Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway
Knowledge of the early life-history and habitat requirements of coastal cod is very sparse. Young of the year cod juveniles from three different locations in northern Norway were collected monthly from August to November 2005 using beach seine. Diet analyses based on stomach contents showed that 0-g...
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Universitetet i Tromsø
2006
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ftunivtroemsoe:oai:munin.uit.no:10037/430 2024-06-02T08:06:57+00:00 Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway Sandneseng, Elida 2006-12-11 489321 bytes application/pdf https://hdl.handle.net/10037/430 eng eng Universitetet i Tromsø University of Tromsø https://hdl.handle.net/10037/430 URN:NBN:no-uit_munin_207 openAccess Copyright 2006 The Author(s) VDP::Matematikk og Naturvitenskap: 400 coastal cod otolith zone patterns Cryptocotyle lingua Master thesis Mastergradsoppgave 2006 ftunivtroemsoe 2024-05-07T08:40:37Z Knowledge of the early life-history and habitat requirements of coastal cod is very sparse. Young of the year cod juveniles from three different locations in northern Norway were collected monthly from August to November 2005 using beach seine. Diet analyses based on stomach contents showed that 0-group cod mainly ate copepods, gammarids, polychaetes, mysids, shrimps and isopods. The three locations differed with regard to prey composition, and copepods were generally most abundant, but benthic (polychaetes) and hyperbenthic species (decapods) had the highest weight proportion. To investigate when the first hyaline (winter) zone is formed, length and width of 122 pairs of otoliths were measured and assessed into four zone pattern categories. The proportion of cod with a hyaline otolith zone increased from 20.5% in October to 67.9% in November. There were clear differences between the locations with regard to the otolith-width fish length relation, and this relation was lowest at the location with the highest cod abundance (Jøvik). Abundance and seasonal infection of the digenean parasite Cryptocotyle lingua differed between the three samplings locations, most likely due to differences in abundance of the intermediate host (the snail Littorina littorea). Cod from Njosken exhibited the heaviest infections, whereas fish from Makkjosen had some and those from Jøvik had almost no parasites. It is suggested that infection of this parasite can be used as a habitat indicator of the cod during summer and autumn. Master Thesis Gadus morhua Northern Norway Copepods University of Tromsø: Munin Open Research Archive Norway Jøvik ENVELOPE(16.523,16.523,68.408,68.408) Njosken ENVELOPE(19.633,19.633,69.467,69.467) |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400 coastal cod otolith zone patterns Cryptocotyle lingua |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400 coastal cod otolith zone patterns Cryptocotyle lingua Sandneseng, Elida Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400 coastal cod otolith zone patterns Cryptocotyle lingua |
description |
Knowledge of the early life-history and habitat requirements of coastal cod is very sparse. Young of the year cod juveniles from three different locations in northern Norway were collected monthly from August to November 2005 using beach seine. Diet analyses based on stomach contents showed that 0-group cod mainly ate copepods, gammarids, polychaetes, mysids, shrimps and isopods. The three locations differed with regard to prey composition, and copepods were generally most abundant, but benthic (polychaetes) and hyperbenthic species (decapods) had the highest weight proportion. To investigate when the first hyaline (winter) zone is formed, length and width of 122 pairs of otoliths were measured and assessed into four zone pattern categories. The proportion of cod with a hyaline otolith zone increased from 20.5% in October to 67.9% in November. There were clear differences between the locations with regard to the otolith-width fish length relation, and this relation was lowest at the location with the highest cod abundance (Jøvik). Abundance and seasonal infection of the digenean parasite Cryptocotyle lingua differed between the three samplings locations, most likely due to differences in abundance of the intermediate host (the snail Littorina littorea). Cod from Njosken exhibited the heaviest infections, whereas fish from Makkjosen had some and those from Jøvik had almost no parasites. It is suggested that infection of this parasite can be used as a habitat indicator of the cod during summer and autumn. |
format |
Master Thesis |
author |
Sandneseng, Elida |
author_facet |
Sandneseng, Elida |
author_sort |
Sandneseng, Elida |
title |
Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway |
title_short |
Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway |
title_full |
Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway |
title_fullStr |
Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway |
title_full_unstemmed |
Variation in abundance, diet, otolith zone patterns and black spot disease (Cryptocotyle lingua) of 0-group coastal cod (Gadus morhua L.) in northern Norway |
title_sort |
variation in abundance, diet, otolith zone patterns and black spot disease (cryptocotyle lingua) of 0-group coastal cod (gadus morhua l.) in northern norway |
publisher |
Universitetet i Tromsø |
publishDate |
2006 |
url |
https://hdl.handle.net/10037/430 |
long_lat |
ENVELOPE(16.523,16.523,68.408,68.408) ENVELOPE(19.633,19.633,69.467,69.467) |
geographic |
Norway Jøvik Njosken |
geographic_facet |
Norway Jøvik Njosken |
genre |
Gadus morhua Northern Norway Copepods |
genre_facet |
Gadus morhua Northern Norway Copepods |
op_relation |
https://hdl.handle.net/10037/430 URN:NBN:no-uit_munin_207 |
op_rights |
openAccess Copyright 2006 The Author(s) |
_version_ |
1800751966775672832 |