Fast Facts About Pond Fish
For many pond owners, the chance to have a few fish swimming their way through the water-lily stems is a big part of the reason they built their water feature in the first place. Anyone who keeps fish in their pond will soon find themselves knowing a good deal about how to look after these quietly fascinating creatures, even if they didn’t before, but there’s a lot more to our fishy friends than just feeding them and keeping an eye out for disease.
With that in mind, here’s a few fast – and generally little-known – facts about the remarkable group of animals that lurk at the bottom of our ponds.
Sense and Sensibility
- The average fish’s brain is fifteen times smaller than that of a similar sized bird or mammal.
- Fish that are active during the day see colour at least as well as humans do.
- The lateral line is sensitive to currents and vibrations in the water.
- Laboratory tests using underwater mazes have shown that fish have good spatial awareness and are good at making decisions using visual clues.
- A fish can control its own buoyancy by adjusting the amount of gas in its swim bladder.
- The number of vertebrae in a fish’s backbone depends on the species, but generally it’s between 40 to 80, although any eels visiting your pond may have 200 or more!
- Most common pond fish have between 40 and 50 scales in their lateral line.
- The scales of a fish have growth rings, just like a tree, and can be used to work out its age.
- Coldwater fish can live for a surprisingly long time; rudd may live to be 12, while carp often make the ripe old age of 50.
- The record for the longest lived goldfish is held by Tish, who died in 1999 – having lived for 43 years after first being won as a prize at a funfair in Yorkshire.
- The longest goldfish in actual length measured 47.4cm (18.7 inches), snout to tail-end and is owned by Joris Gijsbers of The Netherlands.
- The Koi is a domestic version of the Common Carp (Cyprinus carpio)
- Although they are often associated with Japan, Koi originated in China over 1,600 years ago.
- The Japanese word Koi means ‘carp’, but it also sounds like the word for affection, which explains why the fish became popular symbols of love and friendship in Japan.
- A single heron can eat over 300g of fish a day – and double that if it’s raising young!
- It has been estimated that poor husbandry accounts for over 90 per cent of fish health problems.
- In the US, racoons are said to kill more pond fish than cats; in some areas of Britain, foxes are starting to give our moggies a run for their money!