Pseudocalanus minutus
Pseudocalanus minutus is a small copepod found in the Arctic Ocean and surrounding waters.
Description
A small copepod, the female is generally between, and the male typically between in length.
Distribution
Pseudocalanus minutus is found primarily in the Arctic, but it is also found in the northwest Atlantic, the northern Pacific, and more temperate waters where Atlantic and Arctic waters are mixed.
Ecology
In Toyama Bay, P. minutus reproduces from February to April, producing two generations. This is during the temperature minimum and phytoplankton maximum. All stages are found at shallower depths during the night in Toyama Bay during this time. During the annual temperature maximum in September, stage V copepodites migrate to deeper, colder waters to diapause. They moult to adults before January, rising to the surface to breed. In Kongsfjorden, P. minutus reproduces during May and June, producing one generation. It descends in autumn and winter to depths below as a stage III to stage V copepodite. Females and stage I copepodites are found throughout the water column during November. From June and July till May, younger stages tend to be found towards the surface, and older stages tend to migrate to overwinter earlier. It develops during the winter and reproduces with energy gained from the spring phytoplankton bloom, indicating a one year life cycle.
Feeding
Pseudocalanus minutus is opportunistic, being mainly herbivorous except during the winter, when it is either carnivorous or omnivorous.