''Calanus marshallae'' is a species of
copepod
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor) ...
which forms part of the
zooplankton in the northern Atlantic Ocean and the northern Pacific Ocean.
Taxonomy
Several species of copepod in the genus ''
Calanus'' tend to dominate the
zooplankton of the northern oceans; ''
Calanus finmarchicus'' is the best known species, but historically there was little to distinguish it from other closely related species. Analysis in 1974 by the American marine biologist B.W. Frost of specimens gathered throughout the northern Atlantic and Pacific Oceans, and the Arctic Ocean, showed that there are three species present; ''C. finmarchicus'', ''
C. glacialis'' and a new species, ''C. marshallae''. Taxonomic markers were found through which these three species could be identified from each other in the field.
Distribution and habitat
In the northern Atlantic, ''Calanus marshallae'' has been recorded from
Spitsbergen
Spitsbergen (; formerly known as West Spitsbergen; Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipelago in northern Norw ...
,
Saint Lawrence Island
St. Lawrence Island ( ess, Sivuqaq, russian: Остров Святого Лаврентия, Ostrov Svyatogo Lavrentiya) is located west of mainland Alaska in the Bering Sea, just south of the Bering Strait. The village of Gambell, Alaska, Gambell ...
, the
Chukchi Sea
Chukchi Sea ( rus, Чуко́тское мо́ре, r=Chukotskoye more, p=tɕʊˈkotskəjə ˈmorʲɪ), sometimes referred to as the Chuuk Sea, Chukotsk Sea or the Sea of Chukotsk, is a marginal sea of the Arctic Ocean. It is bounded on the west b ...
, the
Bering Sea
The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...
, the coasts of
Greenland, the
Beaufort Sea
The Beaufort Sea (; french: Mer de Beaufort, Iñupiaq: ''Taġiuq'') is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, and west of Canada's Arctic islands. The sea is named after Sir Fr ...
,
Banks Island and the
Aleutian Islands. In the northern Pacific, it is known from the
Gulf of Alaska,
British Columbia and the coasts of
Washington and
Oregon. It is an open water species, and the
nauplius larvae occur at depths of . ''C. glacialis'' is mainly found on the shelf that surrounds the Arctic Ocean, ''C. finmarchicus'' mainly in the northern Atlantic Ocean and ''C. marshallae'' mainly in the Bering Sea and northern Pacific Ocean.
Ecology
Calanid copepods play a key role in the
food web in northern seas, providing a link between the photosynthetically active
primary producers and the commercially important fish which feed in these waters.
As they swim vertically, newly moulted females leave a
pheromone trail behind them in the water some tens of centimetres long. Males swim mainly horizontally and on encountering a trail they do a little wiggle dance before chasing and homing in on the female. Following the first contact, the female jerks away and the male follows. After several touch/jump sequences, mating occurs.
References
{{Taxonbar, from=Q6552031
Calanoida
Crustaceans of the Atlantic Ocean
Animals described in 1974