Morphology of the Saccular Otoliths of Six Species of Lanternfishes of the Genus Symbolophorus (Pisces: Myctophidae)

Variation in the morphology of saccular otoliths (sagittae) among six species of lanternfishes of the genus Symbolophorus is analyzed. A cluster analysis based on a dichotomous matrix of 10 morphological characters separates the 6 species into well-defined groups. Whereas the otoliths of S. evermanni and S. rufinus are indistinguishable, those from males of the undescribed “reversus” morphotype are easily discriminated from them. This suggests that “reversus” might be a valid species. The sagittae of S. veranyi and S. boops form a second group separated from S. californiensis. This study also points out the problems and possibilities of using otolith morphology in helping to resolve the problems within this genus.