Excretion of different forms of zinc by the prawn Palaemon serratus (Pennant)1

Freshly collected specimens of Palaemon serratus from the upper Adriatic Sea were used to determine excretion rates of zinc in “zinc‐free” water by anodic stripping polarographic techniques. Weight‐specific excretion of total zinc varied reciprocally with body weight, apparently in a log‐log relationship. Weight‐specific excretion of ionic‐particulate zinc appeared greatest in short term (1–3 hr) experiments, while weight‐specific excretion of complexed zinc appeared greatest in longer term (4–5 hr) experiments; however, we cannot exclude the possibility that ionic‐particulate zinc and dissolved organic compounds were excreted separately and subsequently combined in the water to yield zinc complex.