Euplectella aspergillum (1) Large Venus's Flower Basket Glass Sponge Porifera Hyalospongiae

Glass Sea Sponge Venus's Flower Basket Large cm 27  Euplectella aspergillum Porifera Hyalospongiae, only a piece , as in photo.
Siliceous skeleton of a sea colonial sponge, collected at a depth of 120 meters on a rocky area in the Camotes Sea, in the Philippines.
Family: Euplectellidae.
Common name: Venus's Flower Basket.

Today it is collected and dried for decorative purposes. In the past, in some traditional Asian cultures such as Japan, it was customary to give it to newlyweds as a wedding gift as a symbol of marital fidelity, since they can contain a pair of shrimps (Spongicola venusta) inside them, which enter as larvae through the pores and as they grow they are no longer able to get out and spend their whole lives in symbiosis with it.

The Venus flower basket (Euplectella aspergillum) is a marine glass sponge of the Porifera phylum. It is found in the deep waters of the Pacific Ocean near the Philippine Islands, usually at depths less than 500 meters. The habitat of this sponge is in the rocky areas of the benthic seabed, where it lives and grows connected to the hard substrate for its entire life. Like other sponges, they feed by filtering sea water to capture plankton and marine sediments. Similar to other glass sponges, they build their skeletons of silica, which forms a unique lattice structure of spicules. Sponges are usually between 10 and 30 cm tall, and their bodies serve as shelter for their mutualistic shrimp partners. Little is known about their reproductive habits, however it is hypothesized that they may be hermaphrodites.
Other species of this genus are found in oceans around the world, including near Japan and in the Indian Ocean.
The body structure of these animals is a thin-walled cylindrical basket-shaped tube with a large central atrium. The body, perforated by numerous openings, is composed entirely of silica in the form of 6-pointed siliceous spicules, which is why they are commonly known as glass sponges. Spicules are microscopic pin-shaped structures within the sponge tissues that provide structural support to the sponge. The spicules "twine" together to form a very fine mesh, which gives the sponge body a rigidity not found in other sponge species and allows glass sponges to survive at great depths in the water column.
It is hypothesized that the sponge uses bioluminescence to attract plankton. Its lattice shape allows it to create tiny vortices inside the sponge which facilitate the mixing of the gametes; furthermore, it would make feeding more efficient for the shrimp living within its lattice.
Sponges often host shrimp, usually a breeding pair, which are typically unable to exit the sponge's lattice due to their size. As a result, they live in and around these sponges, where they establish a mutualistic relationship with the sponge until they die. The shrimp live and mate in the shelter provided by the sponge, and in return they also clean the inside of the sponge. This may have influenced the adoption of the sponge as a symbol of eternal love in Japan, where the skeletons of these sponges are offered as wedding gifts.
The glassy fibers that attach the sponge to the ocean floor, as thin as human hair, are of interest to fiber optic researchers. The sponge extracts silicic acid from seawater and converts it into silica, then arranges it into an elaborate skeleton of glass fibers with complex geometric configurations. Other sponges, such as the orange balloon sponge (Tethya aurantium), can also produce glass biologically. The current optical fiber manufacturing process requires high temperatures and produces a brittle fiber. A low-temperature process to create and organize such fibers, inspired by sponges, could offer greater control over the fibers' optical properties. These nanostructures are also potentially useful for creating more efficient and low-cost solar cells. Additionally, its skeletal structure has inspired a new type of structural lattice with a higher strength-to-weight ratio than other diagonally braced square lattices used in engineering applications.