Re: NANFA-- Schreckstoff (was Creek Chub Removal_

John B (bongi_at_cox-internet.com)
Tue, 09 Sep 2003 22:24:46 -0500

Shrek and Stuff eh? What you are suggesting is that the schreckstoff
chemical is conserved within a superorder? I find it intriguing that a
chemical warning system is so conserved within a superorder that
disparate species may get confused by another species signal. Its
more concievable to me that some species actually mimiced the response
of the piranha to confuse. The piranha responded in time by dropping
the warning altogether. Not altogether different from the strategies
employed by the Monarch butterfly and its mimics.

Oh well,

John


Christopher Scharpf wrote:

>>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
>Baltimore
>/"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
>/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
>/ subscribe, unsubscribe, or help in the body (not subject) of an email to
>/ nanfa-request_at_aquaria.net. For a digest version, send the command to
>/ nanfa-digest-request_at_aquaria.net instead.
>/ For more information about NANFA, visit our web page, http://www.nanfa.org
/-----------------------------------------------------------------------------
/"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
/ nanfa_at_aquaria.net. To subscribe, unsubscribe, or get help, send the word
/ subscribe, unsubscribe, or help in the body (not subject) of an email to
/ nanfa-request_at_aquaria.net. For a digest version, send the command to
/ nanfa-digest-request_at_aquaria.net instead.
/ For more information about NANFA, visit our web page, http://www.nanfa.org