Schulze, 1886 
Cloud sponge (Aphrocallistes vastus) is a primitive organism of the order Hexactinosida in the class Hexactinellida. It is a deep-water reef-forming animal. The species was first described by F.E. Schulze in 1886.
The cloud sponge takes the form of a large cup with an irregularly folded wall about 5 millimetres (0.20 in) thick. This is pierced by many pores about 1 millimetre (0.039 in) wide and covered by a thin dermal membrane. The skeletal elements form a lattice-like structure made up of fused spicules of silica. These mesh together and project into the adjoining canals. There is a fir-tree like concentration of spicules running through the body wall with the branches either having rounded or knobbly ends.  The form of the sponge varies according to the location in which it is found. It often has a mitten-like structure or may be tall and cylindrical or bowl-like but in areas with strong currents can be dense and compact.
The cloud sponge is found in the northern Pacific Ocean. Its range includes Japan, Siberia, the Aleutian Islands and the west coast of North America from Alaska southwards to California and Mexico. It is a reef-building species found in deep waters on the western Canadian shelf growing on sediment-free rocks. It grows and is more easily studied in fiords off the coast of British Columbia at depths of only 25 metres (82 ft).
The cloud sponge is one of several species of glass sponge that form slow growing reefs in deep water. They provide a substrate that is the basis of a community of invertebrates and fish. Its silicaceous body wall makes it unattractive to most predators but it is eaten by the cookie star (Ceramaster patagonicus).
The cloud sponge is fragile and has a texture rather like dry toast. Its growth rate is slow with juveniles growing into moderate sized individuals in ten or twenty years. It is easily damaged by seabed trawling and seems to be killed by severe trauma although small injuries can be repaired.
- "Aphrocallistes vastus Schulze, 1886". World Register of Marine Species. Retrieved 2012-10-06.
- "Aphrocallistes vastus (cloud sponge)". UniProt. Retrieved 2009-03-15.
- Schulze, F. E. (1887). "Aphrocallistes vastus Schulze, 1886". Porifera. Retrieved 2012-10-07.
- Austin, William C.; Conway, Kim W.; Barrie, J. Vaughn; Krautter. Manfred (2007). "Growth and morphology of a reef-forming glass sponge, Aphrocallistes vastus (Hexactinellida), and implications for recovery from widespread trawl damage" (PDF). Porifera Research: Biodiversity, Innovation and Sustainability.
- McDaniel, Neil (2011). "Cookie star (Ceramaster patagonicus)". Sea Stars of the Pacific Northwest. Retrieved 2012-10-06.