Phestilla minor is a benthic sea slug that is a very small, slow-moving organism found in marine habitats all over the world.

Phestilla minor is a small marine invertebrate that can grow to reach a maximum length of approximately 7mm.

This acts as a defence mechanism from potential prey which can include fish, lobster, crabs and also humans.

This species has been recorded from East Africa (Tanzania), Australia (Great Barrier Reef) and Hawaii.

[4] Phestilla minor sea slug feeds on the hard-coral genus Porites, the same one on which it lives.

It has a pair of jaw and a radula (tongue-like organism) that consist of multiple rows of very small teeth which they use to feed e.g. on plankton, algae and jellyfish.

Whilst feeding, Phestilla minor uses many defensive behaviours to protect or harm potential predators.

Phestilla minor spends majority of its life in isolation and attached to one organism, however, during warmer summer seasons, the species gather in masses.

The fertilization process may not take place instantly, but whilst waiting for the eggs to reach their full maturity, the sperm can be stored within an organ called the seminal receptacle.

Because Phestilla minor is such a small organism, this animal is at such high risk and is vulnerable to an array of other sea creatures.

Humans are another predator of the Phestilla minor, being caught for aquarium purposes, to be sold on the exotic pet markets and as part of a dish.

Whilst sea slugs, and particularly Phestilla minor are such a tiny organism, they hold large significance in the field of scientific research.

The slugs provide the basis of many testing grounds for a lot of theories and investigation into how the nervous system works.

Through observation and analysis of the sea slug’s natural behaviours and sensory cues that trigger these, scientists gain new research material by studying them under experimental conditions to be used in laboratories.