Have you ever wondered what language fish speak and if they are able to ‘talk’ to each other? Or how a big school of fish can synchronise their movements. Fish are able to communicate with each other and they do it in several different ways.

Sound to communicate
Some fish are actually able to produce some sound. They do this mostly by vibrating their swim bladder. These sounds have been identified as purrs, pops, chirps, crocks, and grunts, and most are not able to be heard by humans. Fish make these sounds for a few different reasons, while breeding or spawning, fighting, and to alert predators and pray.

Chemical signals/smell
Some fish release pheromones into the water when they are ready to spawn, to indicate to the opposite sex to also do the same. Still there are ongoing studies about fish using smell to communicate, one has even suggested that a particular type of fish will use its urine to communicate with others. And how about one nudibranch finding another in this big wide open ocean.

Bioluminescence to see and be seen
Mostly you will see this in deep water fish, but some will use bioluminescence to communicate. Bioluminescence helps fish with recognition between and within species. For example, Lantern fish have a series of spots that light up along their belly. Some like the Anglerfish will use bioluminescence to entice their prey towards them (I’m sure you will remember this from Finding Nemo).

Electrical impulses
Fish that have special electrical organs can use electrical impulses. These are usually used to warn predators to stay away. They will also use these pulses for navigating, hunting and communication!

These are just a few ways that fish communicate, some similar to us others very different. On your next dive observe and listen carefully, you might be able to hear the language fish speak.

And this might keep you guessing for a little while, just think about how one nudibranch finds another in this big wide open ocean. How they communicate, we will tell you in one of our next posts.