Larvae of the native spiral caddis (Helicopsyche species) make spiral cases using tiny grains of sand, which they attach to their bodies. The weight of the case helps anchor the caddis to the stream bed in fast flowing waters. Typically the species are 2.5 millimetres across, and are found only in very clean waters.
Using this item
Photograph by Stephen Moore
This item has been provided for private study purposes (such as school projects, family and local history research) and any published reproduction (print or electronic) may infringe copyright law. It is the responsibility of the user of any material to obtain clearance from the copyright holder.