Dead man’s fingers

Codium fragile is a green alga commonly known as “dead man’s fingers” due to its soft, finger-like fronds. It is native to the Northwest Pacific and has spread in the Mediterranean Sea. It is dark green in colour, with cylindrical, spongy, and branching thalli. A plant may be about 0.5-1 m tall, with about 12 orders of branching, and weigh up to 3 kg. The surface is velvety, and the structure is formed by a network of siphonous filaments filled with cytoplasm, giving it a distinctive, cushiony texture. It grows attached to hard substrates in a wide range of habitats, including rocky and cobble shores, seagrass beds, oyster reefs, breakwaters, seawalls, docks, and piers, often forming dense stands in intertidal and shallow subtidal zones. Its fast growth and tolerance to environmental stress allow it to displace native species and alter coastal ecosystems.