Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater
Juvenile freshwater dourados (Salminus brasiliensis Cuvier) were stocked in two batches of different size (61 and 133 individuals) with a time lag of 41 days in the headwaters of the Sinos River. A subsample of 25 fish was radio-tagged. Released juveniles displayed a density dependent dispersal patt...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Ictiologia
2012-01-01
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| Series: | Neotropical Ichthyology |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000200016 |
| _version_ | 1819207967756517376 |
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| author | Uwe Horst Schulz Mateus Evangelista Leal |
| author_facet | Uwe Horst Schulz Mateus Evangelista Leal |
| author_sort | Uwe Horst Schulz |
| collection | DOAJ |
| description | Juvenile freshwater dourados (Salminus brasiliensis Cuvier) were stocked in two batches of different size (61 and 133 individuals) with a time lag of 41 days in the headwaters of the Sinos River. A subsample of 25 fish was radio-tagged. Released juveniles displayed a density dependent dispersal pattern. During the first ten days mean covered distance of tagged batch 1 individuals (low density) was approximately 24 m d-1, while batch 2 individuals (high density) moved 296 m d-1. Activity of batch 1 fish increased after the release of batch 2 and remained high (459 m d-1) until 90 days. Activity of batch 2 fish during this period was in same range. After this period, activity levels of both batches decreased to about 60 m d-1. Increased movements in higher density condition are seen as a result of interspecific competition. The mean covered distances per day remained high until stocked individuals become established in their new habitat.<br>Dois lotes de 61 e 133 dourados (Salminus brasiliensis Cuvier) juvenis foram introduzidos nas cabeceiras do rio dos Sinos. O intervalo entre as solturas foi de 41 dias. Uma subamostra de 25 peixes foi marcada com radiotransmissores. A dispersão dos indivíduos após soltura mostrou um padrão dependente da densidade. Durante os primeiros dez dias a distância média dos indivíduos do lote 1 (densidade baixa) foi de 24 m d-1, enquanto os indivíduos do lote 2 (densidade alta) percorreram em média 296 m d-1. A atividade dos peixes do lote 1 aumentou depois da soltura do lote 2 e permaneceu alta (459 m d-1) durante 90 dias. A atividade dos indivíduos do lote 2 ficou no mesmo nível durante este período. Depois os movimentos de ambos os lotes diminuíram até uma média de 60 m d-1. O nível alto de movimentos na situação de maior densidade é visto como resultado da competição intraespecífica. As médias das distâncias percorridas por dia permanecem altas até os indivíduos introduzidos estabelecerem-se nos seus habitats novos. |
| first_indexed | 2024-12-23T05:31:55Z |
| format | Article |
| id | doaj.art-105de80841ec410dbe9e9f8832fef2a3 |
| institution | Directory Open Access Journal |
| issn | 1679-6225 1982-0224 |
| language | English |
| last_indexed | 2024-12-23T05:31:55Z |
| publishDate | 2012-01-01 |
| publisher | Sociedade Brasileira de Ictiologia |
| record_format | Article |
| series | Neotropical Ichthyology |
| spelling | doaj.art-105de80841ec410dbe9e9f8832fef2a32022-12-21T17:58:27ZengSociedade Brasileira de IctiologiaNeotropical Ichthyology1679-62251982-02242012-01-01102409415Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwaterUwe Horst SchulzMateus Evangelista LealJuvenile freshwater dourados (Salminus brasiliensis Cuvier) were stocked in two batches of different size (61 and 133 individuals) with a time lag of 41 days in the headwaters of the Sinos River. A subsample of 25 fish was radio-tagged. Released juveniles displayed a density dependent dispersal pattern. During the first ten days mean covered distance of tagged batch 1 individuals (low density) was approximately 24 m d-1, while batch 2 individuals (high density) moved 296 m d-1. Activity of batch 1 fish increased after the release of batch 2 and remained high (459 m d-1) until 90 days. Activity of batch 2 fish during this period was in same range. After this period, activity levels of both batches decreased to about 60 m d-1. Increased movements in higher density condition are seen as a result of interspecific competition. The mean covered distances per day remained high until stocked individuals become established in their new habitat.<br>Dois lotes de 61 e 133 dourados (Salminus brasiliensis Cuvier) juvenis foram introduzidos nas cabeceiras do rio dos Sinos. O intervalo entre as solturas foi de 41 dias. Uma subamostra de 25 peixes foi marcada com radiotransmissores. A dispersão dos indivíduos após soltura mostrou um padrão dependente da densidade. Durante os primeiros dez dias a distância média dos indivíduos do lote 1 (densidade baixa) foi de 24 m d-1, enquanto os indivíduos do lote 2 (densidade alta) percorreram em média 296 m d-1. A atividade dos peixes do lote 1 aumentou depois da soltura do lote 2 e permaneceu alta (459 m d-1) durante 90 dias. A atividade dos indivíduos do lote 2 ficou no mesmo nível durante este período. Depois os movimentos de ambos os lotes diminuíram até uma média de 60 m d-1. O nível alto de movimentos na situação de maior densidade é visto como resultado da competição intraespecífica. As médias das distâncias percorridas por dia permanecem altas até os indivíduos introduzidos estabelecerem-se nos seus habitats novos.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000200016Density dependenceDispersalIntraspecific competitionMovements |
| spellingShingle | Uwe Horst Schulz Mateus Evangelista Leal Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater Neotropical Ichthyology Density dependence Dispersal Intraspecific competition Movements |
| title | Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater |
| title_full | Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater |
| title_fullStr | Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater |
| title_full_unstemmed | Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater |
| title_short | Effects of stocking density on dispersal behavior of Brazilian freshwater dourado (Salminus brasiliensis) in a subtropical river headwater |
| title_sort | effects of stocking density on dispersal behavior of brazilian freshwater dourado salminus brasiliensis in a subtropical river headwater |
| topic | Density dependence Dispersal Intraspecific competition Movements |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252012000200016 |
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