These types of animals are typically stationary because they are suspension feeders that acquire their food by filtering water. Sponges are anchored in place, so they cannot escape from predators, instead they secrete toxins and antibiotics to defend themselves from infections and attackers.
The reasons why any animal eats a particular organism is never clear. A top reason why Nudibranchs might eat 'toxic sponges' is that there was not much else available to eat and it was easy to eat the sponges. These sponges were a niche that was unfilled and the Nudibranches adapted to take it. The sponges are still partially toxic to Nudibranchs! They often have specially lined stomachs to protect them from the sponges sharp spicules and the toxins from the sponge accumulate in them. When a predator tries to eat a nudibranch it gets a nasty mouthful of these toxins.
In a few marine species, gray cells of the sponges primitive "immune" system and can release toxins that kill all cells in the area as part of the rejection of foreign material.They also produce toxins that prevent other sessile organisms such as bryozoans or sea squirts from growing on or near them.A few species, such as the Caribbean fire sponge, cause a severe rash in humans who handle them and such toxins may protect against predators.The Caribbean chicken-liver sponge secretes toxins that kill coral polyps, allowing the sponges to grow over the coral skeletons.See: http://en.wikipedia.org/wiki/Sponge
Sponges have a variety of defenses against predators, including producing toxins, secreting a distasteful substance, releasing mucous to trap predators, and being able to quickly regenerate if damaged. Some sponges can also contract or close their pores to protect themselves.
sponges use toxins to repel would be predators
Let's go...vamonos (with an accent on the a) This is a positive nosotros command in Spanish.
Many dart frogs secrete lipophilic alkaloid toxins through their skin. It is currently believed that dart frogs sequester these chemicals from their arthropod prey, rather than synthesize the toxins themselves.
Many sea sponges, like anemones, use toxins to repel would-be predators. Some species of sea slugs, however, such as Platydoris scabra, have evolved immunity against the toxins of specific sponge families (in this case, Microcionidae). This adaptation benefits the slugs in two ways. First, they don't have to compete with many other organisms for the sponges. The sea slugs can also concentrate the sponge toxins to foil their own predators -- at least until the slugs' predators also evolve immunity to the toxins.
Round worms secrete toxins and burry in the hosts tissue to reproduce this at many times is fatal if not treated in which they use other combat techniques
Sponges possess the defense mechanism of releasing toxins that make a predator think twice before attacking them. The toxic gases are considered dangerous and any predator would not want to attack a sponge.
Licking a frog can be dangerous as some frogs produce toxins that can be harmful or even deadly if ingested. While some species of frogs secrete toxins that can have psychoactive effects when touched, it is not safe or recommended to intentionally lick a frog to get high.
No, sea sponges are not decomposers. Sponges are filter feeders.