New invertebrates

Copepod abundance and diversity

Copepods are small crustaceans, relatives of the crabs and lobsters, but abundant and diverse in the oceans. There are about 3,000 species of copepods in European waters, and they account for almost 10% of all species contained in the European Register of Marine Species. Copepods are typically the dominant group of multicellular animals in the plankton, but they are also found on and in marine sediments. In the marine sediments they are usually the second most abundant group, after the nematodes.

MarBEF scientists have discovered a whole new copepod genus. They have called it Marbefia to honour the outstanding contributions of MarBEF to our knowledge of marine biodiversity.

Parasitic copepods

Copepods are also parasites on almost every phylum of marine animals, from sponges to chordates, including whales. For example, sixteen copepod families are parasitic on polychaete worms. These parasites are typically rare and our knowledge of their biology and distribution is extremely limited.

In samples from the Norwegian Sea and the White Sea 11 new species were discovered which include 3 new genera of parasitic copepods. These studies have greatly improved our knowledge of the host-specificity of the parasites, their abundance and their distribution in European waters.

Scanning electron micrograph of a parasitic copepod, Herpyllobius polynoes, attached to the head of its host, a polynoid worm. Herpyllobius is an extremely modified copepod, having lost limbs and segmentation. It feeds via an embedded rootlet system that penetrates the skin of the host and directly absorbs nutrients.).

Worm diversity

MarBEF researchers also discovered new worm species from European seas. Among these, Osedax mucofloris is perhaps one of the most remarkable. It burrows into the decaying bones of whale carcasses – an extremely widely dispersed habitat – and derives nutrients from the abundant sulphur compounds in the carcass.

The roundworms or nematodes are one of the most species-rich animal phyla. They have successfully adapted to nearly every ecological niche, from marine to freshwater and from polar to tropical regions. They are present in all freshwater, marine and terrestrial environments, where they often outnumber other animals both in individual abundance and in species counts. Nematodes are found in locations as extreme as Antarctica and oceanic trenches.

The MarBEF MANUELA project studied the nematode diversity and their distribution. 35% (333 species) of the nematode species which were included in this project were identified for the first time for Europe.