Quiz of the Day
Fishing & Rivers
Thursday, 18 June 2026
Go Fishing Day — fish species, river systems, angling records
1. What is the longest river in the United Kingdom?
- River Mersey
- River Trent
- River Severn
- River Thames
The River Severn runs 354 km from its source on Plynlimon in Wales to the Bristol Channel. It has the second-highest tidal range in the world, and its bore wave can reach 2 metres high.
2. What is the world's largest freshwater fish ever recorded?
- Nile perch
- Mekong giant catfish
- Giant freshwater stingray
- Arapaima
In 2022, a giant freshwater stingray weighing 300 kg was caught in the Mekong River in Cambodia. It was nearly 4 metres long from snout to tail and was released after tagging.
3. What does an angler use as 'fly' in fly fishing?
- A small spinning blade
- Live insects
- An artificial lure made to resemble an insect
- A weighted sinker
Fly fishing dates back to at least 200 AD when the Roman author Aelian described Macedonian fishermen using artificial flies made of red wool and rooster feathers to catch trout.
4. Which fish can climb waterfalls using a suction cup on its belly?
- Mudskipper
- Salmon
- Climbing gourami
- Goby fish
Hawaiian goby fish (o'opu) use fused pelvic fins as a suction cup to inch up waterfalls over 100 metres high. They do this to reach predator-free breeding pools at the top — a journey that can take days.
5. What is the most popular recreational fish species targeted by anglers in Britain?
- Pike
- Common carp
- Atlantic salmon
- Brown trout
Carp fishing is huge in the UK, with dedicated anglers spending thousands on specialist equipment. The British carp record is over 70 pounds. Carp were originally introduced to Britain by monks in the Middle Ages as a food source.
6. How do salmon find their way back to the exact river where they were born?
- They remember visual landmarks
- They use the Earth's magnetic field and their sense of smell
- They follow ocean currents
- They follow other salmon
Salmon imprint on the unique chemical signature of their home river as juveniles. They navigate thousands of kilometres across the ocean using magnetic fields, then switch to smell for the final stretch. They can detect their home stream at just a few parts per million.
7. What is the Amazon River's most feared fish?
- Candiru
- Piranha
- Bull shark
- Electric eel
Despite their fearsome reputation, piranha attacks on humans are extremely rare. They mainly scavenge dead animals. Theodore Roosevelt's famous account of piranhas stripping a cow to bones was staged by locals who starved the fish beforehand.
8. What is 'catch and release' in angling?
- A competitive fishing format
- Using a net instead of a hook
- Catching fish and returning them alive to the water
- A casting technique
Catch and release was popularised in the 1950s but the concept dates back to 1890s British fly fishing. When done properly with barbless hooks, survival rates exceed 95% for most species.
9. Which river system is the longest in the world?
- Nile
- Amazon
- Mississippi-Missouri
- Yangtze
The Nile stretches approximately 6,650 km through 11 countries. However, recent measurements suggest the Amazon may actually be longer when its most distant source is counted — the debate continues among geographers.
10. What unusual ability does the archerfish have?
- It produces electric shocks
- It changes colour like a chameleon
- It shoots jets of water to knock insects off branches
- It can fly short distances
Archerfish can hit targets up to 3 metres above the water surface with remarkable accuracy. They compensate for light refraction at the water's surface — a calculation that takes humans complex physics to understand.
11. What is a 'coarse fish' in British angling?
- A bottom-feeding fish only
- Any saltwater fish
- Any freshwater fish that is not a salmonid
- A fish with rough scales
The term dates from British fishing law that distinguished 'game fish' (salmon and trout) from all other freshwater species. The coarse fishing season traditionally ran from June 16 to March 14, giving fish a closed season to spawn.
12. How old can a koi carp live to be?
- Up to 100 years
- Up to 50 years
- Over 200 years
- Up to 25 years
The oldest verified koi was Hanako, who died in 1977 at an estimated age of 226 years. Her age was confirmed by examining growth rings in her scales, similar to counting tree rings.
13. What is the fastest fish in the ocean?
- Mako shark
- Swordfish
- Bluefin tuna
- Sailfish
Sailfish can reach speeds of up to 110 km/h, making them the fastest fish in the sea. They use their large dorsal fin like a sail and can change colour when excited, flashing iridescent blues and silvers.
14. What book by Izaak Walton, published in 1653, is considered the classic text on fishing?
- The Compleat Angler
- A River Runs Through It
- The Old Man and the Sea
- The Art of Angling
The Compleat Angler has been reprinted over 300 times, making it one of the most reprinted books in English after the Bible and the works of Shakespeare. It is part fishing manual, part philosophy of life.
15. What is the phenomenon called when rivers carry so much sediment they appear to have two colours at a confluence?
- Tidal bore
- Sediment bloom
- River stratification
- Meeting of the waters
The most famous example is near Manaus, Brazil, where the dark Rio Negro meets the sandy-coloured Amazon (Rio Solimoes). The two rivers flow side by side without mixing for about 6 km due to differences in temperature, speed, and density.