Hypoptopoma inexspectatum

Aquino, Adriana E., 2010, Systematics Of The Genus Hypoptopoma Günther, 1868 (Siluriformes, Loricariidae), Bulletin of the American Museum of Natural History 2010 (336), pp. 1-110 : 96

cognitum, inexspectatum , machadoi , muzuspi , spectabile , steindachneri , sternoptychum .

In loricariids with a ventrally expanded canal plate, the dorsal margin of the canal plate at the entrance of the branch of the mandibular canal into the preopercle is straight and simple (Schaefer, 1998) (fig. 13A). In the derived condition, the dorsal margin of the canal-bearing plate presents a notch for the anteriormost exit pore of the semicircular canal in the preopercle (fig. 13B–C).

10. Preoperculo-mandibular laterosenory canal passage through fifth infraorbital — bianale , brevirostratum , elongatum , gulare , incognitum , inexspectatum , machadoi , muzuspi , spectabile , steindachneri , sternoptychum .

In Oxyropsis , most Hypoptopomatini , and loricariids generally, the pathway of the preoperculo-mandibular canal from the compound pterotic to the preopercle is either direct or indirect via a small intermediate plate ( Schaefer, 1987: figs. 4, 5A). In the derived state, the preoperculo-mandibular canal exits the compound pterotic to enter the fifth infraorbital, forming a separate canal immediately posterior to the infraorbital canal (figs. 13B–C).