Campus Access Only

All rights reserved. This publication is intended for use solely by faculty, students, and staff of University of the Pacific. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, now known or later developed, including but not limited to photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author or the publisher.

Date of Award

1961

Document Type

Thesis

Degree Name

Master of Arts (M.A.)

Department

Biological Sciences

First Advisor

John S. Tucker

First Committee Member

Joel W. Hedgpeth

Abstract

This study is of five species of isopods common to the Dillon Beach area, each of which represents a different level in the transition toward land life. Cirolana harfordi was used as a completely marine form. Idothea (Pentidotea) wosnesenskii represents a step toward land life as it inhabits an area uncovered by most low tides. Ligia occidentalis is found in the splash zone, receiving spray from the action of the surf. This illustrates another, higher, level in the transition. Alloniscus perconvexus was the fourth species studied. It is commonly found burrowed in the sand in the area of the berm, which is the nearly level portion of the beach formed by high tidal wave action. Finally, the terrestrial form, Porcellio (Porcellion) scaber, was used to illustrate those isopods best adapted to land life. The physiological data presented in this paper includes salinity tolerances and humidity tolerances. Some information on acclimating one species to lowered salinities is also presented. The results of these experiments are used to illustrate the degrees of adaptation to land life shown by the isopods in different areas of the transition. A discussion of the adaptive morphology and behavioral characteristics is also related to the environmental situations in which each animal is found.

Pages

50

Share

COinS
 

Rights Statement

Rights Statement

No Known Copyright. URI: http://rightsstatements.org/vocab/NKC/1.0/
The organization that has made the Item available reasonably believes that the Item is not restricted by copyright or related rights, but a conclusive determination could not be made. Please refer to the organization that has made the Item available for more information. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use.