| Petrosia ficiformis | |
|---|---|
 | |
| Petrosia ficiformis is a purple brown sponge of the Mediterranean and North Atlantic | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Porifera |
| Class: | Demospongiae |
| Order: | Haplosclerida |
| Family: | Petrosiidae |
| Genus: | Petrosia |
| Species: | P. ficiformis |
| Binomial name | |
| Petrosia ficiformis (Poiret, 1879) | |
| Synonyms [1] | |
List
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Petrosia ficiformis, commonly known as the stony sponge, is a species of petrosiid sea sponge in the order Haplosclerida. [1]
Petrosia ficiformis was first described by J.L.M. Poiret as Spongia ficiformers. Its name comes from the Greek: "pétra" - πέτρα - rock, "physis" - φύση - nature, "fórma" - φόρμα - shape, meaning "naturally-shaped rock". It is classified under the subgenus Petrosia of the genus Petrosia . [1]
Petrosia ficiformis occurs in the Mediterranean Sea and in the adjacent eastern Atlantic Ocean. [1] [2] It is found among rocks and in caves and rock crevasses, typically deeper than 5 m (16 ft). [3]
Petrosia ficiformis is usually purple brown in colour due to symbiosis with photosynthetic cyanobacteria, but can be white in the absence of light. It has a compact, hard texture, with spherical oscula irregularly spread over the surface.
Petrosia ficiformis biosynthesizes various acetylene derivatives. A characteristic example of this is petrosynol, [4] a polyacetylene of 30 atoms, which was isolated in 1987 from this animal. It likely helps to protect the sponge from bacterial and fungal infections. [5]
Petrosia ficiformis is specifically known to synthesize various types of petroformynes, a class of polyhydroxylated polyacetylene fatty alcohols with cytotoxic activity. [6] [2] The skeleton of these toxins is formed by a hydrocarbon chain of 46 to 47 carbon atoms. [7]
Petrosia ficiformis is predated by the nudibranch Peltodoris atromaculata . [2] [3] This nudibranch is a specialist on Petrosia, along with the chemically similar Haliclona fulva . There is no evidence that the nudibranch uses the chemical compounds of these sponges in their own defense, as is known for many other nudibranchs. [2]