Publicação
Tetracycline tagging in embryos of two gobiesocid species, L. purpurea and L. lepadogaster
| Resumo: | For the past few years studies of larval dispersal have been gaining notoriety, partially due to the innovating technologies that facilitate these kinds of works. Larval dispersal is crucial in the understanding of population dynamics and connectivity, which have important implications in the design and maintenance of Marine Protected Areas (MPAs). The marking of calcified tissues with the antibiotic tetracycline is a frequently used methodology in scientific studies, and in the past decades it has been used to study population connectivity through larval dispersal. The main goal of this work was to validate the procedure for tetracycline tagging of the otoliths of embryos of two gobiesocid species found in the Portuguese coast: Lepadogaster purpurea and Lepadogaster lepadogaster. This meant determining what would be the minimum tetracycline concentration needed to mark the larvae’s otoliths with an immersion time of only 30 minutes, and to assess if these immersions had any effect on the larvae’s survival rates. For this purpose, eggs, in the pigmented-eye stage, were immersed for 30 minutes in different concentrated tetracycline solutions, in order to determine the appropriate concentration for successful marking of otoliths. In addition, the possible effects of tetracycline in larvae’s survival rates were also analyzed. Observation of otoliths of larvae of different ages, under a fluorescence microscope, showed a high percentage of autofluorescence, both in control and treatment samples, with no otoliths being considered as truly marked. Comparison of results from 30-minutes immersions and longer ones indicate that for this tagging technique, the immersion time also plays a key role, having the 2 and 15-hours immersions produced positively- tagged otoliths. However, after statistical analysis, no correlation between the different tetracycline treatments and the levels of mortality was found, indicating that this immersion in tetracycline solutions for a time period of 30 minutes had no effect on the larvae’s survival rates. |
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| Autores principais: | Rebelo, Ana Sofia Pires, 1986- |
| Assunto: | Larvas Otólitos Embriologia animal Pesca Biodiversidade Teses de mestrado - 2012 |
| Ano: | 2012 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | For the past few years studies of larval dispersal have been gaining notoriety, partially due to the innovating technologies that facilitate these kinds of works. Larval dispersal is crucial in the understanding of population dynamics and connectivity, which have important implications in the design and maintenance of Marine Protected Areas (MPAs). The marking of calcified tissues with the antibiotic tetracycline is a frequently used methodology in scientific studies, and in the past decades it has been used to study population connectivity through larval dispersal. The main goal of this work was to validate the procedure for tetracycline tagging of the otoliths of embryos of two gobiesocid species found in the Portuguese coast: Lepadogaster purpurea and Lepadogaster lepadogaster. This meant determining what would be the minimum tetracycline concentration needed to mark the larvae’s otoliths with an immersion time of only 30 minutes, and to assess if these immersions had any effect on the larvae’s survival rates. For this purpose, eggs, in the pigmented-eye stage, were immersed for 30 minutes in different concentrated tetracycline solutions, in order to determine the appropriate concentration for successful marking of otoliths. In addition, the possible effects of tetracycline in larvae’s survival rates were also analyzed. Observation of otoliths of larvae of different ages, under a fluorescence microscope, showed a high percentage of autofluorescence, both in control and treatment samples, with no otoliths being considered as truly marked. Comparison of results from 30-minutes immersions and longer ones indicate that for this tagging technique, the immersion time also plays a key role, having the 2 and 15-hours immersions produced positively- tagged otoliths. However, after statistical analysis, no correlation between the different tetracycline treatments and the levels of mortality was found, indicating that this immersion in tetracycline solutions for a time period of 30 minutes had no effect on the larvae’s survival rates. |
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