Highly toxic giant porcupine puffer fish gets cleaned of parasites

This porcupine puffer fish is casually swimming over the coral reef in Indonesia, but something important is happening as he does so. The wrasses that are following and swimming around him are cleaning his body of parasites and dead skin. This is a vital service for many fish and animals in the ocean. They have no way of keeping themselves free of lice, and all manner of parasites. This fish would be weakened and vulnerable to health problems without the cleaner fish.
Many fish will seek out an area with wrasses or crabs and they will then adopt an upright, floating position to allow the smaller creatures to pick at their skin and even their teeth. Rotting food in the jaws and teeth of larger fish would also cause them discomfort and health problems. The relationship between the cleaning wrasses and the larger fish is a complex one that is mutually beneficial. It involves a great deal of trust as the smaller fish will often enter the mouth or gills of the larger fish. Surprisingly, this trust seems to never be violated. The wrasses understand that they will not be eaten.
Porcupine puffer fish have a unique adaptation that allows them to inflate their bodies with air or water, increasing them to several times their usual size. They have spines that stand erect, making it almost impossible for all but the largest of predators to swallow them.
But the most effective defense that they have is much more lethal. Their organs contain a highly potent neurotoxin (tetrodotoxin) that is 1200 times more lethal than cyanide. The porcupine puffer fish accumulates this toxin when it consumes food that contains a certain bacteria.
The porcupine puffer fish is a slow moving fish with no ability to be ferocious, but with such effective means of defense, they have very few predators. The ocean is a complex world and the animals who live here are equally complex and mysterious.