Calanus finmarchicus

Calanus finmarchicus is a species of copepods and a part of zooplankton, which is found in enormous amounts in the northern Atlantic Ocean. Calanus finmarchicus is most commonly found in the North Sea and the Norwegian Sea. It is also found throughout the colder waters of the North Atlantic, especially off the coast of Canada, in the Gulf of Maine, and all the way up to western and northern Svalbard. Calanus finmarchicus is one of the most commonly found species of zooplankton in the subarctic waters of the North Atlantic. Sometimes confused with C. helgolandicus and C. glacialis, C. finmarchicus is a large planktonic copepod whose chief diet includes diatoms, dinoflagellates, and other microplanktonic organisms. In fact, some studies have shown that heterotrophic microplankton provide a 'prey resource sufficient for net lipid synthesis as well as egg production'. C. finmarchicus is a key component in the food web of the North Atlantic, providing sustenance for a variety of marine organisms including fish, shrimp, and whales. Although the organism prefers these types of habitats, it has demonstrated that it is capable of surviving a wide range of environmental conditions. In terms of depth, C. finmarchicus can be found living anywhere from the ocean surface down to about 4,000 metres (13,000 ft) deep. It can also live in waters as cold as −2 °C (28 °F) and as warm as 22 °C (72 °F). Other environmental conditions and their ranges include salinity (18–36 pps), oxygen (1–9 mL/L), nitrate (0–45 μmol/L), phosphate (0–3 μmol/L) and silicate (1–181 μmol/L) levels. Calanus finmarchicus primarily feeds on different forms of phytoplankton. This includes diatoms, dinoflagellates, ciliates, and other photosynthetic marine organisms. Some scientific evidence suggests that copepods like C. finmarchicus are feeding on microzooplankton as well. Mesozooplankton are among the most important components of their regional food web. Several species of harvestable fish, including cod, herring and red fish (along with a plethora of other marine life) depend on C. finmarchicus for some form of nourishment. Scientists working in Canada estimate that 90%–100% of larval redfish prey on Calanus eggs in the Gulf of the St. Lawrence. Calanus finmarchicus is especially important ecologically because it shows rapid responses to climate variability, including shifts in species' distribution and abundance, timing of life history events, and trophic relationships. Calanus finmarchicus is considered to be a large copepod, being typically 2–4 millimetres (0.08–0.16 in) long. Copepods like C. finmarchicus represent a major part of dry weight (biomass) mesozooplankton in pelagic ecosystems. Calanus finmarchicus is high in protein and polyunsaturated omega-3 fatty acids.