Calanoides acutus explained

Calanoides acutus is a copepod found in Antarctica and the surrounding waters.

Description

The female ranges from about 3.5mm5.7mm, and the male has an average length of about 4.6mm.^[1]

Distribution

C. acutus is found in Antarctic and sub-Antarctic waters, from sea level to 1000m (3,000feet) in depth.^[1]

Ecology

Life history and reproduction

While C. acutus is only confirmed to breed from November to March,^[2] it likely starts breeding in early October, as a study observed females without eggs and late-stage nauplii presumably belonging to this copepod in mid-November. Stage I through III copepodites are generally found from sea level to 100m (300feet) of depth. Older stages, on the other hand, are found in the top 200m (700feet) during the summer, except during December, when they are found in the top 100m (300feet).^[3] C. acutus starts to descend in February, although this is affected by the food supply, with individuals in the northern portion of the range, like in Drake Passage, only starting to winter during mid-March. Individuals, mainly stage IV and V copepodites,^[3] winter to between about 500mand1000mm (1,600feetand3,000feetm).^[4] There is no evidence of diel vertical migration in this species.^[5]

Notes and References

1. Web site: Razouls C.. de Bovée F.. Kouwenberg J.. Desreumaux N.. Calanoides acutus (Giesbrecht, 1902) . Diversity and Geographic Distribution of Marine Planktonic Copepods. 2018. 8 July 2018. Sorbonne Université, CNRS.
2. Hagen. Wilhelm. Schnack-Schiel. Sigrid B.. Seasonal lipid dynamics in dominant Antarctic copepods: Energy for overwintering or reproduction? . Deep Sea Research Part I: Oceanographic Research Papers. 43. 2. 1996. 139–158 . 10.1016/0967-0637(96)00001-5.
3. Huntley. Mark. Escritor. Florence. Dynamics of Calanoides acutus (Copepoda: Calanoida) in Antarctic coastal waters. Deep Sea Research Part A. Oceanographic Research Papers. 38. 8-9. 1991. 1145–1167 . 10.1016/0198-0149(91)90100-T.
4. Schnack-Schiel. SB. Hagen. W. Mizdalski. E. Seasonal comparison of Calanoides acutus and Calanus propinquus (Copepoda: Calanoida) in the southeastern Weddell Sea, Antarctica. Marine Ecology Progress Series. 70. 1991. 17–27 . 10.3354/meps070017. free.
5. Lopez. MDG. Huntley. ME. Lovette. JT. Calanoides acutus in Gerlache Strait, Antarctica. I. Distribution of late copepodite stages and reproduction during spring. Marine Ecology Progress Series. 100. 1993. 153–165 . 10.3354/meps100153. free.