The reproductive physiology of witch flounder, Glyptocephalus cynoglossus
The witch flounder (Glyptocephalus cynoglossus), or grey sole, as it is commonly known, is a member of the family Pleuronectidae (right eye flounders) and is found in the Northwest Atlantic near Hamilton Bank off southern Labrador, southward over Newfoundland banks, Gulf of St. Lawrence, Scotian She...
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Memorial University of Newfoundland
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ftmemorialuniv:oai:research.library.mun.ca:11426 2023-10-01T03:57:38+02:00 The reproductive physiology of witch flounder, Glyptocephalus cynoglossus Short, Constance Elizabeth 2004 application/pdf https://research.library.mun.ca/11426/ https://research.library.mun.ca/11426/1/Short_ConstanceElizabeth.pdf en eng Memorial University of Newfoundland https://research.library.mun.ca/11426/1/Short_ConstanceElizabeth.pdf Short, Constance Elizabeth <https://research.library.mun.ca/view/creator_az/Short=3AConstance_Elizabeth=3A=3A.html> (2004) The reproductive physiology of witch flounder, Glyptocephalus cynoglossus. Masters thesis, Memorial University of Newfoundland. thesis_license Thesis NonPeerReviewed 2004 ftmemorialuniv 2023-09-03T06:48:19Z The witch flounder (Glyptocephalus cynoglossus), or grey sole, as it is commonly known, is a member of the family Pleuronectidae (right eye flounders) and is found in the Northwest Atlantic near Hamilton Bank off southern Labrador, southward over Newfoundland banks, Gulf of St. Lawrence, Scotian Shelf, Bay of Fundy and Gulf of Maine, to Cape Lookout, NC. The witch flounder has become increasingly important commercially since the 1940's. There was heavy exploitation of witch flounder by foreign ships in the early 1970's but with the introduction of Canada's 200-mile limit in 1977, foreign fishing for the species was reduced and Canada's take increased. -- This study focused on the adaptation of wild witch flounder to captivity and the development of a captive broodstock. Areas of concentration focused on growth and maturation, with emphasis on the reproductive biology (pattern of oocyte development, endocrinology and gamete analysis) of the witch flounder. This information will be used to help determine whether the witch flounder is a good candidate as an aquaculture species. -- The reproductive cycle of both the male and female witch flounder is characterized by distinct seasonal variations and fluctuations in plasma sex steroids associated with reproductive activity. As seen in other teleosts, the circulating levels of sex steroids increased as gamete maturation and gonad growth proceed, reaching peak levels during spawning. -- Oocyte size-class frequency distributions of witch flounder demonstrate the presence of just a single clutch of progressively developing vitellogenic oocytes, indicating group-synchronous development, by far the most common reproductive strategy in teleosts. -- Male witch flounder produce low volumes of viscous milt and sperm is only available for five months of the year (April--August). This correlates with spawning events in the female witch flounder, with ovulated eggs from late June to late August. Thesis Newfoundland Northwest Atlantic Memorial University of Newfoundland: Research Repository Newfoundland Lookout ENVELOPE(77.955,77.955,-68.605,-68.605) Cape Lookout ENVELOPE(156.450,156.450,-83.050,-83.050) Hamilton Bank ENVELOPE(-54.156,-54.156,53.309,53.309) |
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Memorial University of Newfoundland: Research Repository |
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ftmemorialuniv |
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English |
description |
The witch flounder (Glyptocephalus cynoglossus), or grey sole, as it is commonly known, is a member of the family Pleuronectidae (right eye flounders) and is found in the Northwest Atlantic near Hamilton Bank off southern Labrador, southward over Newfoundland banks, Gulf of St. Lawrence, Scotian Shelf, Bay of Fundy and Gulf of Maine, to Cape Lookout, NC. The witch flounder has become increasingly important commercially since the 1940's. There was heavy exploitation of witch flounder by foreign ships in the early 1970's but with the introduction of Canada's 200-mile limit in 1977, foreign fishing for the species was reduced and Canada's take increased. -- This study focused on the adaptation of wild witch flounder to captivity and the development of a captive broodstock. Areas of concentration focused on growth and maturation, with emphasis on the reproductive biology (pattern of oocyte development, endocrinology and gamete analysis) of the witch flounder. This information will be used to help determine whether the witch flounder is a good candidate as an aquaculture species. -- The reproductive cycle of both the male and female witch flounder is characterized by distinct seasonal variations and fluctuations in plasma sex steroids associated with reproductive activity. As seen in other teleosts, the circulating levels of sex steroids increased as gamete maturation and gonad growth proceed, reaching peak levels during spawning. -- Oocyte size-class frequency distributions of witch flounder demonstrate the presence of just a single clutch of progressively developing vitellogenic oocytes, indicating group-synchronous development, by far the most common reproductive strategy in teleosts. -- Male witch flounder produce low volumes of viscous milt and sperm is only available for five months of the year (April--August). This correlates with spawning events in the female witch flounder, with ovulated eggs from late June to late August. |
format |
Thesis |
author |
Short, Constance Elizabeth |
spellingShingle |
Short, Constance Elizabeth The reproductive physiology of witch flounder, Glyptocephalus cynoglossus |
author_facet |
Short, Constance Elizabeth |
author_sort |
Short, Constance Elizabeth |
title |
The reproductive physiology of witch flounder, Glyptocephalus cynoglossus |
title_short |
The reproductive physiology of witch flounder, Glyptocephalus cynoglossus |
title_full |
The reproductive physiology of witch flounder, Glyptocephalus cynoglossus |
title_fullStr |
The reproductive physiology of witch flounder, Glyptocephalus cynoglossus |
title_full_unstemmed |
The reproductive physiology of witch flounder, Glyptocephalus cynoglossus |
title_sort |
reproductive physiology of witch flounder, glyptocephalus cynoglossus |
publisher |
Memorial University of Newfoundland |
publishDate |
2004 |
url |
https://research.library.mun.ca/11426/ https://research.library.mun.ca/11426/1/Short_ConstanceElizabeth.pdf |
long_lat |
ENVELOPE(77.955,77.955,-68.605,-68.605) ENVELOPE(156.450,156.450,-83.050,-83.050) ENVELOPE(-54.156,-54.156,53.309,53.309) |
geographic |
Newfoundland Lookout Cape Lookout Hamilton Bank |
geographic_facet |
Newfoundland Lookout Cape Lookout Hamilton Bank |
genre |
Newfoundland Northwest Atlantic |
genre_facet |
Newfoundland Northwest Atlantic |
op_relation |
https://research.library.mun.ca/11426/1/Short_ConstanceElizabeth.pdf Short, Constance Elizabeth <https://research.library.mun.ca/view/creator_az/Short=3AConstance_Elizabeth=3A=3A.html> (2004) The reproductive physiology of witch flounder, Glyptocephalus cynoglossus. Masters thesis, Memorial University of Newfoundland. |
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_version_ |
1778529493992865792 |