Fig. 8. The ¹³C{¹H} NMR spectrum (150 MHz) of cold-acclimated C. clavipes hemolymph. (A) Expansion of the 22–98 p.p.m. region of the spectrum. Assignments of the major signals are as follows: a, ,-trehalose; b, glycerol; c, proline; d, betaine. The signal at 55.5 p.p.m. is a triplet and that at 68 p.p.m. is a complex multiplet; assignment of these signals to betaine is tentative [other species bearing a –N(CH₃)₃⁺ group may be responsible for these signals]. The signal marked with `x' was unassigned. (B) Expanded carboxyl region of the spectrum showing assignment c of the carboxyl carbon of proline; x was unassigned. (C) Expanded aromatic region of the spectrum, showing two broad multiplets due to presently unknown species. Signals in B and C were very weak compared with those observed in A (note the reduced S/N in B and C relative to A).