(More than 722 specie in scandinavian waters)
Distribution in scandinavian waters
Maximum length: approx. 1,1 cm. Compare
with a hair.
Appearance: Copepods are in many instances transparent eller
semi-transparent with a yellow to red tone. However, certain specie
are light brown or have a distinct blue
green colour. Many of these creatures move with a characteristic
"hop" through the water. Under magnification it is possible to observe
a well developed nauplius
eye on the upper part of the copepods anterior. The copepods anterior
is built up of 6 relatively large ring segments, while the hind parts
are composed of 5 narrow segments. The last hind segment has two clear
outgrowths. Sometimes the different segments can grow into each other
and thereby the limits of each segment can became indistinct. It is
only the anterior of the body that has legs. The first pair of antennae
(antennulae) are long.
Depth: Sea-level and to aleast 4 000 m.
Environment: Pelagic, but certain specie find it congenial close
to or on the bottom.
Misc: Copepods eat most types of plankton: from single celled
organisms to other copepods. Many copepods are an important part of
the fishes diet. Development up to adulthood consists of 11 sloughings
of the exoskeleton. After each sloughing the copepod gets larger, aswell
as an increase in the number of the outgrowths on the hind. Several
generations can arise within the same year. Many copepods spend the
winter in deep water. During the summer the larger specie wander into
deep water during the day and into shallower at night. Many copepods
are parasites and have a particularly different appearance. Copepods
exist globally, even in freshwater.
Classification: Copepods are part of the crustacea group under
the arthropods. In the picture above a species of the group Calanus
© Aquascope 2000 Tjärnö Marine Biological
Laboratory, Strömstad, Sweden
| Martin Larsvik
Loo | Helena