Calanus, like many other animals undergo a dormant period called diapause during their juvenile development, diapause is spoken about alot within the research area of DIAPOD so hopefully this will explain a few things.
Compared to other animals, copepods diapause at great depths within the ocean basin. As they develop they accumulate lipid energy stores, in the image above the more red the copepod has is representing how much lipid reserves the individual has. As you can see from summer to winter then back to summer the lipid reserve is large as it decends into diapause.
Some of the copepods will then continue to develop to adulthood and become reproductively active. During periods of low food availability, other individual copepods will migrate to deep water, slow their metabolism and remain dormant for several months. On exit of diapause, they swim to the surface, develop to adults and mate.
DIAPOD is researching how to a understand and predict the timing of diapause entry and exit and the ‘parking’ depth of the three calanoid species.
Saz Reed (SAMS)