Gudgeon (Gobio gobio)
Current record: 5oz
Water: River Nadder, Sutton Mandeville
Gudgeon are small, unglamorous, and genuinely underrated: a slim, bottom-dwelling fish in shades of silver, bronze, or olive, usually 4-8 inches long, that shoals over clean gravel and sand in slow-moving rivers and streams. They forage almost constantly during daylight hours, picking worms, insect larvae, small molluscs, and fish eggs off the bottom with a small, downturned mouth built exactly for that job.
One genuinely odd fact: gudgeon can make audible squeaking sounds, thought to be a form of communication between fish in the shoal. It's an unusual trait for a coarse fish this size, and worth knowing if you ever hear something strange coming from a gudgeon-filled swim.
Spawning happens communally once water temperatures pass 13°C, roughly April to August, with eggs released above the riverbed, drifting briefly before settling and sticking to the substrate. Fingerlings can reach around 12cm in their first year, and gudgeon typically live up to five years.
They matter more than their size suggests: gudgeon are a staple prey species for otters and kingfishers in particular, making up as much as 45% of a kingfisher's diet by numbers on some rivers. For anglers, they're an easy, reliable catch on light tackle, and a genuinely good way to introduce a beginner to fishing, since bites tend to come thick and fast.