This characteristic blue border is a distinctive point to make the difference with Actinia equina .
Size also can help as Actinia mediterranea is a bit larger ( 5 to 7 cm ) than its close relative ( 3 to 5 cm ) .
This characteristic blue border is a distinctive point to make the difference with Actinia equina , but size also can help as Actinia mediterranea is a bit larger ( 5 to 7 cm ) than its close relative ( 3 to 5 cm ) .