IR Home
MEPS
Home
Editors
Forthcoming
Information
Subscribe
Journals
Home
MEPS
AME
CR
DAO
ESEP
ESR
Search
Subscribe
Book Series
EE Books
Top Books
ESEP Books
Order
EEIU Brochures
(pdf format)
Discussion Forums
Home
Research
IR Research
Institutions
International Ecology Institute
Eco-Ethics International Union
Foundation
Otto Kinne Foundation
 | |
MEPS 283:113-125 (2004)
|
Abstract
|
Effect of mesograzers and nutrient levels on induction of defenses in several Brazilian macroalgae
Kerstin Weidner1, Bruno G. Lages2, Bernardo A. P. da Gama2, Markus Molis3,4,*, Martin Wahl3, Renato C. Pereira2
1Interdisciplinary Ecology Centre, Technical University Bergakademie Freiberg, Leipziger Straße 29, 09599 Freiberg, Germany
2Departamento de Biologia Marinha, Instituto de Biologia, Universidade Federal Fluminense, CP
100.644, CEP 24001-970 Niterói, Rio de Janeiro, Brazil
3Leibniz Institute of Marine Sciences, Marine Ecology/Marine Zoology, Düsternbrooker Weg 20, 24105 Kiel, Germany
4Present address: Marine Biological
Station Helgoland, Foundation Alfred Wegener Institute for Polar and Marine Research,Kurpromenade 201, 27498 Helgoland, Germany
*Corresponding author. Email: mmolis@awi-bremerhaven.de
ABSTRACT: Herbivory can greatly modify benthic community structure by affecting the distribution of algal species. To deter herbivores, algae have developed several mechanisms, including the induction of chemical and morphological defenses, which may be
influenced by nutrient availability. We tested 4 red (Chondrophycus flagellifera, Cryptonemia seminervis, Osmundaria obtusiloba, Pterocladiella capillacea), 4 brown (Dictyota menstrualis, Lobophora variegata,
Sargassum vulgare, Stypopodium zonale), and 1 green (Codium decorticatum) algae for inducible defenses following exposure to direct consumption by an amphipod community dominated by Elasmopus brasiliensis. In addition,
the effects of water-borne cues from nearby grazed conspecifics and non-grazing consumers on the induction of defenses were examined in C. decorticatum under natural and enhanced (200% natural) nutrient levels. Induction of defense was assessed in
choice-feeding assays, using live algae or artificial food containing non-polar extracts of amphipod-exposed (treated) and non-exposed (control) algae. Palatability levels, estimated as the relative difference in wet mass due to consumption in feeding
assays between grazer-exposed and control plants, declined significantly in 3 species after the acclimatization period. Tissue from the directly consumed red alga P. capillacea (live alga) was significantly less palatable than tissue from the
control plants. Likewise, a significant effect was observed in the brown alga L. variegata. Similar, although not statistically significant, trends were observed in 6 other species. For the green alga C. decorticatum, nutrient enrichment did
not affect induction of defenses by herbivores, yet unfertilized plants were more palatable than fertilized conspecifics.
KEY WORDS: Plant–animal interaction · Tropical seaweeds · Mesograzer · Nutrient enrichment · Feeding preference
Full text in pdf format
Published in MEPS Vol.
283
(2004) on November 30
Print ISSN: 0171-8630; Online ISSN: 1616-1599.
Copyright © Inter-Research, Oldendorf/Luhe, 2004
|
