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Oelberg, Leslie Dana
Embryonalentwicklung von coregoniden Fischen (Coregonus sp. Hallstätter See): spontane Variabilität in der Ausprägung von Entwicklungsmerkmalen unter den Bedingungen ökotoxikologischer Standardprüfverfahren.
Embryo development of coregonid fishes (Coregonus sp. Hallstätter See): spontaneous variability in developmental character values under the conditions of ecotoxicological standard testing procedures
Diplomarbeit, Vet. Med. Univ. Wien, pp. 71.
The subject of the present study is the characterisation of the embryonic development of Coregonus sp., Hallstättersee, a native representative of the fish family Coregonidae (Whitefishes).
Under the conditions of standardised ecotoxicological tests, the spontaneous variability of developmental characteristics were investigated, which included velocity of development, hatching and abnormality rate as well as the size of eggs and hatchlings. Furthermore a photographic documentation of fish development is provided for the following stages: blastula, gastrula, segmentation, pharyngula, an embryo ready for hatching and a yolk-sac larva (one day old).
The suitability of Coregonus sp. for standardised early life-stage toxicity testing was examined with respect to practicability and compliance with the biotic validity criteria. The character states of the developmental characteristics studied were compared among the different taxa of alpine whitefishes including data from the literature and discussed with respect to ecological interpretation eventually.
Ecotoxicological testing with small warm water fish species (for example zebrafish, Danio rerio) is well described in literature whereas data on cold water fishes, whitefishes in particular is scarce.
The importance of fish for ecotoxicity testing is primarily due to its position in the food chain. Early life-stages of fishes are subject to significant ecotoxicological, biological and medical research, as their development may be impaired in waters, polluted by anthropogenic chemical substances. Whitefishes are of high commercial relevance for fishery and aquaculture. Moreover, various coregonid taxa are threatened with extinction and listed in national and international Red Lists of threatened or declining fishes.