Opisthopteryx, [611]

Opostomias, [571];

O. micripnus, photophores, [178], [179], [181]

Opsanus, [711]

Opsariichthys, [582]

Oral hood, [116], [119], [136]

Oreinus, [582]

Oreosoma, [683]

Orestias, [616]

Orodus, [445]