Brazilian Institute of Environment and Renewable Natural Resources

About: Brazilian Institute of Environment and Renewable Natural Resources is a government organization based out in Brasília, Brazil. It is known for research contribution in the topics: Population & Deforestation. The organization has 549 authors who have published 732 publications receiving 13999 citations. The organization is also known as: IBAMA.

Fitase e digestibilidade aparente de nutrientes de rações por tilápias-do-nilo

Abstract: The nutrient apparent digestibility of diet with increasing phytase levels based on vegetable ingredients fed to 90 Nile Tilapia juveniles averaging 120.0 g and allotted to none tanks (ten fishes/tank) was determined. The experiment was analyzed as a complete randomized design with nine treatments and six replicates. The treatments consisted of: control (with phosphorus supplementation) and eight treatments without phosphorus supplementation (with 500, 1,000, 1,500, 2,000, 2,500, 3,000, 3,500, and 4,000 units of phytase [UF]/kg of diet). All diets were formulated to be isoenergy and isoprotein. The 1,500 UF treatment increased DM and GE digestibility and dietary Ca and P availability. The 1,000 UF treatment increased Zn and Mn availability.

Fertilização e desenvolvimento embrionário: Morfometria e análise estereomicroscópica dos ovos dos híbridos de surubins (pintado, Pseudoplatystoma corruscans x cachara, Pseudoplatystoma fasciatum)

Abstract: This study aimed to analyze the morphometry of hybrids’ eggs under stereomicroscopy. The induced reproduction was carried out in specimens of pintado’s females (P. corruscans) and cachara’s males (P. fasciatum) from Cepta - Ibama, Pirassununga, state of Sao Paulo, Brazil. Samples were collected in extrusion moment, during the fertilization, in times of 10 and 30 seconds, 1, 2, 5, 8, 10, 15, 20, 30 and 45 minutes, 1 hour, at every 15 minutes until completing 2 hours, and afterwards, at every hour until the larval hatching. Oocytes and eggs’ external morphology were observed, photographed and 30 samples from each moment were measured in stereomicroscopy. Oocytes, in the time of extrusion, and the eggs presented a spherical form and yellowish color. Characteristics such as wide perivitelinic space, somites, presence of optical vesicle and the main phases of embryonic development as egg-cell (blastodisc), 2, 4, 8, 16, 32 and 64 blastomeres, morula, blastula, gastrula, epiboly movements, formation and larvae hatching were verified.

A method for testing the host specificity of ectoparasites: give them the opportunity to choose

Abstract: Host-choice experiments were carried out with rodent and bat ectoparasites on Ilha Grande, state of Rio de Janeiro, Brazil. We constructed experimental chambers that enclosed three different rodent or bat host species, and then introduced a selected set of ectoparasitic arthropods. When given the opportunity to choose among host species, the ectoparasites showed a strong tendency to select their primary hosts, and reject novel host species. These kinds of simple experiments can be valuable tools for assessing the ability of ectoparasites to locate and discern differences between host species, and make choices about which hosts to infest, and which hosts to avoid.

Vulnerability of Cerrado threatened mammals: an integrative landscape and climate modeling approach

Abstract: Species vulnerability is defined based on their exposition, sensitivity and adaptive capacity to a given impact Considering limitations to estimate the sensitivity component, we developed a framework integrating the knowledge on ecological niche models and extinction thresholds, generating species sensitivity scenarios at the landscape scale Our aim was to assess species and landscape vulnerability for threatened mammal species from the Brazilian Cerrado by considering seven types of human-impacts and climatic suitability We assumed that climatic-suitable landscapes with less than 50% of remaining natural vegetation are not suitable for species, while in landscapes with 50–60% of remaining natural vegetation, populations are highly vulnerable We found a spatial match between climatic-suitable areas and highly-impacted landscape (< 50% of remaining vegetation), specifically in southern Cerrado We attribute this result to two main reasons: (1) similar characteristics affecting both suitability for species and human activities; and (2) highly impacted landscapes are likely to shelter threatened species Vulnerable cells, with 50–60% of remaining vegetation, were distributed throughout Cerrado, meaning that there is no spatial bias within their distribution Range-restricted species exhibited higher variability in vulnerability compared to widely-distributed species, what could be explained by human occupation being spatially clumped Agriculture is the major impact affecting highly-impacted landscapes (< 50% of remaining vegetation), transport infra-structure has higher impact on vulnerable landscapes We believe that our approach can be easily applied for assessing species and landscape vulnerability in many ecological domains by adapting extinction thresholds according to the focus taxon