Quantitative Larvenanalyse des Rügenschen Frühjahrsherings in den Laichsaisons 1991 und 1992

Das bereits vom ehemaligen Institut für Hochseefischerei, Rostock, routinemäßig durchgeführte Heringslarvenprogramm im Greifswalder Bodden wird als Beitrag zur Bestandsschätzung des Rügenschen Frühjahrsherings (RFH) zunehmend unter ökologischen Gesichtspunkten im Institut für Ostseefischerei (IOR) in Kooperation mit der Universität Rostock (Fachbereich Biologie) weitergeführt. Die quantitative Larvenanalyse ermöglicht über den Anteil des aus dem Greifswalder Bodden stammenden Nachwuchses eine Voraussage über den Erfolg der in einem weitaus größeren Seegebiet (ICES SD 22+24) produzierten Nachwuchsjahresklassen. Vorliegende Publikation dokumentiert erste Ergebnisse hinsichtlich der Heringslarvenverteilung im Saisonverlauf 1991 und 1992.

Saprolegnia on roach (Leuciscus rutilus) and carp (Cyprinus carpio) [Translation from: Acta zool.pathol.Antverpiensia 43 107-123, 1976]

There is, in nature, as well as in the aquarium, a parasitic disease known as 'mousse' and which attacks predominantly fish. It is caused by Phycomycete fungi, genus Saprolegnia. The fungus causes external lesions and covers the fish with a thick white layer from whence comes the name 'mousse', commonly attributed to the disease, for which the scientific name is Saprolegnia. This article provides an overview of Saprolegnia infections on fish in nature and aquaria and then discusses symptomology of Saprolegnia in the mirror caro and t roach in more detail.

Mussel eggs as indicators of mutagen exposure in coastal and estuarine environments

The aim of this study was to develop a short-term genotoxicity assay for monitoring the marine environment for mutagens. Based on the developing eggs and embryos of the marine mussel Mytilus edulis, an important pollution indicator species, the test employs the sensitive sister chromatid exchange (SCE) technique as its end-point, and exploits the potential of mussel eggs to accumulate mutagenic pollutants from the surrounding sea water. Mussel eggs take up to 6 months to develop while in the gonad, which provides scope for DNA damage to be accumulated over an extended time interval; chromosome damage is subsequently visualised as SCEs in 2-cell-stage embryos after these have been spawned in the laboratory. Methods which measure biological responses to pollutant exposure are able to integrate all the factors (internal and external) which contribute to the exposure. The new cytogenetic assay allows the effects of adult exposure to be interpreted in cells destined to become part of the next generation.