Are Unicorn Fish Real? 9 Impressive Facts
In mythology, unicorns are mythical horses with spiral horns on the top of their heads. Despite being completely fictional, they lend their name to some very real, and very beautiful animals. In this blog, we’ll look more closely at the striking unicornfish to learn something new about these interesting species.
What is a unicornfish?
The unicornfish belongs to the genus Naso, and there are a number of different species. They are part of the wider family Acanthuridae, making them related to tangs. They are known for their horn-like protrusion, just like a unicorn!
Despite this weird and wonderful adaptation, it’s not the only interesting thing about this fish; so, let’s take a look at some other interesting facts you need to know about the unicornfish!
Interesting unicornfish facts you need to know
From their diet to their amazing colour-changing behaviour, there’s more than meets the eye with unicornfish.
There are 20 species of unicornfish
Across the subtropical waters of the Indo-Pacific, 20 recognised species of unicornfish can be found. The largest species is the margin unicornfish (Naso annulatus), which can reach sizes of up to 1 metre. On the other end of the spectrum, blackspine unicornfish (Naso minor), which only reaches lengths of about 30cm.
Not all unicornfish have a large horn
Contrary to popular belief, not all unicornfish have a horn; some only have a small bump, and some, like the sleek unicornfish (Naso hexacanthus), don’t have any protrusions at all.
The horn develops with age
Much like rhinos and elephants, unicornfish aren’t born with horns. Instead, they hatch with an almost distinct bump on their head, and over time, their horns develop, being seen as a sign of unicornfish maturity.
Scientists can’t confirm why unicornfish have developed horn-like features
You might think that unicornfish develop their horns as a defence mechanism, but scientists don’t believe this is true. Unicornfish have razor-sharp spines on their tail, which are used for defence. This then begs the question: what are the horns on a unicornfish for?
They can change body colour based on mood and behaviours
Their connection to the mythological doesn’t end with their horn! Unicornfish are actually able to change their colour based on mood and behaviour, like chameleons. Of course, this isn’t magic; it’s actually complex and brilliant biology.
They play an important role in the coral reef ecosystem
Acting as the coral reef’s natural gardeners, unicornfish graze on seaweed, helping to keep the balance of the coral reef. This is an important job, as it stops this type of macroalgae from smothering delicate corals. Coral reefs are incredibly important to the global ecosystem and they’re declining, so any way that they can be protected is a good thing.
Currently, they are considered a ‘Least Concern’ species
Thankfully, unicornfish are currently listed as Least Concern by the International Union for Conservation of Nature (IUCN). They do, however, face the same issues that other coral-dwelling animals face. Climate change is slowly destroying the unicornfish’s habitat, which could see their numbers decrease in the coming years.
They are most active during the day
Unicornfish are most active during the day. They use this time to graze on seaweed and navigate strong currents to find shelter so that they can sleep during the night. They seek safety in reef crevices, which prevents larger predators from eating them.
Their diet changes as they age
When unicornfish are young, they are primarily herbivores, feeding on benthic algae (marine plants) growing on rocks and coral. As they age and begin to explore deeper waters, their diet shifts to being planktivorous, eating primarily soft zooplankton floating in the water.
Look out for unicornfish at Blue Planet Aquarium
You don’t have to go snorkelling in the Indian Ocean to see unicornfish up close; you can actually see them much closer to home. Blue Planet Aquarium is home to three unique species of unicornfish, including the whitemargin unicornfish (Naso annulatus), orange-spine unicornfish (Naso lituratus) and Vlaming’s or bignose unicornfish (Naso vlamingii).
All of our unicornfish can be found within our Ocean Tunnel and Coral Cave exhibits, where they are joined by other plants and animals that can be found in their natural habitat.
If you’d like to see our unicornfish, as well as countless other incredible fish, amphibians, reptiles, and arachnids, book your tickets to Blue Planet Aquarium and open your eyes to the wonders of the natural world.
