''Calanus propinquus'' is a

copepod Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat. Some species are planktonic (inhabiting sea waters), some are benthic (living on the ocean floor), a number of species have p ...

found in Antarctica, and the surrounding waters.

Description

The female averages about in length, whereas the male has an average of about . The female usually ranges between around , and the male ranges from about .

Distribution

''C. propinquus'' is found off Antarctica, southern Africa, and southern South America.

Ecology

Life cycle and reproduction

Reproduction occurs from October to March. In February, the population of ''C. propinquus'' greatly increases. During this time, the population is mostly concentrated in the top of the sea. The next month, the population shifts, with stages I through III found from sea level to in depth. The females, on the other hand, are usually found deeper than . In the Southern Hemisphere autumn, some stage III through V copepodites migrate to overwinter below depths of (probably in diapause). Most of these copepodites, however, stay at the surface, overwintering in an active state. During October and November, most of the population is found between of depth. The

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids incl ...

content of this species changes throughout its lifecycle. The highest concentration of lipids are found in adults, with lipids making up about 40%, on average, of the dry weight of females during the summer. It has the highest lipid content during the autumn, and the lowest during the spring. These stores decrease as its gonads develop. Most of the accumulated lipids are

triglyceride A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and '' glyceride''). Triglycerides are the main constituents of body fat in humans and other vertebrates, as ...

s, contrasting with other calanoid copepods that primarily use

wax ester A wax ester (WE) is an ester of a fatty acid and a fatty alcohol. Wax esters comprise the main components of three commercially important waxes: carnauba wax, candelilla wax, and beeswax.. Wax esters are formed by combining one fatty acid with ...

s. This is partially achieved through the elongation of 11-Eicosenoic acid into

erucic acid Erucic acid is a monounsaturated omega-9 fatty acid, denoted 22:1ω9. It has the chemical formula CH3(CH2)7CH=CH(CH2)11COOH. It is prevalent in wallflower seed and other plants in the family Brassicaceae, with a reported content of 20 to 54% in ...

, which serves to concentrate the energy found. ''C. propinquue'' primarily uses triglycerides likely because most individuals are active during winter. The percentage of lipids that are triglycerides increases as the copepod ages; about 42% of the lipids in stage II copepodites are triglycerides, whereas in females, this increases to about 91% of the total lipid content.

References

{{Taxonbar, from=Q6553171 Calanoida Crustaceans described in 1883