Carbon stable isotope (13C) natural abundance of some foods and its contribution to the pintado juvenile growth, Pseudoplatystoma corruscans (Agassiz, 1829) (Osteichthyes, Pimelodidae)

Abstract

The aim of this study is to determine the natural abundance of carbon stable isotope (¹³C) of some food components and determine its contribution to the pintado juvenile growth, in laboratory conditions. 150 fishes were used with average weight of 1.39 g, and stocked in two net ponds with 125L each, during 60 days. Every 10 days a water sample was collected to analyse phytoplakton and zooplankton. Clacocera was dominant in the analysis of the stomach contents, following Chironomidae and Copepoda. A fish sample was collected in the beginning, and at the end of the experiment to analyses the isotopic signal. An average value of -20.94; -15.36 and -18.81 δ ¹³C‰ was obtained for phytoplankton, Cladocera and Chironomidae, respectively. Cladocera was the main carbon source and contribution with carbon average 89.24% in feeding this species, while the Chironomid contribution was 10.76%. The δ ¹³C was effective as carbon tracer in food chain, because the consumer reflects its diet isotopicly.