THE USE OF COOLING AND FREEZING FOR ANESTHESIA OF Phrynops geoffroanus TURTLES (PLEURODIRA: CHELIDAE) AND THE ESTABLISHMENT OF LOW INCIPIENT LETHAL TEMPERATURE

Abstract

The use of hypothermia for anesthesia and euthanasia in ectothermic individuals has promoted many discussions, especially in the last four decades, and yet it continues today as a method that is prohibited or restricted to certain procedures. Despite this, some studies have shown satisfactory results in obtaining anesthetic plans, raising questions about the real possibility of using this method in research. The aim of the present experiment was to determine the time patterns to generate anesthesia and low incipient lethal temperature in Phrynops geoffroanus through cooling and freezing. Turtles reached the anesthesia grade nine within 30 minutes, making ease handling due to muscle relaxation, and, in 80 minutes, they reached anesthesia grade 11, becoming insensitive. The low incipient lethal temperature (LILT) shows that 1°C is the limit freezing from where the turtle can recover its motor activities while lower temperatures cause death. The low incipient lethal temperature was determined in a 300-minute period independently of the individual's size or weight.