Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma. Some experts believe glass sponges are the longest-lived animals on earth; these scientists tentatively estimate a maximum age of up to 15,000 years.
Hexactinellid
Bolosoma stalked glass sponge
Venus' flower basket, Euplectella aspergillum
Euplectella aspergillum
Sponges, the members of the phylum Porifera, are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.
Sponge
Sponge biodiversity and morphotypes at the lip of a wall site in 60 feet (20 m) of water. Included are the yellow tube sponge, Aplysina fistularis, the purple vase sponge, Niphates digitalis, the red encrusting sponge, Spirastrella coccinea, and the gray rope sponge, Callyspongia sp.
Spongia officinalis, "the kitchen sponge", is dark grey when alive.
Euplectella aspergillum, a glass sponge known as "Venus' flower basket"
