Ecology of Chironomidae (Diptera) in a Polar Lake
The six common genera of Chironomidae (Diptera) in Char Lake, Resolute, Northwest Territories (74°42′N lat.) were studied intensively from 1969 to 1972. Heterotrissocladius oliveri and a Trissocladius species are characteristic of the sediment zone, while two species of Orthocladius, Pseudodiamesa a...
Published in: | Journal of the Fisheries Research Board of Canada |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1976
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/f76-034 http://www.nrcresearchpress.com/doi/pdf/10.1139/f76-034 |
id |
crcansciencepubl:10.1139/f76-034 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/f76-034 2023-12-17T10:47:42+01:00 Ecology of Chironomidae (Diptera) in a Polar Lake Welch, H. E. 1976 http://dx.doi.org/10.1139/f76-034 http://www.nrcresearchpress.com/doi/pdf/10.1139/f76-034 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Journal of the Fisheries Research Board of Canada volume 33, issue 2, page 227-247 ISSN 0015-296X General Medicine journal-article 1976 crcansciencepubl https://doi.org/10.1139/f76-034 2023-11-19T13:38:48Z The six common genera of Chironomidae (Diptera) in Char Lake, Resolute, Northwest Territories (74°42′N lat.) were studied intensively from 1969 to 1972. Heterotrissocladius oliveri and a Trissocladius species are characteristic of the sediment zone, while two species of Orthocladius, Pseudodiamesa arctica, Paracladius quadrinodosus, and Lauterbornia sp. are restricted mainly to the rocky and moss zones. Life cycles are 2 or 3 yr, depending upon the species. Year-classes could be discriminated by instar frequency distribution. Populations increased steadily during the study period, for an average increase in strength of 5 times between the 1968 and 1971 year-classes. Summer emergence and egg-laying conditions are of overriding importance to year-class strength. Mortality within year-classes is undetectable until the last 4 mo of larval life, when mortality due to char predation is about 65% between April and the time of emergence. The physiology of these chironomids does not seem unusual aside from continuing activity down to 0 C, and there is no indication of metabolic compensation. Net growth efficiency averages 36%. Assimilated energy (growth + respiration) at 8.6 kcal m −2 yr −1 is very low compared with temperate zone populations, but is more similar as a percent of photosynthesis, 4.1%. The relatively large detritus pool and the presence of both 2- and 3-yr species tend to stabilize chironomid energy flow. Definition of long-term averages for chironomid populations in Char Lake would require a decade or more of study. Article in Journal/Newspaper Northwest Territories Canadian Science Publishing (via Crossref) Northwest Territories Journal of the Fisheries Research Board of Canada 33 2 227 247 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Medicine |
spellingShingle |
General Medicine Welch, H. E. Ecology of Chironomidae (Diptera) in a Polar Lake |
topic_facet |
General Medicine |
description |
The six common genera of Chironomidae (Diptera) in Char Lake, Resolute, Northwest Territories (74°42′N lat.) were studied intensively from 1969 to 1972. Heterotrissocladius oliveri and a Trissocladius species are characteristic of the sediment zone, while two species of Orthocladius, Pseudodiamesa arctica, Paracladius quadrinodosus, and Lauterbornia sp. are restricted mainly to the rocky and moss zones. Life cycles are 2 or 3 yr, depending upon the species. Year-classes could be discriminated by instar frequency distribution. Populations increased steadily during the study period, for an average increase in strength of 5 times between the 1968 and 1971 year-classes. Summer emergence and egg-laying conditions are of overriding importance to year-class strength. Mortality within year-classes is undetectable until the last 4 mo of larval life, when mortality due to char predation is about 65% between April and the time of emergence. The physiology of these chironomids does not seem unusual aside from continuing activity down to 0 C, and there is no indication of metabolic compensation. Net growth efficiency averages 36%. Assimilated energy (growth + respiration) at 8.6 kcal m −2 yr −1 is very low compared with temperate zone populations, but is more similar as a percent of photosynthesis, 4.1%. The relatively large detritus pool and the presence of both 2- and 3-yr species tend to stabilize chironomid energy flow. Definition of long-term averages for chironomid populations in Char Lake would require a decade or more of study. |
format |
Article in Journal/Newspaper |
author |
Welch, H. E. |
author_facet |
Welch, H. E. |
author_sort |
Welch, H. E. |
title |
Ecology of Chironomidae (Diptera) in a Polar Lake |
title_short |
Ecology of Chironomidae (Diptera) in a Polar Lake |
title_full |
Ecology of Chironomidae (Diptera) in a Polar Lake |
title_fullStr |
Ecology of Chironomidae (Diptera) in a Polar Lake |
title_full_unstemmed |
Ecology of Chironomidae (Diptera) in a Polar Lake |
title_sort |
ecology of chironomidae (diptera) in a polar lake |
publisher |
Canadian Science Publishing |
publishDate |
1976 |
url |
http://dx.doi.org/10.1139/f76-034 http://www.nrcresearchpress.com/doi/pdf/10.1139/f76-034 |
geographic |
Northwest Territories |
geographic_facet |
Northwest Territories |
genre |
Northwest Territories |
genre_facet |
Northwest Territories |
op_source |
Journal of the Fisheries Research Board of Canada volume 33, issue 2, page 227-247 ISSN 0015-296X |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f76-034 |
container_title |
Journal of the Fisheries Research Board of Canada |
container_volume |
33 |
container_issue |
2 |
container_start_page |
227 |
op_container_end_page |
247 |
_version_ |
1785571637938094080 |