Semiannual-life-cycle
Guides
Calliopius laeviusculus
Planktonic Amphipod
Calliopius laeviusculus is a marine amphipod crustacean distributed across the North Atlantic in both European and North American waters. The species exhibits a semiannual life cycle in southern parts of its range, with overwintering adults releasing young in spring and early summer. Population dynamics are tightly coupled to seasonal food availability, particularly capelin egg deposits. Multiple generations per year occur in warmer regions, while single-generation annual cycles prevail in colder northern waters.