Population dynamics and production of Euphausiids: 3. Meganyctiphanes norvegica and Nytiphanes couchi in the North Atlantic Ocean and the North Sea
Lindley, J.A. (1982). Population dynamics and production of Euphausiids: 3. Meganyctiphanes norvegica and Nytiphanes couchi in the North Atlantic Ocean and the North Sea. Mar. Biol. (Berl.) 66(1): 37-46 In: Marine Biology: International Journal on Life in Oceans and Coastal Waters. Springer: Heidelberg; Berlin. ISSN 0025-3162; e-ISSN 1432-1793, more |  |
| Keywords | Cycles > Life cycle
Population dynamics
Production rate > Productivity
Meganyctiphanes norvegica (M. Sars, 1857) [WoRMS]; Nyctiphanes couchi (Bell, 1853) [WoRMS]
Marine/Coastal |
| Abstract | Seasonal changes in abundance, size and aspects of the population structure of Meganyctiphanes norvegica (M. Sars) and Nyctiphanes couchi (Bell) are described from samples taken with the "Continuous Plankton Recorder"at 10 m depth over a 2 yr period (1966 and 1967) in the North Atlantic Ocean and the North Sea. M. norvegica lived for a maximum of just over 2 yr, and adults of both year-classes spawned during a limited breeding season in the spring or summer. N. couchi spawned over a prolonged breeding season, giving rise to a complex of cohorts with overlapping size ranges. It was concluded that 3 or 4 cohorts were spawned in each year and that the maximum life span was probably greater than 1 yr, although maturity may be attained in less than a year. Estimated annual production at 10 m depth for M. norvegica ranged from 0.80 to 18.74 mg m-3yr-1 and for N. couchi from 0.67 to 8.23 mg m-3yr-1. P:B ratios ranged from 1.3:1 to 6.3:1 for M. norvegica and 4.0:1 to 5.5:1 for N. couchi. |
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