European import, settled in slow rivers
- Size
- Length: 30–50 cm, Weight: 1–3 kg
- Lifespan
- 10–15 years
- Diet
- Feeds on insects, crustaceans, plants and detritus. Lives in slow warm weedy waterways including farm ponds, drainage ditches and slow rivers. Muddy bottom grubber in stagnant places.
- Habitat
- Slow warm weedy waterways including farm ponds, drainage ditches and backwaters of slow rivers. Fish of still stagnant places where nothing else wants to live in lowland zones.
- Range
- South Island particularly in Canterbury, Otago and Southland. Most common in lowland waterways with warm weedy conditions. Introduced from Europe now established in many lowland waterways.
- Endemism
- Invasive
- Main Threats
- None significant. This introduced species is established in many lowland waterways throughout South Island. Not considered major pest though it competes with native fish for food and habitat.
- Population
- Introduced and locally common. Established populations in many lowland waterways throughout South Island. Not as widespread as perch or catfish but in right spots they can be abundant.
- Conservation Status
- Introduced
The grumpy old man of the freshwater world. A fish that looks like it has seen too much. Thick heavy body covered in tiny dark green to olive-brown scales. They feel like velvet. Rounded dark fins define the silhouette. Small red eyes scan the murk. The mouth is turned down at the corners. This gives a permanent disapproving frown. A fish that looks like it has seen too much and cares too little. Not its best angle. But it is an honest one.
Bottom-feeders with a taste for the gross stuff. Tench grub through mud. They suck up worms, insect larvae, snails and anything else they can find. Incredibly tough, they survive in water that is warm, stagnant and low in oxygen. When the pond dries up, they burrow into the mud. They wait for the rain to return. A fish that does not need much. The resilience is biological. The tolerance is extreme. It occupies the niche others abandon.
A reputation among anglers as a lazy, boring fish. Tench do not fight hard. They do not jump. They do not look pretty. But they are surprisingly hard to catch. Shy and suspicious, they spit out a bait if they feel the slightest resistance. A fish that is smarter than it looks. The caution is learned. Or instinctive. The result is the same. The hook remains empty. The angler remains frustrated.
To catch a tench is to catch the survivor. The fish that lives where no one else wants to live. It eats what no one else wants to eat. It keeps going when everything else gives up. No Māori name exists because it is not a native fish. European settlers introduced it from Europe. There it was a popular pond fish. Here it is an interloper. A guest who overstayed.
Today it is the fish of the drainage ditch. The one caught when not trying to catch anything. Unsure what to do with it when it is caught. The ditch is stagnant. The tench grubs in the mud. Red eyes watching. Mouth frowning. The angler casts. The tench ignores the bait. It has seen this trick before. The indifference is total. The survival is assured by obscurity.
It persists in the shadows. In the weeds. In the mud. It does not seek glory. It seeks sustenance. The environment is harsh. The competition is low. The tench thrives. It grows fat on the detritus. It waits out the drought. It survives the neglect. It carries on.