Too sick to migrate? Immune function and partial migration in Roach
(2019) BION02 20182Degree Projects in Biology
- Abstract
- Partial migration is a widespread phenomenon over various animal taxa where one part of the population migrates whereas the other part stays resident. Reasons triggering individuals to migrate while others stay are of high importance to understand ecological and evolutionary processes. Physiological parameters such as immune function have previously been shown to affect wintering decision in birds. However, this has not been investigated within aquatic ecosystems so far. Roach (Rutilus rutilus), a common planktivorous fish in northern shallow lakes, show seasonal partial migration. In this thesis, I provide first insights into the relationship between immune function as well as experimentally triggered immune response (via injection of... (More)
- Partial migration is a widespread phenomenon over various animal taxa where one part of the population migrates whereas the other part stays resident. Reasons triggering individuals to migrate while others stay are of high importance to understand ecological and evolutionary processes. Physiological parameters such as immune function have previously been shown to affect wintering decision in birds. However, this has not been investigated within aquatic ecosystems so far. Roach (Rutilus rutilus), a common planktivorous fish in northern shallow lakes, show seasonal partial migration. In this thesis, I provide first insights into the relationship between immune function as well as experimentally triggered immune response (via injection of Lipopolysaccharide, LPS) and wintering decision of roach. I found that the decision to migrate was not correlated with any of the investigated immune function parameters. However, by triggering immune response significantly less fish migrated compared to the control group. LPS triggered immune responses during separation in winter did not change wintering decision. However I found differences in immune parameters between autumn and winter suggesting immune function might be dependent on the season. Based on this study, baseline immune function do not seem to predict partial migration. However, triggered immune response due to infection or inflammation could explain individual wintering decision. This thesis provides novel insights into immune function and its role on partial migration of roach concerning costs and benefits of different wintering strategies. (Less)
- Popular Abstract
- Many animals migrate between different habitats, often on a seasonal basis. Partial migration is a phenomenon in which part of the population migrates while the other part stays resident. It is widely spread throughout all migratory animals. Changes of migratory behaviour can have major impacts on ecosystem dynamics making it crucial to understand processes causing partial migration. So far, causes that trigger individuals to either migrate or stay resident are poorly understood. Immune function has been suggested to have an impact on partial behaviour due to its importance for survival but high costs to maintain. Roach, a common fish species in shallow lakes, is partially migrating from the lakes into connecting streams during winter. My... (More)
- Many animals migrate between different habitats, often on a seasonal basis. Partial migration is a phenomenon in which part of the population migrates while the other part stays resident. It is widely spread throughout all migratory animals. Changes of migratory behaviour can have major impacts on ecosystem dynamics making it crucial to understand processes causing partial migration. So far, causes that trigger individuals to either migrate or stay resident are poorly understood. Immune function has been suggested to have an impact on partial behaviour due to its importance for survival but high costs to maintain. Roach, a common fish species in shallow lakes, is partially migrating from the lakes into connecting streams during winter. My thesis focused on the question if differences in immune function may be a cause or consequence of partial migration.
I caught roach in two shallow lakes and tagged them to monitor if individuals migrated or not. To relate partial migration to immune function I used two main approaches. Firstly, I took and analyzed blood samples of roach in autumn and winter to determine baseline immune parameters. Secondly, I induced immune response in roach by injecting a protein which is also produced by bacteria (LPS) and simulates bacterial infection. Thus, I analyzed if differences in immune function parameters as well as induced immune response are related to the decision of individual roach to migrate into the stream or stay resident in the lake.
By connecting the analyzed baseline immune parameters and the decision to migrate or stay resident I found that immune function did not differ between migrants and residents in autumn before the migration period started. This implies that the decision of roach to migrate or stay resident is independent of baseline immune function.
By comparing blood samples of migrants and residents in winter during separation I found that there was no difference between the two groups. Therefore, immune function does not seem to be influenced by migration and, thus, is not a consequence of partial migration. However, immune function of migrants differed between autumn and winter suggesting that immune function might be dependent on the season. An explanation could be a decrease in temperature or general food shortage in winter.
Looking at the behaviour of roach with increased immune response due to injection of LPS in autumn before migration, I found that injected roach had a higher tendency to stay in the lake compared to the control fish. This suggests that bacterial infection or inflammation could be a cause of partial migration. However, when injection was performed in winter during separation, roach did not change their migratory behaviour.
Overall, in this study I provide a novel understanding of immune function and its role on partial migration of roach. This serves as a solid foundation to further investigate causes and consequences of partial migration concerning costs and benefits of different wintering strategies.
Master’s Degree Project in Biology, 45 ECTS
Department of Biology, Lund University
Supervisor: Arne Hegemann and Anders Nilsson
Department of Biology, Aquatic Ecology Unit (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/8990431
- author
- Weber, Rike
- supervisor
-
- Arne Hegemann LU
- Anders Nilsson LU
- organization
- course
- BION02 20182
- year
- 2019
- type
- H2 - Master's Degree (Two Years)
- subject
- language
- English
- id
- 8990431
- date added to LUP
- 2019-07-09 11:34:48
- date last changed
- 2019-07-09 11:34:48
@misc{8990431,
abstract = {{Partial migration is a widespread phenomenon over various animal taxa where one part of the population migrates whereas the other part stays resident. Reasons triggering individuals to migrate while others stay are of high importance to understand ecological and evolutionary processes. Physiological parameters such as immune function have previously been shown to affect wintering decision in birds. However, this has not been investigated within aquatic ecosystems so far. Roach (Rutilus rutilus), a common planktivorous fish in northern shallow lakes, show seasonal partial migration. In this thesis, I provide first insights into the relationship between immune function as well as experimentally triggered immune response (via injection of Lipopolysaccharide, LPS) and wintering decision of roach. I found that the decision to migrate was not correlated with any of the investigated immune function parameters. However, by triggering immune response significantly less fish migrated compared to the control group. LPS triggered immune responses during separation in winter did not change wintering decision. However I found differences in immune parameters between autumn and winter suggesting immune function might be dependent on the season. Based on this study, baseline immune function do not seem to predict partial migration. However, triggered immune response due to infection or inflammation could explain individual wintering decision. This thesis provides novel insights into immune function and its role on partial migration of roach concerning costs and benefits of different wintering strategies.}},
author = {{Weber, Rike}},
language = {{eng}},
note = {{Student Paper}},
title = {{Too sick to migrate? Immune function and partial migration in Roach}},
year = {{2019}},
}