Do fishes have relationships and how can you help?

Do fish have relationships with each other?

You may think that all fishes of the same species look identical. It can certainly be hard for us to differentiate individual fishes, but is it hard for fishes themselves to tell the difference?

Fish recognise faces

Not for the cichlid. A cichlid is a tiny striped fish that is native to East Africa. A 2017 study showed that cichlids recognise each other using the stripe patterns on their faces - differences that humans would struggle to see. Despite having stripes all over their bodies, cichlids specifically look at facial stripes to determine friend from foe, much like how we identify other people by their faces rather than their torso or legs!

Fish work in teams

Fishes have also been known to use teamwork to increase successful hunting; one behavioural ecologist observed a grouper fish and an eel hunting together. The grouper would signal with its head where it wanted the eel to go, and the eel would use its long, agile body to slip between cracks to hunt the prey that the grouper would have otherwise been unable to reach.

Fish build communities

Another partnership of the sea is in the case of the ‘cleaner fish’, or wrasse. The cleaner fish will attach to bigger fishes in the ocean and strip them of unwanted parasites in return for a tasty meal. You may think this sounds more like a chance encounter rather than a relationship, but cleaner fishes have been demonstrated to have the same clients returning to them, suggesting that they are a trusted service. They have been likened to a car wash!

There have also been instances of cleaner fishes biting their clients, trying to get more tasty food, and clients retaliating by boycotting these cleaners for their bad service.

And fishes can help each other feel less afraid, too. ‘Social buffering’ is a behaviour in humans where we are less likely to feel scared, and more likely to act calm in the face of danger, if we are in the company of others. A study on zebrafishes showed that they too exhibit social buffering. When they were exposed to a dangerous substance, the fishes showed fewer signs of panic and fear when they were in a group than when they were alone.

But what about romantic relationships? Do fishes fall in love?

Do fish fall in love?

Well, we can’t say that for sure. However, some species of fish are monogamous. The seahorse (often not recognised as a fish due to its unusual characteristics) is known to mate exclusively for a breeding season and in some cases have been shown to mate for life. But did you know that seahorses will dance with their partners? A seahorse couple will dance every morning before they part ways for the day. It is not fully known why they do this, but scientists think that the aim is to reinforce their bond.

There have also been several instances of fishes having symbiotic relationships with other aquatic animals in their marine environment. From teaming up with octopuses for hunting, to pilot fishes using sharks as bodyguards, it appears that relationships extend to other underwater species, too.

Fish get heart-broken too

Perhaps the most relatable piece of evidence on fish relationships is from a 2019 study that showed fishes are more pessimistic after enduring a break-up. The study looked at monogamous fish species and how they would respond to a test of optimism after being separated from a chosen partner. The fishes that had been separated from their partner were far less likely to display optimistic behaviours, suggesting that they were left feeling pessimistic from the break-up.

Do fish have relationships with humans?

If fishes can bond with one another, how will they react to humans in their environment?

Much like the cichlid has been shown to recognise other fishes’ faces, fishes have also been shown to recognise human faces too. In a study conducted by the University of Oxford and the University of Queensland, fishes were shown to identify one human face from up to 44 other new faces - with an 86% total accuracy rate. This study reinforces the claims of many fish-owners that their companion fish knows them and will swim over to say hi when they approach the tank.

There have also been numerous accounts of divers striking up unlikely friendships with fishes. A heartwarming news story is the tale of a 79-year-old diver and an Asian sheepshead wrasse who have been friends for nearly thirty years. The diver, Hiroyuki Arakawa from Japan, helped to rescue the wrasse (known fondly to him as Yoriko) when he noticed she had a damaged mouth.

To save her from starvation, Hiroyuki fed Yoriko for ten days by hand until she got better. Since this event over a quarter of a century ago, the unlikely pair have continued their friendship, with Hiroyuki visiting Yoriko regularly. Hiroyuki says that the two have a deep sense of trust which has enabled their friendship to last so long.

Hiroyuki even claims to have given Yoriko a kiss on one occasion! And it is true that fishes have been shown to enjoy being touched. There have been examples of fishes swimming into the hands of people to be petted, something that fish specialist Jonathan Balcombe again puts down to the fish trusting whoever they are receiving attention from.

However, not all fishes want to be stroked! Fishes have very delicate skin with a thin mucus membrane protecting their scales, so it’s best to err on the side of caution so as not to harm them.

What next?

Whether fishes experience relationships in the same way that we do or not, one thing for sure is that they deserve protection from harm and suffering. Visit our campaign page and find out how you can help to protect the UK’s forgotten fishes.

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