They can grow as large as your hand and live for more than 100 years, making them one of the longest-lived invertebrates. A mussel may very occasionally bear a pearl.
The freshwater pearl mussel is a protected species throughout its range in Scotland therefore you must not wilfully disturb or touch it.
Report suspicious activity.You should call Police Scotland on 101 urgently if you see any suspicious activity in or near a river that may contain freshwater pearl mussels.