Abstract
Taxonomic relationship of the lottiid gastropod "Collisella heroldi" complex have been investigated based on various morphological characters of soft and hard parts. As a result, it was revealed that the complex comprises four morphologically distinct species, i.e. Lottia luchuana (Pilsbry, 1901), L. kogamogai n. sp., L. tenuisculpta n. sp., and L. lindbergi n. sp. Based on the observations on the lectotype specimens, it is unavoidably concluded that long-established name, Collisella heroldi (Dunker, 1861), is reduced to a synonym of Patelloida pygmaea (Dunker, 1860). The four above-mentioned species are distinguishable in shell sculpture, radular teeth and basal plate morphology, and presence or absence of median teeth of the jaw. The radula is the most stable taxonomic character for identification of each taxon of this complex beyond doubt, although its ontogenetic and geographical variations came to light in L. kogamogai through detailed morphological variation analysis. The separation of the species is corroborated by temporal reproductive segregation inferred from seasonal change in gonad development and also supported by difference in geographical distribution and habitat preference.
