Author: Bradley T. Scheer
Publisher:
Published: 2003-01-01
Total Pages: 304
ISBN-13: 9780758116765
DOWNLOAD EBOOK →Author: Bradley T. Scheer
Publisher: Palala Press
Published: 2018-02-20
Total Pages: 316
ISBN-13: 9781378208281
DOWNLOAD EBOOK →This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Author: M. J. Wells
Publisher: Springer Science & Business Media
Published: 2013-06-29
Total Pages: 436
ISBN-13: 9401724687
DOWNLOAD EBOOK →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.