Estrategias para el control microbiano durante el desarrollo embrionario y larvario de la cabrilla arenera, Paralabrax maculatofasciatus (Steindachner, 1868)
The spotted sand bass have been used in México as a model for the study and development of aquaculture procedures. As occurs in most marine fish, a factor that affects the mass production is the high mortality during the early development. The specific causes of this mortality remains unknown, howev...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:cf95jb648 |
| Acceso en línea: | https://doi.org/10.24275/uami.cf95jb648 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Fishes -- Diseases info:eu-repo/classification/LEM/Fishes -- Microbiology info:eu-repo/classification/LEM/Peces -- Enfermedades info:eu-repo/classification/LEM/Peces -- Biología info:eu-repo/classification/LEM/Fishes -- Biology info:eu-repo/classification/LEM/Peces -- Microbiología info:eu-repo/classification/cti/6 |
| Sumario: | The spotted sand bass have been used in México as a model for the study and development of aquaculture procedures. As occurs in most marine fish, a factor that affects the mass production is the high mortality during the early development. The specific causes of this mortality remains unknown, however, has been suggested that are produced by the low tolerance at manipulation, the inadequate nutritional quality of the given feeds and the introduction of pathogenic bacteria into the cultures through the foods and water. In this thesis, it was analyzed the microbial component as a cause of larval mortality and were developed procedures for their control. The establishment of the microbiota was analyzed during the larval development of the spotted sand bass, discriminating between the internal and external bacteria and analyzing their potential origins. Vibrio alginolyticus, V. campbelli, V. carchariae (sinon. harveyi), V. mediterranei, V. metschnikovii, V. parahaemolyticus, V. proteolyticus, Aeromonas allosacharophila, A. hydrophila, A. media and A. veronii were isolated as microbiota of spotted sand bass larvae and from the live feeds provided during this stage. It was found that the acquisition of the microbiota in the spotted sand bass larvae occurs during the first feeding, also, that the rotifers and Artemia are the vectors of potentially pathogenic bacteria. In order to evaluate the role of the isolated bacteria, challenge test was implemented under bacteria free conditions. Under these conditions we found that some bacteria, commonly considered pathogenic for fish larvae, do not affect the rotifer cultures and can promote their growth when are used as a sole source of food. By contrast, Aeromonas media, Aeromonas sp and Vibrio carchariae (sinon. harveyi) are pathogenic for spotted sand bass larvae, increasing significantly the mortality. None of the tested bacteria improve the larval survival. Also, the strain C303 (V. carchariae) produces 100% mortality in less than 8 hours, when was inoculated by intraperitoneal injection in juvenile fish. In consequence, procedures were developed for their control. In first instance through the disinfection of embryos in order to reduce the vertical transmission of opportunistic pathogens. The best results were obtained with 7 min in H2O2 at 3%. With the disinfection of eggs we obtained an increase in the survival at hatching, which indicate a negative effect of the bacteria from the corion surface. The decontamination of rotifers was achieved in order to prevent the contamination by the trophic chain. The use of Trimetoprim Sulfametoxasole (Bactrim® Roche) in the amictic eggs, produces a bacteria free progenie. Also, we found that some strains of Tetraselmis have an antibacterial effect on several strains of Vibrio, including the strains isolated in this study. In consequence we evaluate the use of Tetraselmis spp as a biologic control during the rotifer production. We found a significant reduction in the number of vibrios of the rotifer microbiota during the cohabitation with Tetraselmis spp. Finally, the use of bacteria as a method of biologic control for the culture of larvae was analyzed. Some bacteria were isolated from diferent sources, and they were selected according to their probiotic potential. The selected bacteria have anti-Vibrio properties, however, when were evaluated during the larvae growth, no improvements on survival were observed. |
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