Introduction
Considering animals most people think about vertebrates and thereby especially mammals and birds. These are often considered the most sophisticated and evolutionary successful animals on Earth. However, this is not true taking into account evolutionary history, biodiversity, ecology or biomass. Invertebrates outshine vertebrates in all these categories. Moreover, invertebrates have evolved novel structures and inhabited habitats unoccupied by vertebrates. Hence, invertebrates have much to teach us about evolution in general and in particular. On the other hand, except for a few flagship species and groups, invertebrates are heavily understudied, especially considering marine invertebrates. The latter is especially important as all animals live depends on water and originated from the marine realm. Hence, understanding the evolution of marine invertebrates will help us to understand evolution at much more detailed and complete level.
The topic of this thesis will build upon the results of the ArtsDatabanken-project “Biodiversity in the marine algae belt”. The marine algae belt comprising kelp forests, seagrass meadows and rocky reefs with coralline red seaweeds is one of the most active primary producing environments in the sea. It also harbors a great diversity of animals including sea squirts, ribbon worms, nick worms, serpulid worms, spionid worms and skeleton shrimps. The species of these groups occupy important ecological functions as herbivores, predators and filter feeding organisms and can be sessile or agile as well as solitary or colonial. Globally these taxa comprise more than 7,000 species with around 250 species documented from Norwegian waters. This is why we conducted a field inventory and collected species of these taxa in Norway (from the Skagerrak up to Troms?). With morphological and molecular methods, we determined species and learned more about their distribution and their association with Norwegian nature types. These efforts resulted into the record of 624 collection samples with 944 specimens of 73 species from these animal groups and 43 localities in Viken, Tr?ndelag, Vestland, and Troms og Finnmark comprising 19 Norwegian nature types. Our results show that we have found 3 species and 1 subspecies, which are new to Norway, and at least 10, which are new to science, but there may be 7 additional ones. However, the first analyses concerning the new species also showed that much more detailed studies on these are necessary. This is where this Master project will work on.
Nemertea (ribbon worms) comprise predatory species predominantly occurring in marine habitats. They are dorsoventrally flattened. They 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. Globally about 1,300 species are known.
We found 14 species of nemerteans across all the targeted habitats. Three of the species might be new to science. One of three is probably a new species of the Lineus ruber/viridis complex, which already has been shown to comprise three species instead of two. Two of the three species (L. ruber and L. viridis) have been found by us and were confirmed by the molecular data. However, one specimen is different and in a group containing an additional 52 specimens from different European localities. Another new species within the family Lineidae is possible the species morphologically identified as Micrura fasciolata. It occurs in two localities in the Troms? and Trondheim region associated with algae and seagrass habitats. It is about 4.5% different to the group of specimens from Sweden identified as M. fasciolata as well. A detailed taxonomy assessment is needed taking into account the type specimens and locality of the species. Finally, we possibly found a new hoplonemertean Tetrastemma species. The three specimens are morphologically similar to T. candidum and occur in two kelp habitats in the Trondheim and Troms? region. They form a group of their own, which is 6% different to another group with mostly specimens of T. robertianae and T. candidum specimens. It is also about 12% different yet to another group with only two T. candidum specimens. In the molecular tree, it is more closely related to T. flavidum than to T. vermiculus. Again, like in the cases before, the results require detailed taxonomic revisions including additional samples and molecular markers as well as detailed morphological studies to reveal the species status of the three possible new species. In your thesis, you obtain additional molecular data for new markers and specimens, as well as conduct detailed morphological studies using different forms of microscopy. You will compare your data with the publicly available data and literature and conduct a taxonomic revision of these species in Norwegian waters.
What you will learn:
You will learn to conduct taxonomic identification, extensive literature research and distribution mapping. This will include among others molecular barcoding and microscopy. You will apply programs for phylogenetic reconstruction and conduct statistical analyses of your results.
What we offer:
First and foremost, we offer a friendly and kind mentoring environment. We offer a membership in ForBio (the research school in biosystematics) where you will be able to take courses in several places in Norway. You will potentially be able to attend international courses if they fit with the objectives. You will be able to participate in a national conference (ForBio meeting) and potentially in an international conference depending on funding. If you are interested, we will be able to discuss travel opportunities and a travelling period abroad.
What we expect from you:
Commitment and dedication
Outcomes:
One (or more) scientific publications, conference communication
Supervision and teaching:
You will be supervised by Torsten Struck, and Ana Teresa Capucho (both UiO) and Joern von Doehren (University of Oslo).
For further inquiries, please contact Torsten Struck (t.h.struck@nhm.uio.no)