The tench (Tinca tinca) is a native freshwater fish species in the UK, commonly found in lakes, ponds, and slow-moving rivers. Known for its olive-green body and red eyes, the tench is a bottom-dwelling fish that thrives in weedy, nutrient-rich waters. It is highly valued by anglers and plays a key role in aquatic ecosystems as both a predator of invertebrates and a prey species for larger fish and birds.