Verification of otolith origin used for aging channel catfish by fisheries managers

In teleost fishes, three pairs of otoliths exist: lapilli, sagittae, and asterisci.  For most freshwater fish, the sagittae are the largest and most often used.  Conversely, in ostariophysan fish, such as Siluriformes (catfish), the largest otoliths are the lapilli and are located anterior to and above the sagittae.  Most authors of otolith-based catfish aging studies cited using the sagittal otolith, or described using “otoliths” in general, without stating which otolith was used.  Based on analyses of whole otoliths removed from channel catfish (Ictalurus punctatus), scanning electron microscope (SEM) microphotographs of channel catfish otoliths, x-ray computed tomography (CT) scans of a channel catfish head, descriptions of techniques used to removed otoliths from channel catfish reported in the literature and now made available in training videos; it is clear that lapilli are most often used for channel catfish aging studies, not sagittae as has been previously reported.  We recommend that fisheries managers that obtain otoliths from channel catfish by cutting dorsally through the supraoccipital bone report the otolith as the lapillus.  When other methods are used to obtain otoliths from channel catfish, care should be taken to document the identity of the otolith.