Padronização de parâmetros bioquímicos e hemogasométricos para Phrynops williamsi e Phrynops geoffroanus (Testudines, Chelidae) de vida livre: Parque Nacional do Iguaçu

Abstract

Global aquatic ecosystems are undergoing severe degradation due to urban, industrial, and agricultural anthropogenic pressures, compromising the viability of numerous biological populations. In this context, the Iguaçu River stands out negatively as the second most polluted river in Brazil. However, along its terminal stretch (Lower Iguaçu), the river borders the Iguaçu National Park (INP), a Strict Protection Conservation Unit that harbors a significant remnant of the Atlantic Forest and functions as a regional biological buffer zone. Despite this protection, sub-basins draining into the park, such as the Silva Jardim River basin, are strongly influenced by agricultural activities, directly contrasting with highly preserved areas such as the Floriano River basin. To assess the effectiveness of these protected areas and the impacts of environmental degradation gradients, biomonitoring of local fauna is essential. Reptiles, due to their physiological sensitivity (such as ectothermy and slow metabolism) and high habitat fidelity, serve as excellent ecotoxicological bioindicators. Therefore, the present study aims to establish integrated profiles and reference values for serum biochemistry and venous blood gas analysis in free-ranging populations of two species with distinct ecological traits: Phrynops geoffroanus, a generalist species tolerant of impacted environments, and Phrynops williamsi, a rheophilic specialist inhabiting fast-flowing waters, vulnerable to extinction and threatened by habitat fragmentation resulting from hydroelectric power plants. The study also aims to evaluate the influence of body size on these parameters and to characterize correlations among analytes, providing unprecedented support for health monitoring and conservation of these taxa. The assessment of the homeostatic, adaptive, and health status of these populations will be conducted through serum biochemical profiling, whose theoretical framework encompasses both the pre-analytical stability of samples and the dynamic behavior of essential biomarkers. Finally, the integration and comparison of interspecific biochemical and physiological responses under different conservation gradients will provide fundamental insights into the resilience of these animals to pollution and habitat fragmentation, generating robust data to guide effective conservation strategies for the order Testudines in the Atlantic Forest. This study is justified by the first description of blood gas parameters for both species investigated, as well as the first biochemical characterization of Phrynops williamsi.