Figure 5.

Patterns of respiration and photosynthesis in two groups of Exaiptasia pallida experimentally re-infected with homologous Symbiodinium ITS2-type A4 or heterologous, ITS2-type B1 S. minutum, respectively. (A) Symbiont cell densities (10⁶ cells mg⁻¹); (B) Symbiont photosynthetic output (pmol O₂ cell⁻¹ h⁻¹); (C) Holobiont respiration rate normalized to host protein content (μmol O₂mg⁻¹ h⁻¹); (D) Host (white box, black markers) and symbiont (gray box, white markers) specific citrate synthase (CS) activities (mU mg⁻¹); (E) The proportion of symbiont-derived CS activity relative to total holobiont CS activity (R_Sym); (F) The relationship between R_Sym and symbiont biomass as a fraction of total biomass (1-ß; Muscatine et al., 1981). Boxes represent means (thick black line) ± 1 standard error, whiskers represent 1 standard deviation. Between-group comparisons for data in (A–C,F), and host CS specific activity in (D), were conducted using t-tests. Between-group comparisons for symbiont CS specific activity (D) and R_Sym (E) were conducted using Wilcoxon Rank-Sum tests.