In search of unknown spaghetti worms
Despite their bright colours and long tentacles, we don't know much about the spaghetti worms that live in Swedish waters. Now marine biologist Arne Nygren and his colleagues at the Department of Marine Sciences have received SEK 3.5 million to map the unknown group of bristle worms.
Spaghetti worms are a group of conspicuous bristle worms that are common along the Swedish coast. They grow to between two millimetres and two decimetres in length. Most are found on the west coast, but some species also live in the brackish waters of the Baltic Sea.
"According to previous studies, there are about sixty species in Swedish waters, but the species identification was done before today's modern DNA technology. We suspect that several species have been misidentified and that there may be more species involved," says Arne Nygren.
Spaghetti worms are named after the thin tentacles on their heads. Almost all species build tubes, both on mud bottoms, in sand and on rocks. The long tentacles are used to search for food on the bottom.
Now, researchers at the University of Gothenburg have received SEK 3.5 million from the Swedish University of Agricultural Sciences to investigate the diversity of the group through DNA sequencing.
"Cryptic species are common among polychaetes and many other marine species, i.e. species that may look similar but differ genetically. We will therefore first look for genetic differences and then examine how they differ morphologically, i.e. how they look and are structured," says Arne Nygren.
Seeking help from divers
Spaghetti worms live in different environments and at different depths. The researchers will therefore collect worms using different techniques. Firstly, they will make collections in connection with the annual soft bottom inventory along the Swedish coast. They will also make special collection trips from Tjärnö Marine Laboratory with the research vessel Nereus.
"We also plan to use citizen science by enlisting the help of diving clubs to collect worms for us. With their bright colours, they are easy to see in the water, for example when lifting rocks," says Arne Nygren.
Text: Karl-Johan Nylén
The project will map the diversity of the family Terebellidae in Swedish waters. The aim is to publish an updated checklist of all species found in Sweden, create a reference library of DNA barcodes for all species in Sweden and describe new species.
The project, which runs from 2025 to 2027, will contribute to the overall goal of The Swedish Taxonomy Initiative to identify and map all species of multicellular plants, fungi and animals in the country.
