The thermal tolerance of these species was determined by the
dynamic method described in Mora and Ospina (2001). The aim
was to determine the Critical Thermal Maximum (CTMax), which
is defined as the “arithmetic mean of the collective thermal points
at which the end-point is reached” (Mora and Ospina, 2001). The
end-point was equilibrium loss. To determine the CTMax animals
were exposed to a constant rate of water-temperature increase, in
a thermostatized bath, MultiTemp III Pharmacia Biotech, with
constant aeration, and observed continuously