The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand

Coral reef resilience is greatly influenced by herbivory. There is a need to identify key fish species fulfilling this critical function in biogeographically distinct regions. This experimental in situ study investigated fish herbivory in coral reefs of the lower Gulf of Thailand characterized by a...

Full description

Bibliographic Details
Main Authors: Malika Müller, Constanze F. K. Staab, Laura D. Puk, Eike M. Schoenig, Sebastian C. A. Ferse, Christian Wild
Format: Article
Language:English
Published: MDPI AG 2021-03-01
Series:Diversity
Subjects:
Online Access:https://www.mdpi.com/1424-2818/13/3/123
_version_ 1827697784374951936
author Malika Müller
Constanze F. K. Staab
Laura D. Puk
Eike M. Schoenig
Sebastian C. A. Ferse
Christian Wild
author_facet Malika Müller
Constanze F. K. Staab
Laura D. Puk
Eike M. Schoenig
Sebastian C. A. Ferse
Christian Wild
author_sort Malika Müller
collection DOAJ
description Coral reef resilience is greatly influenced by herbivory. There is a need to identify key fish species fulfilling this critical function in biogeographically distinct regions. This experimental in situ study investigated fish herbivory in coral reefs of the lower Gulf of Thailand characterized by a considerably low herbivorous fish biomass and diversity, but high live coral and low macroalgal cover. This provided an intriguing situation for macroalgal browsing research. Visual census techniques assessed the abundance of local herbivorous fish species, and filmed single-choice assays using the macroalga <i>Turbinaria</i> evaluated mass-standardized bites (ms-bites) and biomass removal. Multiple-choice assays offering four locally abundant macroalgae identified specific biomass removal and ms-bites to uncover selection and avoidance patterns of observed fish species. The rabbitfish <i>Siganus</i><i>virgatus</i> constituted only 39% of herbivore biomass but accounted for 90% of ms-bites. In multiple-choice assays, fishes took most (61%) bites on <i>Sargassum</i>, followed by <i>Padina</i> (28%) and <i>Turbinaria</i> (11%), while <i>Lobophora</i> was avoided. <i>S. virgatus</i> exhibited the most generalized browsing pattern of all species observed. Coinciding with recent studies, our findings suggest that <i>S. virgatus</i> plays a key functional role in reefs characterized by low diversity of herbivores and low functional redundancy.
first_indexed 2024-03-10T13:16:39Z
format Article
id doaj.art-a1de7622d754473ebe7a8a7a84bdd6ae
institution Directory Open Access Journal
issn 1424-2818
language English
last_indexed 2024-03-10T13:16:39Z
publishDate 2021-03-01
publisher MDPI AG
record_format Article
series Diversity
spelling doaj.art-a1de7622d754473ebe7a8a7a84bdd6ae2023-11-21T10:23:40ZengMDPI AGDiversity1424-28182021-03-0113312310.3390/d13030123The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of ThailandMalika Müller0Constanze F. K. Staab1Laura D. Puk2Eike M. Schoenig3Sebastian C. A. Ferse4Christian Wild5Marine Ecology and Coral Reef Ecology Group, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, GermanyMarine Ecology and Coral Reef Ecology Group, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, GermanyMarine Ecology and Coral Reef Ecology Group, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, GermanyCenter for Oceanic Research and Education–COREsea, Surat Thani 84280, ThailandMarine Ecology and Coral Reef Ecology Group, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, GermanyMarine Ecology and Coral Reef Ecology Group, Faculty of Biology and Chemistry, University of Bremen, 28359 Bremen, GermanyCoral reef resilience is greatly influenced by herbivory. There is a need to identify key fish species fulfilling this critical function in biogeographically distinct regions. This experimental in situ study investigated fish herbivory in coral reefs of the lower Gulf of Thailand characterized by a considerably low herbivorous fish biomass and diversity, but high live coral and low macroalgal cover. This provided an intriguing situation for macroalgal browsing research. Visual census techniques assessed the abundance of local herbivorous fish species, and filmed single-choice assays using the macroalga <i>Turbinaria</i> evaluated mass-standardized bites (ms-bites) and biomass removal. Multiple-choice assays offering four locally abundant macroalgae identified specific biomass removal and ms-bites to uncover selection and avoidance patterns of observed fish species. The rabbitfish <i>Siganus</i><i>virgatus</i> constituted only 39% of herbivore biomass but accounted for 90% of ms-bites. In multiple-choice assays, fishes took most (61%) bites on <i>Sargassum</i>, followed by <i>Padina</i> (28%) and <i>Turbinaria</i> (11%), while <i>Lobophora</i> was avoided. <i>S. virgatus</i> exhibited the most generalized browsing pattern of all species observed. Coinciding with recent studies, our findings suggest that <i>S. virgatus</i> plays a key functional role in reefs characterized by low diversity of herbivores and low functional redundancy.https://www.mdpi.com/1424-2818/13/3/123<i>Siganus virgatus</i>macroalgaebrowserherbivorous fishassay
spellingShingle Malika Müller
Constanze F. K. Staab
Laura D. Puk
Eike M. Schoenig
Sebastian C. A. Ferse
Christian Wild
The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand
Diversity
<i>Siganus virgatus</i>
macroalgae
browser
herbivorous fish
assay
title The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand
title_full The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand
title_fullStr The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand
title_full_unstemmed The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand
title_short The Rabbitfish <i>Siganus virgatus</i> as Key Macroalgae Browser in Coral Reefs of the Gulf of Thailand
title_sort rabbitfish i siganus virgatus i as key macroalgae browser in coral reefs of the gulf of thailand
topic <i>Siganus virgatus</i>
macroalgae
browser
herbivorous fish
assay
url https://www.mdpi.com/1424-2818/13/3/123
work_keys_str_mv AT malikamuller therabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT constanzefkstaab therabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT lauradpuk therabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT eikemschoenig therabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT sebastiancaferse therabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT christianwild therabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT malikamuller rabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT constanzefkstaab rabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT lauradpuk rabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT eikemschoenig rabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT sebastiancaferse rabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand
AT christianwild rabbitfishisiganusvirgatusiaskeymacroalgaebrowserincoralreefsofthegulfofthailand