The nudibranch can then position these nematocysts at the tip of the cerata. If the slug is disturbed by a potential predator, it can open up the top of the cera and release the nematocyst similarly to the way it is done in cnidarians. Some slugs are capable of releasing a secretion that causes a predator to retreat. In some species, this secretion is highly acidic. Other species that are inconspicuous use this characteristic as a defense.
Inconspicuous species are generally harder to detect so are often spared from predation.
Feeding All nudibranchs are carnivorous feeding on sessile or sedentary organisms. Each suborder of nudibranch has a major food source. For dorids, most food comes from preying on bryozoans and sponges while aeolid's and dendronotaceans prey upon cnidarian species. Just as the suborder Arminacea is diverse, so is the food they consume. It is important to remember that the substrate a nudibranch is found on may not necessarily be its food source.