抄録
The marine snail genus Littorina has been treated as a model group for ecological and evolutionary studies. It includes a morphologically and ecologically enigmatic species in East Asia, Littorina horikawai. Here, we illustrate the shell colour dimorphism of L. horikawai collected in Tsushima Island in Nagasaki Prefecture, Japan. Molecular analysis indicated that shell colour dimorphism is intra-specific variation. Because the morphological characteristics, including shell colour variation, of L. horikawai have not been sufficiently studied in the entire distribution area, further investigation is necessary to understand the morphological diversities of L. horikawai.
