Octopus: Physiology and Behaviour of an Advanced Invertebrate
between the organ systems of cephalopods and those of less ambitious molluscs. Octopus does, as we would predict, live close to the limits set by its own physiology. The circulation, to take one example, is barely adequate for such an active animal, mainly because of the absence of any system for pack aging the blood pigment; haemocyanin in solution is a poor oxygen carrier. Cephalopod blood can transport less than 5 millilitres of oxygen per 100 ml of blood (compared with about 15 vol% in fish) and the whole supercharged system of triple hearts, high blood pressure and pulsating blood vessels succeeds only in returning blood that retains less than 30% of its dissolved oxygen by the time it reaches the gills. This at rest; the effect of exercise is immediate and surprisingly long lasting even in octopuses as small as 300 g, which must very swiftly run into oxygen debt when they flee from predators or pursue their prey (Sections 3.2.2, 3.2.4). Digestion, too would seem to be limiting. As with other molluscs, digestion in Octopus is based on secretion absorption cycles by a massive diverticulum of the gut, an adequate system in a less hectic past, but scarcely appropriate in a predator that must be an opportunist in the matter of feeding. Octopus feeds mainly at night, and spends a great deal of every day sitting at home.
What people are saying - Write a review
We haven't found any reviews in the usual places.
Respiration circulation and excretion
Feeding and digestion
Reproduction and growth
Touch and the role of proprioception in learning
Effectors and motor control
1 Mainly tactile learning
2 Visual learning
What an octopus sees
Other editions - View all
Alexandrowicz animals appear attack axons basal lobes behaviour blood body weight Boletzky Boycott and Young brain lesions branchial hearts buccal Budelmann caecum cephalopods chromatophore coelomic colour crabs crista cuttlefish cyanea digestion discrimination distinguish dofleini ducts effect eggs Eledone experiments females fibres fluid follicle cells Froesch function ganglion Graziadei hair cells hectocotylus hepatopancreas horizontal hormone inferior frontal system input intact longitudinal male mantle mature motor move movements muscles nerve cords nervous neurones neurosecretory normal objects octopods Octopus vulgaris optic glands optic lobes optic nerves organs orientation ovary oviducts pairs peduncle lobe posterior salivary glands proprioceptive protein radula receptors rectangles response retina rhabdomes rotation salivary glands seawater Section Sepia shapes side sperm spermatophore statocyst stimulation stripes structure suboesophageal subpedunculate lobe suckers superior frontal supraoesophageal Sutherland Table tactile tank tissue touch learning transfer tests trials tyramine vertebrates vertical lobe removal visual yolk