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

First published online March 30, 2006
Journal of Experimental Biology 209, 1463-1486 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02147

This Article Figures Only Full Text Full Text (PDF) Supplementary Material Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JEB 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 Townley, M. A. Articles by Neefus, C. D. Search for Related Content PubMed PubMed Citation Articles by Townley, M. A. Articles by Neefus, C. D.

Changes in composition of spider orb web sticky droplets with starvation and web removal, and synthesis of sticky droplet compounds

Mark A. Townley^1,*, Edward K. Tillinghast¹ and Christopher D. Neefus²

¹ Department of Zoology, University of New Hampshire, 46 College Road, Durham, NH 03824-2617, USA
² Department of Plant Biology, University of New Hampshire, 46 College Road, Durham, NH 03824-2617, USA

^* Author for correspondence (e-mail: mtownley{at}cisunix.unh.edu)

Accepted 6 January 2006

The sticky spiral of araneoid spider orb webs consists of silk fibers coated with adhesive droplets. The droplets contain a variety of low-molecular-mass compounds (LMM). Within a species, a fairly consistent ratio of LMM is often observed, but substantial variability can exist. To gain insight into factors influencing LMM composition, spiders of three araneid species were starved and LMM from their webs were analyzed for changes in composition. To determine if these changes were consistent with the spider's ability to synthesize the different organic LMM, synthetic capacities were estimated following the feeding of radiolabeled metabolites. Some changes in droplet composition were broadly consistent with differing synthetic capacities: molar percentages of less readily synthesized compounds (e.g. choline, isethionate, N-acetyltaurine) typically declined with starvation, at least during a portion of the imposed fast, while more readily synthesized compounds (e.g. GABamide, glycine) tended to increase. Most striking was the apparent partial substitution of N-acetylputrescine by the more readily synthesized GABamide in fasting Argiope trifasciata. However, departures from expected compositional shifts demonstrated that synthetic capacity alone does not adequately predict sticky droplet compositional shifts with starvation. Moreover, feeding controls exhibited some changes in composition similar to starving spiders. As the webs of both feeding and starving spiders were removed for chemical analysis and could not be recycled, the loss of LMM contained in these webs likely contributed to similarities between treatments. In addition, feeding spiders molted, oviposited and/or built heavier webs. The added metabolic demands of these activities may have contributed to changes in composition similar to those resulting from starvation.

Key words: 4-aminobutyramide, Araneus cavaticus, choline, glycine, glycine betaine, isethionic acid, orb web, putrescine, resource allocation, spider web recycling, sticky spiral, taurine

Related articles in JEB:

STICKY WEBS SUFFER FROM STARVATION

Kathryn Phillips
JEB 2006 209: i. [Full Text]  

This article has been cited by other articles:

				K. Phillips STICKY WEBS SUFFER FROM STARVATION J. Exp. Biol., April 15, 2006; 209(8): i - ii. [Full Text] [PDF]