Hatchling Smooth Softshell Turtles (Apalone mutica) Perform Respiratory Pushup While Overwintering

Abstract

We observed overwintering behavior of bimodally respiring hatchling Smooth Softshell Turtles, Apalone mutica, in two small outdoor ponds that differed in depth. Hatchlings buried themselves shallowly in a sand/mud substrate at the bottom of the ponds. In the deep pond, hatchlings periodically raised and lowered the posterior portion of their body into the water column in a respiratory “pushup” fashion. In the shallow pond, hatchlings did not perform pushups nor snorkel to breathe air. Pushups were similar in appearance and form among turtles but occurred with variable frequency within and among individual turtles. Pushup frequency of hatchling A. mutica was 43% slower than reported for larger A. mutica.