BIO 308: ANIMALS : FORMS AND FUNCTIONS TITLE Abstract Introduction Octopuses are one of the smartest animals in the world. Octopuses live in oceans all over the world including pelagic waters ( near water's surface near the shells), coral reefs and crevices. Anatomy Octopuses are non skeletal organisms which are able to move around the water with speed and grace. They are able to fit into the space which is much smaller than their body size. Adult octopuses usually weigh 15 kgms and an arm span of 4.5 feets. The smallest species recognized is Octopus wolfi with a size around 2.5 cm and weighs less than 1 gm. They are the most evolved among cephalopod class. Cephalopod literally means head-footed. Octopus is bilaterally symmetrical …show more content…
The alimentary tract of starts from mouth, there they have beak for breaking the prey’s shell and it is broken down to small pieces in that buccal mass consisting of mouth, pharynx, radula and salivary glands. Salivary glands secrete digestive enzymes while another pair secretes a toxin which paralyses the prey making it easy. Then food passes through oesophagus which has more digestive glands and transferred to crop which is a temporary storage of partly digested food before it enters the stomach. Stomach is a very muscular organ here the food is churned up into a slush in the stomach and it enters the caecum. In the caecum, where most of the absorption happens, food is sorted into fluids and particles. Nutrients absorbed from here are dispersed throughout the body through blood. Indigestible food move on the next stage. Remainings go through the intestine and further digestion and absorption takes place. Then the undigested food then exits through the anus. Both humans and octopuses have a ‘complete’ digestive tract( two openings with a one-way flow). They both have a specialized organ with maximized surface area where most of the absorption takes place. Both possess glands that secrete and ducts that deliver digestive