NANFA-- Schreckstoff (was Creek Chub Removal_

Christopher Scharpf (
Tue, 09 Sep 2003 22:42:20 -0400

> Is it fairly common for a wounded cyprinid to release something alerting the
> rest of the school?
> If so, is that only true of North American cyprinids as opposed to European,
> S.E. Asian or African cyprinids or do cyprinids world wide do that??

Minnows belong to a large and disparate superorder of fishes called
Ostariophysi, which also includes suckers, loaches, catfishes, characins,
knifefishes, and the electric eel, among others. One ostariophysan trait is
the ability to produce a chemical substance called Schreckstoff (from the
German words for fright and stuff). When an ostariophysan fish is bitten by
a predator, special skin cells release Schreckstoff into the water. This
sends a message to schoolmates and other closely related species to take a
variety of escape actions.

Some ostariophysan fishes have lost their ability to produce Schreckstoff
for adaptive reasons. For example, piranhas do not release an alarm
substance since many of their prey are ostariophysans, and it wouldn't make
sense for them to flee each time they bit into a fish.

Chris Scharpf
/"Unless stated otherwise, comments made on this list do not necessarily
/ reflect the beliefs or goals of the North American Native Fishes
/ Association"
/ This is the discussion list of the North American Native Fishes Association
/ To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ For a digest version, send the command to
/ instead.
/ For more information about NANFA, visit our web page,