The Venus' flower basket (Euplectella aspergillum) is a glass sponge in the phylum Porifera. It is a marine sponge found in the deep waters of the Pacific ocean.
As other glass sponges, they build their skeletons out of silica, which is of great interest in materials science as their optical and mechanical properties are on some ways superior to man-made materials.
The sponges are often found to house glass sponge shrimp, usually a breeding pair, who are typically unable to exit the sponge's lattice due to their size.
Consequently, they live in and around these sponges, where the shrimp perform a mutualistic relationship with the sponge until they die.
Source
As other glass sponges, they build their skeletons out of silica, which is of great interest in materials science as their optical and mechanical properties are on some ways superior to man-made materials.
The sponges are often found to house glass sponge shrimp, usually a breeding pair, who are typically unable to exit the sponge's lattice due to their size.
Consequently, they live in and around these sponges, where the shrimp perform a mutualistic relationship with the sponge until they die.
Source