DOI: 10.5061/dryad.mw6m9064w
title: Data from: Biogeographical diet variation within and between the rabbitfishes Siganus corallinus, Siganus doliatus, Siganus trispilos and Siganus virgatus

description: Feeding habits of herbivorous fishes play an important role in shaping
 form and function of coastal marine ecosystems. Rabbitfishes (Siganidae)
 are important consumers of macroalgae on Indo-West Pacific coral reefs.
 However, it is unclear how their diet varies among and within species at
 biogeographical scales, casting doubt on their precise functional roles
 across different regions. The present study assessed the inter- and
 intraspecific diet variation of four rabbitfishes (Siganus trispilos,
 Siganus coralinus, Siganus virgatus, and Siganus doliatus) factored by
 morphological relatedness among populations from Ningaloo Reef (western
 Australia), the Great Barrier Reef (GBR, eastern Australia) and the
 Yaeyama Islands (Okinawa Prefecture, Japan). Results showed that region
 had a strong effect on diet, effectively reducing the expected effect of
 morphologic similitude. While intraspecific differences were only
 significant when populations inhabited different regions; interspecific
 differences were not as predicted, with different morphotypes having
 similar diets when populations inhabited the same regions. Rabbitfishes
 consumed more corticated and filamentous macroalgae on the GBR, more
 foliose and membranous macroalgae at the Yaeyama Islands, and more
 leathery macroalgae at Ningaloo Reef. The findings indicate that
 rabbitfishes have high diet plasticity, and hence their functional role as
 mediators of competition between macroalgae and corals can change across
 biogeographic regions. Local context is therefore important when assessing
 the diet and functional role of herbivorous fishes. As climate change
 unfolds, shifts in the distribution, trophic behaviour and function of
 species are expected, making the study of trophic plasticity more
 important.
description: <strong>Species of study and diet
 information</strong>  
 The study focused on four closely-related species of rabbitfish
 (<em>Siganus virgatus, S. doliatus, S. corallinus, and S.
 trispilos</em>; Siqueira, Bellwood & Cowman 2019) that have
 populations in three regions set apart by thousands of kilometres: Okinawa
 (Yaeyama Islands), the Great Barrier Reef (GBR; Turtle Group and Lizard
 Island), and Ningaloo Reef (Coral Bay). Specimens of <em>S. virgatus
 </em>and <em>S. trispilos</em> were collected by spear
 [Murdoch University ethics permit number R3349/21 and Department of
 Fisheries (DPIRD) exemption 3699] between 9 am and 11 am in backreef and
 lagoon habitats of Bateman (23°02'28"S, 113°47'04"E),
 Five Fingers (23°10'54"S, 113°45'51"E) and Yalobia
 (23°12'22"S, 113°45'33"E) reefs, Ningaloo Reef,
 Western Australia, during June 2022 and March-April 2023. Captured
 specimens were euthanised, stored in ice, and dissected fresh at the Coral
 Bay Research Station (Murdoch University). The alimentary tract was
 removed, dissected open, and the gut content preserved in a solution of
 80% ethanol. Diet data from these samples were collected in the laboratory
 using a stereo microscope, similarly to previous studies (Nanami 2018).
 Food items were spread evenly over a petri dish divided into a grid of 100
 cells, identified to the lowest taxonomic level possible and assigned a
 proportion of the total gut content based on the proportional number of
 grid squares covered using the program ImageJ (rsb.info.nih.gov/ij/).
 Macroalgae in the diet were grouped into morpho-functional groups:
 Filamentous/corticated, foliose/membranous, leathery, and calcareous.
 Categories other than macroalgae comprised seagrass, cyanobacteria,
 phytoplankton, mobile zoobenthos, sessile invertebrates, detritus and
 sediment. Diet information for the populations of rabbitfishes from the
 GBR, was obtained from a diet database created by Hoey et al. (2013). Diet
 data from Okinawa were obtained from Nanami (2018) using the software
 Datathief III (Flower, McKenna & Upreti 2016).
  
 <strong>References</strong>
   Hoey, A. S., Brandl, S. J., &
 Bellwood, D. R. (2013). Diet and cross-shelf distribution of rabbitfishes
 (f. Siganidae) on the northern great barrier reef: Implications for
 ecosystem function. Coral Reefs, 32(4), 973–984. https://doi.org/10.1007/s00338-013-1043-z    Nanami, A. (2018). Spatial distributions, feeding ecologies, and behavioral interactions of four rabbitfish species (Siganus unimaculatus, S. virgatus, S. corallinus, and S. puellus). PeerJ, 6, e6145. https://doi.org/10.7717/peerj.6145
description: # Data from: Biogeographical diet variation within and between the
 rabbitfishes Siganus corallinus, Siganus doliatus, Siganus trispilos and
 Siganus virgatus Access this dataset on Dryad:
 [https://doi.org/10.5061/dryad.mw6m9064w](https://doi.org/10.5061/dryad.mw6m9064w) The data consists on one single file containing information on the diet of populations of the rabbitfishes *Siganus trispilos, Siganus corallinus, Siganus virgatus*, and *Siganus doliatus* across coral reefs in Ningaloo Reef (Western Australia), Great Barrier Reef (Eastern Australia) and Okinawa (Japan) (Zarco-Perello et al. 2024 Data from Biogeographical Diet Variation of Rabbitfishes.csv). Diet values represent the proportions of each food item/category in the digestive system of each individual fish (% of gut content). ## Description of the data and file structure * *Species*: Currently valid scientific name. * *Population ID*: Name identifying the different populations of each species. * *Individual ID*: Name identifying each individual from each population of each species. * *Sister taxa*: Morphological grouping: short snout (Snout) and long snout (Lsnout). * *Family*: Taxonomical family of the fish species. * *Reference*: Sources of diet information. * *Location*: Regions where the different populations reside. * *Corticated/Filamentouse*: Gut content proportion (%) of macroalgae with cylinder-like morphology. * *Foliose/Membranous*: Gut content proportion (%) of macroalgae with sheet-like morphology. * *Leathery*: Gut content proportion (%) of macroalgae with tough/leathery morphology. * *Calcareous*: Gut content proportion (%) of macroalgae with calcareous tissue. * *Cyanobacteria*: Gut content proportion (%) of cyanobacteria. * *Diatoms/Dinoflagellates:* Gut content proportion (%) of phytoplankton organisms. * *Seagrass*: Gut content proportion (%) of marine angiosperms. * *Mobile Zoobenthos*: Gut content proportion (%) of mobile benthic invertebrates (*e.g.* crabs). * *Zooplankton*: Gut content proportion (%) of planktonic invertebrates (*e.g*. copepods). * *Sessile Inverts*: Gut content proportion (%) of sessile invertebrates (*e.g*. coral). * *Detritus*: Gut content proportion (%) of detrital biomass. * *Sediment*: Gut content proportion (%) of sediment particles.