A tench (Tinca tinca) is a freshwater fish belonging to the Cypriniformes order, which also includes carp. They are known for their adaptable nature.
Physical Traits and Natural Environment
Tench possess a distinct appearance, characterized by a stocky, carp-like body and olive-green skin that can range from dark olive to pale golden tan, often darker above and nearly golden underneath. Their small, red-orange eyes are on their rounded heads. The mouth is narrow, with a small barbel at each corner, which they use to locate food. Their body is covered in small scales embedded within a thick, slimy skin, historically leading to the nickname “doctor fish” due to a belief that their slime possessed healing properties for other fish.
Adult tench typically measure 30 to 50 cm (12 to 20 inches) in length, though they can reach up to 70 cm (28 inches). Their weight usually ranges from 2 to 3 kg (4.4 to 6.6 pounds), with larger females reaching up to 7 kg (15 pounds). Tench prefer slow-moving or still waters with muddy or clayey bottoms and abundant aquatic vegetation, including ponds, lakes, and lowland rivers.
Native to Europe and parts of Asia, their range extends from Western Europe to the Ob and Yenisei Rivers. They are hardy, capable of tolerating low oxygen concentrations. Tench primarily feed at night on small invertebrates like chironomid larvae, snails, pea clams, and other bottom-dwelling organisms, along with some plant matter.
Significance to Ecosystems and People
In their natural habitats, tench play a role within the aquatic food web. As bottom feeders, they help maintain ecosystem health by consuming detritus and certain invertebrates, contributing to water clarity. They also serve as prey for larger fish, birds, and animals such as otters. Their tolerance for low oxygen levels allows them to occupy niches that other fish might avoid.
Tench are significant for human activities, particularly angling. They are a popular sport fish, known for their strong fight when hooked. Beyond sport, tench are considered an edible fish and are consumed in various cultures, sometimes serving as a substitute for carp in culinary dishes. Their hardiness and adaptable nature also make them suitable for aquaculture in many European and Asian countries, providing a food source. Additionally, a selectively bred “golden tench,” exhibiting pale gold to dark red coloration, is kept as an ornamental fish in garden ponds.