Imagine trying to eat a poisonous basketball with spikes and sunglasses. That is the challenge a predator faces when confronted with the spiny puffer fish, Diodon holocanthus, illustrated on this month’s cover.

The puffers are a group of nearly 100 species of mostly epipelagic fish, and are so named because of their ability to swell their bodies two to three times their original size until they are almost completely round.

The spiny puffer is perhaps the best known member of the families Tetraodontidae and Diodontidae, and has been studied in some detail. Perhaps only this species of all extant organisms combines the ability to inflate its body with the concomitant erection of nettlesome, pointed spines as a spectacular defence mechanism. The stomach can expand to nearly 100 times it original size by utilising extensive tissue pleating much like a kilt. Even the stomach pleats have pleats, and those pleats have pleats and so on. The puffer’s body is prepared for this expansion by …