VOLPEDO Alejandra Vanina
Seasonal and ontogenetic change in diet composition of wild new world silverside Odontesthes argentinensis in temperate coastal area (South America)
THOMPSON, GUSTAVO A.; BIOLÉ, FERNANDA; VOLPEDO, ALEJANDRA V.
ESTUARINE COASTAL AND SHELF SCIENCE
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Año: 2022 vol. 270 p. 1 - 12
The Southwestern Atlantic coast (32?38◦S) is one of the regions most affected by environmental changes (temperature, salinity, etc.), which can influence all life stages of fish species like de ones belong to the family Atherinopsidae (neotropical silversides). Considering that silverside species adapt easily to changing environments,we studied the diet composition and feeding strategy in relation with seasonal changes (intra- and interannual)and ontogenetic development of the silverside Odontesthes argentinensis. Stomach content of 416 specimenssampled between October 2015 and March 2017 (Partido de La Costa) and 68 specimens between July2017 and August 2018 (Samboromb´on Bay) were analyzed. Zooplankton samples were taken and seawaterenvironmental parameters were measured. The relative contribution of each prey was calculated and their evaluation by Amundsen graphical method, determined that importance of each prey, feeding strategy and nichewidth of O. argentinensis, changed not only among development stage but also among season and years. Results suggested that these variations were a reply to the complex environmental variation which affected the availabilityof food, so O. argentinensis could be used as regional indicator of environmental variations. The informationobtained in this study evidences the importance of knowing variations in feeding strategy to get a better growth rate during rearing in captivity.