Rhincalanus nasutus

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Rhincalanus nasutus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Copepoda
Order: Calanoida
Family: Rhincalanidae
Genus: Rhincalanus
Species:
R. nasutus
Binomial name
Rhincalanus nasutus
Giesbrecht, 1888

Rhincalanus nasutus is a copepod in the family Rhincalanidae.

Taxonomy and phylogeny[edit]

Rhincalanus nasutus is a species complex, composed of at least two cryptic species: one species consisting of, at the very least, individuals off of Peru, in the Sulu Sea, and in the California Current, in addition to another species composed of specimens from the Kuroshio Current, the southwest Pacific, and the northern Atlantic. In its genus, it is sister to R. gigas.[1]

Description[edit]

The female of R. nasutus ranges anywhere from about 2.8 to 6.1 millimetres (0.11 to 0.24 in) in length, and the male is generally between about 2.7 and 4.5 millimetres (0.11 and 0.18 in).[2]

Distribution[edit]

Rhincalanus nasutus is found in waters across the globe,[2] primarily in the open ocean[3] and continental shelf and slope waters.[4]

Ecology[edit]

Life cycle and reproduction[edit]

Rhincalanus nasutus is seasonal in terms of the timing of reproduction. Off of the waters of southern California, it generally reproduces from February to April, and it also can reproduce in late summer, as late as June. This reproduction is likely to be limited by food, as evidenced by this copepod failing to breed in the absence of food.[5] Copepodite stages I through IV are usually found in the surface waters (from sea level to 200 metres (660 ft) in depth). The abundance of individuals in the surface, however, varies seasonally: they are most abundant during the spring, and are not present during summer and autumn. Stage V copepodites and adults are generally distributed below 200 metres (660 ft) in depth, and especially below 500 metres (1,600 ft).[6] In seasonal waters, such as the Gulf of Aqaba, stage V copepodites go into diapause to moult into females. During this time, they also rapidly accumulate wax esters, possibly for future reproduction.[3]

References[edit]

  1. ^ Goetze, E. (2003). "Cryptic speciation on the high seas; global phylogenetics of the copepod family Eucalanidae". Proceedings of the Royal Society B: Biological Sciences. 270 (1531): 2321–2331. doi:10.1098/rspb.2003.2505. ISSN 0962-8452. PMC 1691510. PMID 14667347.
  2. ^ a b Razouls C.; de Bovée F.; Kouwenberg J.; Desreumaux N. (2018). "Diversity and Geographic Distribution of Marine Planktonic Copepods". Sorbonne Université, CNRS. Retrieved 30 July 2018.
  3. ^ a b Schnack-Schiel, S. B.; Niehoff, B.; Hagen, W.; Böttger-Schnack, R.; Cornils, A.; Dowidar, M. M.; Pasternak, A.; Stambler, N.; Stübing, D.; Richter, C. (2008). "Population dynamics and life strategies of Rhincalanus nasutus (Copepoda) at the onset of the spring bloom in the Gulf of Aqaba (Red Sea)". Journal of Plankton Research. 30 (6): 655–672. doi:10.1093/plankt/fbn029. ISSN 0142-7873.
  4. ^ Castro, L.R.; Bernal, P.A.; Troncoso, V.A. (1993). "Coastal intrusion of copepods: mechanisms and consequences on the population biology of Rhincalanus nasutus". Journal of Plankton Research. 15 (5): 501–515. doi:10.1093/plankt/15.5.501. ISSN 0142-7873.
  5. ^ Mullin, Michael M. (1993). "Reproduction by the oceanic copepod Rhincalanus nasutus off southern California, compared to that of Calanus pacificus". CalCOFI Reports. 34: 98–103.
  6. ^ Shimode, Shinji; Takahashi, Kazutaka; Shimizu, Yugo; Nonomura, Takumi; Tsuda, Atsushi (2012). "Distribution and life history of two planktonic copepods, Rhincalanus nasutus and Rhincalanus rostrifrons, in the northwestern Pacific Ocean". Deep Sea Research Part I: Oceanographic Research Papers. 65: 133–145. doi:10.1016/j.dsr.2012.03.008. ISSN 0967-0637.