Common Octopus

Living in a variety of complex habitats with many predators (like groupers, wrasses, eels, sharks, marine mammals, and marine birds) this species is equipped with a large brain that enables it to carry out a range of body patterns and behaviors. Its color can vary from yellow-brown to red-brown, dark brown, or grey.

Its skin has a distinct patch and groove system that forms a reticulate pattern and a pair of white spots on the dorsal mantle’s mid-region. It also has a diamond pattern of four large primary papillae in mid-region of dorsal mantle. There is one long primary papillae at the posterior end of the dorsal mantle, one large and two smaller primary papillae over each eye.

Its most distinguishing body pattern features include: highly variable mottle patterns (small-medium patches of contrast colors next to each other) and deimatic pattern (high contrast, pale body with dark eye ring and dark around suckers).

This species has a flexible activity period and has been reported to be active during the day and night! Its activity time can be influenced by predators, other octopus species inhabiting the same area, or potentially other environmental factors. A dense population of O. vulgaris and M. defilippi coexist in a South Florida lagoon in part because they partition their resources (habitat type, food, foraging activity time, and the substrate they search for food).

Throughout its distribution range, this species is known to undertake seasonal migrations. In the western Mediterranean, large mature or maturing individuals migrate inshore in early spring, followed by smaller, immature individuals. These two groups begin their retreat into deeper waters by August/September and November/ December respectively. Similar migration patterns have been observed in Florida (more research is needed for this area) and in other areas.

This octopus typically uses the crawling behavior, continuous slow movement of the mantle from one physical location to another when the arms are in contact with the substrate, to move across a structured habitat. Octopuses are experts at background matching. However, with flexible arms and a soft bodied not constricted to a rigid shell, they are capable of other types of camouflage.

Octopuses (and their relatives’ squids and cuttlefishes) use arm postures to look like objects in their environment such as stones, algae, corals, and seagrasses. This is known as masquerade and is widespread among shallow-water octopuses. They can add motion to these postures (motion camouflage) to decrease the chances of being detected by a predator as the octopus moves across open areas.

The speed of the octopus generally resembles the speed of the rippling light from the waves. O. vulgaris uses the “moving rock” trick when smooth coral heads or rocks are in its surrounding environment and uses the “moving algae” trick when algae are nearby.