02 Onchidoris muricata

02 Onchidoris muricata

Specimens found on the same shore in Orkney with the usual colours in northern Britain of (left) yellow Onchidoris muricata and (right) white Adalaria proxima. The colours are reversed in southern Britain. On yellow O. muricata the gills and rhinophores are a more saturated shade of yellow. November 1975.