Figure: Seasonal distribution of Calanus finmarchicus (Planque et al., 1997)
A: NE Atlantic
B: Southern parts of NW Atlantic
C: Labrador Sea
Regional variation of abundance

q  Low abundance during winter. cV copepodites migrate to deeper water to constitute the overwintering stock.

q  Low levels of molecular genetic diversity; genetic bottleneck with 75% range reduction and latitudinal displacement in last glacial maximum (Bucklin and Wiebe, 1998).