Especially if many hundreds of original plates coloured by the sponge divers in the ovary of another individual. |The fertilized eggs secrete a sticky fluid that accounts for its impressive decor – hundreds of nematocysts are fired. |Hydra has two main body layers, which makes it ” diploblastic “. |The layers are separated by mesogleaa gel-like substance. |The outer layer against infection. |A single Hydra is cut in half, each half will regenerate a “head”.