Creature of the week
Common Octopus
(wheke )
Octopus maorum
Copyright © 2003 - Orana Wildlife Trust
Arm span of no more than 1.5 m
This is a 1980 car sticker we used to try
and sell the idea of MERC !
Description :
Believe it or not, but this eight-armed carnivore belongs to the shellfish (mollusc) family so is related to
limpets, oysters, slugs and the garden snail!! It has no shell. However, its closest relatives are the squid and
cuttlefish.
Soft body and well developed brain to process sensory information and to control all the arms as they
struggle with various prey. There is a highly developed Eye on each side of head for vision but the animal is
totally deaf. Arms have two rows of suckers. If an octopus loses one of its tentacles it will grow another in
its place. It propels itself by jetting water from its mantle cavity through a siphon tube or walking with its
tentacles. It is a master of camouflage, controlling body colour and patterning almost instantly to match
those of its surroundings. The octopus can release ink as a defensive mechanism, which it may squirt in the
direction of any potential danger. Rather than hiding the octopus, this is thought to either confuse any
predator with another ‘octopus shaped’ cloud of ink, or to discourage the predator with a chemical irritant
found within the ink. There is a pair of sharp beaks. The octopus has three hearts! One to pump blood
around its body and another two to help push blood through its two gills.
Habitat:
Rock pools, subtidal, Usually stays in dens during the day and hunts at night or on dark dreary days. The soft
body allows it to hide in any hole or crevice – even bottles!. In muddy areas it will get in a hole and cover
itself with dead shells and debris awaiting prey.
Diet;
Octopus usually live in dens and will either venture out in search of prey or will wait by the entrance and
ambush any unwary fish, crabs, crayfish in their pots, or other edible invertebrate that passes within reach.
They will leap on their potential prey, enveloping it within their arms and paralyzing it with their salivary
toxin. This may be accompanied by biting and tearing from their parrot-like beak (the only rigid part of an
octopus’ body) in order to break the animal into digestible pieces. It sucks out the flesh and discards the
empty shell.
Reproduction:
The male is easily identified by the third arm on its right hand side, which has a round spoon-like tip. This
arm is used insert a package of sperm called a spermatophore into the females body cavity where it fertilises
the females eggs. The female will then lay her eggs in ‘grape-like’ clusters within rocky recesses, staying to
ventilate her eggs by pumping water over them. She will remain with the eggs until she has finished brooding
them for the 11 weeks before they hatch and will then generally die shortly afterwards.
Age:
It is thought that Octopus maorum is fast growing and relatively short lived, living to about 18 – 24 months.
Reference and picture the www.southernencounter.co.nz/animal_info/octopus.htm escape artist, with its b
dy able to fit through any hole that it can fit its h