Fig. 5.

Schematic drawing of the upper respiratory tract of the sandfish. The blue area marks the nasal cavity (n.c.), the red area shows the oral cavity (o.c.) and the green area shows the pharynx (ph.). The airflow is represented by arrows; the green arrows show the main airflow, and the yellow ones mark the flow through the olfactory chamber. ao.s., antiorbital space; ch.d., choanal duct; Co, concha; e.n., external naris; i.n., internal naris; nph., nasopharynx; oph., oropharynx; p., proprium; p.c., palatine cleft; ve., vestibulum; v-n.o, vomero-nasal organ.