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.
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. Herein, we concentrated on the family Serpulidae (e.g., the serpulids Serpula, Hydroides, Spirorbis). Serpulidae are filter-feeding organisms living throughout their life in the same calcareous tube attached to different habitats such kelp leaves. Some serpulid species are known as very successful invasive species, which might cause substantial economic losses due to biofouling.
We found 16 species and 1 subspecies with about 270 specimens. However, we could only obtain molecular data for the subfamily Serpulinae, while we were not able to obtain any molecular data for the 11 species of the subfamily Spirorbinae. Accordingly, we could identify them solely on morphology thus far. Two of the species (Spirorbis rupestris and Pileolaria berkeleyana) as well as the subspecies (Circeis armoricana fragilis) are new to Norway. Pileolaria berkeleyana is associated with different kelp and other brown algae habitats and has been found in two localities of the Bergen region. It is known invasive species of Europe with its type locality being in Mexico. Spirorbis rupestris was found in only one locality from the Bergen region in exposed regions and in association with kelp and brown algae. So far, its distribution seemed to be restricted to the British islands. Finally, C. armoricana fragilis has been found at three localities of the Troms? region and is associated with exposed algae habitats and harbors. Like for S. ruprestris, the distribution seems to be restricted to the British islands. Given the discrepancies between morphological and molecular identification in the other groups of our project, the morphological identifications should be confirmed for all 10 species using molecular data. Serpulidae in general are known to be difficult to retrieve DNA barcodes from as the amplification primers do not reliably work even using species-specific primers within the same species. In addition, the species of Spirorbinae in our project were very small with only a few millimeters in body length. Of this, only a small posterior piece was taken for molecular analyses, while the remainder of the body was preserved as a specimen voucher. In conclusion, a targeted barcoding approach is not the best approach for such species and a genome skimming approach possibly combined with whole genome amplification for small-sized samples like our Spirorbinae specimens is more suitable to obtain DNA barcodes. The Biodiversity Genomics Europe project, of which is our group a collaboration partner, already applies such an approach to museum samples. You will apply such genome skimming approach to some of the specimens to confirm or reject the morphological species identification, to develop new primers for the DNA barcoding region and to test these new primers on other specimens from the same species. Additionally, in some cases, your results might reveal complexes of cryptic species.
What you will learn:
You will learn to conduct taxonomic identification, genomic approaches 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, Ana Teresa Capucho and Samaneh Pazoki (all UiO).
For further inquiries, please contact Torsten Struck (t.h.struck@nhm.uio.no)