East Pacific Red Octopus

East Pacific Red Octopus
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Octopoda
Family:	Octopodidae
Genus:	Octopus
Subgenus:	Octopus
Species:	O. rubescens
Binomial name
Octopus rubescens Berry, 1953
Synonyms
Octopus punctatus Gabb, 1862 Polypus hongkongensis Hoyle, 1885 Octopus dofleini Wülker, 1910 Polypus dofleini Wülker, 1910 Polypus apollyon Berry, 1912 Paroctopus apollyon Berry, 1912 Polypus gilbertianus Berry, 1912 Octopus gilbertianus Berry, 1912 Octopus pricei Berry, 1912 Octopus apollyon Berry, 1913

The East Pacific Red Octopus (Octopus rubescens) is the most commonly occurring shallow-water octopus on much of the North American west coast and a ubiquitous benthic predator in these habitats.^[1] Its range extends from the southern Gulf of California at least to the Gulf of Alaska, but may also occur in the western Pacific Ocean. O. rubescens occurs intertidally to a depth of 300 m.^[2]

Taxonomy

In the years prior to the description of this species in 1953, O. rubescens was widely considered to be a young Enteroctopus dofleini. Many early descriptions were based on a combination of O. rubescens and E. dofleini.^[2][3] To this day, the taxonomy of this species remains somewhat unresolved. S.S. Berry’s 1953 description is in truth a brief diagnosis,^[4] and considering the exceptionally wide range of the species, it may prove that the animals currently covered under O. rubescens represent several subspecies or a species complex.

Size and description

Octopus rubescens generally grows to a mantle length of 8-10 cm, and arm length of 30-40 cm. Adult weight is generally 100-150 grams, however occasionally animals up to 400 grams in weight have been observed.^[5][2]

Like all octopuses, O. rubescens can change its color and texture, making its appearance highly variable. Color can vary from a deep brick red, to brown, to white, or mottled mixtures of the three. O. rubescens can be easily confused with small individuals of Enteroctopus dofleini in the northern end of this species' range. The two can be differentiated by the presence of three eyelash-like papillae below the eyes of O. rubescens that are absent in E. dofleini.^[6]

Intelligence

See also: Cephalopod intelligence

Like most octopuses, O. rubescens is thought to be among to the most intelligent of invertebrates. The presence of individual personalities is a hallmark of intelligence, and O. rubescens was the first invertebrate in which individual personalities was demonstrated.^[7]

Diet and foraging behavior

O. rubescens is a generalist predator and has been maintained on a wide variety of gastropods, bivalves, crabs and barnacles in the lab.^[5] There has so far been very little quantification of O. rubescens' diet in the wild. The two studies on the subject determined diet in Puget Sound, Washington to be dominated by gastropods, particularly Nucella lamellosa^[1] and Olivella baetica, but also composed of clams, scallops and crabs.^[8] The planktonic larvae of O. rubescens have also been observed in the wild consuming krill. ^[9]

As part of its feeding behavior, O. rubescens will pounce on prey and display a stereotyped sequence of color changes at the moment of capture.^[10] Following the capture of bivalve prey, O. rubescens will often drill a hole through the shell to deliver venom and more easily open the shell. The octopuses will often concentrate their drill holes near the adductor muscles of the bivalve prey.^[11]

References

1. ^ ^{a b} Onthank, K.L. (2008). Aerobic metabolism and dietary ecology of Octopus rubescens.PDF (2.4 MB) . M. Sc. Walla Walla University, College Place, WA: 91
2. ^ ^{a b c} Hochberg, F.G. (1997). Octopus rubescens. Proceedings of the workshop on the fishery and market potential of octopus in California. Smithsonian Institution (Washington, DC).
3. ^ Hochberg, F.G. (1998). Octopus rubescens. In: P.V. Scott & J.A. Blake (Eds.) Taxonomic Atlas of the Benthic Fauna of the Santa Maria Basin and the Western Santa Barbara Channel: Vol. 8. (pp. 213-218). Santa Barbara, California, Santa Barbara Museum of Natural History.
4. ^ Berry, S.S. 1953. Preliminary diagnoses of six west American species of Octopus. Leaflets in Malacology 1:51-58.
5. ^ ^{a b} Dorsey, E.M. (1976). Natural history and social behavior of Octopus rubescens (Berry). M. Sc. University of Washington, Seattle, WA: 44.
6. ^ Anderson, R.C. (2006). "On West Coast Octopuses including a field key to west coast species." The Festivus 38(1): 5-6.
7. ^ Mather, J.A. & R.C. Anderson (1993). "Personalities of Octopuses (Octopus rubescens)." Journal of Comparative Psychology 107(3): 336-340.
8. ^ Anderson, R.C., P.D. Hughes, J.A. Mather & C.W. Steele (1999). "Determination of the diet of Octopus rubescens though examination of its beer bottle dens in Puget Sound." Malacologia 41(2): 455-460.
9. ^ Laidig, T.E., Adams, P.B., Baxter, C.H. & Butler, J.L. (1995). Feeding on euphausiids by Octopus rubescens. California Fish and Game Technical Report 81 77-79.
10. ^ Warren, L. R., Scheier, M. F. & Riley, D.A. (1974). Colour changes of Octopus rubescens during attacks on unconditioned and conditioned stimuli. Animal Behaviour, 22 211-219.
11. ^ Anderson, R. C., Sinn, D. L. & Mather, J.A. (2008). Drilling localization on bivalve prey by Octopus rubescens Berry, 1953 (Cephalopoda: Octopodidae). The Veliger, 50 326-328.

External links

• CephBase: East Pacific Red Octopus
• Walla Walla University Marine Invertebrate Key