About the project
The main goal of the project is to generate an overview about the distribution of marine invertebrate species associated with the marine algae belt of the shallow, subtidal coastal waters along the Norwegian coastline. In specific, we will focus on species from the taxa Tunicata, Entoprocta, Nemertea, Spionidae, Serpulidae, and Amphipoda/Caprellidae occurring in kelp forests, sea grass meadows and rocky reef habitats with coralline red seaweeds. Globally these taxa comprise more than 7,000 species with around 250 species documented from Norwegian waters. Despite this the knowledge about their taxonomy and distribution in Norway is at best poor and in dire need of improvement.
Tunicates are marine suspension feeders comprising among others sea squirts, which are targeting in this project. Sea squirts are sessile benthic organisms ranging in size from <1 mm to 60 cm and species are solitary or colonial. Colonies can be several meters in size. Sea squirts are found in all three targeted habitats. Several ascidian species are also very successful marine invasive species causing strong habitat transformation and economic loss in aquaculture. On the other hand, a high degree of cryptic species has also been found in Tunicata including among others the new model system Ciona intestinalis (Linnaeus, 1767). From Norwegian waters, a total of 76 tunicate species is recorded, but they are still categorized as poorly known with respect to ecology, distribution and taxonomy due to lack of information, and no barcodes were present in NorBOL at the beginning of the project.
Entoprocta (or Kamptozoa, nick worms,) are one of the smaller animal phyla with only about 200 described species. 25 species are recorded from Norway and 30 species are expected to occur in Norwegian waters. Like seq squirts, they are sessile or colonial filter feeders, which are mostly exclusively marine. Especially, the colonial forms can live attached to various substrates, which include different forms of algae, but also shells and rocks. Accordingly, they can be found in all three targeted habitats, but predominantly in rocky reefs with coralline red seaweeds. Even though they are not uncommon in shallow waters, they are often mistaken for cnidarian polyps or overlooked due to their small size. Hence, their taxonomy in Norwegian waters is regarded as barely known, their distribution as poor and their ecology as non-existent. Similar to sea squirts, there are no barcodes available in NorBOL.
Nemertea (ribbon worms) comprise predatory species predominantly occurring in marine habitats. They are dorsoventrally flattened and hunt their prey by sneaking up on it and catching it with an expandable proboscis, which is usually equipped with pincer-like structures. Moreover, the body is extremely stretchable, so that the expanded body length can be three times larger than the retracted one. For example, Lineus longissimus (Gunnerus, 1770) can be up to 60 m long and hence is the longest free-living animal on Earth. As for many marine groups, the degree of occurrence of cryptic species might be high and the number of nemertean species higher than presently described even in better characterized areas. Globally about 1,300 species are known and for Norway 60 species, but 90 are expected. The status of Nemertea for taxonomy and distribution is poor and for ecology weak. However, several species of the habitats of this project have no barcodes.
Annelida (segmented worms) is a species-rich group with >20,000 species occurring in all habitats on Earth. In the three targeted habitats many different annelid families are found ranging from filter-feeding species to predators and these occupy different positions in the food webs of these habitats. Several projects on Annelida have been conducted in Artsdatabanken and some families are well-known. However, for many families or genera our knowledge is still very limited, and the occurrence of cryptic species is high. This includes the families Serpulidae and Spionidae occurring in these habitats. While Serpulidae are filter-feeding organisms living throughout their life in the same calcareous tube attached to different habitats such kelp leaves, Spionidae are agile organisms, which are also suspension feeders. Some serpulid and spionid species are known as very successful invasive species, which might cause substantial economic losses due biofouling or burrowing in bivalve shells in aquaculture. In Norway, 29 serpulid and 51 spionid species are known and little more are expected to be found. The status for taxonomy, distribution and ecology is for both families either weak or moderate. However, in NorBOL no barcodes are available for any species of the genera occurring in the habitats of our project.
Finally, Caprellidae (ghost shrimps) belong to the species-rich “Crustacea” > 70,000 species globally. Caprellidae are characterized by their string-like morphology due to several reductions and losses of the crustacean body plan. They are quite common in shallower waters including the targeted habitats, as clingers to flora and larger fauna, and are grazers, scavengers, filter feeders or predators with important ecological functions. However, as it is the case with most of the above taxa species are often difficult to identify due to their small body size (5-30 mm), immaturity and the occurrence of sexual dimorphism in most species. In Norway 8 out of the 100 known genera can be found with a total of 15 species, including invasive species like the invasive species Caprella mutica. This species is rapidly spreading through most of Northern Europe including records from Norway on man-made structures like harbors. Caprella mutica effectively outcompetes native caprellid species upon introduction, which often happens unnoticed. At the moment, knowledge of taxonomy, distribution and ecology of ghost shrimps in Norway is poor. In NorBOL, a barcode for 1 species is present.
Thus far, we recorded of 949 specimens of at least 80 species from Tunicata (206 specimens), Nemertea (151 specimens), Entoprocta (19 specimens), Spionidae (81 specimens), Serpulidae (293 specimens) and Caprellidae (199 specimens) and 43 localities in Viken, Trøndelag, Vestland, and Troms og Finnmark. We have extracted the DNA, amplified and sequenced the COI barcoding region for 401 specimens. In caprellids, despite being identified by taxonomic experts about 45% of the specimens were misidentified based on morphology. This has ramification for the spread of C. mutica along Norwegian coastlines. Most of the misidentified species were molecularly identified as C. mutica due to that they were juveniles, or females. This means that C. mutica has a much higher spread along the Norwegian coastline and might have already replaced many of the native species in the depth range of our project. Additionally, C. mutica does not only occur in harbors or similar human-influenced environments or close to them, but also in natural habitats. This is in contrasts to the previous records for Norway. Moreover, several of records of native Caprella species like C. linearis, C. equilibra and Aeginina longicornis supposed to occur in the same habitat might have been misidentified as well if the records are based only morphological identification. Accordingly, our morphological records of C. equilibra are dubious, and also the three previous records of this species in Norway should be treated with cautious. So far, molecular data could not confirm the morphological identification of any of the supposedly C. equilibra. Polydora onagawensis (Spionidae) is a species new to Norway.