The veliger has a shell, but once the larvae has settled out of the plankton, the shell is released and they enter a juvenile stage. Nudibranchs have a number of defenses. The nematocysts that aeolid nudibranchs ingest from eating species of cnidarians can be incorporated into the body undischarged. 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.