Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel)
Fritillaria borealis is a cosmopolitan species, very frequent in sub-antarctic and antarctic waters. The objective of this paper was to analyze its size structure and maturity stages at two sites in Ushuaia Bay: a coastal site exposed to anthropogenic pressure (E1) and a reference site (E2) located...
Main Authors: | , , |
---|---|
Format: | Journal/Newspaper |
Language: | unknown |
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.12110/paper_16798759_v63_n3_p279_Presta |
id |
ftunibueairesbd:todo:paper_16798759_v63_n3_p279_Presta |
---|---|
record_format |
openpolar |
spelling |
ftunibueairesbd:todo:paper_16798759_v63_n3_p279_Presta 2023-10-29T02:30:44+01:00 Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel) Presta, M.L. Hoffmeyer, M.S. Capitanio, F.L. https://hdl.handle.net/20.500.12110/paper_16798759_v63_n3_p279_Presta unknown http://hdl.handle.net/20.500.12110/paper_16798759_v63_n3_p279_Presta info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar Appendicularians Beagle channel Maturity stages JOUR ftunibueairesbd https://doi.org/20.500.12110/paper_16798759_v63_n3_p279_Presta 2023-10-05T01:22:47Z Fritillaria borealis is a cosmopolitan species, very frequent in sub-antarctic and antarctic waters. The objective of this paper was to analyze its size structure and maturity stages at two sites in Ushuaia Bay: a coastal site exposed to anthropogenic pressure (E1) and a reference site (E2) located in the external zone of the bay. Zooplankton was collected during the 2012 seasonal cycle. The sampling method involved the use of a 67 μm-mesh net. Appendicularians were classified in four maturity stages: I) undifferentiated gonads, II) testis and ovary differentiated, III) expanded testis, IV) discharged testis, expanded ovary. Our results showed that the highest densities of F. borealis occurred in spring and summer at both sites; coinciding with high values of chlorophyll-a. The percentage of juveniles (I and II) exhibited a spatial and temporal pattern similar to that observed for chlorophyll-a values. During spring-summer, juveniles and mature specimens (III and IV) showed a greater gonadal development than those individuals found in autumn-winter. In conclusion, the mismatching in the population structure and the pattern of densities of F. borealis between coastal and external zones would suggest the existence of two sub-populations susceptible to the influence of the anthropogenic impact in the bay. © 2015, Universidade de Sao Paulo. All Rights Reserved. Journal/Newspaper Antarc* Antarctic Biblioteca Digital FCEN-UBA (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires) |
institution |
Open Polar |
collection |
Biblioteca Digital FCEN-UBA (Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires) |
op_collection_id |
ftunibueairesbd |
language |
unknown |
topic |
Appendicularians Beagle channel Maturity stages |
spellingShingle |
Appendicularians Beagle channel Maturity stages Presta, M.L. Hoffmeyer, M.S. Capitanio, F.L. Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel) |
topic_facet |
Appendicularians Beagle channel Maturity stages |
description |
Fritillaria borealis is a cosmopolitan species, very frequent in sub-antarctic and antarctic waters. The objective of this paper was to analyze its size structure and maturity stages at two sites in Ushuaia Bay: a coastal site exposed to anthropogenic pressure (E1) and a reference site (E2) located in the external zone of the bay. Zooplankton was collected during the 2012 seasonal cycle. The sampling method involved the use of a 67 μm-mesh net. Appendicularians were classified in four maturity stages: I) undifferentiated gonads, II) testis and ovary differentiated, III) expanded testis, IV) discharged testis, expanded ovary. Our results showed that the highest densities of F. borealis occurred in spring and summer at both sites; coinciding with high values of chlorophyll-a. The percentage of juveniles (I and II) exhibited a spatial and temporal pattern similar to that observed for chlorophyll-a values. During spring-summer, juveniles and mature specimens (III and IV) showed a greater gonadal development than those individuals found in autumn-winter. In conclusion, the mismatching in the population structure and the pattern of densities of F. borealis between coastal and external zones would suggest the existence of two sub-populations susceptible to the influence of the anthropogenic impact in the bay. © 2015, Universidade de Sao Paulo. All Rights Reserved. |
format |
Journal/Newspaper |
author |
Presta, M.L. Hoffmeyer, M.S. Capitanio, F.L. |
author_facet |
Presta, M.L. Hoffmeyer, M.S. Capitanio, F.L. |
author_sort |
Presta, M.L. |
title |
Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel) |
title_short |
Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel) |
title_full |
Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel) |
title_fullStr |
Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel) |
title_full_unstemmed |
Population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): Seasonal cycle in Ushuaia Bay (Beagle Channel) |
title_sort |
population structure and maturity stages of fritillaria borealis (appendicularia, tunicata): seasonal cycle in ushuaia bay (beagle channel) |
url |
https://hdl.handle.net/20.500.12110/paper_16798759_v63_n3_p279_Presta |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/20.500.12110/paper_16798759_v63_n3_p279_Presta |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar |
op_doi |
https://doi.org/20.500.12110/paper_16798759_v63_n3_p279_Presta |
_version_ |
1781061510043271168 |