Green tarantula weed
Green tarantula weed is still one of the most common green algae on Icelandic seashores. This filamentous and branched alga forms 5 to 10 cm of green mats at the bottom when submerged. On the dry, however, it resembles green slime.
The green tarantula weed is found very widely in the northern hemisphere, both in the Pacific and in the Atlantic Oceans.