<b>Estimate of the condition factor of fish of the <em>Tracydoras paraguayensis species</em>: a Bayesian perspective</b> - DOI: 10.4025/actascianimsci.v29i1.263

Abstract

The factor of fish condition expresses the weight-lengthrelationship and it is accepted as an indicator for the evaluation of the animal "well-being";as larger the weight, best should be your survival condition. This work aims to fit a Gammamodel, from the exponential family with power link function, to data of lengthmeasurements and weight of fish from the Trachydoras paraguayensis species, observed in thebasin of the Paraná River, Paraná-Brazil. The estimates of the parameters of the model wereobtained by two different processes: by a classic method (maximum likelihood) and byBayesian method (MCMC). It was observed that the Bayesians estimates (posterior mean)of the parameters of interest were similar to the classic estimates, the dispersion parameter,it underestimated the classic estimate, however the dispersion parameter is inferior to theobtained by the classic estimate, besides supplying a standard mistake 30% smaller.