Pinnoctopus macropus, also known as the Atlantic white-spotted octopus, white-spotted octopus, grass octopus or grass scuttle, is a species of octopus found in shallow areas of the Mediterranean Sea, the warmer parts of the eastern and western Atlantic Ocean, the Caribbean Sea, and the Indo-Pacific region. This octopus feeds on small organisms which lurk among the branches of corals.

Description Pinnoctopus macropus grows to a mantle length of 20 cm (8 in) with a total length of 150 cm (59 in). The first pair of arms are a metre or so long, and are much longer than the remaining three pairs. The arms are all connected by a shallow web. This octopus is red, with white blotches on its body, and paired white spots on its arms. When it is disturbed, its colour becomes more intense, deimatic behaviour which may make it appear threatening to a potential predator.

Distribution and habitat Populations of Pinnoctopus macropus form a species complex found in the Mediterranean Sea, the temperate and tropical Atlantic Ocean and the Caribbean Sea. It is also present in the Pacific and Indian Oceans. It lives near the shore at depths down to about 17 m (56 ft).