"Episamic organisms" is not a recognized term in biology. It seems like you might be referring to epibionts, which are organisms that live on the surface of another organism, called the host.

Here are some examples of epibionts:

* Barnacles on whales: Barnacles attach themselves to the skin of whales, feeding on plankton in the water.

* Algae on sea turtles: Algae can grow on the shells of sea turtles, benefiting from the constant movement through the water.

* Mollusks on coral reefs: Various species of mollusks, like snails, attach themselves to coral structures, consuming algae and other small organisms.

It's important to note that the relationship between an epibiont and its host can be:

* Commensal: One organism benefits, while the other is neither harmed nor helped.

* Parasitic: One organism benefits at the expense of the other.

* Mutualistic: Both organisms benefit from the relationship.

If you can provide more context about what you're interested in, I can give you a more specific answer!