Hornwrack – Flustra foliacea



I took these images on a beach whilst visiting Wales. They are the dried out remains of Bryozoans, which means ‘moss animals’, but they are also referred to as sea mats or lace corals. They are aquatic invertebrates which live in colonies in thin encrusting patches mainly on rocks and seaweeds. They usually have a fine mesh-like or lacy appearance, and within each compartment lives a tiny animal called a zooid. These mats are made up of maybe a few up to millions of zooids. They have a ring of tentacles but do not sting. They use these to filter feed microscopic plankton from the water.

Length up to 15cm. Also called the ‘Broad-leaved Hornwrack’, it is light grey-brown in colour and forms bushy colonies and can be easily mistaken for seaweed. Fresh specimens smell of lemon.

Found attached to rocks in the sublittoral zone, but bleached specimens are often discovered washed up on the strand line or high tide mark. Widespread and locally common.