| Autor: |
N. Pals, P. Valentijn, D. Verwey |
| Rok vydání: |
1981 |
| Předmět: |
|
| Zdroj: |
Netherlands Journal of Zoology. 32:495-512 |
| ISSN: |
1568-542X |
| DOI: |
10.1163/002829682x00193 |
| Popis: |
The purpose of the experiments reported in this paper was to find out whether the electrosensitive elasmobranchs use local geo-electric fields for their spatial orientation. Since local electric fields occur only very close to the seabed we used a typically bottom-living elasmobranch as a test subject, the dogfish Scyliorhinus canicula. In our introductory experiments dogfish were found to react spontaneously to food-correlated olfactory stimuli and to light/shade patterns. These parameters were then used in conditioning experiments, which indicated that dogfish are capable of compass orientation in an electric field. Our dogfisch showed the same prey-catching reactions to small electric dipoles as reported by KALMIJN (1971). We found different reactions, however, in dogfish of different lengths. The smaller animals showed more avoidance reactions and less bite reactions than the larger ones. Dogfish were kept in total darkness in an experimental tank with a large dipole field along one of the walls. When the same electric field pattern was applied in the middle of the tank some of the dogfish reacted to the dipole as if there was a wall. We conclude from our experiments that nocturnal short-range migrations of the dogfish are guided to some degree by local electric fields. It is not certain whether dogfish use local or regional electric fields during long-range migrations but our results indicate that they are capable of doing so. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
