Mussel are prepared. Both marine and freshwater mussels are filter feeders; they feed on plankton and other microscopic sea creatures which are free-floating in seawater. A mussel draws water in through its incurrent siphon. The water is then brought into the branchial chamber by the actions of the cilia located on the gills for ciliary-mucus feeding. The wastewater exits through the excurrent siphon. The labial palps finally funnel the food into the mouth, where digestion begins. Marine mussels are usually found clumping together on wave-washed rocks, each attached to the rock by its byssus. The clumping habit helps hold the mussels
Microbial mat the causes, cyanobacteria are the most self-sufficient of the mat organisms and were well-adapted to strike out on their own both as floating mats and as the first of the phytoplankton, which forms the basis of most marine food chains. The time at which eukaryotes first appeared is still uncertain: there is reasonable evidence that fossils dated between and represent eukaryotes, but the presence of steranes in Australian shales may indicate that eukaryotes were present . There is still debate about the origins of eukaryotes, and many of the theories focus on the idea that a bacterium first became an