They only have four teeth
Pufferfish have four large teeth that are fused into the upper and lower plates of their jaw. These are used to break and crush the tough exoskeletons of crabs and other crustaceans. The fish are thought to develop their poison via this diet.
They make patterns in sand to attract mates
Pufferfish mating rituals are, as you might expect from this strange creature, highly unusual. Mating varies from one species of puffer to the next, but some pufferfish males create displays to attract females. These are large circular structures in the sand of the seabed that could provide a safe place for her to lay her eggs.
Pufferfish are poisonous if prepared incorrectly
Their reproductive organs and liver contain large quantities of tetrodotoxin, an extremely potent neurotoxin 1,200-times more poisonous than cyanide, which has no known cure. It’s deadly to most animals but despite this, pufferfish, or fugu, is considered a delicacy in Japan and fugu chefs receive special training to safely prepare the fish.
They are slow in the water
Pufferfish are poor swimmers, which would make them easy targets if it weren’t for their defence mechanism. Their stomachs enable them to rapidly ingest water and sometimes air too, inflating them to several times their original size.
Pufferfish make poor pets
While they can be interesting pets, pufferfish are hard work. At the least a warm temperature needs to be maintained in the tank. They’re also quite territorial, will nip at the fins of other fish and will even eat smaller species given the chance.