Disruptive Effects of Chlorpyrifos on Predator-Prey Interactions of Ceratophrys ornata Tadpoles: Consequences at the Population Level Using Computational Modeling

SALGADO COSTA, CAROLINA; RIMOLDI, FEDERICO; PANTUCCI, MORENA JOHANA; RUBIO PUZZO MARÍA LETICIA; TRUDEAU VANCE LIONEL; NATALE, GUILLERMO SEBASTIÁN

Santiago

Congreso; SETAC Latin America 14th Biennial Meeting "Latin America, Diversity of Knowledge for a Sustainable Future"; 2021

Society of Environmental Toxicology and Chemistry

Large-scale ecotoxicological studies have technical and ethical limitations related to the need to expose large numbers of individuals to potentially harmful compounds. Also, if we consider the growing interest in the effects of pollutants on behavioral traits, more limitations emerge since traditional ecotoxicological tools requires a detailed analysis of many simultaneous interactions, a non-disturbing video recording system, and the exposure of many living organisms that will likely perish during the test. The advance of knowledge and the possibility of developing new techniques in accordance with the care and welfare of laboratory animals, call for novel and rigorous ecotoxicological procedures. The aim of this study was to evaluate the effects of chlorpyrifos (CPF) on intra and interspecific interactions of Ceratophrys ornata tadpoles, complementing traditional ecotoxicological tools with a theoretical analysis verified by computational simulations. The design consisted of an experimental stage to obtain information about predator-prey interactions of the species, followed by a theoretical stage which consisted of running three different models based on experimental observations: Model I without an antipredator mechanism, Model II with an antipredator mechanism, and Model III (= Model II + insecticide) which simulates the behavior of the exposed individuals. The study was based on the Monte Carlo method in order to understand the behavior of a given system of particles characterized by unknown parameters, many of which are difficult to determine experimentally. The models were based on the particle-concept by focusing on tadpole's interactions with their neighbors; they were tested by Computational Simulations and were then compared with those of the experiments performed. Results were computed based on repeated random sampling, and statistical analysis allowed solving deterministic problems. Results showed that computational modeling accurately reproduced the experimental conditions, being a useful tool to understand complex systems. This tool could be used not only to evaluate potential effects of compounds with similar modes of action to CPF on C. ornata, but also to model the effects of CPF and related compounds on related species with similar behavior. In this way, the tool would allow preventive conservation decisions to be made even before bioassays are conducted, reducing the number of animals used for toxicity tests.