A NEW SPECIES OF AMPELISCA (CRUSTACEA: AMPHIPODA) FROM EASTERN NORTH AMERICA, WITH NOTES ON OTHER SPECIES OF THE GENUS

Abstract

Ampelisca vadorum is described from eastern North American coastal waters. It has been confused since 1903 with the European Ampelsca spinipes Boeck, but differs considerably in morphology and ecology. A. spinipes is redescribed and figured. A deep-water record of A. spinipes from Cabot Strait refers to A. spinimana Chevreux. "Intersexes" in A. vadorum are really subadult males. Two generations per year occur north of Cape Hatteras. A small undescribed sibling species occurs in the same areas. Ten other western Atlantic Ampelisca species are discussed briefly, and a key is given to all species of the area.