Calanus propinquus Brady 1883 articles

Calanus propinquus

provided by wikipedia EN

Calanus propinquus is a copepod found in Antarctica, and the surrounding waters.

Description

The female averages about 5.3 millimetres (0.21 in) in length, whereas the male has an average of about 5.1 millimetres (0.20 in). The female usually ranges between around 4.8 and 6.0 millimetres (0.19 and 0.24 in), and the male ranges from about 4.8 to 5.3 millimetres (0.19 to 0.21 in).^[1]

Distribution

C. propinquus is found off Antarctica, southern Africa, and southern South America.^[1]

Ecology

Life cycle and reproduction

Reproduction occurs from October^[2] to March.^[3] In February, the population of C. propinquus greatly increases.^[4] During this time, the population is mostly concentrated in the top 150 metres (490 ft) of the sea. The next month, the population shifts, with stages I through III found from sea level to 25 metres (82 ft) in depth. The females, on the other hand, are usually found deeper than 500 metres (1,600 ft).^[3] In the Southern Hemisphere autumn, some stage III through V copepodites migrate to overwinter below depths of 200 metres (660 ft) (probably in diapause). Most of these copepodites, however, stay at the surface, overwintering in an active state.^[5] During October and November, most of the population is found between 100 and 500 metres (330 and 1,640 ft) of depth.^[4]

The lipid 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.^[6] It has the highest lipid content during the autumn, and the lowest during the spring. These stores decrease as its gonads develop.^[2] Most of the accumulated lipids are triglycerides, contrasting with other calanoid copepods that primarily use wax esters.^[6] This is partially achieved through the elongation of 11-Eicosenoic acid into erucic acid, which serves to concentrate the energy found.^[7] C. propinquue primarily uses triglycerides likely because most individuals are active during winter.^[5] 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.^[6]

References

^ ^a ^b Razouls C.; de Bovée F.; Kouwenberg J.; Desreumaux N. (2018). "Diversity and Geographic Distribution of Marine Planktonic Copepods". Sorbonne Université, CNRS. Retrieved 6 July 2018.
^ ^a ^b Hagen, Wilhelm; Schnack-Schiel, Sigrid B. (1996). "Seasonal lipid dynamics in dominant Antarctic copepods: Energy for overwintering or reproduction?". Deep Sea Research Part I: Oceanographic Research Papers. 43 (2): 139–158. Bibcode:1996DSRI...43..139H. doi:10.1016/0967-0637(96)00001-5. ISSN 0967-0637.
^ ^a ^b Kosobokova, K. N. (1994). "Reproduction of the calanoid copepod Calanus propinquus in the southern Weddell Sea, Antarctica: Observations in laboratory". Reproduction of the calanoid copepod Calanus propinquus in the southern Weddell Sea, Antarctica: observations in laboratory. pp. 219–227. doi:10.1007/978-94-017-1347-4_29. ISBN 978-90-481-4490-7.
^ ^a ^b Schnack-Schiel, SB; Hagen, W; Mizdalski, E (1991). "Seasonal comparison of Calanoides acutus and Calanus propinquus (Copepoda: Calanoida) in the southeastern Weddell Sea, Antarctica". Marine Ecology Progress Series. 70: 17–27. Bibcode:1991MEPS...70...17S. doi:10.3354/meps070017. ISSN 0171-8630.
^ ^a ^b Bathmann, U.V.; Makarov, R.R.; Spiridonov, V.A.; Rohardt, G. (1993). "Winter distribution and overwintering strategies of the Antarctic copepod species Calanoides acutus, Rhincalanus gigas and Calanus propinquus (Crustacea,Calanoida) in the Weddell Sea". Polar Biology. 13 (5). doi:10.1007/BF00238360. ISSN 0722-4060.
^ ^a ^b ^c Kattner, G.; Graeve, M.; Hagen, W. (1994). "Ontogenetic and seasonal changes in lipid and fatty acid/alcohol compositions of the dominant Antarctic copepods Calanus propinquus, Calanoides acutus and Rhincalanus gigas". Marine Biology. 118 (4): 637–644. doi:10.1007/BF00347511. ISSN 0025-3162.
^ Kattner, G.; Hagen, W. (1995). "Polar herbivorous copepods — different pathways in lipid biosynthesis". ICES Journal of Marine Science. 52 (3–4): 329–335. doi:10.1016/1054-3139(95)80048-4. ISSN 1054-3139.