QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online December 10, 2003
Journal of Experimental Biology 207, 225-232 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.00741

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Papastamatiou, Y. P. Articles by Lowe, C. G. Search for Related Content PubMed PubMed Citation Articles by Papastamatiou, Y. P. Articles by Lowe, C. G. Social Bookmarking                         What's this?

Postprandial response of gastric pH in leopard sharks (Triakis semifasciata) and its use to study foraging ecology

Yannis P. Papastamatiou^* and Christopher G. Lowe

Department of Biological Sciences, California State University Long Beach, 1250 Bellflower Blvd, Long Beach, CA 90840 USA

^* Author for correspondence at present address: Hawaii Institute of Marine Biology, University of Hawaii at Manoa, PO Box 1346, Kaneohe, HI 96744, USA (e-mail: yannis{at}hawaii.edu)

Accepted 3 October 2003

Changes in gastric pH of leopard sharks Triakis semifasciata were quantified as an indicator of feeding frequency and ration size. Continuous in situ measurements of gastric pH were made in captive adult leopard sharks using an autonomous pH/temperature probe for periods ranging from 5-16 days. Instrumented sharks were fed meals of squid at different ration sizes. Gastric fluid samples were also taken from non-instrumented juvenile leopard sharks at different time intervals after feeding, and the pH measured to quantify effects of the pH probe in the stomach. Continuous in situ measurements of pH show that empty stomachs have a low pH of 1.54±1.42 (mean ± S.D.) and that feeding causes a rapid increase in pH to 3.11±0.71, followed by a gradual decrease back down to baseline levels. There was a positive relationship between changes in pH and meal size (r²=0.72, P=0.001). There were no significant differences in pH between continuous in situ and laboratory serial sample measurements. Together these findings indicate that gastric acid secretion may be continuous in leopard sharks, and that changes in gastric pH may be used to estimate feeding chronology, frequency and ration size of leopard sharks in the field.

Key words: digestion, feeding chronology, acid secretion, gastric evacuation, leopard shark, Triakis semifasciata

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				C. M. Wood, A. G. Schultz, R. S. Munger, and P. J. Walsh Using omeprazole to link the components of the post-prandial alkaline tide in the spiny dogfish, Squalus acanthias J. Exp. Biol., March 1, 2009; 212(5): 684 - 692. [Abstract] [Full Text] [PDF]

				C. M. Wood, M. Kajimura, C. Bucking, and P. J. Walsh Osmoregulation, ionoregulation and acid-base regulation by the gastrointestinal tract after feeding in the elasmobranch (Squalus acanthias) J. Exp. Biol., April 15, 2007; 210(8): 1335 - 1349. [Abstract] [Full Text] [PDF]

				C. M. Wood, M. Kajimura, T. P. Mommsen, and P. J. Walsh Alkaline tide and nitrogen conservation after feeding in an elasmobranch (Squalus acanthias) J. Exp. Biol., July 15, 2005; 208(14): 2693 - 2705. [Abstract] [Full Text] [PDF]