Figure 1. Stable isotope enrichment of ¹³C and ¹⁵N in coral mucus, sponge tissue and sponge detritus.

Above-background isotope tracer incorporation Δδ¹³C (%) (dark bars) and Δδ¹⁵N (%) (light bars) in: (a) coral mucus, sponge tissue, and sponge detritus from the warm-water sponge Mycale fistulifera; with tissue and detritus sampled after 3 and 5 days exposure to ¹³C and ¹⁵N labeled warm-water coral mucus, and (b) coral mucus, sponge tissue, and sponge detritus from the cold-water sponge Hymedesmia coriacea sampled after 4 days exposure to ¹³C and ¹⁵N labeled cold-water coral mucus. Data presented as mean ± SD*. *Note that the cold-water sponge tissue data are from three sponge specimens maintained in a single experimental chamber during the labeling procedure. Subsequent detritus production incubations were conducted in individual chambers.