Staring at a fish the size of your head with a mouth full of sharp teeth as it stares right back at you is, to put it mildly, terrifying.

Titan triggerfish, when they aren’t zipping around at a couple meters per second, are actually somewhat silly looking. They’re brightly colored, a light green body clashing with orange fins. They have strange proportions, too: their dorsal and anal fins are oversized, dwarfing their tail fin, and they are strangely diamond-shaped with large lips. Most triggerfish share these odd proportions, but on a much smaller scale. Titan triggerfish are called titans for a reason.

As our diving group approached a nest – a shallow bowl in the sand, in which light pink eggs could be seen – our dive guide signaled us to stay back. He needn’t have bothered; we could all see the two aggressive titans fending off an endless stream of scavenging fish. One swam above the nest and chased away anything that came too close. The other hunkered down directly next to the clutch of eggs, lunging at fish that managed to get past the guard. Occasionally, they switched positions. None of us had any doubt that even an impact from one of the parents at top speed would be enough to bruise. To say nothing of their bite.

A titan triggerfish. Credit to Alex for the photo.

The drive to reproduce and pass one’s genes is the ultimate, primal goal for all life on the planet, and it shapes complex behaviors. Watching the titanic parents in their endless quest to keep their eggs safe fascinated me. Each chase or lunge cost energy, energy that might have been spent getting food or maintaining bodily processes, both things which would better ensure the survival of the individual triggerfish. But it would not do anything to ensure that its unique genetic code survived.

And so the titans defend their most precious treasure, a group of pearly eggs you could hold in two cupped hands

– Delphine