Scheder C.,Consultants in Aquatic Ecology and Engineering |
Lerchegger B.,Consultants in Aquatic Ecology and Engineering |
Jung M.,Consultants in Aquatic Ecology and Engineering |
Csar D.,Consultants in Aquatic Ecology and Engineering |
Gumpinger C.,Consultants in Aquatic Ecology and Engineering
Hydrobiologia | Year: 2014
The critically endangered freshwater pearl mussel (Margaritifera margaritifera Linnaeus 1758) is the target species of an Austrian conservation project that involves captive breeding. In order to optimize the operational procedure, controls were conducted at several decisive stages, including infection of host fish (for which a time- and work-saving enclosure approach was tested), larval growth during the parasitic stage, growth of juvenile mussels in climate chambers at different temperatures, and growth and survival of re-introduced juveniles in field cages. High infection rates could be attained under near natural conditions. Distinctive patterns in the way the gill arches of the host fish were infected could be detected. Encysted glochidia showed significantly different successive growth stages, related to water temperature. In all, five distinctive growth stages could be detected in the course of the first 562 days of observation. The stages are described and the respective daily increments given. Very high survival rates were achieved during hibernation in the field as well as at the laboratory. The study suggests a way for saving time in the infection procedure that can more effectively be invested in an intensive maintenance of juveniles at the laboratory and during hibernation in the field. © 2013 Springer Science+Business Media Dordrecht.