Gemmules are small protective structures that form before the sponge dies off in the fall and winter. They are able to withstand winter temperatures, extended periods of anoxia, and are resistant to dessication. Gemmules can be carried by wind, water, or even the feet of waterfowl to new locations where favorable conditions will initiate the growth of a new sponge colony. Spicules are the mineral skeleton of the sponge and are made up of siliceous strucutres. Gemmoscleres are simply highly magnified spicules that make up the gemmules. Megascleres are highly magnified spicules which make up the body of the sponge. Megascleres and gemmoscleres are the structures needed to identify the species of the sponge.