Table 2.
Relative composition of lipid biomarkers and their average δ13C values in sponge tissue
| lipid biomarker sources | H. (S.) methanophila | I. methanophila | ||
|---|---|---|---|---|
| % of all lipids | δ13C (‰) (av.) | % of all lipids | δ13C (‰) (av.) | |
| MOX (MUFAs) | 27 | −46 | 14 | −50 |
| Sponge (demospongic acids, MUFAs) | 28 | −47 | 39 | −43 |
| Sponge (sterols) | 29 | −41 | 26 | −43 |
| Various sources (saturated n-fatty acids) | 12 | −36 | 16 | −35 |
| Bacteria, usually SRB (tb fatty acids) | 1 | NM | 1 | NM |
| Various bacteria (diplopterol) | 3 | −47 | 4 | −43 |
MOX methane-oxidizing bacteria, SRB sulfate-reducing bacteria, tb terminally-branched, MUFAs monounsaturated fatty acids, av. average, NM not measured