Calcarea Sponges (calcareous sponges) are identified by their skeleton like structure which is made up of calcium carbonate spiracles, which are needle like structures on the organism. These organisms are normally found in the rocky shallow areas of a continental shelf. They normally lack in color and are relatively small in size ranging from 0.01 to a max of 0.3 meters.

Clathrina clathrus (Schmidt, 1864)

Common name: Yellow Network Sponge
Description: A system of soft and dense interwoven tubes about 2-10 cm in diameter. Usually white or yellow, sometimes they have brown in them as well. They’re attached to rocky overhangs and cave walls in calm water.
Distribution: British Isles and southward.
Ieranto: Small bay, near the platform and into the canyon.
Fun fact: The name comes from the Greek word clathrum, which means lattice or grate.

Clathrina rubra (Sara, 1958)

Common name: Red net sponge
Description: Its color ranges from red to orange and it can be up to 2 cm in diameter. It is made up of thin tubes that form a lattice, or net, structure.
Distribution: Mediterranean Sea.
Ieranto: Small bay, near the platform.
Fun fact: It is very soft and therefore easily damaged.

Ieranto: Small bay, near the end of the canyon, on the floor (left image). Small bay (right image).