Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths
Abstract Aging Antarctic icefish is difficult because of their lack of scales and poorly calcified bones. Icefish ages must therefore be estimated from otoliths. We describe a method of reading daily micro-increments in connection with shape, size and mass analyses of the otoliths of the South Georg...
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ftunivoulu:oai:oulu.fi:nbnfi-fe202102235702 2023-07-30T03:58:00+02:00 Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths Traczyk, R. (Ryszard) Meyer-Rochow, V. B. (Victor Benno) Hughes, R. M. (Robert M.) 2021 application/pdf http://urn.fi/urn:nbn:fi-fe202102235702 eng eng Inter-Research Science Center info:eu-repo/semantics/openAccess © The authors 2021. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited. https://creativecommons.org/licenses/by/4.0/ Aging analyses Daily micro-increments Light microscopy Scanning electron microscopy Southern Ocean info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftunivoulu 2023-07-08T19:57:37Z Abstract Aging Antarctic icefish is difficult because of their lack of scales and poorly calcified bones. Icefish ages must therefore be estimated from otoliths. We describe a method of reading daily micro-increments in connection with shape, size and mass analyses of the otoliths of the South Georgia icefish Pseudochaenichthys georgianus. Changes in otolith morphology and mass correlate with fish size and age group. The otolith micro-increment analysis is capable of establishing the age of an icefish by relating the daily micro-increment count to the life history of the fish. Micro-increment measurements and analyses are relatively simple to do by light and scanning electron microscopy and by using micro-densitometer and digitizing equipment. Drastic changes in the life history of an individual are reflected by measurable changes in its otolith micro-increment data as seen in our analyses of age groups 0-VI. The initial drastic change in daily micro-increment shapes and periodicities occur in connection with the hatching period of the icefish. The next drastic change in otolith shape and daily micro-increments occurs when ~7 cm long fish shift from pelagic to benthic habitats. As the fish age beyond group III, individual otolith variability lessens until they begin spawning. Our results indicate a single population of P. georgianus between the Antarctic Peninsula and South Georgia. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Icefish Southern Ocean Jultika - University of Oulu repository Antarctic Antarctic Peninsula Southern Ocean The Antarctic |
institution |
Open Polar |
collection |
Jultika - University of Oulu repository |
op_collection_id |
ftunivoulu |
language |
English |
topic |
Aging analyses Daily micro-increments Light microscopy Scanning electron microscopy Southern Ocean |
spellingShingle |
Aging analyses Daily micro-increments Light microscopy Scanning electron microscopy Southern Ocean Traczyk, R. (Ryszard) Meyer-Rochow, V. B. (Victor Benno) Hughes, R. M. (Robert M.) Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths |
topic_facet |
Aging analyses Daily micro-increments Light microscopy Scanning electron microscopy Southern Ocean |
description |
Abstract Aging Antarctic icefish is difficult because of their lack of scales and poorly calcified bones. Icefish ages must therefore be estimated from otoliths. We describe a method of reading daily micro-increments in connection with shape, size and mass analyses of the otoliths of the South Georgia icefish Pseudochaenichthys georgianus. Changes in otolith morphology and mass correlate with fish size and age group. The otolith micro-increment analysis is capable of establishing the age of an icefish by relating the daily micro-increment count to the life history of the fish. Micro-increment measurements and analyses are relatively simple to do by light and scanning electron microscopy and by using micro-densitometer and digitizing equipment. Drastic changes in the life history of an individual are reflected by measurable changes in its otolith micro-increment data as seen in our analyses of age groups 0-VI. The initial drastic change in daily micro-increment shapes and periodicities occur in connection with the hatching period of the icefish. The next drastic change in otolith shape and daily micro-increments occurs when ~7 cm long fish shift from pelagic to benthic habitats. As the fish age beyond group III, individual otolith variability lessens until they begin spawning. Our results indicate a single population of P. georgianus between the Antarctic Peninsula and South Georgia. |
format |
Article in Journal/Newspaper |
author |
Traczyk, R. (Ryszard) Meyer-Rochow, V. B. (Victor Benno) Hughes, R. M. (Robert M.) |
author_facet |
Traczyk, R. (Ryszard) Meyer-Rochow, V. B. (Victor Benno) Hughes, R. M. (Robert M.) |
author_sort |
Traczyk, R. (Ryszard) |
title |
Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths |
title_short |
Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths |
title_full |
Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths |
title_fullStr |
Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths |
title_full_unstemmed |
Age determination in the icefish Pseudochaenichthys georgianus (Channichthyidae) based on multiple methods using otoliths |
title_sort |
age determination in the icefish pseudochaenichthys georgianus (channichthyidae) based on multiple methods using otoliths |
publisher |
Inter-Research Science Center |
publishDate |
2021 |
url |
http://urn.fi/urn:nbn:fi-fe202102235702 |
geographic |
Antarctic Antarctic Peninsula Southern Ocean The Antarctic |
geographic_facet |
Antarctic Antarctic Peninsula Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctic Peninsula Icefish Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Icefish Southern Ocean |
op_rights |
info:eu-repo/semantics/openAccess © The authors 2021. Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are unrestricted. Authors and original publication must be credited. https://creativecommons.org/licenses/by/4.0/ |
_version_ |
1772820727001513984 |