photosynthesis (converts energy from sunlight and nutrients)
to 15 inches (38 cm)
sea lettuce and other green seaweeds; Order: Codiales, Family: Codiaceae
temperate waters worldwide
The dark, spongy "fingers" of this seaweed dangle from the tops and sides of rocks. In the constant struggle for living space in the intertidal and upper subtidal zones, this alga also plays host to others: a small red alga specializes in living on clumps of dead man's fingers.
Though it may look rugged, the rocky shore—home to dead man's fingers—is fragile. Rocky shore creatures are at risk from coastal development and from pollution (including waste oil and agricultural runoff). And some tide pools are in danger of being "loved to death" by visitors. Tread lightly as you explore tide pools to avoid crushing plants and animals, and always leave them in their tide pool homes when you return to yours.
A clump of dead man's fingers is all one cell!
At one time dead man's fingers were used as packing material for shipping live marine invertebrates.