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

Rossi-Wongtschowski, C. L., Clemmesen, Catriona, Ueberschär, Bernd and Ferraz-Dias, J. F. (2003) Larval condition and growth of Sardinella brasiliensis (Steindachner, 1879): preliminary results from laboratory studies Scientia Marina, 67 . pp. 13-23.

[img]
Preview
Text
sm67n1013.pdf - Published Version

Download (255Kb)

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.

Document Type: Article
Keywords: Ichthyology; Brazilian sardine larvae, larval condition and growth, RNA/DNA ratio, tryptic enzyme activity, otolith microstructure.
Research affiliation: OceanRep > GEOMAR > FB3 Marine Ecology > FB3-EV Evolutionary Ecology of Marine Fishes
Refereed: Yes
ISSN: 0214-8358
Date Deposited: 17 Nov 2009 12:24
Last Modified: 08 Sep 2016 07:20
URI: http://eprints.uni-kiel.de/id/eprint/5548

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...