Fig. 1. Schematic of the carp oropharyngeal cavity, indicating endoscope insertion site. The roof of the oropharynx is illustrated on the left, with the palatal organ (po) shown in coarse stippling and the region of po observed through the endoscope in fine stippling. The floor of the oropharynx is illustrated on the right, with ceratobranchials I—IV (cb I—IV) shown as black bars. The location of the gill rakers is shown by the gray shading. The hatched region of the gill arches was observable through the endoscope. Modified from Sibbing et al. (1986).