Is an octopus an animal?

Octopuses Have Three Hearts. All vertebrate animals have one heart, but an octopus is equipped with three: one that pumps blood throughout this cephalopod's body (including its arms), and two that pump blood through its gills, the organs that enable it to breathe underwater by harvesting oxygen. read more

The octopus is bilaterally symmetrical along its dorso-ventral axis; the head and foot are at one end of an elongated body and function as the anterior (front) of the animal. The head includes the mouth and brain. read more

All animals are categorized by a seven-part classification system. What type of animal an octopus is depends on the taxonomic level being discussed. The broadest level is kingdom, followed by phylum, class, order, family, genus and species. All octopuses belong to the order Octopoda. read more

All vertebrate animals have one heart, but an octopus is equipped with three: one that pumps blood throughout this cephalopod's body (including its arms), and two that pump blood through its gills, the organs that enable it to breathe underwater by harvesting oxygen. read more

Octopus species that produce larger eggs – including the southern blue-ringed, Caribbean reef, California two-spot, Eledone moschata and deep sea octopuses – do not have a paralarval stage, but hatch as benthic animals similar to the adults. read more