Hydrozoa is a class of cnidarians among the jellyfishes. The pelagic representatives that live in the open sea include both hydromedusae and siphonophorae. As predators on other zooplankton they play an important role in the pelagic ecosystem.
But working with these gelatinous predators is challenging, as they are fragile and difficult to sample in good condition. Many of the fixatives normally used for zooplankton cause distortion and shrinkage of the gelatinous zooplankton, rendering the animals difficult or impossible to identify morphologically. As a result, pelagic hydrozoans and other gelatinous zooplankton have often been neglected in zooplankton studies in favor of the hardier and easier to work with crustaceans, and there is still a lot we don’t know about their taxonomy and ecology. HYPNO aims to chart the currently insufficiently understood diversity of pelagic Hydrozoa in Norwegian waters, and to document it in a manner that facilitates easier future identification of hydromedusae and siphonophores by both scientists and non-specialists.
The project will study the species composition of pelagic Hydrozoa in several environments along the Norwegian coast, including Oslofjord, North Sea, western Norwegian fjords and the Arctic, by combining gentle sampling, followed by a careful morphological examination and documentation of live specimens, with novel molecular methods. This will help to settle diversity even in cases where species are superficially very similar, as is often the case with pelagic hydrozoans. The project will produce an up-to-date list of pelagic hydrozoans found in Norwegian seas, with several new species records for Norway expected. The work will result in both scientific and popular publications describing the Norwegian diversity of pelagic Hydrozoa, a good reference collection available at the University Museum of Bergen, and an increased number of pelagic hydrozoan species with publicly available DNA barcodes. As such, it will lay a solid foundation for future work on pelagic Hydrozoa.
Project leader: Aino Hosia, University Museum of Bergen, University of Bergen
Project period: April 2015 – March 2018
Collaborating partners: Natural History Museum of Geneva, University of Oslo and Institute for Marine Research