Respiration rate of the shrimp Palaemon elegans: a methodological approach

Abstract

Mesopelagic decapods perform diel vertical migrations, transporting carbon to deep waters. Measurements of respiration rates are essential to understand their contribution to the biological carbon pump. However, collecting live specimens in deep waters for respiration estimates is difficult, making enzyme activity measurements the most widely method to assess the oxygen consumption. In the present study, we used the shrimp Palaemon elegans, Rathke, 1837 as a model species to compare the oxygen consumption and the enzyme activity of the electron transfer system (ETS), using the balance method to obtain respiration rates in incubation bottles. We also used a swimming tunnel in order to provide a first account of respiration under different activity levels. The classical incubations were performed from 1 to 6 hour, while the swimming tunnel allowed to measure respiration at different body lengths·s-1. We obtained average values of 2.53 ± 0.97 µL mg-1 DW h -1 using the balance method, and 10.44 ± 5.64 µL mg-1 DW h -1 using the swimming tunnel. ETS activity ranged between 17.56 and 338.50 µL O2·ind-1·h-1 and showed an average value of 10.00 ± 5.92 µLO2·mg-1 DW·h-1. Finally, the R/ETS ratio was 0.43 ± 0.42 which is in the range of values normally found in the literature.