[The motility test, an early warning system for biological water control].
A satisfying continuous control of waters on toxicants by chemical and physical analysis is not possible, and therefore biological methods must be used in addition. Hereby the fish test obtained special importance. To perform this test qualified experimental fish are put into the water, which should be controlled, and the effect of the water upon the fish is observed. As is known fish react to every small change of the quality of water by changing their motility behaviour. Consequently, the most sensitive fish test method is a Motility Test, then with it toxicants appearing in waters can be registered already in such low concentrations, by which the test fish feel disturbed first only in their well-being. Thus, the Motility Test can be used as "early warning system" in the biological control of waters. The prior condition to perform the Motility Test is a reliable technique for registrating the body movements if fish. Well qualified is the principle of magnet induction. Hereto the test fish is marked by a small permanent magnet and kept in the sensitive area of a wire coil. If the fish moves, voltage impulses are induced in the coil, which are registered as measure of the animal moving activity. In this work the practicability of the Motility Test by means of magnet marked trouts (Salmo gairdneri, 260-320 g) was checked: In the first series of tests the "normal" motility of trouts in freshwater was registered. Thereby, the influence of feeding, of a hiding shelter, of holding in groups, and of the water temperature upon the spontaneous activity of the fish was studied. In the second series of tests the chemo-physical quality of the water was modified (O2-decrease, CO2-increase, pH-change), and the changes of the motility of the test trouts effected thereby were registered. In the third series of tests there was measured the motor reaction of trouts upon some toxicants (ammonia, nitrite, phenol, detergents, zinc) given into the water. The results are shown by some representative actograms. In addition "reaction values" (toxicant concentration in the water) determined in the tests at the beginning of the motor unrest of the fish were listed in a table. According to the positive results obtained in all these tests the Motility Test by means of magnet marked trouts can be recommended as an useful early warning system for the biological control of waters.
D000818:Animals; D005618:Fresh Water; D006863:Hydrogen-Ion Concentration; D008280:Magnetics; D009043:Motor Activity / Q000187:drug effects; D013696:Temperature; D014337:Trout / Q000502:physiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000494:pharmacology; D014877:Water Pollution, Chemical / Q000032:analysis*
D014874:Water Pollutants, Chemical
Der Motilitätstest, ein Frühwarnsystem zur biologischen Gewässerkontrolle.