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.