Fig. 1

Illustration of transplantation experiment, in situ fixation, sample collection and dissection. Deep-sea mussels in net bags were translocated to a peripheral site and kept there for six days. Deep-sea mussel samples were in situ fixed in transplantation site and original site by RNA stabilizing solution filled chamber, and were dissected into three parts (the stomach and gastrointestinal tract (GI) segments I and II) onboard immediately