Volumen 44 - Número 3: 539-549 | 2009
Article

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Employment of morphometric variables to assess nutritional condition of Argentine anchovy larvae Engraulis anchoita Hubbs & Marini, 1935

Marina V. Diaz1,2*, Marcelo Pájaro2 and Ramiro P. Sánchez2

1Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rivadavia 1917, C1033A AV, Ciudad Autónoma de Buenos Aires, Argentina
2Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Paseo Victoria Ocampo N° 1 Escollera Norte, B7602HSA, Mar del Plata, Argentina

*This email address is being protected from spambots. You need JavaScript enabled to view it.

Most important causes of larval mortality are predation and starvation. The latter can be assessed by the measurement of the nutritional condition. The objective of the present study was to evaluate the nutritional condition of E. anchoita larvae employing morphometric techniques in three different hydrographic areas of the Argentine sea in order to establish regional and interpopulation variability: El Rincón coastal area, Outer-shelf and Península Valdés tidal front. Sampled larvae from El Rincón coastal area showed a higher growth rate (growth curve slope= 3.575) but had lower weight, and thus low Fulton (15.71 ± 3.58, n= 41) and Le Cren (0.63 ± 0.13, n= 41) condition indices, in comparison to specimens from the other two areas (P < 0.001). The Principal Component Analysis, employing morphometrical variables and weight, separated larvae from El Rincón from larvae captured in the other areas. These results could be explained as a consequence of an increase in density dependent mortality or food competition in El Rincón due to a year with an exceptional high larvae production. Our results showed that the use of morphometrical variables and weight allow to find differences in growth rate and nutritional condition among anchovy larvae collected in areas characterized by dissimilar oceanographic scenarios.

Key words: Engraulidae, southwest Atlantic Ocean, morphometrics, Principal Component Analysis

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1Laboratorio de Zooplancton, Instituto de Ciencias del Mar y Limnología,Universidad Nacional Autónoma de México. A. P. 70-305, 04510 México, D. F. México