Marine Wildlife Encyclopedia
Sea Lettuce Ulva lactuca
Sea lettuce is common worldwide on seashores and in shallow subtidal areas, growing in a wide range of conditions and habitats. Its frond is a bright green, flat sheet, which is often split or divided, and has a wavy edge. The plant is very variable in shape and size, ranging from short, tufted plants on exposed shores to sheets over a yard long in sheltered, shallow bays, especially where extra nutrients are available in polluted harbors. Sea lettuce reproduces by releasing gametes from some cells, and it can also spread vegetatively by regeneration of small fragments. Large fronds lying on the seabed may be full of holes made by grazing animals. It is a also popular food for humans in many parts of the world.