Chemical transfer of warning information in non-injured fish

In this study we describe pacus, Piaractus mesopotamicus, detecting the presence of a predator by conspecific alerting pheromone. Moreover, we investigate whether this chemical information indicates the presence of a specific predator, or whether it indicates general disturbance. We exposed groups of pacus to the view of a predator fish (trahira, Hoplias malabaricus), a non-predator fish (piracanjuba, Brycon orbignyanus) or an aquarium without any fish (control), and then we transferred their water to isolated conspecifics. We set up six trials of each condition in which we analysed the dispersion and the distance from the visual stimulus in water-donor fish and the distance from the chemical stimulus in water-receiver pacus. This study showed that pacus visually identified the presence of another fish and recognised it as predator or non-predator. This is interpreted as an innate response. Such heterospecific detection affects the behaviour of pacus, which release chemicals that induce conspecifics to adopt a similar behavioural response. At least two chemicals might be involved, one of them possibly an alerting pheromone.

A radar reflectivity-runoff model for use in flood warning

This model connects directly the radar reflectivity data and hydrological variable runoff. The catchment is discretized in pixels (4 Km × 4 Km) with the same resolution of the CAPPI. Careful discretization is made so that every grid catchment pixel corresponds precisely to CAPPI grid cell. The basin is assumed a linear system and also time invariant. The forecast technique takes advantage of spatial and temporal resolutions obtained by the radar. The method uses only the measurements of the factor reflectivity distribution observed over the catchment area without using the reflectivity - rainfall rate transformation by the conventional Z-R relationships. The reflectivity values in each catchment pixel are translated to a gauging station by using a transfer function. This transfer function represents the travel time of the superficial water flowing through pixels in the drainage direction ending at the gauging station. The parameters used to compute the transfer function are concentration time and the physiographic catchment characteristics. -from Authors

Complex Call with Different Messages in Bokermannohyla ibitiguara (Anura, Hylidae), a Gladiator Frog of the Brazilian Cerrado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pan-Assay interference compounds (PAINS): warning signs in biochemical-pharmacological evaluations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)