Why would sponging and spicules discourage predators from eating sponges?
Yes, they have. Spicules are the defensive structures in sponges which are needle like. Special fringes and pallisades of spicules guard the apertures to prevent the entry of intruders. Sponges not only have spicules to defend but also have other mechanisms to defend their enemies. some produce unpleasant odour and some produce poisonous substances. These poisonous substances when handled cause irritation of the skin and have strong oxidizing action and some may be fatal.
Porifera are sea sponges. They have no symmetry (asymmetrical) and they are one of the most basic forms of life. They have a 2 cell layer wall made of collar cells, spicules, amoeba like cells, and a layer of epidermal like cells. The spicules and the amoeba like cells are in between the layer of collar cells and epidermal cells. Sponges also have pores throughout their structure. Porifera include freshwater sponges as well of marine…
No, sponges do not have eyes. In fact, they don't have any organs at all. Sponges are among the simplest forms of multicellular life. They have simple tissues made up of different cell types, and some have support structures called spicules, but none have any of the true organs or organ systems that we see in more advanced organisms.