Why do many predators avoid eating animal sponges?

Many predators avoid eating sponges primarily due to their disagreeable taste and smell, which serve as a natural deterrent. Additionally, sponges are protected by hard skeletal elements known as spicules, which provide structural support and defense.12

Some sponges also possess chemical defenses; for instance, certain species are classified as crinotoxic, meaning they release toxins into their environment that can cause skin irritation, swelling, and other adverse reactions upon contact. While these defenses effectively discourage many enemies, some specialized predators—such as certain mollusks, crustaceans, and fishes—are still able to consume them.31