Nutritional condition and otolith growth of Engraulis anchoita larvae: the comparison of two life traits indexes

DO SOUTO, MARINA; BROWN, DANIEL; LEONARDUZZI, EZEQUIEL; CAPITANIO, FABIANA; DIAZ, MARINA VERA

JOURNAL OF MARINE SYSTEMS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2019 vol. 193 p. 94 - 102

0924-7963

Engraulis anchoita larvae were captured in 16 surveys carried out at a fixed sampling station (EPEA) in the Argentinean Sea between 2008 and 2017. Nutritional condition and growth of 214 anchovy larvae were estimated through RNA/DNA index and analysis of otolith microstructure. Standard length, developmental stage, age, weight, otolith radius, recent otolith growth rate (RGR), RNA/DNA index (sRD) and a derived index of growth performance were determined for each larva. Significant differences in nutritional condition and otolith growth rates were found among seasons and developmental stages, with slower RGR and lower sRD in larvae captured during winter and in the preflexion stage. We observed that both otolith growth rate (RGR) and sRD showed a strong connection with seasonality and larval size. However, the amount of variability explained by ontogeny and seasonality was not equal in both indexes. We observed signs that spring would be the most propitious season for larval survival while winter would be the worst. The need to reveal seasonal and temporal patterns in the physical and biological variables of the ocean, in a context of climate change, makes this kind of studies necessary for the understanding and protection of the marine ecosystem.