Analisis espacio-temporal del estado nutricional de larvas de anchoita Engraulis anchoita [recurso electronico] : relacion con las caracteristicas hidrograficas y la disponibilidad de alimento = Spatio-temporal analysis on nutritional condition of Engraulis anchoita larvae: its relation with hydrographical features of nursery grounds and food availability / Marina Vera Diaz ; director, Gustavo Macchi, Marcelo Pajaro.

Format:

Book

Thesis/Dissertation

Author/Creator:

Diaz, Marina Vera.

Contributor:

Macchi, Gustavo, dir.

Marcelo, Pajaro, dir.

Language:

Spanish

Subjects (All):

Biologia.

Inmunologia.

Biology.

Immunology.

Local Subjects:

Biologia.

Inmunologia.

Biology.

Immunology.

Physical Description:

272 p.

Other Title:

Spatio-temporal analysis on nutritional condition of Engraulis anchoita larvae : its relation with hydrographical features of nursery grounds and food availability

Place of Publication:

Buenos Aires, Argentina : Universidad de Buenos Aires, 2010.

Summary:

El estudio de la condicion nutricional de las larvas de peces permite evaluar individualmente el estado fisiologico de los ejemplares y detectar asi areas de cria favorables para la supervivencia y el crecimiento larval. En el presente trabajo se emplearon tecnicas morfometricas, histologicas y bioquimicas para determinar la condicion nutricional de larvas de anchoita, Engraulis anchoita, recolectadas en el mar. Los resultados obtenidos fueron complementados con los datos oceanograficos y las abundancias de diferentes componentes del plancton, tanto predadores como presas de las larvas de anchoita. Se ha observado que los factores que determinan la distribucion de las larvas de esta especie serian principalmente de naturaleza fisico-quimica. Si bien no se encontraron diferencias significativas entre areas, la condicion nutricional fue algo mejor en las zonas caracterizadas por aguas de mezcla dentro las estructuras frontales presentes en el area de estudio. Por otra parte, la condicion nutricional se veria favorecida durante las estaciones del ano en las que no se observan altas densidades larvales. Probablemente las condiciones sean propicias para el crecimiento larval durante todo el ano y las densidades bajas o intermedias de larvas de peces permitan a las larvas de anchoita evitar o reducir la competencia intra e interespecifica por el alimento. Por otra parte, muy pocas larvas presentaron valores bajos de condicion nutricional, esto podria indicar que E. anchoita encuentra durante todo el ano en la zona estudiada las condiciones ambientales adecuadas para su supervivencia y crecimiento larval.

Nutritional condition studies allow the assessment of physiological state of each larva and thus, the establishment of favourable nursery areas which provide better survival and growth. In the present work, morphometrical, histological and biochemical techniques were employed to assess nutritional condition of anchovy, Engraulis anchoita, larvae captured in the sea. Its results were complemented with oceanographic data and information about zooplankton abundances, both prey and predators of anchovy larvae. Anchovy larvae abundance and distribution would be mainly determined by physico-chemical variables. Even though no significant differences were found in larval nutritional condition among the studied areas, larval condition was slightly better in frontal areas characterized by mixed water masses. On the other hand, anchovy larvae condition seems to be favoured during seasons when larval abundances remain low. Probably, ocean conditions are almost always favourable for larval growth and survival during the whole year, but low or intermediate larval densities allow avoiding both intra and inter-specific competition. As only a small number of anchovy larvae were described as in starving condition, it can be assumed that E. anchoita finds environmental conditions that favour its growth and survival. during all seasons in the studied area.

Notes:

Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales.

OCLC:

811371997