Crastrums

Anatomy
Crastrums have two basic tissues, a photosynthetic tissue which acts as a cover for the organism, and a steam tissue which changes the temperature of water inside it to expand or contract in size and acts a muscle.

Behavior
Most crastrums use a suction cup found on their underside to stay in one spot, they will swim in a pumping motion to get away from danger.

Diet & Energy
All crastrums have photosynthetic cells and use light to produce food, but one line took up a parasitic lifestyle and fed on blood, and another filter-feeds.

Locomotion
Crastrums move using steam-powered muscles, since these muscles rely on heating and cooling crastrums so far move rather slowly.

Reproduction
Crastrums reproduce through budding.

Senses
Most crastrums have no significant senses, although they seem to have the ability to sense danger as they will escape when their host is being attacked, and the xeno crastrum has spines used for sensing touch.

Size
Most crastrums are under 10 cm across,the largest being the 40 cm xeno crastrum.