The difference between dolphins and octopus is that dolphins have skeletons and octopuses don't! There are many differences between a dolphin and an octopus such as an octopus has tenicles and dolphins dont. Plus they eat very different diets. Octopuses may eat plankton while the dolphin eats small fish
Penises.
Dolphins breathe with lungs while sharks breathe with gills.
whales and dolphins both have fins, but dolphins are much smaller than whales
Nothing they are the same...
Dolphins are marine mammals, zebras are terrestrial mammals. Zebras are herbivores, but dolphins are carnivores. Thus zebras are prey animals and dolphins are predators. But the biggest difference between these to animals is that they do not look the same.
There are many differences between the shark and the dolphin. Sharks are cartilaginous fish whereas the dolphin is a mammal. Sharks take air in through their gills while dolphins breathe fresh air using their lungs.
Very little apart from their size, Dolphins and Whales belong to the same Genus of Mammals. http://42explore.com/whale.htm
risso dolphins sharks and beluga whales eat octopuses
Natural predators of octopus are moray and conger eels, dolphins and sharks. - From a Google search.sharks
Octopuses, or octopi, are predators. They hunt crabs, prawn, fish, and mollusks. However, in turn they are also hunted by sharks, dolphins, and other sea animals, so they are also prey.
Invertebrates don't have a backbone, like octopuses, crabs, worms, etc
Sharks have straight dorsal fins, dolphins have curved dorsal fins and whales don't have dorsal fins :)