Communicating editor: C. Katsaros.
Effects of nutrient enrichment and herbivory on morphology, reproduction and chemical content of Turbinaria conoides (Phaeophyceae)
Article first published online: 10 JUN 2013
© 2013 Japanese Society of Phycology
Volume 61, Issue 4, pages 270–276, October 2013
How to Cite
Mayakun, J., Kim, J. H., Lapointe, B. E. and Prathep, A. (2013), Effects of nutrient enrichment and herbivory on morphology, reproduction and chemical content of Turbinaria conoides (Phaeophyceae). Phycological Research, 61: 270–276. doi: 10.1111/pre.12023
- Issue published online: 17 OCT 2013
- Article first published online: 10 JUN 2013
- Manuscript Accepted: 12 APR 2013
- Manuscript Received: 4 MAY 2011
- Thailand Research Fund. Grant Number: 4. B. PS/50/L. 1
- Graduate School, PSU
- brown alga;
- resource allocation
The effects of nutrient enrichment and herbivory on resource allocation patterns among morphology, reproduction, and chemical content of the brown alga, Turbinaria conoides (J. Agardh) Kützing were tested in the shallow subtidal zone of the Gulf of Thailand. The field experimental design comprised 36 plots (50 × 50 cm2) with and without herbivores, and two nutrient levels. Cages (uncaged and fully caged plots) were used to exclude herbivorous fishes and two nutrients levels were achieved by experimental enrichment above ambient nutrient concentrations. For morphology of Turbinaria, the maximum length (holdfast to frond apex), the width of the base of the stipe, number of blades, holdfast and stipe diameter were measured. Biomass, reproductive output, and tissue nutrient (carbon: nitrogen: phosphorus) content of T. conoides were examined. Phlorotannin concentrations were examined using a modified Folin-Ciocalteu method. The results showed that herbivory had no effect on morphology, reproduction, or phlorotannin concentrations. This could be due to the structural and morphological deterrents of alga, which might minimize grazing effects from herbivorous fishes. Nutrient enrichment had no effect on morphology and reproduction of T. conoides, possibly due to low nutrient demand in Turbinaria. However, nutrient enrichment did affect phlorotannin concentrations, as phlorotannins in the enriched plots were lower than the ambient plots. These results support, in part, the carbon–nutrient balance hypothesis that states algae will allocate fewer resources to production of anti-herbivore chemical compounds when enriched with potential growth-limiting nutrients.