Distribution of populations of broad-snouted caiman (Caiman latirostris, Daudin 1802, Alligatoridae) in the São Francisco River basin, Brazil

We surveyed populations of the broad-snouted caiman, Caiman latirostris, throughout the São Francisco River basin, from Três Marias reservoir, State of Minas Gerais, to the river delta, at the boarder of Sergipe and Alagoas states. We registered the occurrence of crocodilians in 61% of all surveyed localities (n = 64), in which the presence of C. latirostris was confirmed in 44% of the surveyed sites. Caimans occurred in both lentic and lotic habitats, although there was a preference for small dams, oxbow lakes and wetlands. Despite the hunting pressure and human impact on natural habitats, our results indicate that the populations of C. latirostris in the São Francisco basin are not fragmented

Infection patterns of Paradollfusnema amphisbaenia (Nematoda: Cosmocercidae) in a population of Amphisbaena wuchereri (Squamata: Amphisbaenidae) from Minas Gerais state, south-eastern Brazil, and its relations with host size, sex and fat body mass

Specimens (n= 41) of the amphisbaenid Amphisbaena wuchereri taken from a population in Minas Gerais state, south-eastern Brazil, were examined for gastrointestinal parasites. A single nematode species was found, Paradollfusnema amphisbaenia. This was a new host record for this nematode species. This parasite was encountered in the large intestine (prevalence of 100%), in the stomach (prevalence of 2%) and in the small intestine (prevalence of 7.3%). The intensity of infection ranged from 1 to 457 individual parasites per host and was positively correlated with body size of both male and female amphisbaenians. The discrepancy index (D) indicated that P. amphisbaenia tended to an even distribution in this host population. The nematode, which did not affect fat body mass, induced inflammatory infiltrations in the small intestine, indicating that the parasites might injure the host's organs. Copyright © Cambridge University Press 2012

Settleable atmospheric particulate matter affects cardiorespiratory responses to hypoxia in Nile tilapia (Oreochromis niloticus)

International audienc

Growth rate, leaf:stem ratio and height in crotalaria (Crotalaria juncea L.) planted at different densities

Objetive: To evaluate the growth rate, leaf:stem ratio and height of crotalaria plants (Crotalaria juncea L.), cultivated at different densities, in the dry tropics of the state of Guerrero, Mexico. Desing / Methodology / Approach: The treatments were: four planting densities at 400,000, 200,000, 100,000 plants ha-1 and trickling. A growth analysis was also evaluated at 30, 38, 45, 52, 60, 68 and 75 days of growth, including that the pod was fully developed. The variables evaluated were: growth rate, leaf:stem ratio and plant height. Results: The best growth rate was found at a density of 400,000 plants ha-1, at 75 days of development, with 577 kg DM ha-1 d-1; similar to plant height, which at this density presented 281 cm. Contrary to the leaf:stem ratio, which was greater than 30 days. Regardless of age, a descending behavior was found in the following order: 100,000 ˃ chorrillo ˃ 200,000 ˃ 400,000 plants ha-1 with 0.65, 0.60, 0.59 and 0.55 (p < 0.05). Study Limitations / Implications: This study is essential for future research because these variables have not been evaluated in this crop; being important for forage production. Findings / Conclusions: It is recommended to sow at a density of 400,000 plants ha-1, finding a higher leaf:stem ratio at 30 days of development and a plant height at day 75, when pod production also begin

Morphology and forage quality in buffel, rhodes, and blue grama grasses in Valle del Mezquital: Grasses of semiarid

The objective of the study was to evaluate the production and quality of forage in buffel (Pennisetum ciliare), rhodes (Chloris gayana) and blue grama (Bouteloua gracilis) with three defoliation dates at 50, 80 and 110 days after regrowth (dar) in Valle del Mezquital. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), total digestible nutrients (TDN), relative forage value (RFV) and metabolic energy (ME) were determined. A completely randomized design with three repetitions was used and Tukey for separation of means (α 0.05) and GLM SAS to analyzer data. The highest forage production occurs in rhodes grass at 110 dar (12936 kg DM ha-1). The highest CP (10.6%) was found in buffel at 50 ddr, in rhodes grass both values (80 and 110) dar the ​​were lower than 7%. The largest RFV were for exotic grasses; however, blue grama registered higher TDN. The lowest ME is operated in rhodes at 80 dar (1.76) and higher for buffel at 50 dar (1.91). The three varieties could defoliate when the plants show intermediate values ​​in yield and nutritional value, that is, after 80 days of regrowth; individually it is recommended to defoliate buffel and rhodes at 50 dar.This study aims to evaluate the production and quality of buffel (Pennisetum ciliare), rhodes (Chloris gayana), and blue grama (Bouteloua gracilis) forage with three defoliation dates —at 50, 80, and 110 days after regrowth (dar)— in Valle del Mezquital. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), total digestible nutrients (TDN), relative feed value (RFV), and metabolizable energy (ME) were determined. A completely randomized design with three repetitions, a Tukey test for mean separation (α 0.05), and SAS Proc GLM for data analysis were used. The highest forage production occurs in the rhodes forage at 110 dar (12,936 kg DM ha-1). The highest CP (10.6%) was found in the buffel forage at 50 dar; in the rhodes forage, both values (80 and 110) were lower than 7%. The highest RFV was obtained by exotic grasses; however, higher TDN was recorded for the blue grama grass. Rhodes grass obtained the lowest ME at 80 dar (1.76), while the highest ME was obtained by buffel at 50 dar (1.91). The three varieties can be defoliated when the plants show intermediate yield and nutritional value, i.e., 80 days after the regrowth begins; nevertheless, buffel and rhodes should be defoliated at 50 dar

The electrocardiogram of vertebrates: Evolutionary changes from ectothermy to endothermy

The electrocardiogram (ECG) reveals that heart chamber activation and repolarization are much faster in mammals and birds compared to ectothermic vertebrates of similar size. Temperature, however, affects electrophysiology of the heart and most data from ectotherms are determined at body temperatures lower than those of mammals and birds. The present manuscript is a review of the effects of temperature on intervals in the ECG of ectothermic and endothermic vertebrates rather than a hypothesis-testing original research article. However, the conclusions are supported by the inclusion of original data (Iguana iguana, N = 4; Python regius, N = 5; Alligator mississippiensis, N = 4). Most comparisons were of animals of approximately 1 kg. Compared to mammals and birds, the reptiles at 35–37 °C had 4 fold lower heart rates, 2 fold slower atrial and ventricular conduction (longer P- and QRS-wave durations), and 4 fold longer PR intervals (atrioventricular delay) and QT intervals (total ventricular repolarization). We conclude that the faster chamber activation in endotherms cannot be explained by temperature alone. Based on histology, we show that endotherms have a more compact myocardial architecture. In mammals, disorganization of the compact wall by fibrosis associates with conduction slowing and we suggest the compact tissue architecture allows for faster chamber activation. The short cardiac cycle that characterizes mammals and birds, however, is predominantly accommodated by shortening of the atrioventricular delay and the QT interval, which is so long in a 1 kg iguana that it compares to that of an elephant1441629CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNão temNão tem2016-20158-6; 2012/16537-0RF and MRS received a scholarship from the São Paulo Research Foundation (FAPESP) (#2016-20158-6 and 2012/16537-0); LBTC received a scholarship from the Coordination for the Improvement of Higher Education Personnel (CAPES - DS); ASA was funded by the National Council for Scientific and Technological Development (CNPq) and FAPESP through the Institute of Science and Technology for Comparative Physiology (INCT-FisC).WJ received an EliteForsk travel grant from the Danish Ministry of Higher Education and Science to visit the research groups of BJ and DAC II. BJDB was supported by the Dutch Heart Foundation (2016T047). BJ was kindly allowed to photograph the sperm whale heart kept at the Faculty of Veterinary Medicine, Utrecht, The Netherland