Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio
Male snow crabs, Chionoecetes opilio (Majidae), use their modified chelae to retain females for weeks before copulation. Consequently, adaptations for such sustained activity were examined in the chela-closer muscle responsible for clasping. Based on an allometric increase in the ratio of chela size...
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Canadian Science Publishing
1992
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Online Access: | http://dx.doi.org/10.1139/z92-316 http://www.nrcresearchpress.com/doi/pdf/10.1139/z92-316 |
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crcansciencepubl:10.1139/z92-316 2023-12-17T10:28:49+01:00 Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio Govind, C. K. Read, A. T. Claxton, W. T. Elner, R. W. 1992 http://dx.doi.org/10.1139/z92-316 http://www.nrcresearchpress.com/doi/pdf/10.1139/z92-316 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 70, issue 12, page 2356-2363 ISSN 0008-4301 1480-3283 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 1992 crcansciencepubl https://doi.org/10.1139/z92-316 2023-11-19T13:39:32Z Male snow crabs, Chionoecetes opilio (Majidae), use their modified chelae to retain females for weeks before copulation. Consequently, adaptations for such sustained activity were examined in the chela-closer muscle responsible for clasping. Based on an allometric increase in the ratio of chela size to carapace width, male snow crabs were categorized as morphometrically mature or immature, the former displaying precopulatory clasping more readily than the latter. However, the two types were similar in terms of the properties of the chela-closer muscle, which was examined in this study. The motor pattern during clasping consisted of low-frequency firing of one of the excitor motoneurons, which gives rise to small synaptic potentials. The other excitor motoneuron, which produces large synaptic potentials, fired only when the female struggled during the embrace. The synaptic potentials of both axons showed little if any fatigue at these low firing frequencies. The neuromuscular terminals of these motoneurons displayed areas of synaptic contact larger than most found in other tonically active crustacean muscles. The majority of these synapses had an active site for transmitter release denoted by a dense bar, with many containing more than three dense bars. The closer muscle had typically slow features, with 10 or 11 thin filaments surrounding a thick filament, and sarcomere lengths of 9 – 10 μm. Overall, the closer muscle with its slow-fiber composition, tonic motoneurons, and neuromuscular synapses is well suited to sustained, low-level activity such as precopulatory clasping. Article in Journal/Newspaper Chionoecetes opilio Canadian Science Publishing (via Crossref) Canadian Journal of Zoology 70 12 2356 2363 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Govind, C. K. Read, A. T. Claxton, W. T. Elner, R. W. Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
Male snow crabs, Chionoecetes opilio (Majidae), use their modified chelae to retain females for weeks before copulation. Consequently, adaptations for such sustained activity were examined in the chela-closer muscle responsible for clasping. Based on an allometric increase in the ratio of chela size to carapace width, male snow crabs were categorized as morphometrically mature or immature, the former displaying precopulatory clasping more readily than the latter. However, the two types were similar in terms of the properties of the chela-closer muscle, which was examined in this study. The motor pattern during clasping consisted of low-frequency firing of one of the excitor motoneurons, which gives rise to small synaptic potentials. The other excitor motoneuron, which produces large synaptic potentials, fired only when the female struggled during the embrace. The synaptic potentials of both axons showed little if any fatigue at these low firing frequencies. The neuromuscular terminals of these motoneurons displayed areas of synaptic contact larger than most found in other tonically active crustacean muscles. The majority of these synapses had an active site for transmitter release denoted by a dense bar, with many containing more than three dense bars. The closer muscle had typically slow features, with 10 or 11 thin filaments surrounding a thick filament, and sarcomere lengths of 9 – 10 μm. Overall, the closer muscle with its slow-fiber composition, tonic motoneurons, and neuromuscular synapses is well suited to sustained, low-level activity such as precopulatory clasping. |
format |
Article in Journal/Newspaper |
author |
Govind, C. K. Read, A. T. Claxton, W. T. Elner, R. W. |
author_facet |
Govind, C. K. Read, A. T. Claxton, W. T. Elner, R. W. |
author_sort |
Govind, C. K. |
title |
Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio |
title_short |
Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio |
title_full |
Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio |
title_fullStr |
Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio |
title_full_unstemmed |
Neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, Chionoecetes opilio |
title_sort |
neuromuscular analysis of the chela-closer muscle associated with precopulatory clasping in male snow crabs, chionoecetes opilio |
publisher |
Canadian Science Publishing |
publishDate |
1992 |
url |
http://dx.doi.org/10.1139/z92-316 http://www.nrcresearchpress.com/doi/pdf/10.1139/z92-316 |
genre |
Chionoecetes opilio |
genre_facet |
Chionoecetes opilio |
op_source |
Canadian Journal of Zoology volume 70, issue 12, page 2356-2363 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z92-316 |
container_title |
Canadian Journal of Zoology |
container_volume |
70 |
container_issue |
12 |
container_start_page |
2356 |
op_container_end_page |
2363 |
_version_ |
1785581008146399232 |