Fish with airbag, how to outsmart predators

Underwater world is full of great predators who wait for their prey. But their prey is not always unarmed, there are many ways how to outsmart predators. I once witnessed how tiny little fish won her battle with grouper.

She belonged to the fish order Tetraodontidae (Puffers). These fishes have great strategy how to survive attack of a predator. They could inflate themselves by drawing water into a specialized chamber near stomach. Their body is than more than twice bigger. Porcupinefishes have similar defence strategy but belong to the order Diodontidae, they have lots of spines over head and body which are evolutionary in fact just modified scales.
Puffers have another interesting trait- they have poisonous viscera, gonads and skin. Their body is full of one of the most powerful toxines in the world- tetratodoxin.

So the day I was once again diving in my favourite diving place in Dahab, Egypt where I know every stone and coral, but everytime there is something which surprise me. This place is full of great little stories and now I am going to tell you how one tireless young grouper tried to swallow a Yellowspotted puffer (Torquigener flavimaculatus). From the picture you see it seems like the puffer is near it´s end, but not everything is what it seems for the first time. I just started the dive and immediatelly I saw something is going on near concrete block where ropes from buoys are attached. I come closer and saw about 2 cm big puffer fully inflated and behind about 10 cm small Lyretail grouper (Variola louti), who could have more than 80 cm when fully grown.

After a while the grouper started to come closer to the puffer because it was going down. Grouper looked like thinking what to do exactly and than just attacked. It catched the puffer and try to swallow it, but again the puffer just inflated and it was too big to go trough grouper´s mouth. They were like this for a few minutes, puffer being more or less inflated, grouper trying again and again if he can swallow. One more grouper watched this show with me, seemed to be very enjoying it and as though he lived out similar experience.

Our tireless grouper few times spitted out the puffer to take a break or to give up, when after few moments it changed his mind and catch it again. It seemed like this battle has no end, when finally the grouper let small puffer go like a winner and started to look for something easy to eat.