This week is Halloween and we often like to dress up like our favourite movie star, animal or superhero. But what if someone would be dressing up like you, forever. Is it Halloween or not?
In the underwater world this is quite normal and known as mimicry. Many fish pretend to be other fishes to look more dangerous (Bates mimicry, ‘sheep in wolf’s clothing’), to look less dangerous (aggressive mimicry), or to fit in the group (social mimicry). Protective resemblance is when an animal resembles an object that is of no interest to the predator.
An example of Bates mimicry is the mimic filefish that mimics to be a saddled pufferfish. The pufferfish is a poisonous fish that’s avoided by predators, because the mimic filefish has mimicked the pufferfish almost perfectly the predators will leave the filefish alone as well.
Same holds for the grouper that’s called the false scorpionfish, mimicking the poisonous scorpion fish. One of the most famous examples is the talented mimic octopus, capable of mimicking up to 15 different species!
Aggressive mimicry often occurs by mimicking cleaner fish. Several fish like the false cleaner blenny and springer’s dottyback mimic the harmless and trusted cleanerfish to get close to their prey and feed of the victim’s scales, fins or skin.
Social mimicry is a way to fit in the group. Schools of fish offer protection in numbers. The odd one is more vulnerable to predation, so the more the fish look like each other, and the lower the chance of being the prey. This is also called dilution of risk. Mimic goatfish is an example; they mimic to be blue-line snapper to swim with during the day while at night they separate themselves to feed.
With protective resemblance there are plenty of examples in the marine world, for example: the flatfish resembling the bottom and changing colour depending on the composition, frogfish resembling sponges, leaf scorpionfish resembling leaves and stonefish resembling stones. The list of fish that protect themselves using resemblance is large, which ones do you know? Add them in the comments below!
Mimicry and resemblance is very important, aiding the survival of many marine species. When diving the first couple of times you’ll overlook many of the fish for common objects and might misidentify a bunch. But that does make diving more special, because every dive is a new discovery, and every dive you’ll see something new.
The underwater world is incredible and at Two Fish Divers we’re happy to enjoy it every day again!