Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta)
Abstract: Reproductive output is an important parameter of individual fitness. As a rule, insect offspring number is correlated with specimen size, and for a given species smaller adults lay fewer eggs than larger individuals. Whether small individuals may at the same time lay smaller eggs than larg...
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ftpubman:oai:pure.mpg.de:item_1503010 2023-08-20T04:09:23+02:00 Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta) Zwick, P. 1999-04 http://hdl.handle.net/11858/00-001M-0000-000F-C899-9 eng eng http://hdl.handle.net/11858/00-001M-0000-000F-C899-9 New vistas in aquatic microbial ecology Archiv für Hydrobiologie Special Issues Advances in Limnology info:eu-repo/semantics/article 1999 ftpubman 2023-08-01T21:36:23Z Abstract: Reproductive output is an important parameter of individual fitness. As a rule, insect offspring number is correlated with specimen size, and for a given species smaller adults lay fewer eggs than larger individuals. Whether small individuals may at the same time lay smaller eggs than larger specimens was studied for two species of Leuctra. However, direct measurements of egg size proved impractical because of continuous changes of egg size during development. The volume of many insect eggs is known to increase during development. For several stonefly species, the process is described here. In diapausing plecopteran eggs (Protonemura intricata, Amphinemura standfussi) swelling occurs in two steps. The size of freshly laid eggs increases a little after immersion; after a few days size remains stable. When development begins a pronounced size increase is observed which is a good indicator of diapause termination and of beginning development which are otherwise less easily determined. The initial swelling seems to correspond to water uptake by the egg establishing an osmotic equilibrium between the egg and its dilute surrounding medium. Subsequent egg swelling during development follows a sigmoidal pattern, and size is related to developmental stage; maximum increase occurs at katatrepsis. The swelling during development is probably also driven by osmosis, the initial equilibrium being offset by large molecular storage materials in the yolk being metabolized and broken down into smaller compounds. Space requirements and mechanical pressure of the increasingly complex structure of the embryo may be additional causes for the observed increase of egg size. Because of these permanent changes of egg size, offspring size had to be determined in freshly hatched larvae. Size of hatchlings (head capsule width, HCW) in the two Leuctra spp. was unrelated to maternal size (expressed as wing length, a good measure of maternal biomass). However, females of L. digitata produced significantly larger offspring than ... Article in Journal/Newspaper Protonemura intricata Max Planck Society: MPG.PuRe |
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English |
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Abstract: Reproductive output is an important parameter of individual fitness. As a rule, insect offspring number is correlated with specimen size, and for a given species smaller adults lay fewer eggs than larger individuals. Whether small individuals may at the same time lay smaller eggs than larger specimens was studied for two species of Leuctra. However, direct measurements of egg size proved impractical because of continuous changes of egg size during development. The volume of many insect eggs is known to increase during development. For several stonefly species, the process is described here. In diapausing plecopteran eggs (Protonemura intricata, Amphinemura standfussi) swelling occurs in two steps. The size of freshly laid eggs increases a little after immersion; after a few days size remains stable. When development begins a pronounced size increase is observed which is a good indicator of diapause termination and of beginning development which are otherwise less easily determined. The initial swelling seems to correspond to water uptake by the egg establishing an osmotic equilibrium between the egg and its dilute surrounding medium. Subsequent egg swelling during development follows a sigmoidal pattern, and size is related to developmental stage; maximum increase occurs at katatrepsis. The swelling during development is probably also driven by osmosis, the initial equilibrium being offset by large molecular storage materials in the yolk being metabolized and broken down into smaller compounds. Space requirements and mechanical pressure of the increasingly complex structure of the embryo may be additional causes for the observed increase of egg size. Because of these permanent changes of egg size, offspring size had to be determined in freshly hatched larvae. Size of hatchlings (head capsule width, HCW) in the two Leuctra spp. was unrelated to maternal size (expressed as wing length, a good measure of maternal biomass). However, females of L. digitata produced significantly larger offspring than ... |
format |
Article in Journal/Newspaper |
author |
Zwick, P. |
spellingShingle |
Zwick, P. Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta) |
author_facet |
Zwick, P. |
author_sort |
Zwick, P. |
title |
Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta) |
title_short |
Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta) |
title_full |
Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta) |
title_fullStr |
Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta) |
title_full_unstemmed |
Egg diapause, egg swelling and mother-child size relationships in Plecoptera (Insecta) |
title_sort |
egg diapause, egg swelling and mother-child size relationships in plecoptera (insecta) |
publishDate |
1999 |
url |
http://hdl.handle.net/11858/00-001M-0000-000F-C899-9 |
genre |
Protonemura intricata |
genre_facet |
Protonemura intricata |
op_source |
New vistas in aquatic microbial ecology Archiv für Hydrobiologie Special Issues Advances in Limnology |
op_relation |
http://hdl.handle.net/11858/00-001M-0000-000F-C899-9 |
_version_ |
1774722306073952256 |