Did you know that sea sponges are actually animals? Pretty simple animals mind you. They don’t have nervous, digestive or respiratory systems and are really just a collection of specialised cells. The scientific name for sponge is Porifera, which means "Pore bearer" - this is because they are covered in holes through which seawater is drawn in. Within the sponge is a central cavity lined with little beating hair-like structures called cilia. These create a continuous current of seawater and collect the little morsels of food suspended in it. Wastewater is then pushed out of larger outlet vents. In the breadcrumb sponge, these outlet vents look like chimneys! The breadcrumb sponge is common around the UK and found on rocky shores and on rocky seabeds or cobbles beneath the low water mark. It is what is known as an encrusting sponge, meaning it grows on the surface of rocks and is common on damp overhangs on rocky shores. It comes in lots of different colours, from cream to olive green, as well as many different forms. It can have tall chimneys, grow in smooth sheets or even have a granular breadcrumb-like surface that led to its common name. Because of all of these different forms, it was thought to be lots of different species - but it is in fact just one... albeit with many different guises!
How to identify
A thick spongey animal, normally pale cream but sometimes olive green. It has many different forms - sometimes a flat sheet, sometimes with tall chimneys, often with a rough granular surface that looks like breadcrumbs.
Did you know?
The breadcrumb sponge has a very strong smell - with some people likening it to exploded gunpowder. This smell comes from a substance produced by the sponge to deter hungry predators.
How people can help
When rockpooling, be careful to leave everything as you found it - replace any rocks you turn over, put back any crabs or fish and ensure not to scrape anything off its rocky home. If you want to learn more about our rockpool life, Wildlife Trusts around the UK run rockpool safaris and offer Shoresearch training - teaching you to survey your local rocky shore. The data collected is then used to protect our coasts and seas through better management or through the designation of Marine Protected Areas. The Wildlife Trusts are working with sea users, scientists, politicians and local people towards a vision of 'Living Seas', where marine wildlife thrives. Do your bit for our Living Seas by supporting your local Wildlife Trust or checking out our Action Pages.
