INTERSEXUALITY IN BENTHIC HARPACTICOID COPEPODS IN THE FIRTH OF FORTH, SCOTLAND

Following the discovery of a high frequency of intersexuality in Param phiascella hyperborea in the vicinity of Edinburgh's long-sea sewage o utfall, the seabed off the Edinburgh coast was surveyed in spring and autumn to examine the distribution of intersexuality in relation to th e sewage outfall. From these and previously collected samples it was f ound that intersexuality was common in both P. hyperborea and Stenheli a gibba and also present in two species of Halectinosoma. Intersexuali ty was widespread along the Edinburgh coastline, being recorded up to 10 km from the discharge but there was no evidence for a correlation b etween intersex frequency and proximity to the discharge. Possible rea sons for the high level on intersexuality in the Firth of Forth are di scussed. Most intersexes displayed similar secondary sexual characters , with the sexually dimorphic prosome appendages taking the female for m, the 5th leg intermediate between male and female and the 6th leg an d urosome segmentation male in character.