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Sex Differences in Migration, Behavior, and Shape in Roach (Rutilus rutilus)

Ulusu, Ezgi (2013) BIOM20 20111
Degree Projects in Biology
Abstract
Abstract

Migration is a fascinating aspect of animal ecology that has been studied over thousands of years. There is a lot of variation in migratory behavior in nature, both between species and within species. The role of sex in explaining variation in migration within species has been well studied in some taxa, such as birds, but less well studied in fish. I studied sex differences in migration, behavior, and shape in roach (Rutilus rutilus). I found no sex differences in timing, the probability of migration, and the behavior. No correlations have been found between the behaviors. I found shape differences between males and females where males tend to have a shallower body shape. This difference in body shape potentially due to... (More)
Abstract

Migration is a fascinating aspect of animal ecology that has been studied over thousands of years. There is a lot of variation in migratory behavior in nature, both between species and within species. The role of sex in explaining variation in migration within species has been well studied in some taxa, such as birds, but less well studied in fish. I studied sex differences in migration, behavior, and shape in roach (Rutilus rutilus). I found no sex differences in timing, the probability of migration, and the behavior. No correlations have been found between the behaviors. I found shape differences between males and females where males tend to have a shallower body shape. This difference in body shape potentially due to different ecological requirements. This study highlights other factors apart from sex take part in the partial migration of roach. (Less)
Abstract
Popular science summary

To Migrate or Not to Migrate!

An interesting experiment to test how gender, personality traits, size, and condition affect migration in Roach (Rutilus rutilus).

Partial migration is a phenomena in which migration does not take place in every individual’s lifecycle. The reason for this type of migration has not yet been totally understood. However, there has been studies in order to figure out the features affecting the migration behaviour. Roach, a freshwater cyprinid fish, has a trade-off to take into account while migrating. Main predators of roach are pike Esox lucius and perch Perca fluviatilis which are high in amount in the Lake Krankesjön. Roach can choose to migrate towards the streams where there... (More)
Popular science summary

To Migrate or Not to Migrate!

An interesting experiment to test how gender, personality traits, size, and condition affect migration in Roach (Rutilus rutilus).

Partial migration is a phenomena in which migration does not take place in every individual’s lifecycle. The reason for this type of migration has not yet been totally understood. However, there has been studies in order to figure out the features affecting the migration behaviour. Roach, a freshwater cyprinid fish, has a trade-off to take into account while migrating. Main predators of roach are pike Esox lucius and perch Perca fluviatilis which are high in amount in the Lake Krankesjön. Roach can choose to migrate towards the streams where there are few predators. However, streams are not as rich as the lake when thought about the food source for the roach. When avoiding the predation risk by migrating towards the streams, zooplanktons and benthic macro-invertebrates are left behind at the same time. This is called “Predation Risk / Growth Rate” trade-off. Then migrate or not to migrate, that is the question.

In order to understand why different choices are made within the same species, when the subject is migration, a series of experiments were conducted on about 1700 fish which were caught from March 17 through April 14 of 2012. Caught fish were stunned by MS 222 solution which gave us the possibility of sexing the fish and inserting pit-tags in order to track their migration behaviour.

Pit tags allowed us to have data on the probability and timing of both female and male migration. No sex differences were found between migrants and residents. Moreover, the timing of migration found to have no correlation between sexes of the fish.

For behavioural trials, 70 fish were caught on April 20, 2012 and kept in 3 opaque containers. When they acclimatized to their new environment, two different trials were applied on each fish; boldness and activity. It is a challenging subject which we tried to shed light on to. However, it was found that more active fish is not the bolder one or vice versa.

Results have shown physiological and morphological differences between sexes. Females were found to be in a better body condition than males and also were larger and deeper bodied (see the pictures on the right). Since the examination was done through the spawning season, it is thought to be the reason for the female fish to have a wider and heavier body since the fish is full of eggs. In any case, the differences were found to have no correlation with the migration behavior.

Our study is one of the first studies that have been conducted in this subject. Even though our results show no differences in migration due to sex and behavior, the subject deserves future studies.


Advisors: Ben Chapman, Kaj Hulthén
Master´s Degree Project 30 credits in Limnology, 2013
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Ulusu, Ezgi
supervisor
organization
course
BIOM20 20111
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
4195122
date added to LUP
2013-12-12 16:07:51
date last changed
2013-12-12 16:07:51
@misc{4195122,
  abstract     = {Popular science summary

To Migrate or Not to Migrate!

An interesting experiment to test how gender, personality traits, size, and condition affect migration in Roach (Rutilus rutilus).

Partial migration is a phenomena in which migration does not take place in every individual’s lifecycle. The reason for this type of migration has not yet been totally understood. However, there has been studies in order to figure out the features affecting the migration behaviour. Roach, a freshwater cyprinid fish, has a trade-off to take into account while migrating. Main predators of roach are pike Esox lucius and perch Perca fluviatilis which are high in amount in the Lake Krankesjön. Roach can choose to migrate towards the streams where there are few predators. However, streams are not as rich as the lake when thought about the food source for the roach. When avoiding the predation risk by migrating towards the streams, zooplanktons and benthic macro-invertebrates are left behind at the same time. This is called “Predation Risk / Growth Rate” trade-off. Then migrate or not to migrate, that is the question. 

In order to understand why different choices are made within the same species, when the subject is migration, a series of experiments were conducted on about 1700 fish which were caught from March 17 through April 14 of 2012. Caught fish were stunned by MS 222 solution which gave us the possibility of sexing the fish and inserting pit-tags in order to track their migration behaviour.

Pit tags allowed us to have data on the probability and timing of both female and male migration. No sex differences were found between migrants and residents. Moreover, the timing of migration found to have no correlation between sexes of the fish.

For behavioural trials, 70 fish were caught on April 20, 2012 and kept in 3 opaque containers. When they acclimatized to their new environment, two different trials were applied on each fish; boldness and activity. It is a challenging subject which we tried to shed light on to. However, it was found that more active fish is not the bolder one or vice versa.

Results have shown physiological and morphological differences between sexes. Females were found to be in a better body condition than males and also were larger and deeper bodied (see the pictures on the right). Since the examination was done through the spawning season, it is thought to be the reason for the female fish to have a wider and heavier body since the fish is full of eggs. In any case, the differences were found to have no correlation with the migration behavior.

Our study is one of the first studies that have been conducted in this subject. Even though our results show no differences in migration due to sex and behavior, the subject deserves future studies. 


Advisors: Ben Chapman, Kaj Hulthén
Master´s Degree Project 30 credits in Limnology, 2013
Department of Biology, Lund University},
  author       = {Ulusu, Ezgi},
  language     = {eng},
  note         = {Student Paper},
  title        = {Sex Differences in Migration, Behavior, and Shape in Roach (Rutilus rutilus)},
  year         = {2013},
}