Phylum Porifera encompasses the sponges of the sea.

Development along coastal areas can result in runoff, which changes the salinity of the water and can kill the corals. But, like a coral reef, corals of Point Reyes are extremely sensitive to change in salinity and temperature. Coral is well known for the reefs it can form with its calciferous skeleton, but in central California, coral doesn’t form reefs. Sometimes, the coral may become stressed and it can eject the algae, which is known as “coral bleaching”.

The algae provide carbohydrates to the corals, while the corals provide carbon dioxide for the algae. Many live symbiotically with algae that are extremely colorful. Most corals are known for being very colorful, but they don’t actually have color. The shapes of corals can be incredibly diverse, but they are all groups of tentacled creatures that live on a calcareous skeleton and share nutrients. Corals are in class Anthozoa and are sessile polyps that live in colonies which act as a single organism. Most animals in this phylum have a capability to sting prey with nematocyst cells which either sting or inject a toxin. Their name comes from the Greek word cnidos which means stinging nettles. Phylum Cnideria contains corals, anemones, and jellyfish (including Velella velella). Aggregating anemones ( Anthopleura elegantissima).

Sponges and some cnidarians do not move