi, Gynaecometra bahiensis, Oswaldofilaria sp., Parapharyngodon sp., Parapharyngodon largitor, Parapharyngodon sceleratus, Pharyngodon travassosi, Physaloptera sp., Physaloptera lutzi, Physaloptera retusa, Physalopteroides venancioi, Subulura lacertilia) and an unidentified species of cestode (Oochoristica sp.) were recovered from lizard hosts. Thirteen new host records and 7 locality records are reported.

Helminths from Seven Species of Lizards (Reptilia: Squamata) at the Cerrado of Mato Grosso do Sul State, Brazil

Sixteen specimens representing 7 species of lizards (Hoplocercus spinosus, Ophiodes striatus, Polychrus acutirostris, Stenocercus caducus, Tropidurus guarani, Tropidurus itambere, and Tupinambis merianae) collected in the Cerrado biome at the Brazilian state Mato Grosso do Sul were examined for helminths. Nine species of nematodes were recovered from lizard hosts (Cruzia travassosi, Cyrtosomum sp., Diaphanocephalus galeatus, Gynaecometra bahiensis, Pharyngodon cesarpintoi, Physaloptera sp., Skrjabinellazia intermedia, Strongyluris oscari, and an unidentified species of nematode). Five new host records and 3 new locality records were reported.

Seasonal changes in testicular and epididymal histology of the tropical lizard, Tropidurus itambere (Rodrigues, 1987), during its reproductive cycle

The reproductive cycles of lizards, including Tropidurus species, have been widely studied. However, few studies describe in detail the ultrastructure and the epithelial changes in the epididymis. Using histology and trasmission electron microscopy, we show the seasonal changes in the testis and epididymis of the lizard Tropidurus itambere, during its annual reproductive cycle. The reproductive cycle of T. itambere was analysed from June 1988 to June 1989 and from June 2001 to June 2002. While the frequency of reproductive males in the population varied throughout the year, there were reproductive males in most months except for February through April. During this nonreproductive period, there is a reduction in the mean seminiferous tubule volume and few sperm were found in both the testis and the epididymis.

Padrões de parasitismo por Eutrombicula alfreddugesi (Oudemans) (Acari, Trombiculidae) em três espécies de Tropidurus Wied (Squamata, Tropiduridae) do Cerrado brasileiro

This study concerns the patterns of parasitism by the larvae of Eutrombicula alfreddugesi (Oudemans, 1910) on three species of Tropidurus Wied, 1820 from Cerrado habitats of Central Brazil: T. oreadicus Rodrigues, 1987 (n = 97), T. itambere (n = 85) and T. torquatus (Wied, 1820) (two samples n = 75, n = 23). The highest prevalence value was observed in T. itambere (88.2%), followed by T. oreadicus (87.6%), and T. torquatus (17.3% and 65.2%). The most important sites of infestation were the mite pockets and skin folds, especially on the neck and inguinal region. Tropidurus itambere Rodrigues, 1987 was the most heavily parasitized species (mean intensity of infestation: 36.67 ± 41.09), followed by T. oreadicus (15.38 ± 21.08), and T. torquatus from Unai, Minas Gerais (12.13 ± 21.09). The lowest intensity of infestation was found in T. torquatus from urban and periurban areas of Brasilia, Distrito Federal (1.97 ± 5.43). The analysis did not indicate differences in intensity of infestation between sexes for any of the species. Differences in the patterns of parasitism among the three lizard species may be related to the morphological and numerical variation of the skin folds (especially mite pockets), to the degree of conservation of the host’s habitats, and to selective processes related to reduction of damage to the host’s bodies, to the evolution of mechanisms of decreasing illness transmission by parasites, or even to some behavioral traits of the lizards.

Patterns of parasitism by Eutrombicula alfreddugesi (Oudemans) (Acari, Trombiculidae) in three species of Tropidurus Wied (Squamata, Tropiduridae) from Cerrado habitat of Central Brazil

This study concerns the patterns of parasitism by the larvae of Eutrombicula alfreddugesi (Oudemans, 1910) on three species of Tropidurus Wied, 1820 from Cerrado habitats of Central Brazil: T. oreadicus Rodrigues, 1987 (n = 97), T. itambere (n = 85) and T. torquatus (Wied, 1820) (two samples n = 75, n = 23). The highest prevalence value was observed in T. itambere (88.2%), followed by T. oreadicus (87.6%), and T. torquatus (17.3% and 65.2%). The most important sites of infestation were the mite pockets and skin folds, especially on the neck and inguinal region. Tropidurus itambere Rodrigues, 1987 was the most heavily parasitized species (mean intensity of infestation: 36.67 ± 41.09), followed by T. oreadicus (15.38 ± 21.08), and T. torquatus from Unaí, Minas Gerais (12.13 ± 21.09). The lowest intensity of infestation was found in T. torquatus from urban and periurban areas of Brasília, Distrito Federal (1.97 ± 5.43). The analysis did not indicate differences in intensity of infestation between sexes for any of the species. Differences in the patterns of parasitism among the three lizard species may be related to the morphological and numerical variation of the skin folds (especially mite pockets), to the degree of conservation of the host's habitats, and to selective processes related to reduction of damage to the host's bodies, to the evolution of mechanisms of decreasing illness transmission by parasites, or even to some behavioral traits of the lizards.

Ultrastructural immunocytochemical evidence for actin in the acrosomal complex during spermiogenesis of the lizardTropidurus itambere(Rodrigues, 1987) (Reptilia: Tropiduridae)

AbstractDuring spermiogenesis of the lizard Tropidurus itambere early developmental stages of the acrosomal complex have been analysed and new suggestions made as to their origin. Actin has been detected in the acrosomal granule and pro-acrosomal vesicle of spermatid, using an antibody for α-smooth muscle actin (monoclonal α-SMA). Intense marking also identified actin in two regions of the acrosomal complex; the subacrosomal cone and the perforatorium. The acrosomal and subacrosomal granules appear to participate to the formation of the perforatorium, while the pro-acrosomal vesicle is responsible for the formation of the subacrosomal cone. The results therefore endorse the view that, in lizards, the perforatorium and subacrosomal cone are homologous, in composition and probably also in function.

Helminths of the exotic lizard Hemidactylus mabouia from a rock outcrop area in southeastern Brazil

The helminth fauna of 291 Hemidactylus mabouia (Lacertilia: Gekkonidae) from a rock outcrop area in the state of São Paulo, Southeastern Brazil, was studied. Five species were recovered, namely one unidentified species of centrorhynchid acanthocephalan (present only as cystacanths) and the nematodes Parapharyngodon sceleratus, P. largitor (Oxyuroidea: Pharingodonidae), Physaloptera sp. (Spiruroidea: Physalopteridae) and one indeterminate species of Acuariidae (Acuaroidea), with the latter two forms present only as larvae. Infection rates tended to increase with host size, but appeared to be unaffected by season. Hemidactylus mabouia shared most of its helminth fauna with two other sympatric lizard hosts, Mabuya frenata and Tropidurus itambere. The helminth assemblage of the H. mabouia population appears to have been entirely acquired by this exotic gecko from the local helminth species pool, rather than possessing any species from the parasite faunas of the original African populations.

Sperm ultrastructure and spermatogenesis in the lizard, Tropidurus itambere

Spermatogenesis, with emphasis on spermiogenesis, is described for the lizard, Tropidurus itambere, using light microscopy, phase contrast and epifluorescence, as well as scanning and transmission electron microscopy. Cellular differentiation involves events of chromatin condensation, nuclear elongation and the formation of structural complexes, such as the acrosomal and axonemal ones. Other new characteristics, exclusive for this species, include various aspects of the subacrosomal granule, the insertion of the pro-acrosomal vesicle and the development of these structures to participate in the acrosomal complex. Radial projections occurjust above the nuclear shoulders, which have been recognized already from the beginning of cellular elongation. The development of the midpiece, the dense bodies, formation of the flagellum and elimination of residual cytoplasm result in the final characterization of the mature spermatozoon. Comparisons between Tropiduridae and other lizard families are made.

Cytochemical study of spermiogenesis and mature spermatozoa in the lizard Tropidurus itambere (Reptilia, Squamata)

The present study was undertaken to detect essential components of spermatozoa by ultrastructural and cytochemical analyses of testis and epididymis of the lizard Tropidurus itambere at different points of its annual reproductive cycle. Cytochemical investigations of spermiogenesis have not been performed so far in Squamata and are scarce for lower vertebrates. Essential components are: 1) polysaccharides, identified by PAS staining, abundantly present in Sertoli cell elongations, acrosomal vesicles and the acrosome of sperm cells; 2) glycoconjugate variations, labeled by different lectins and used to investigate cell modifications during spermiogenesis and found in mature spermatozoa in the female's seminal receptacle; 3) basic proteins, present in large quantities in spermatozoa in the subacrosomal cone, the pericentriolar material, the midpiece dense bodies, the peripheral fibers of the axoneme, and the fibrous sheath of the flagellum; 4) the final reaction product of acid phosphatase activity in several stages of acrosome development, specifically in the clear zone and epinuclear electron-lucent region of spermatozoal acrosomes, as well as in very active lysosomes found during the quiescent period of the reproductive cycle; 5) lipids, abundantly present in the cytoplasm of Leydig cells during the quiescent period. The cytochemical methods show that the ultrastructurally complex acrosome is also biochemically heterogeneous, with specific layers rich in glycoproteins, basic proteins or acid phosphatase. These different components may play a role during sperm penetration into the ovule. Basic proteins are largely responsible for structures surrounding the axoneme to provide resistance to the flagellum. In the quiescent period, acid phosphatase activity is involved in the elimination of superfluous sperm cells, whereas lipids in Leydig cells are used for hormone synthesis which starts at this time point to initiate a new reproductive cycle. Variations in lectin staining revealing glycoconjugates show that spermatozoa undergo post-testicular maturation up to their storage in the female.

Tail loss in the Syntopic Lizards Tropidurus itambere (Tropiduridae) and Mabuya frenata (Scincidae) in Southeastern Brazil

Tail autotomy rates were assessed for two syntopic lizards (Tropidurus itambere, Tropiduridae and Mabuya frenata, Scincidae) in Valinhos, São Paulo state, Brazil. Tail-break frequencies did not differ significantly between sexes in either species, though female T. itambere and male M. frenata generally had higher frequencies within a given size range. M. frenata had a considerably higher frequency of tail autotomy (82.4%; N = 216) than T. itambere (23.0%; N = 547), which we believe to be mainly due to phylogenetic differences in ease of tail shedding between the two genera. We also compare our results with data for several other cisandean South American lizards.

Growth and Body Condition of the Saxicolous Lizard Tropidurus itambere in Southeastern Brazil

I studied the growth of Tropidurus itambere in an outcrop formation in Sao Paulo State, southeastern Brazil. I noosed lizards monthly from February 1993 to January 1995. Growth rate estimates were based on sizes (snout-vent length) of lizards recaptured within 25 to 40-day intervals. Male T: itambere grew faster (x = 0.15 mm/day) than females (x = 0.11 mm/day; ANCOVA, P < 0.01) and this difference may account for the sexual dimorphism observed in this species. There was no significant difference in size- independent growth rates between lizards with intact tails and those which lost their tails, suggesting that the energetic costs of tail loss and regeneration are not high enough to affect growth in this species. Female growth rates were not significantly affected by temperature, arthropod availability, or reproduction, but the overall effect of these variables significantly affected male growth rates. Arthropod biomass affected only female body condition. Age at maturity for males and females was approximately 150 and 180 days, respec- tively.

Nematodes infecting the lizard Tropidurus itambere in southeastern Brazil

Nematodes infecting the lizard Tropidurus itambere in southeastern Brazil

Food Habits of the Lizard Tropidurus itambere (Tropiduridae) in Southeastern Brazil

Food Habits of the Lizard Tropidurus itambere (Tropiduridae) in Southeastern Brazil

The Reproductive Cycle of Tropidurus itambere (Sauria: Tropiduridae) in Southeastern Brazil

The reproductive cycle of the lizard Tropidurus itambere was studied in an open area near Campinas, Sao Paulo State, southeastern Brazil. Females had vitellogenic follicles or oviductal eggs only during the wet season, whereas males had large testes with spermatozoa throughout the year. Hatchlings were found from the height of the rainy season to its end (January to May). Mean growth rate was inversely related to snout-vent length. Juveniles from eggs laid at the beginning of the rainy season could potentially have reproduced in the first wet season after they hatched

Notes on mimicry between two tropical beetles in south-eastern Brazil

Unpalatable animals with warning colouration or some other sign to warn predators are termed aposematic and may serve as models for palatable species, so-called Batesian mimics (Bates 1862). The literature on animal colour patterns, aposematism and mimicry is very extensive, and includes many reviews (e.g. Cott 1940, Edmunds 1974, Waldbauer 1988a, Wickler 1968). However, there is little informationon the phenological relationships between models, mimics and their predators (Waldbauer 1988b). One of the most abundant and widespread groups of tropical flea-beetles is the subtribe Oedionychina (Chrysomelidae) which has many unpalatable species, such as Homophoeta octoguttata Fabr., a toxic and conspicuous member of the Alticinae, that eliminates a yellow deterrent buccal fluid when handled (see Begossi & Benson 1988). In this paper I investigate a possible case of Batesian mimicry between H. octoguttala (model) and Adesmus colligathus Redtenbacher (mimic, Cerambycidae), comparing their field densities in a tropical forest. The study site, Serra do Japi, in the municipality of Jundiai (230 11' S, 46? 52' W), State of Sao Paulo, is similar in vegetation type to Atlantic coast forests (detailed description in Morellato 1991). The climate of the area is characterized by a rainy/hot season from September to early June, and a dry/cold season from July to early August. Field observations were made three times per month during 1988 and 1989. During each visit 7 km of forest trails were monitored for 6 h, from 0900 h to 1500 h. Along the forest trails and in a zone 2 n wide to either side, all beetles of both species that were flying, or seen on plants, were recorded. Predation observations were performed in the laboratory with the lizard (N = 3) Tropidurus itambere Rodrigues (Iguanidae), which has a considerable part of its diet (approximately 19%/ in volume) composed of beetles (Van Sluys 1990) .