Figure 1.
Invasive macroalga Acanthophora spicifera occurs exclusively within the territories of the algal farming damselfish Stegastes marginatus.
A) Oblique view of Stegastes marginatus (arrow) feeding patches with dense growths of the invasive red macroalga Acanthophora spicifera (A.s.), turf algae (T) and sand (S). B) S. marginatus defending a lush canopy of A. spicifera. C) Percent cover of benthos inside and outside S. marginatus territories in May and September 2010.
Figure 2.
Herbivore grazing intensity on A. spicifera was highest outside the territorial defenses of S. marginatus.
A) Percent loss of A. spicifera algal biomass from tethers placed inside S. marginatus territories, outside territories, or in caged controls. B) Number of bites min−1 on tethered A. spicifera placed inside and outside S. marginatus territories. C) Percentage of bites taken by different fish species inside and outside S. marginatus territories. Data are plotted as mean ± SE and bars with different letters indicate significant differences at p<0.05.
Figure 3.
Stegastes marginatus acts as an opportunistic browser on A. spicifera outside its territorial borders.
Examples of Stegastes marginatus feeding outside their territories on tethered Acanthophora spicifera alongside (A) the surgeonfish Acanthurus nigrofuscus (A.n.), and (B) another S. marginatus (S.m.). C) The total number of occurrences from 400 min of filming when S. marginatus was observed feeding on tethered A. spicifera either alone (S.m. alone), along with another S. marginatus (≥2 S.m.), or with another fish species in the outside territory treatments (S.m. with other spp.).