Alternative common names:
Cliona celata is a yellow to orange excavating (or boring) sponge, occurring in two distinct forms. One is the boring form, recognizable as yellow papillae sticking out of limestone (calcareous rocks, shells, etc.); the other is a massive, wall-shaped sponge covered with characteristic flattened papillae. The massive form often forms a thick plate-like structure standing on its edge, up to 1 m across and 25 cm thick. The massive form is very common around the west coasts of Britain and France. The boring form is very common in oyster and mussel beds, where they cause damage to shellfish farming.
Where does this species come from?
Cliona celata is widespread around the coast of Britain and Ireland although the massive form is only common around the southwest coasts of Britain and lacking in the North Sea.
What is its invasive status in South Africa?
NEMBA 2020 Category XX: Cliona celata has not been recorded in South African waters.
Where in South Africa is it a problem?
Cliona celata has not been recorded in South African waters.
How does it spread?
Sponges are generally sessile as adults and spend their lives attached to a fixed substratum. They do not show movement over large distances as do free-swimming marine invertebrates. However, sponge cells are capable of creeping along substrata.
Why is it a problem?
Cliona celata has negative impacts on economically valuable native and non-native molluscs, such as sea scallops (e.g. Placopecten magellanicus), pearl oysters, abalones (e.g. Haliotis tuberculate) and oysters (Ostrea edulis).
What does it look like?
Description: Yellow to orange excavating (or boring) sponge. The boring form, recognizable as yellow papillae sticking out of limestone. The massive form often forms a thick plate-like structure standing on its edge, up to 1 m across and 25 cm thick.
Habitat: Both forms of C. celata occur on a variety of coasts ranging from wave exposed, open coasts to silty estuaries, sometimes at considerable depths. The species can withstand sediment.
Breeding: Marine sponges have two modes of reproduction, asexually via budding and sexually (often as a hermaphrodite). Asexual budding occurs when a cluster of cells form a ‘mini’ sponge on the exterior of the parent sponge. Sexual reproduction usually involves egg cells and sperm cells being produced within the same sponge.