Yes. They can release spikes. When a potential predator touches a spike, it releases poison.
Other than its skin, nothing.
sponges, their zooxanthellae and smaller organisms for protection
They do not really have protection. Most of them have s soft outsides and do not really have any self defense mechanisum.
Yes, breadcrumb sponges, belonging to the family Halichondriidae, do have spicules. These spicules are typically made of silica and serve as a structural element, providing support and protection to the sponge. However, unlike some other sponges, breadcrumb sponges may have a relatively low density of spicules, contributing to their softer, more pliable texture.
No, sea sponges are not decomposers. Sponges are filter feeders.
no sponges are not unicellular.
No, sponges are not parasitic.
no sponges do not have bones
Sponges are asymmetrical, although a few species have nearly radial symmetry.
To answer your question no sponges do not hibernate
Yes sponges have organs.
No. Sponges are animals, which are heterotrophic.