Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs
The identification of developmental stages in fish eggs from plankton samples is often complicated by deformation of the embryos due to mechanical stress during the sampling procedure and by dehydration during formaldehyde fixation. The effects of formaldehyde fixation and mechanical stress on Balti...
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ftdtupubl:oai:pure.atira.dk:publications/aa8d5ae0-baae-42ea-a193-e5326e2fb66b 2023-08-27T04:09:31+02:00 Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs Geldmacher, A. Wieland, Kai 1999 https://orbit.dtu.dk/en/publications/aa8d5ae0-baae-42ea-a193-e5326e2fb66b eng eng info:eu-repo/semantics/restrictedAccess Geldmacher , A & Wieland , K 1999 , ' Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs ' , Journal of Applied Ichthyology-Zeitschrift für Angewandte Ichthyologie , vol. 15 , no. 2 , pp. 75-79 . klima Habitat article 1999 ftdtupubl 2023-08-09T22:55:28Z The identification of developmental stages in fish eggs from plankton samples is often complicated by deformation of the embryos due to mechanical stress during the sampling procedure and by dehydration during formaldehyde fixation. The effects of formaldehyde fixation and mechanical stress on Baltic cod eggs (Gadus morhua callarias L.) were examined separately by visually comparing the morphological features of treated vs. live eggs of identical ontogenetic age. Microphotographs were made concurrently for documentation. In stage IA eggs, mechanical treatment resulted in scattered blastodiscs surrounded by single cells, while in further advanced stages the yolk membrane collapsed entirely, the yolk coagulated and the embryo extending over the yolk shrank. Formaldehyde fixation caused the yolk and the blastodisc or embryo to darken, and in some cases crystalline enclosures occurred. Eggs mechanically deformed during handling were clearly distinguishable from those that died prior to catching; however, staging was generally less accurate for formaldehyde- preserved eggs when compared with living specimens. Article in Journal/Newspaper Gadus morhua Technical University of Denmark: DTU Orbit |
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Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
topic |
klima Habitat |
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klima Habitat Geldmacher, A. Wieland, Kai Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs |
topic_facet |
klima Habitat |
description |
The identification of developmental stages in fish eggs from plankton samples is often complicated by deformation of the embryos due to mechanical stress during the sampling procedure and by dehydration during formaldehyde fixation. The effects of formaldehyde fixation and mechanical stress on Baltic cod eggs (Gadus morhua callarias L.) were examined separately by visually comparing the morphological features of treated vs. live eggs of identical ontogenetic age. Microphotographs were made concurrently for documentation. In stage IA eggs, mechanical treatment resulted in scattered blastodiscs surrounded by single cells, while in further advanced stages the yolk membrane collapsed entirely, the yolk coagulated and the embryo extending over the yolk shrank. Formaldehyde fixation caused the yolk and the blastodisc or embryo to darken, and in some cases crystalline enclosures occurred. Eggs mechanically deformed during handling were clearly distinguishable from those that died prior to catching; however, staging was generally less accurate for formaldehyde- preserved eggs when compared with living specimens. |
format |
Article in Journal/Newspaper |
author |
Geldmacher, A. Wieland, Kai |
author_facet |
Geldmacher, A. Wieland, Kai |
author_sort |
Geldmacher, A. |
title |
Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs |
title_short |
Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs |
title_full |
Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs |
title_fullStr |
Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs |
title_full_unstemmed |
Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs |
title_sort |
implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of baltic cod eggs |
publishDate |
1999 |
url |
https://orbit.dtu.dk/en/publications/aa8d5ae0-baae-42ea-a193-e5326e2fb66b |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Geldmacher , A & Wieland , K 1999 , ' Implications of mechanical deformation and formaldehyde preservation for the identification of stage-specific characteristics of Baltic cod eggs ' , Journal of Applied Ichthyology-Zeitschrift für Angewandte Ichthyologie , vol. 15 , no. 2 , pp. 75-79 . |
op_rights |
info:eu-repo/semantics/restrictedAccess |
_version_ |
1775350960549265408 |