"The pale head and the large regular blue spots clearly point to this individual being Thuridilla splendens. Confirmation would be achieved by a knowledge of its size (Thuridilla splendens reaches 41 mm; whereas Thuridilla bayeri only reaches 26 mm) and behaviour (Thuridilla splendens does not “nod” its head as it crawls along; whereas Thuridilla bayeri does)."
Comment from Richard Willan
The pale head and the large regular blue spots clearly point to this individual being Thuridilla splendens. Confirmation would be achieved by a knowledge of its size (Thuridilla splendens reaches 41 mm; whereas Thuridilla bayeri only reaches 26 mm) and behaviour (Thuridilla splendens does not “nod” its head as it crawls along; whereas Thuridilla bayeri does).