|Food and feeding strategies of water mites of the genus Hygrobates and the impact of their predation on the larval population of their predation on the larval population of the chironomid Gladotanytarsus mancus (walker) in Lake Maarsseveen|
Ten Winkel, E.H.; Davids, C.; De Nobel, J.G. (1989). Food and feeding strategies of water mites of the genus Hygrobates and the impact of their predation on the larval population of their predation on the larval population of the chironomid Gladotanytarsus mancus (walker) in Lake Maarsseveen. Neth. J. Zool. 39(3-4): 246-263
In: Netherlands Journal of Zoology. E.J. Brill: Leiden. ISSN 0028-2960, more
|Authors|| || Top |
- Ten Winkel, E.H.
- Davids, C.
- De Nobel, J.G.
The role of several aquatic animals, as food for the water mites Hygrobates nigromaculates and H.trigonicus, was examined. Both water mite speceis are able to enter the sediments and pray on different larval stages of chironomids. H. nigromaculatus fed on both cladocerans and chironomids, while H. trigonicus preyed only upon chironomid larvae. H. trigonicus burrowed in the sediment independent of the presence of prey. In H. nigromaculatus on the contrary, the burrowing activity entirely dissapeared in vials with a high number of Daphnia. Prey vulnerability is significantly increased in experiments without sediment. In a temperature range from 5° to 20°C, prey consumption rates increased about five times. The destiny of the chironomid Cladotanytarsus mancus declined by about 50% (27.000 to 13.000 per m2) in winter.Hygrobates (about 1000 per m2) was found to be the most important predator, despite the fact that Cladotanytarsus larvae inhabit tubes constructed of sand-grains, which inhibits predation. Due to their small size, benthivorous fish will not feed on these larvae. Virtually no other predators of these chironomids were present. The numerical decline of the chironomid closely matched the population food requirements of the water mite Hygrobates between November and May. It is concluded that the mite is almost entirely responsible for this decline. Cladotanytarsus is an indispensable food source for the mite during winter and spring, and is a source of energy when the eggs of the new generation are formed.