Summary 1. Effective tools are needed to measure the ‘health’ of rivers at scales large enough be useful for management. Indicators assessing complex variables that constitutes river health need ecologically based, efficient, rapid and consistently applicable in different ecological regions. 2. A large‐scale survey New South Wales, Australia provided data test Index Biotic Integrity (IBI). The IBI employs fish‐community attributes, identified using regional river‐size data, expected a reach...

Rates of growth and survival in wild populations are affected by the physical environment, biotic interactions, density-dependent processes, such as fecundity. However, relative importance these factors long-lived reptiles is poorly understood. We analyzed rates Melanosuchus niger Caiman crocodilus coexisting two areas Brazilian Amazon with very different environmental characteristics. Growth at sites were similar, but M. grew more slowly area higher productivity density caimans. same...

We studied the feeding behaviors of two sympatric species caimans (Melanosuchus niger and Caiman crocodilus) during dry season in Mamirauá Sustainable Development Reserve, Amazonas State, Brazil. Observations were made 50 × 13 m plots located along land-water interface. investigated influence interspecific density effects temperature water depth on both species. identified three principal categories behavior: trapping (with body perpendicular to shore, caiman captures prey swimming close...

The jaguar (Panthera onca) is the largest Neotropical felid and in many parts of its range reptiles form a significant but relatively minor component diet. However, seasonally flooded varzea forests Amazon, terrestrial mammals, which an important diet other habitats, are largely absent jaguars switch to alternative prey, including arboreal mammals reptiles. In Mamirauá Sustainable Development Reserve western Brazilian we document predation by on two species caiman (Caiman crocodilus...

TIMMIS, W. H. 1969. Observations on Pacific boas at Sydney Zoo. Int. Zool. Y. B., Vol. 9:53. UNDERWOOD, G. 1970. A systematic analysis of boid snakes. Linn. Soc. Symp. Ser. No. 3:151-175. VITT, L. J., AND J. D. CONGDON. 1978. Body shape, reproductive effort, and relative clutch mass in lizards: resolution a paradox. Amer. Natur. 112: 595-608. WYNN, A. H., R. ZUG. 1985. the biology Candoia carinata (Serpentes, Boidae). The Snake 17:15-24.

Schneider’s dwarf caiman Paleosuchus trigonatus is one of the smallest living crocodilians. Due to its broad distribution, cryptic behavior, and small home range, species well suited for study phylogeographic patterns on a continental scale. Additionally, this under threat due habitat loss, trade harvest, but considered at low conservation risk by IUCN. In present we test hypothesis that P. comprised geographically structured lineages. Phylogenetic reconstructions mitochondrial cytochrome b...

Stomach contents were collected from 213 Caiman crocodilus with snout-vent lengths (SVL) between 15 cm and 115 cm, 25 Melanosuchus niger SVLs to 95 in the Anavilhanas Archipelago, Rio Negro, Central Amazonia. The prey types consumed by two species generally similar. However, fish common diet of C. but absent M. niger. Snails (Po- macea) occurred 24% stomachs niger, only 2% crocodilus. mean mass food proportion increased, while terrestrial invertebrates decreased significantly size class...

Abstract Total mercury (Hg) concentrations of muscle, liver, blood, and epidermal keratin were measured in typically consumed, economically culturally important species turtle ( Podocnemis unifilis expansa ) caiman Melanosuchus niger Caiman crocodilus from the Rio Purus Amazon basin, Brazil. Methylmercury (MeHg) also muscle tissue, representing first analysis MeHg Amazonian reptile species. In tissues Hg was mostly (79–96%) for all No correlations existed between animal size total or any...

Caiman crocodilus and Melanosuchus niger occur throughout most of the Anavil- hanas Archipelago, located in lower Rio Negro, Central Amazonia. The observed densities these species vary from 0 to 58 per km shoreline 8 shoreline, respectively. Multiple regression analysis indicated that temperature difference between water air, depth affected density C. during spotlight surveys Archipelago. Percentage illumination by moon, cloud cover, frequency occurrence grass, food availability did not...

The genetic structure of Caiman crocodilus was investigated using a 1085 bp mtDNA fragment the cytochrome b gene. Inferences were based on 125 individuals from nine localities in Peru, Brazil and French Guiana. With exception Mamirauá Lake, Anavilhanas Archipelago Tapará Community which show signal demographic expansion, sampled are mutation-drift equilibrium. Divergence between Amazon basin extra-Amazon is significant; however, inference Nested Clade Analysis cannot distinguish continuous...

Between 1995 and 1998 we studied the effects of water level, moon phase, site on number caimans observed in spotlight surveys Mamirauá Sustainable Development Reserve, Brazilian Amazonia. Multiple linear regression analyses including level Amazon River phase explained 91 73% variance Melanosuchus niger seen Lago Cano Mamirauá, respectively, 60 76%, Caiman crocodilus seen. Water had a statistically significant negative effect M. C. Moon no seen, but more were detected nights with light. The...

Reference intervals for physiologic parameters, crucial assessing the health status of animals, have been documented various crocodilian species across globe. Nonetheless, establishment plasma biochemical reference specific to Amazonian crocodilians remains incomplete. In an effort address this gap, we procured blood samples from 65 black caimans (Melanosuchus niger) and 58 spectacled (Caiman crocodilus) during period September–December 2019 within Anavilhanas National Park in Brazilian...

Abstract We used the mitochondrial cytochrome b gene to study population genetic structure of Melanosuchus niger (Brazil: Negro and Purus Rivers, Lake Janauacá; French Guiana: Kaw River swamps), Caiman crocodilus River, swamps). found 10 haplotypes in M. 9 C. . Nested clade analysis indicated that isolation‐by‐distance was an important dynamic , but unable differentiate between isolation‐by‐distance, historical fragmentation or range expansion Fu's Fs statistic supported hypothesis a...

Abstract The formation of dominance hierarchies in which the female mates with a large dominant male is common among crocodilians. However, there possibility polyandry, females mate multiple partners during single breeding season and generate offspring paternity. In present study, eight pairs heterologous primers developed for Alligator mississippiensis Caiman latirostris were used to determine whether paternity exists Black Caiman, Melanosuchus niger . For such, we analyzed 34 from...

Although nesting ecology is well studied in several crocodilian species, it not known how nest attendance influences physiology and body condition of females. In this study, we describe serum biochemical values female, non-nesting female male spectacled caiman (Caiman crocodilus) black (Melanosuchus niger) two areas Central Amazonia. We also evaluated the effect age distance to water on blood parameters Body plasmatic concentrations glucose, triglycerides, lactate uric acid females were...

We assessed the spatial distribution of genetic variability Melanosuchus niger from 11 localities in South America using 1,027 base pairs mitochondrial cytochrome b gene. Screening 132 animals, we found 41 haplotypes, high values diversity, low nucleotide diversity and significant deviations neutral expectation allelic frequencies some localities. Mantel test nested-clade analysis indicated that isolation-by-distance was an important population dynamic for species as a whole. Wright's...

The Boa constrictor is one of the world's largest vertebrate carnivores and often found in urban areas city Manaus, Brazil. morphological identification ticks collected from 27 snakes indicated occurrence Amblyomma dissimile Koch 1844 on all individuals sampled. In contrast, rotundatum was only two snakes. An analysis 16S rRNA molecular marker confirmed these ectoparasites.

Hunting caimans (Caiman spp.) with baited hooks in the Brazilian Amazon represents one of largest illegal wildlife industries world. Our objective was to evaluate effects water level, distance from settlements, and hunting effort on caiman meat production. In 2008, we accompanied 31 expeditions around a wetland protected area located Amazon-Purus interfluve Brazil. We measured weighed all captured caimans. used simple multiple linear regressions analyze our data. The technique is not...

The Amazon aquatic ecosystems have been modified by the human population growth, going through changes in their water bodies and biota. spectacled alligator (Caiman crocodilus crocodilus) has a wide distribution adaptability to several environments, even those polluted ones. This study aimed investigate if Caiman species living urban streams of Manaus city (Amazonas State, Brazil) is affected environmental pollution. For that, it was used classical molecular cytogenetic procedures, addition...

Predation is one of the major causes crocodilian egg mortality. Many studies have suggested that opening nests, handling eggs, and capturing attending females may increase predation rates, but influence such activities on nest has not been quantified. For reason, we studied impacts different research nests wild Spectacled Caimans (Caiman crocodilus crocodilus) from a flooded forest (várzea) in Piagaçu-Purus Sustainable Development Reserve, Central Amazonia. During 2010 nesting season, eggs...

We describe the morphology of digestive tube Podocnemis expansa, unifilis, sextuberculata, erythrocephala, and Peltocephalus dumerilianus. The esophagus in these species has two distinct regions: anterior region esophageal papillae posterior longitudinal folds. Esophageal glands are absent but goblet cells occur mucosa esophagus. stomach P. erythrocephala consists cardiac fundic regions is without glands; more-posterior pyloric contains gastric that extend into lamina propria. In a J-shape,...