Methodology
Samples
One thousand seven hundred thirty specimens of rockpool prawn1P. elegans, six of baltic prawn Palaemon adpersus and 24 of common prawn P. serratus were collected from six littoral sites (polluted and non-polluted) of Tenerife in the Canary Islands (Spain), during a 2-year period, every 2 months. The difference in the number of collected specimens is due to the high variability, regarding quantity and availability, in the population of the studied species. All specimens were collected in shallow water of harbours and coastal rockpools during low tide with a little net (2 mm mesh).