0 1987, by the American Society of Limnology and Oceanography, II-S. Energy sources for recruitment of the subantarctic copepod Neocalanus tonsus l

• Main Author: M. D. Ohman
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Austral; New Zealand; Pacific; Subarctic; Copepods
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.124.8316; http://aslo.org/lo/toc/vol_32/issue_6/1317.pdf

Neocalanus tonsus Brady was collected in subantarctic waters off southeastern New Zealand to test experimentally the importance of storage lipids and particulate matter as energy sources for recruitment. Reproductive copepods occur in mesopelagic depths (1,OOO-500 m) in austral winter and in epipelagic depths (150-O m) in spring. Winter copepods released up to 19 eggs female- ’ d-l in filtered seawater; spring copepods required a particulate food source to release eggs. Winter females ingcstcd diatoms at half the rate of spring females. Winter CVs did not ingest diatoms, in contrast to spring and summer CVs. Winter females had 24 times the wax ester content, half the phospholipid, and half the nitrogen content of spring females. In contrast, the two groups did not differ in dry mass or carbon content. Application of a proposed method for estimating reproductive potential, combined with experimental results, suggests that stored lipids are the energy source for recruitment of mesopelagic winter animals but not epipelagic spring animals. Subantarctic N. tonsus is distinguished from subarctic Pacific Neocalanus plumchrus and Neo-Calanus cristatus by residence of adult females in surface waters, active suspension feeding, and the dcpcndence of egg production on particulate food in spring. Divergent life history traits may be observed for copepod species occupying parallel subpolar habitats in the southern and northern hemispheres. Subpolar zooplankton assemblages in the southern hemisphere, subantarctic ocean and the northern hemisphere, subarctic Pa-cific are dominated by copepods currently referred to the genus Neocalanus. Neocal-anus tonsus Brady is endemic to the oceanic subantarctic, bounded approximately by the polar front to the south and the subtropical convergence to the north (Vervoort 1957;