Aquarium

The underwater world of the Sihl

The aquarium is home to native fish species and endangered native crayfish. At the window overlooking the otter enclosure, you can observe tiny creatures such as water snails, caddisfly larvae, amphipods and leeches. 

A particular highlight of the exhibition is the popular window overlooking the otter enclosure, which offers a fascinating glimpse beneath the water’s surface. Thanks to a new, large magnifying glass, even the tiniest underwater creatures can be spotted and observed.

The audience favorite, the otter

With a bit of luck, you might even spot the otters. They swim past from time to time to check whether the automatic feeder has dropped another tasty morsel into their feeding basket. Wooden benches and large stones from the River Sihl invite you to sit and linger. And at a new audio station, the otter recounts its daily life, whilst information boards illustrate the ecological interrelationships within this sensitive habitat.

Life in the Sihl

Did you know, that of the 54 indigenous fish species, 42 are either endangered (bleak), threatened with extinction (brook lamprey) or already extinct (sturgeon)?Seven native fish species and one crab species still live in the Sihl. The original index species, the river trout, is now a rarity, while the barbel and the chub are commonplace. You will find the following species in our aquarium in Sihlwald.

Common minnow

Lateral line generally extends only to the middle of the body, with a golden longitudinal stripe above.
Common minnows have excellent senses of smell and hearing. If eaten, they emit an alarm substance, which deters others of their species from that location.

Gudgeon

Obtuse snout, two short labial barbels at the corners of the mouth, row of dark patches along the flanks.
These patches act as excellent camouflage on sandy and gravelly substrates.

Tailor

A small, gregarious schooling fish. Ventral fins with a reddish base. A striking feature is the deeply curved lateral line, which is bordered by two dark stripes that resemble a tailor’s seam. 

Noble crayfish

Usually dark in colour, but highly variable; ‘blue ones’ are relatively common.
Noble crayfish hibernate during the winter. They can also survive out of the water for a short time. Native crayfish species are under serious threat from the introduction of non-native species. American crayfish species carry the dangerous crayfish plague, but are themselves immune to it. For native crayfish species, however, the disease is fatal.

Better access to the Sihl thanks to #hallowasser

The exhibition at the otter enclosure in Sihlwald has been redesigned as part of the Canton of Zurich’s #hallowasser project. The aim of the project is to provide the public with better access to the water.