The use of premaxillary bones of six fish species in giant otter (Pteronura brasiliensis) diet analysis
The premaxillary bones of fish are considered key bones due to their highly differentiated features, allowing the identification to species level. When these bones are present in the latrines of giant otter (Pteronura brasiliensis), they can be used to identify fish species and estimate the size of prey consumed. We briefly describe the differentiable morphological characteristics of premaxillary bones,useful for the successful identification of six fish species which are important prey for giant otter in the Paraguá river (Bolivian Amazon): Hoplias malabaricus (family Erithrynidae), Serrasalmus rhombeus, Pygocentrus nattereri (family Characidae), Chaetobranchus flavescens, Satanoperca pappaterra and Astronotus crassipinnis (family Cichlidae). We also present the linear regression equations which can be used to estimate the standard length ofthese fish species based on their bone measurements. Overall, 19 latrine samples were analyzed, which contained 109 premaxillarybones of these six species. Of the bones collected, 53% allowed successful estimation of the standard length of the fish consumed. The use of premaxillary bones in diet studies has a high potential as it permits the identification and estimation of prey size for the majority of species consumed. This method is important for studying the size of the giant otter’s fish prey.