December 2, 2015 | surya wijaya Maybe sometimes you were wondering how fish communicate with each other. Maybe you would be surprised if we tell to you that there is a bewildering array of ways in which they achieve it. To understand them however, you need to know what to look for. Visual Signals Visual signals can be very important for getting the message across, for example the colouration. The colouration of fishes can certainly be used to communicate, and it can be extremely important for reef fish, renowned for their vivid colours, living as they do in an environment with very generally clear water and good visibility. Contrary to popular belief, the scales of fish don’t actually possess colour, they are transparent, but it’s the skin underneath that fulfils this role. The skin is covered with tiny ‘bags’ of pigment known as chromatophores, which are under muscular control. Expansion and contraction of the chromatophores allows for the colouration of the fish to alter. This in itself is quite remarkable. Most fish, in fact, can change colour to some extent, and this can be to convey mood to others in a shoal, to attract a mate, or to flash warning signals. But they only display dynamic signals when is needed because it would be a disadvantage to use conspicuous colours when they are not needed as they make the fish vulnerable to predators. Visual signals are also important when fish try to impress a partner. Wired for sound. Surely fish don’t communicate through sound? For a start, they don’t have ears. Or do they? Well, yes, in fact they do. The structure of a fish’s inner ear is remarkably similar to ours. Sound actually travels extremely well in water, it can travel for great distances and for that matter, any animal using it to communicate can use it in the dark, or in turbid, murky water. Many fish species actually communicate lewat sound, with various clicks, chirpings, buzzing and thumps making up their language. They might grind their teeth together and some can rub their fin rays or even bones together. We’re juicet beginning to find out juicet how prevalent the use of sound is in the fish world as many of the sounds generated are actually outside the range of human hearing, and it is only now that technology is allowing us to listen in on the fishes’ ‘conversations. ‘ Olfactory Communication – scents and smells. The sense of smell in fish is highly variable ; some species don’t have a particularly good sense of smell, whereas in others it may be highly acute. Chemical signals known as pheromones can be used to transmit a variety of messages including information about social status, sexual receptivity and even threats to others. Fish have evolved a variety of ways of ‘talking’ to one another, but we’re juicet beginning to understand them, there are plenty more discoveries to be bikinan this. For more information about Marine Fish Keeping why not visit the Marine World situs or subscribe to the magazine.