Copepoda—Their Status and Ecology in the Red Sea

Abstract

The subclass Copepoda is an important driving force in linking the lower trophic to higher trophic levels in aquatic ecosystems. Despite their ecological importance in marine waters, very little work has been done along the Red Sea since the early 19th century. Until now, about 276 species from 76 genera, 55 families, and 6 orders of copepods have been recorded in the Red Sea. This chapter discusses the diversity, distribution and ecology of the Red Sea copepods, which show an increasing gradient of species richness and biomass from north to south. Moreover, the standing stock of zooplankton in the southern Red Sea is higher than the central and northern parts. The majority of copepods recorded are during the winter season. The epipelagic zone in the Red Sea is usually dominated by small-sized genera, especially Acrocalanus, Calocalanus, Clausocalanus, Corycaeus, Ctenocalanus, Macrosetella, Oithona, Oncaea, Paracalanus, Paraoithona and Parvocalanus. With increasing depths, microcopepods belonging to the family Oncaeidae become numerically more important than the calanoid copepods. A special focus has been provided with reference to the effect of UV-B radiation on their biology, which shows that the maximum mortality rates of copepods under ambient solar radiation levels average a five-fold increase over the average mortality in the dark. The chapter also discusses the symbiotic and parasitic relationship of copepods with other organisms, such as corals and coral-reef fishes. A preliminary report shows that symbiotic copepods attain a high diversity from scleractinian coral genera, such as Pocillopora sp., Acropora sp., Stylophora sp., Favia sp. and Fungia sp. This chapter provides a baseline introduction on copepods and possible research in different aspects of their biology, which may provide a new step in copepod research in the Red Sea.