In vitro protein synthesis capacities in a cold stenothermal and a temperate eurythermal pectinid
1. The temperature dependency of protein synthesis was studied in vivo in five species of Pacific fish collected in the Galapagos and Perlas Islands: batfish (Ogcocephalus darwini), groupers (Epinephelus labriformis), catfish (Netuma platypogan), puffers (Arothron hispidus) and triggerfish (Sufflamen verres). 2. Liver protein synthesis, assayed by a rapid pulse injection technique, showed a moderate temperature dependency (Q10 = 2-3) in the 15-30 degree C range for all species except puffers (Q10 = 10-20). Synthesis was inhibited above 32 degrees C. 3. Protein synthesis in triggerfish was measured by the constant-infusion technique. Synthetic rates (% of tissue protein synthesized per day) at 25 degrees C were 20% for liver, 10% for gill, 1.8% for red muscle and 0.6% for white muscle. Q10 in the 20 degrees-30 degrees C range was 3.0 +/- 0.5 degrees C for all tissues.