ANATOMY
For each specimen, the standard length (SL; cm) and body weight (g) were recorded. The digestive tract was dissected, and the lengths (mm) of the oral cavity, oesophagus, intestine (CI; mm) and pyloric caeca were measured and quantified. Subsequently, the intestinal coefficient (CO) was calculated using the equation: CO = CI/SL, according to Angelescu and Gneri (1949). To check the adaptations of the oral cavity in relation to food capture and seizure, the following were described: the shape of the lips and tongue, the morphology of the pharyngeal teeth and the type of pharyngeal teeth apparatus. The structures of the digestive tract: oral cavity, oesophagus and pyloric caeca were measured using a digital caliper (DIGIMESS - accuracy of 0.01 mm). For intestine measurement, a tape measure (MACROLIFE) was used to promote more accuracy when measuring length and flexure. All structures were analyzed using an Olympus SZ – 11 stereomicroscope.