|Chaetognaths and ctenophores in the holoplankton of the Bristol Channel|
Williams, R.; Collins, N.R. (1985). Chaetognaths and ctenophores in the holoplankton of the Bristol Channel. Mar. Biol. (Berl.) 85: 97-107
In: Marine Biology. Springer: Heidelberg; Berlin. ISSN 0025-3162, more
Pleurobrachia pileus (O. F. Müller, 1776) [WoRMS]; Sagitta elegans Verrill, 1873 [WoRMS]; Marine
|Authors|| || Top |
- Williams, R.
- Collins, N.R.
The geographical distributions, seasonal variations in numerical abundance and biomass (mg C m super(-3)) of the predators of the holoplankton of the Bristol Channel, between November 1973 and February 1975, are described. The predator numbers and biomass were dominated by the chaetognath Sagitta elegans Verrill. This species represented 96% of the holoplankton carnivore biomass in the outer, seaward region of the Channel and 60% in the inner region; the remainder being ctenophores. The maximum numerical abundance of S. Elegans occurred in September at 129 individuals m super(-3) ( identical with 18 mg C m super(-3)), juveniles (<5 mm) reached maximum during June, August and September, demonstrating the reproductive activity of the population. The tentaculate ctenophores were represented by Pleurobrachia pileus (O. F. Mueller). The highest abundance was 81 individuals m super(-3) ( identical with 3.0 mg C m super(-3)) at a single site in July in the South Central Channel. When the population reached its peak abundance in June, the estimated food requirement outstripped the daily production of copepods and a decline in both the prey and predator standing stocks was observed.