Two types of dominant male cichlid fish: behavioral and hormonal characteristics
Male African cichlid fish, Astatotilapia burtoni, have been classified as dominant or subordinate, each with unique behavioral and endocrine profiles. Here we characterize two distinct subclasses of dominant males based on types of aggressive behavior: (1) males that display escalating levels of agg...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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The Company of Biologists
2016-08-01
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| Series: | Biology Open |
| Subjects: | |
| Online Access: | http://bio.biologists.org/content/5/8/1061 |
| _version_ | 1818436258100150272 |
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| author | Rosa M. Alcazar Lisa Becker Austin T. Hilliard Kai R. Kent Russell D. Fernald |
| author_facet | Rosa M. Alcazar Lisa Becker Austin T. Hilliard Kai R. Kent Russell D. Fernald |
| author_sort | Rosa M. Alcazar |
| collection | DOAJ |
| description | Male African cichlid fish, Astatotilapia burtoni, have been classified as dominant or subordinate, each with unique behavioral and endocrine profiles. Here we characterize two distinct subclasses of dominant males based on types of aggressive behavior: (1) males that display escalating levels of aggression and court females while they establish a territory, and (2) males that display a stable level of aggression and delay courting females until they have established a territory. To profile differences in their approach to a challenge, we used an intruder assay. In every case, there was a male-male confrontation between the resident dominant male and the intruder, with the intruder quickly taking a subordinate role. However, we found that dominant males with escalating aggression spent measurably more time attacking subordinates than did dominant males with stable aggression that instead increased their attention toward the females in their tank. There was no difference in the behavior of intruders exposed to either type of dominant male, suggesting that escalating aggression is an intrinsic characteristic of some dominant males and is not elicited by the behavior of their challengers. Male behavior during the first 15 min of establishing a territory predicts their aggressive class. These two types of dominant males also showed distinctive physiological characteristics. After the intruder assay, males with escalating aggression had elevated levels of 11-ketotestosterone (11-KT), testosterone, estradiol, and cortisol, while those with stable aggression did not. These observations show that the same stimulus can elicit different behavioral and endocrine responses among A. burtoni dominant males that characterize them as either escalating or stable aggressive types. Our ability to identify which individuals within a population have escalating levels of aggressive responses versus those which have stable levels of aggressive responses when exposed to the same stimulus, offers a potentially powerful model for investigating the underlying molecular mechanisms that modulate aggressive behavior. |
| first_indexed | 2024-12-14T17:05:55Z |
| format | Article |
| id | doaj.art-1688e053bc7b4cc0a79d264ee969927e |
| institution | Directory Open Access Journal |
| issn | 2046-6390 |
| language | English |
| last_indexed | 2024-12-14T17:05:55Z |
| publishDate | 2016-08-01 |
| publisher | The Company of Biologists |
| record_format | Article |
| series | Biology Open |
| spelling | doaj.art-1688e053bc7b4cc0a79d264ee969927e2022-12-21T22:53:43ZengThe Company of BiologistsBiology Open2046-63902016-08-01581061107110.1242/bio.017640017640Two types of dominant male cichlid fish: behavioral and hormonal characteristicsRosa M. Alcazar0Lisa Becker1Austin T. Hilliard2Kai R. Kent3Russell D. Fernald4 Biology Department and Neuroscience Institute, Stanford University, Stanford, CA 94305, USA Biology Department and Neuroscience Institute, Stanford University, Stanford, CA 94305, USA Biology Department and Neuroscience Institute, Stanford University, Stanford, CA 94305, USA Biology Department and Neuroscience Institute, Stanford University, Stanford, CA 94305, USA Biology Department and Neuroscience Institute, Stanford University, Stanford, CA 94305, USA Male African cichlid fish, Astatotilapia burtoni, have been classified as dominant or subordinate, each with unique behavioral and endocrine profiles. Here we characterize two distinct subclasses of dominant males based on types of aggressive behavior: (1) males that display escalating levels of aggression and court females while they establish a territory, and (2) males that display a stable level of aggression and delay courting females until they have established a territory. To profile differences in their approach to a challenge, we used an intruder assay. In every case, there was a male-male confrontation between the resident dominant male and the intruder, with the intruder quickly taking a subordinate role. However, we found that dominant males with escalating aggression spent measurably more time attacking subordinates than did dominant males with stable aggression that instead increased their attention toward the females in their tank. There was no difference in the behavior of intruders exposed to either type of dominant male, suggesting that escalating aggression is an intrinsic characteristic of some dominant males and is not elicited by the behavior of their challengers. Male behavior during the first 15 min of establishing a territory predicts their aggressive class. These two types of dominant males also showed distinctive physiological characteristics. After the intruder assay, males with escalating aggression had elevated levels of 11-ketotestosterone (11-KT), testosterone, estradiol, and cortisol, while those with stable aggression did not. These observations show that the same stimulus can elicit different behavioral and endocrine responses among A. burtoni dominant males that characterize them as either escalating or stable aggressive types. Our ability to identify which individuals within a population have escalating levels of aggressive responses versus those which have stable levels of aggressive responses when exposed to the same stimulus, offers a potentially powerful model for investigating the underlying molecular mechanisms that modulate aggressive behavior.http://bio.biologists.org/content/5/8/1061CichlidsBehaviorAggressionStressEndocrine responsesHPI/A axis |
| spellingShingle | Rosa M. Alcazar Lisa Becker Austin T. Hilliard Kai R. Kent Russell D. Fernald Two types of dominant male cichlid fish: behavioral and hormonal characteristics Biology Open Cichlids Behavior Aggression Stress Endocrine responses HPI/A axis |
| title | Two types of dominant male cichlid fish: behavioral and hormonal characteristics |
| title_full | Two types of dominant male cichlid fish: behavioral and hormonal characteristics |
| title_fullStr | Two types of dominant male cichlid fish: behavioral and hormonal characteristics |
| title_full_unstemmed | Two types of dominant male cichlid fish: behavioral and hormonal characteristics |
| title_short | Two types of dominant male cichlid fish: behavioral and hormonal characteristics |
| title_sort | two types of dominant male cichlid fish behavioral and hormonal characteristics |
| topic | Cichlids Behavior Aggression Stress Endocrine responses HPI/A axis |
| url | http://bio.biologists.org/content/5/8/1061 |
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