Determination and differentiation of sex in Pacific salmon

Chum salmon embryonal discs were smeared and the cells stained with acetocarmine (60° C.) for chromosome content. Thirty-eight chromosomes (granular, sigmoid, and j-shaped) were counted, but the number was not considered absolute. The presence of sex chromosomes could not be established. Chromosomes...

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Main Author: Robertson, James Grant
Format: Text
Language:English
Published: University of British Columbia 1951
Subjects:
Online Access:https://dx.doi.org/10.14288/1.0106906
https://doi.library.ubc.ca/10.14288/1.0106906
id ftdatacite:10.14288/1.0106906
record_format openpolar
spelling ftdatacite:10.14288/1.0106906 2023-05-15T17:59:40+02:00 Determination and differentiation of sex in Pacific salmon Robertson, James Grant 1951 https://dx.doi.org/10.14288/1.0106906 https://doi.library.ubc.ca/10.14288/1.0106906 en eng University of British Columbia article-journal Text ScholarlyArticle 1951 ftdatacite https://doi.org/10.14288/1.0106906 2021-11-05T12:55:41Z Chum salmon embryonal discs were smeared and the cells stained with acetocarmine (60° C.) for chromosome content. Thirty-eight chromosomes (granular, sigmoid, and j-shaped) were counted, but the number was not considered absolute. The presence of sex chromosomes could not be established. Chromosomes in cells of differentiating gonads showed such excessive clumping that a count could not be made. Sex differentiation was followed in chum salmon. Sections from alevins (three weeks old) showed the gonads to be indifferent. Isolated nests of germ cells appeared which eventually formed a continuous cord (five weeks). At nine weeks the primordial ovary developed oocytes and in the succeeding week formed an endovarial canal. At this time the testis was first recognized (ten weeks). It was a small compact organ containing spermatogonia. Up to the final examination (fifteen weeks) the ovary showed no new structures excepting a prominent vena commites anteriad, while the testis retained its primitive features. The sex of pink and chum salmon fry migrants were shown by dissection. Ultraviolet light and temperature treatment of developing chum, pink, and sockeye embryos did not show that these factors would influence the sex ratio. Temperature data were decidedly inconclusive. An equal distribution of the sexes in pink and chum fry and sockeye smolts was found in data compiled from migrant runs at Port John, B. C. It is suggested that precocious male sockeye mature in the sea. The sex ratios at stages in the life history of the pink salmon are presented to show that there had occurred a natural sea mortality of 40.2 percent. Text Pink salmon DataCite Metadata Store (German National Library of Science and Technology) Pacific Sockeye ENVELOPE(-130.143,-130.143,54.160,54.160)
institution Open Polar
collection DataCite Metadata Store (German National Library of Science and Technology)
op_collection_id ftdatacite
language English
description Chum salmon embryonal discs were smeared and the cells stained with acetocarmine (60° C.) for chromosome content. Thirty-eight chromosomes (granular, sigmoid, and j-shaped) were counted, but the number was not considered absolute. The presence of sex chromosomes could not be established. Chromosomes in cells of differentiating gonads showed such excessive clumping that a count could not be made. Sex differentiation was followed in chum salmon. Sections from alevins (three weeks old) showed the gonads to be indifferent. Isolated nests of germ cells appeared which eventually formed a continuous cord (five weeks). At nine weeks the primordial ovary developed oocytes and in the succeeding week formed an endovarial canal. At this time the testis was first recognized (ten weeks). It was a small compact organ containing spermatogonia. Up to the final examination (fifteen weeks) the ovary showed no new structures excepting a prominent vena commites anteriad, while the testis retained its primitive features. The sex of pink and chum salmon fry migrants were shown by dissection. Ultraviolet light and temperature treatment of developing chum, pink, and sockeye embryos did not show that these factors would influence the sex ratio. Temperature data were decidedly inconclusive. An equal distribution of the sexes in pink and chum fry and sockeye smolts was found in data compiled from migrant runs at Port John, B. C. It is suggested that precocious male sockeye mature in the sea. The sex ratios at stages in the life history of the pink salmon are presented to show that there had occurred a natural sea mortality of 40.2 percent.
format Text
author Robertson, James Grant
spellingShingle Robertson, James Grant
Determination and differentiation of sex in Pacific salmon
author_facet Robertson, James Grant
author_sort Robertson, James Grant
title Determination and differentiation of sex in Pacific salmon
title_short Determination and differentiation of sex in Pacific salmon
title_full Determination and differentiation of sex in Pacific salmon
title_fullStr Determination and differentiation of sex in Pacific salmon
title_full_unstemmed Determination and differentiation of sex in Pacific salmon
title_sort determination and differentiation of sex in pacific salmon
publisher University of British Columbia
publishDate 1951
url https://dx.doi.org/10.14288/1.0106906
https://doi.library.ubc.ca/10.14288/1.0106906
long_lat ENVELOPE(-130.143,-130.143,54.160,54.160)
geographic Pacific
Sockeye
geographic_facet Pacific
Sockeye
genre Pink salmon
genre_facet Pink salmon
op_doi https://doi.org/10.14288/1.0106906
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