Identification of the copepodite developmental stages of twenty-six North Atlantic copepods. Occasional Publication of the Marine Biological Association 21.

In zooplankton copepod studies there is often the requirement to be able to identify the six copepodite developmental stages of different species, or to know their body dimensions. However, this information is not available for many species, or is dispersed through the literature. This guide gathers together both original and previously published information on morphology and measurements for the stages of twenty-six common North Atlantic copepod species and tabulates them in a standard format. For each species additional notes useful in their identification are also given.

Biodiversity of North Atlantic and North Sea calanoid copepods

Spatial patterns in pelagic biodiversity are the result of factors acting from a global to a local scale. The global patterns have been studied intensively using taxa such as foraminifera and euphausiids. However, these studies do not allow direct comparisons of neritic and oceanic regions or examination of relationships between local and regional patterns of pelagic diversity. Here we present a map of the diversity of calanoid copepods, a key planktonic group, summarising 40 yr of continuous monthly investigations in the North Atlantic and North Sea. The high number of samples (168 162) allowed mesoscale patterns in diversity to be detected for the first time at an ocean-basin level. Our results demonstrate pronounced local spatial variability in planktonic diversity and refine previous global studies at a lower resolution. They form a baseline at which long-term changes in planktonic diversity can be better assessed and ecosystem management plans implemented.

Zooplankton Of The Bristol Channel And Severn Estuary - The Distribution Of 4 Copepods In Relation To Salinity

The seasonal variations in distribution and abundance of the common zooplankton species in the Bristol Channel and Severn Estuary were related to the salinity regimes observed over the period November 1973 to February 1975. The dominant constituents in all regions were the calanoid copepods, which reached maximum densities in July: approximately 100 times their winter levels. Four zooplankton assemblages were recognised using an objective classification program which computed similarity coefficients and used group-average sorting. The assemblages existed along the salinity gradient observed from the Severn Estuary to the Celtic Sea. The assemblages were classified as true estuarine, estuarine and marine, euryhaline marine and stenohaline marine and were characterized by the copepods Eurytemora affinis (Poppe) (<30‰S), Acartia bifilosa var. inermis (rose) (27 to 33.5‰S), Centropages hamatus (Lilljeborg) (31 to 35‰S) and Calanus helgolandicus (Claus) (>33‰S), respectively.