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


Document Type


Degree Name

Master of Science (M.S.)


Biological Sciences

First Advisor

Joel W. Hedgpeth

First Committee Member

John S. Tucker

Second Committee Member

Gilbert C. Hughes III


In August 1959 Pacific Marine Station (P.M.S.) located at Dillon Beach, began a program of oceanographic study as a member of the California Cooperative Oceanic Fisheries Investigations (C.C.O.F.I.). The program continued throughout the summer of 1963 and consisted of a monthly hydrographic station and sampling the plankton at the head of Bodega Submarine Canyon, located twenty-five miles west of Bodega Bay. Two plankton tows were taken on each ocean run. One of the samples, along with collection and hydrographic data, was sent to Scripps Institute of Oceanography. The other sample was retained at P.M.S. and constitutes the material for the present study.

Pelagic gastropods were present in every tow in varying numbers and species. Two groups, pteropods and heteropods, were found in the samples. One species of pteropod, Limacina helicina, was the dominant member in all of the tows and occurred during the entire year. Little work has been done on the pelagic gastropods of the North Pacific. The information available has been mainly compiled by Tesch in the Dana Reports and McGowan (1960). Taxonomically the group has been extensively studied, but little is known about the life cycles, size ranges, growth rates, physiology, behavior, distribution and abundance. No previous study on the pelagic gastropods collected by P.M.S. has been made. This paper is a discussion of the pelagic gastropods collected over a period of four years. It is the purpose of this study to identify, examine, and present information of the local specimens collected by Pacific Marine Station.



Included in

Life Sciences Commons



Rights Statement

Rights Statement

No Known Copyright. URI:
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.