Larval condition and growth of Sardinella brasiliensis (Steindachner, 1879): preliminary results from laboratory studies

Authors

  • Carmen Lúcia del Bianco Rossi-Wongtschow 1Instituto Oceanográfico da Universidade de São Paulo
  • Catriona Clemmesen Institut für Meereskunde an der Universität Kiel
  • Bernd Ueberschär Institut für Meereskunde an der Universität Kiel
  • June Ferraz Dias 1Instituto Oceanográfico da Universidade de São Paulo

DOI:

https://doi.org/10.3989/scimar.2003.67n113

Keywords:

Brazilian sardine larvae, larval condition and growth, RNA/DNA ratio, tryptic enzyme activity, otolith microstructure

Abstract


Brazilian sardine, the most important resource along the southeastern Brazilian coast, presented great variations and declines in its stocks. The main factors contributing to this are: oceanographic structure changes; recruitment failures; excessive catches of juveniles and increase in fishery effort. In spite of this, no alterations in the density-dependent parameters were detected. Consequently, methods analysing the condition of the larvae coupled with methods determining growth using sagittae otolith increment width were applied to evaluate growth under experimental conditions. The results of the readings on the sagittae were compared with the age of the laboratory-reared sardine larvae and confirmed that increments are formed on a daily basis. Under poor feeding conditions, sardine larvae showed a low growth expressed by dry weight, RNA/DNA ratio and tryptic enzyme activity and by the narrow and low contrast increments in the otoliths. The results of the biochemical indices showed an unexpected decline in the feeding group coupled with a decrease in width of increment numbers 8 and 10. Other factors than food availability were affecting the condition of the larvae and might be indicative of physiological processes and ontogenetic changes occurring in sardine larvae.

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Published

2003-03-30

How to Cite

1.
del Bianco Rossi-Wongtschow CL, Clemmesen C, Ueberschär B, Ferraz Dias J. Larval condition and growth of Sardinella brasiliensis (Steindachner, 1879): preliminary results from laboratory studies. scimar [Internet]. 2003Mar.30 [cited 2022Oct.4];67(1):13-2. Available from: https://scientiamarina.revistas.csic.es/index.php/scientiamarina/article/view/449

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Articles