Figure 1

The natural symbiotic association between cnidarian and Symbiodinium.
(A) The wild A. pulchella (B) The brown algae inside the host called Symbiodinium, which is always found in the gastrodermis layer. (C) Two Symbiodinium cells were surrounded by the symbiotic gastrodermal cell (SGC), (D) Symbiodinium cells isolated from A. pulchella containing several common organelles, such as nucleus (N), pyrenoid (pyr), chloroplasts (ch), cell wall (cw), lipid droplets (LDs).