An anatomical study of the trunk lateral-line system of the channel catfish revealed three sensory organs: small pit organs, superficial neuro masts and canal neuro masts.  The small pit organ and the superficial neuro masts were located in the epidermis adjacent to the lateral-line.  The canal neuro masts were located in the medial wall of the lateral-line canal.  The small pit organs possessed microvilli.  The canal neuro masts had one large kinocilium and several smaller stereocilia.

The catfish possesses a well developed olfactory system comprised of two bilaterally located organs in olfactory sacs which have anterior and posterior nares.  Each organ contains bilaterally symmetric olfactory rosettes composed of numerous lamellae radiating outward from a midline raphe. The lamellae contain an area of ciliated sensory epithelium and an area of ciliated non-sensory epithelium.  The olfactory lamellae are easily removed from the olfactory sac and can be distinguished by surface features with scanning electron microscopy.  Histopathologic changes of the olfactory cilia were observed with the scanning electron microscope after exposure to ammonia.  Structural changes of the surface epithelium of the sensory organs in the channel catfish may serve as an early warning indicator of an environment insult.