Here we present a commented list of mammals registered in the Serra da Bocaina National Park. Three field trips (February, 2010, and May and July, 2011) were accomplished along the RJ-165 highway in the Municipality of Paraty, State of Rio de Janeiro, Brazil. Forty-eight species belonging to nine orders were recorded. The local mammal fauna could be considered diverse and rich, with some species regarded as biological indicators of habitat quality. Endangered and rare rodent species like Blarinomys breviceps, Juliomys rimofrons, and Thaptomys nigrita were captured. Road and hunting impacts on mammals are discussed.

The kinematics of each joint of the guinea pig Cavia porcellus were studied during the locomotor cycle at increasing speed by high-speed cinefluorography. The main objective was to reveal the functional specific features of these structural elements in each dynamic phase of the cycle and also which limb joints are important during the increase of animal speed. Most of the analysed angles in C. porcellus were affected as the speed increased, both in trot and gallop. However, only a few of them were correlated with speed. There were also differences with respect to symmetrical or asymmetrical gaits. Both pairs of limbs responded differently to the increase of speed; while the forelimb joints modified the duration of their action (frequency) more than the amplitude (stride length), the hindlimbs acted inversely. The movements of the joints during the stance phase changed dramatically with speed, particularly in the hindlimb. At knee level, the flexion amplitude increases to maintain the stiffness of the leg spring, a principle previously discussed as essential for the running process. In the swing phase, inertial effects are the main constraints and, as in the stance phase, the knee joint in the swing phase is correlated with speed both during trot and gallop, confirming the major importance of this joint to increasing speed.

BackgroundMorphological descriptions comparing Leposternon microcephalum and L. scutigerum have been made previously. However, these taxa lack a formal quantitative morphological characterization, and comparative studies suggest that morphology and burrowing performance are be related. The excavatory movements of L. microcephalum have been described in detail. However, there is a lack of studies comparing locomotor patterns and/or performance among different amphisbaenids sharing the same skull shape. This paper presents the first study of comparative morphometric variations between two closely related amphisbaenid species, L. microcephalum and L. scutigerum, with functional inferences on fossorial locomotion efficiency.MethodsInter-specific morphometric variations were verified through statistical analyses of body and cranial measures of L. microcephalum and L. scutigerum specimens. Their burrowing activity was assessed through X-ray videofluoroscopy and then compared. The influence of morphological variation on the speed of digging was tested among Leposternon individuals.ResultsLeposternon microcephalum and L. scutigerum are morphometrically distinct species. The first is shorter and robust with a wider head while the other is more elongated and slim with a narrower head. They share the same excavatory movements. The animals analyzed reached relatively high speeds, but individuals with narrower skulls dug faster. A negative correlation between the speed and the width of skull was determined, but not with total length or diameter of the body.DiscussionThe morphometric differences between L. microcephalum and L. scutigerum are in accord with morphological variations previously described. Since these species performed the same excavation pattern, we may infer that closely related amphisbaenids with the same skull type would exhibit the same excavatory pattern. The negative correlation between head width and excavation speed is also observed in others fossorial squamates. The robustness of the skull is also related to compression force in L. microcephalum. Individuals with wider heads are stronger. Thus, we suggest trade-offs between excavation speed and compression force during burrowing in this species.

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The amphisbaenian Leposternon octostegum (Duméril, 1851) is redescribed based on newly collected material from the state of Bahia, Brazil.  Species validity was confirmed, and comparisons made to other Leposternon species and to the scarce literature available on Leposternon octostegum taxonomy.  Aspects of meristic annuli methodology are reviewed, and nomenclatural adjustments for some scales are proposed.  To place this information in its taxonomic context, a species identification key for the Brazilian species of the genus Leposternon is provided.  The present redescription contributes to a better understanding of Amphisbaenia taxonomy, thus also enabling the design of more adequate conservation and management strategies for the species belonging to this group.

SUMMARY:The anaconda Eunectes murinus (Linnaeus, 1758) inhabits large hydrographic basins in tropical America and figures among the world's largest snakes, attaining a length of 12 m. This study analyzed the growth of three female anaconda siblings, with records from their birth in captivity up to around 14 months of age. The snakes were kept in a controlled environment with constant temperature and data related to biometry, feeding and skin shedding were recorded. At the end of these 445 days, the siblings had grown on average 2.6 times their initial length and increased their initial weight by 3830.10g, incorporating about 43.5% of total food ingested to their body mass. They showed a total of 0.69 skin sheddings per month in that period, and did not exhibit significant differences in shedding intervals, nor in body growth (weight and length), when compared among themselves. Food was refused at times, coinciding with the days that preceded the ecdyses. Sheddings do not seem to be explained by feeding or growth, which suggests a relation to other endogenous factors. A more detailed study of this species is needed to better understand its growth to the adult phase and its hormonal levels during growth.

Imantodes cenchoa (Duméril, 1853) is an arboreal, nocturnal and oviparous xenodontine snake, which feeds on amphibians and lizards. It is found in Central and South America, including northern and central Brazil. In this work, we investigated the relationship between topographic anatomy and habitat in I. cenchoa. Twenty specimens (13 non pregnant females and 7 males) were examined. The topographic anatomy study was realized through observations of the internal anatomy, particularly the position and size of lung, heart, liver, left and right gonads and left and right kidneys. Results showed that all the organs are located in a posterior position in relation to the snout vent length (SVL). The centre of gravity is found at about 74% of SVL in both males and females. In males, no positive allometry was observed among the positions of the organs. Negative allometry in females was observed regarding the position of the anterior tip of the left kidney, the anterior and posterior tips of the right kidney and in both ovaries. In males, negative allometry is present in the position of all the or gans. The distance between the last follicle and the cloaca was 8.78% of SVL. Our data corroborate the idea that the posterior position of all internal organs is linked to a habitat specialization of a snake, linking the arboreal species I. cenchoa with a relatively posterior internal topography.

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