Feeding habits of Engraulis anchoita en las aguas costeras de la provincia de Buenos Aires, Argentina

• Published in: Latin american journal of aquatic research Vol. 39; no. 1; p. 16
• Main Authors: Sato, Natalia E, Hernandez, Daniel, Vinas, Maria D
• Format: Journal Article
• Language: Spanish
• Published: Pontificia Universidad Catolica de Valparaiso, Escuela de Ciencias del Mar 01.03.2011
• Subjects: Fishes
• ISSN: 0718-560X; 0718-560X
• DOI: 10.3856/vol39-issue1-fulltext-2

The diet of Engraulis anchoita larvae (Hubbs & Marini, 1935) was analyzed using samples collected once a month at a permanent coastal station off Buenos Aires Province, Argentina (Station EPEA), from March 2000 to April 2001. A total of 869 individuals were examined. Eggs (54.05%), copepod nauplii (10.13%), and copepodites (11.82%) were the dominant prey items. The feeding index varied from 1.69 to 40.48%, without showing a clear seasonal pattern. Correlations between predator size and prey size were determined and the results showed significant relationships (P < 0.01) in all cases. In spring and summer, the larvae were small in size, corresponding to first-feeding larvae (< 6.9 mm length) and preyed mainly on small organisms from < 45 to 134 width. In autumn and winter, the size of the larvae increased (7.0-19.9 mm length), and they fed mainly on larger prey, from 135 to 279 width. Keywords: Engraulis anchoita, fish larvae, diet, seasonal variation, southwestern Atlantic, Argentina. Se analizo la dieta de las larvas de Engraulis anchoita (Hubbs & Marini, 1935) a partir de muestras colectadas, una vez al mes, en una estacion costera permanente de la Provincia de Buenos Aires, Argentina (Estacion EPEA) durante el periodo marzo 2000-abril 2001. Se examino un total de 869 individuos. Los huevos (54,05%), nauplios de copepodos (10,13%) y copepoditos (11,82%) constituyeron las presas dominantes. El indice alimentario vario entre 1,69 y 40,48%, sin mostrar un claro patron estacional. Las relaciones entre el tamano del depredador y el tamano de la presa fueron determinadas y en todos los casos, los resultados mostraron correlaciones significativas (P < 0,01). Las larvas en primavera y verano, presentaron tallas pequenas, correspondientes a larvas de primera alimentacion (< 6,9 mm de largo) y consumieron principalmente organismos menores de 45 a 134 [micron]m de ancho. Las larvas mostraron un aumento en la talla (7,0-19,9 mm de largo), y consumieron mayormente presas grandes entre 135 y 279 [micron]m de ancho, en otono e invierno. Palabras clave: Engraulis anchoita, larvas de peces, dieta, variacion estacional, Atlantico sudoccidental, Argentina.