Calanus finmarchicus (Gunnerus) stratify narrowly near 500 m depth during their fifth copepodite resting phase in North Atlantic Slope Water off southern New England, USA. They probably achieve this by migration to a specific, daytime isolume. Photoperiod information provided by light intensity at depth could serve as a cure for...
An attempt has been made to interbreed populations of Acartia clausi from Woods Hole, Massachusetts, and Yaquina Bay, Oregon. Individuals from these populations are morphologically similar, but differ somewhat in size. Cultures from both sources produced many successive generations in the laboratory, but interbreeding with production of viable offspring did...