Category Archives: Student Projects

Hello Jorunna artsdatabankia; new sea slug for Norway and to the World!

In 2018 former master student Jenny Neuhaus started working under supervision of Manuel Malaquias and Cessa Rauch on the sea slug species Jorunna tomentosa.

Jenny presenting her work on Jorunna tomentosa on the world malacology conference in the USA

It was known already for some time that this sea slug occurs in a wide variety of colour patterns (morphotypes). With the increased discovery of cryptic species due to improved molecular techniques we wondered if we were dealing with a single species or several cryptic lineages.

For a long time the different colours and patterns were regarded as natural variation within the species, consisting of shades of grey-white, cream-yellow, pale orange and either plain of blotched with light brown or chocolate brown spots of various sizes, distributed either irregularly or in lines, or combination of both!

But it was this variety that tossed up the question eventually whether we are dealing with a single species after all.

The diversity within Jorunna tomentosa

The nudibranch genus Jorunna consisted of eleven recognized species occurring in European waters. At that time, Jorunna tomentosa (Cuvier, 1804) was the only known species of this genus to be found along the Norwegian coastline. Prior to the study, the northernmost record of J. tomentosa was listed from Vestvågøy, Lofoten, Nordland. Today we know that the species is found at least 550 km further North in the Magerøysundet, Troms og Finnmark.

Jorunna tomentosa has an oval-elongate body shape with different colours varying from grey-white to cream-yellow and pale orange. They can reach a size up to 55 mm and occur at depths from a few meters down to more than 400m. They feed on sponges of the species Halichondria panicea, Haliclona oculata and Haliclona cinerea. J. tomentosa can be found from Finnmark in northern Norway, southwards along the European Atlantic coastline, the British Isles, the French coast, Iberian Peninsula, Mediterranean Sea up to Turkey, and the Azores and Canary Islands. Besides the species has even been recorded from South Africa.

Jenny Neuhaus in the lab of Prof. Marta Pola in Spain dissecting specimens for anatomical studies

Jenny compared specimens from different parts of the world, including Norway, Ireland, Spain, France, Portugal including the Azores and South Africa. She took tissue samples for genetic studies and dissected them for their anatomy.

For the genetic studies we selected three different gene markers called COI, 16S and H3 to check how these morphotypes compare with each other and evaluate the meaning of genetic distances.

From the genetic distance analyses, it became clear that we were dealing with a “cryptic species complex”, as a clade of three specimens showed substantial genetic difference compared to J. tomentosa but seemed morphologically indistinguishable from another at first glance.

As sea slug anatomy is a matter of complexity, especially since each animal possesses both male and female reproductive organs (hermaphrodite), the expertise of Prof. Marta Pola from the University of Madrid was essential to conduct detailed morpho-anatomical studies. We were able to detect structural differences in the rasping tongue (radula) and parts of the reproductive apparatus.

Meet Jorunna artsdatabankia!

Jenny sequenced the DNA of 78 specimens of which 60 where successful for using in the final phylogenetic analyses. Her results supported the presence of a new Jorunna species, and in addition a possible case of incipient speciation in J. tomentosa with two genetic lineages morphologically undistinguishable. The new Jorunna species was based on material collected from Norway (Kristiansund, Frøya & the North Sea).

Jorunna artsdatabankia

J. artsdatabankia has a plain white to yellow background colour accompanied by small brownish spots irregularly placed on the body surface. Its distributional range is so far restricted to Norway, being recorded from Skogsøya, Frøya (Trøndelag), Brattøya, Kristiansund (Møre og Romsdal), and a North Sea plateau (60.726944 0.505371) with a depth range from 27 to 350 meters, suggesting a sympatric occurrence with J. tomentosa.

Jorunna artsdatabankia in comparison to Jorunna tomentosa

The name attributed to this new species was chosen to recognize the work of the Norwegian Biodiversity Information Centre (Artsdatabanken) for their instrumental role promoting and supporting biodiversity research in Norway.

– Cessa Rauch, Jenny Neuhaus, Manuel Malaquias

 

Sea slugs of Norway Instagram: @seaslugsofnorway

Sea slugs of Norway Facebook: www.facebook.com/seaslugsofnorway

The paper can be found here:

The genus Jorunna (Nudibranchia: Discodorididae) in Europe: a new species and a possible case of incipient speciation. Jenny Neuhaus, Cessa Rauch, Torkild Bakken, Bernard Picton, Marta Pola, Manuel António E Malaquias (2021), Journal of Molluscan Studies, Volume 87, Issue 4, December 2021, eyab028, https://doi.org/10.1093/mollus/eyab028

On the study of the diversity of Euphysa in Norwegian Waters

NorHydro’s student and collaborator Carla García has just defended her MSc thesis! We asked her to share with us a little bit about her project and this is what she had to say:

During summer 2020 I started learning about hydrozoans through online chats with my supervisor, Luis Martell. At that time, I was not familiar with these curious animals but they caught my attention and by September that year I had already fallen in love with them so I moved to Mallorca to pursue a Master’s Degree in Marine Ecology and work with hydrozoan diversity. For my master’s thesis I worked in a case that was part of project NorHydro (Norwegian Marine Benthic Hydrozoa), led by Luis at the University Museum of Bergen. The global pandemic has put many limits and obstacles in the way of my project, but I have been able to cope with them successfully by combining presential lessons in Mallorca with online courses and meetings with my fellows in Norway.

Me in Mallorca sampling my first benthic hydrozoans (Pennaria disticha and Eudendrium sp.) Picture credits: María Capa and Carla García.

My research was focused in the diversity of genus Euphysa (family Corymorphidae), which had not been assessed in Norway before. I wanted to determine which and how many species of this genus are present in Norwegian and adjacent waters and to characterise them morphologically and genetically. The problem with these animals is that many Euphysa species are not easy to tell apart from each other and there is a big taxonomic controversy within this group. For example, Euphysa aurata is one of the most frequently reported species in Norway, but are we sure that all the records belong to the same species?

Detailed observations of the samples raised my suspicions about the possibility that a complex of species could be hidden within this species name. To try to solve this problem I used an integrative approach combining molecular (DNA barcoding) and morphological analyses (documenting diagnostic characters). The result of this was that we discovered a new species of Euphysa in the waters outside Bergen and we are in the process to describe it!

Medusae of Euphysa aurata (top row) and Euphysa sp. nov. (bottom row), the main taxa covered in my project and two easily confused species. Picture credits: NorHydro and HYPNO.

The first step in the approach I followed was the field work. I gathered samples of hydromedusae and polyps from different localities across the Northeast Atlantic waters and also used some preserved specimens from the University Museum of Bergen. Because last year’s restrictions during the pandemic, part of my samples had to be sent by post to Mallorca, where I carried out the second step: laboratory work. This part included all the steps that go from the DNA extraction to the sequencing of three specific DNA fragments (called barcodes), which allow us to identify and distinguish between species based on similarity with reference sequences from online databases. Then, I applied some phylogenetic analyses and species delimitation tools. What these techniques do is to infer the evolutionary history of the three DNA markers that I sequenced (COI, 16S, and ITS). The results are visualized in the form of phylogenetic trees that we have to interpret and to decide if they are reliable or not. Then, I used species delimitation software to delineate species boundaries. The last step was to look again at the morphology and search for diagnostic characters that allow us to differentiate the species of Euphysa.

Sampling with my lab partners Mariana Strauss and Raúl González. We were looking for hydroids, small worms, and goose barnacles for our respective research projects. Picture credits: María Capa and Carla García.

Each and every life form that make up our planet, no matter how small it is, is a key component to the functioning of the Earth as a whole, and for that they deserve to be studied. Knowing how many species inhabit the Earth has always been one of the main questions of science, so I am really happy to contribute to a better understanding of ocean biodiversity and concretely, to hydrozoan systematics.

If like me, hydrozoans have piqued your curiosity and you want to know more on the activities of NorHydro and my results, you can check NorHydro’s home page and Facebook page, as well as the hashtags #HYPNO and #NorHydro inTwitter.

-Carla García-Carrancio

On the Hunt for Tiny Polyps

Two weeks ago I had the chance to go field-sampling on the research vessel Hans Brattström. The sampling this time was focused on a broad range of marine invertebrates ranging from Hydrozoans, Bryozoans, Polychaetes, Phoronids and Brachiopods. I was especially on the hunt for polyps of the family Hydractiniidae (Cnidaria: Hydrozoa) that grow preferably on shells of molluscs or hermit-crabs. I was happy to look for new specimens for NorHydro and my master’s project, especially since opportunities to go field-sampling have been rare due to the covid-19 restrictions. The area of Bergen has been sampled quite well for the NorHydro project, but I was especially looking for rare species or species that haven’t been sampled before.

The first sampling for NorHydro this season – and with great conditions! Picture Credit: Lara Beckmann

To collect hydractiniids, we took bottom samples using a triangular dredge and a grab sampler. When the dredge gets back on board, the sample gets sorted on a large table on deck. Then the detailed search begins, and every stone and cranny gets inspected. The polyps I was looking for can be tiny, ranging from less than 1 mm up to 8 mm. The substrates that they grow on vary in size and shape, it can be crabs, molluscs but also algae or stones, often not larger than a few centimeters. So it isn’t an easy task to find the polyps in a freshly collected sample. Luckily I found several conspicuous hermit crabs and also one snail that I took back to the museum. At first, I didn’t see the polyps – only under the microscope in the museum laboratory I was able to see that hydractiniid colonies were growing on the shells.

Video: A polyp colony of the species Podocoryna areolata (Family Hydractiniidae). The polyps were growing on the shell of a living mollusc, probably of the species Steromphala cineraria. Video Credit: Lara Beckmann

One colony of the species Podocoryna areolata was growing on the shell of a living mollusk. The mollusk provides a nice substrate because the movements of the snail provide the polyps with more opportunities to encounter food. Also, the colony is protected by the small wrinkles of the shells surface where the polyps can hide. The polyps of this species are super difficult to measure, but most are smaller than 0.5 mm. When disturbed, the polyps shrink to small blobs even smaller than this. When relaxed, they can extend a bit longer in size. Especially the tentacles reach out to get hold of any potential food that swims by, such as small crustaceans. This species releases medusae, which can frequently be found in the plankton in this area.

A single polyp of the same colony of Podocoryna areolata. Picture Credit: Lara Beckmann

On shells inhabited by hermit crabs of the species Pagurus bernhardus, I found several colonies of a yet unidentified species of the genus Podocoryna. This species is very commonly found as polyp almost along the entire Norwegian coast. I’m still studying the specimen to figure out the correct identification. Since there is a lot of confusion in the hydractiniid taxonomy, I need to combine genetic information and morphology to overcome the existing problems in their identification and naming. The colony was reproductive and medusa buds were growing on it. Interestingly the medusa of this species is rarely found in the plankton.

Polyps of the genus Podocoryna. On the right are parts of the grasping claws visible belonging to the hermit crab Pagurus bernhardus. Picture Credit: Lara Beckmann

All over the colony were medusa buds. These are growing medusae, which will be released in the water when they are mature. The medusae can do what the colony itself can’t: releasing eggs and sperm and thus reproduce sexually. Picture Credit: Lara Beckmann

Besides the polyps, I found several other organisms living with the colonies on the shells including Crustaceans, Nudibranchia, Foraminiferans and other hydroids. The shells provide a home for a diverse range of marine life and it resembles a tiny forest. But it is not all peace and harmony in there, the smallest amphipods were quickly munched by the Podocoryna polyps. Those, in turn, get eaten by nudibranchs, that crawl on the colonies and some species feed specifically on hydroid polyps.

Video: An amphipod that lives on top of the hermit crab shell, walking through the colony of Podocoryna polyps. Video Credit: Lara Beckmann

 

I didn’t find any more hydrozoan species that were interesting for NorHydro during the sampling trip (at least not while scanning with the bare eye). But, I want to show one more very common species around Bergen –Ectopleura larynx– just because it is such a nice-looking hydrozoan. It even was reproductive and released its larvae right into my petri-dish. The small bulbs that grow between the polyp tentacles contain the larvae, which are called actinula. They break free and swim around, swinging their tiny tentacles until they will settle on a piece of algae for example, and grow to a large colony again.

The species Ectopleura larynx is a common species at the Norwegian coast. On the left the released larvae, called actinula. On the right a polyp that usually grows in a large colonies with up to a hundred polyps. Picture Credit: Lara Beckmann

-Lara

You want to learn more about hydrozoans and why it is important to study them? Read more about it in my blog article for Ecology for the Masses: link.

Also, keep up with the activities of NorHydro here in the blog, on the project’s facebook page  and in Twitter with the hashtag #NorHydro.

What’s growing on the shell? – Insights into the Diversity of Hydractiniidae in Norway

This summer I started my master degree project at the University Museum of Bergen and joined the research of Luis Martell and Aino Hosia. I’m a student in the program ‘Biodiversity & Systematics’ at the University of Stockholm and for my 1-year thesis project I wanted to learn more about hydrozoans. Looking for hydrozoan biologists, which there are not so many, I came across the project NorHydro led by Luis and Aino and I decided to go to Bergen to study and learn more about this fascinating group.

My thesis project especially focuses on the diversity of the hydrozoan family Hydractiniidae. Most commonly hydractiniids are encountered on snail- or hermit crab shells where they can build a mat of polyps. Those shells are often inhabited by other animals and the polyps feed on the left-over meals of those and in return defend their host against predators. With their small tentacles, which are equipped with hundreds of cells containing venomous stingers (the nematocysts) they are great predators and catch tiny animals from the plankton.

Schuchertinia allmanii growing on Pagurus pubescens hermit crab. Picture credit: Bernard Picton

Each individual polyp is connected to each other and build a colony of polyps with different functions. Some act as food suppliers, some as reproductive polyps. From those polyps some hydractiniid species grow tiny medusae (jellyfish) which will be released in the water column. The medusa is morphologically comparable to the polyps, equipped with tentacles, a stomach, gonads and nematocysts – but living upside down and not attached to the sea floor. With their ability to swim around they contribute to disperse themselves in the water and can produce a lot of offspring.

Video of a Pagurus bernhardus hermit crab. A hydractiniid polyp colony is growing on the underside of the shell. Video credit: Lara Beckmann

Several species in this family are often used in development biology or immunology research. For example the species Hydractinia echinata led among other organisms to the discovery of stem cells and is still widely used as a so-called model-organism nowadays. This is because this animal group shows a high ability to regenerate and if you cut a hydroid polyp in two pieces, it will just re-grow again to its initial state.

The life-cycle in hydractiniids can include a polyp and medusa stage. Species of the genus Podocoryna release medusae from their colony. Other genera in this family develop only reduced medusae and lack a free-swimming jelly. Illustration credit: Lara Beckmann

The hydromedusa Podocoryna borealis is released from a polyp colony that can grow on various substrates such as snails or worm tubes. Picture credit: Lara Beckmann.

But despite this spotlight to some species, the diversity of this family is still poorly known and there is little attention to hydractiniid species because of their inconspicuousness and difficult identification. To highlight the problem I did some research: how many and what species are commonly recorded in Norway? Which species could potentially occur in this region according to species descriptions? In private observations and ecological surveys only three species were commonly recorded. However, our preliminary results suggest at least 6 species in Norwegian waters with some surprisingly frequent species that are rarely recorded in surveys. This indicates, that there happens a lot of misidentification in the field and we need to get a better estimate of the true diversity of Hydractiniidae in this region in order to improve awareness and to prevent misidentification in the future.

Two polyps of a colony of the species Clava multicornis. You can see reproductive units (so-called sporosacs) growing on the polyp body, which will release eggs or sperm when fully grown. Picture credit: Luis Martell

In order to do that I study this group in much detail. A great advantage of being a taxonomists in these days is that we can use a variety of different sources of information to develop and test for species hypothesis. This so-called integrative approach includes morphological, ecological and genetical information in order to define taxa diversity from several perspectives.

The first step in this process is to gather polyps and medusae of Hydractiniidae from various spots in Norway ranging from Olso, via Bergen and up north to Bodø. I will use already collected samples from previous years and hopefully will also be able to add some more samples from field-trips in the next months.

Getting the plankton-net back on board – and Maryam and me trying to open the jar carefully without spilling the fragile plankton inside. After removing the jar from the net, we directly pick the hydrozoans and put them in a cold environment, so that we can look at them alive when we are back in the lab. Picture credit: Maryam Rezapoor

With fresh material the first step is to take pictures of the living animal. Since hydrozoans tend to shrink and lose a lot of it characteristic traits in the ethanol preservative it is important to take pictures right away when the animal is still alive. Furthermore the samples are identified using a microscope, identification keys and additional literature. With additional collected data such as habitat, location, sample depth and so forth we create a large database for our samples and develop so-called e-vouchers: an electronic data storage for each individual to ensure to gather and store as much information as possible. That makes it possible to go back to the database and look at the specimen data e.g. where did it live? On what substrate was it growing on? How deep was the sampling site? This way I don’t only rely on the preserved material but can easily use the e-voucher material and the additional collected data that can be useful for further analyses.

Besides the morphological and ecological data I also include molecular information: what does the DNA tell us about the specimen? For that I use three different genetic markers (short DNA fragments, or genes) to see how those differ in their sequence of bases between the sampled hydractiniid specimen. In the course of evolution, DNA sequences change due to selection, genetic drift, gene flow and random mutations. That is why we are able to infer evolutionary relationships between biological entities – in this case we are interested in species – and with mathematical models and some simplified assumptions we can delimit species based on their molecular attributes.

Me in the DNA lab waiting for the first results of lab work for this project! Picture credit: Maryam Rezapoor

In order to do so, I will process the sampled material in the lab. First, I extract the DNA from a tiny piece of polyp or medusa tissue and then amplify the specific target region using PCR (Polymerase-Chain-Reaction). This short DNA fragment will further be sequenced which outcome I will check, process and analyze using different computer programs and algorithms. The final results will be summarized and visible in so-called gene trees, revealing the evolutionary history of those three different DNA markers. I will use the gene genealogies to delimit the species and observe how much diversity of hydractiniids we have in Norway.

Using specific genes also facilitate us with species barcodes which are used to create a reference library. This in return enables researchers to identify a specimen without the need to identify the sample using its morphology. This can be the case e.g. for metabarcoding projects (sequencing a mass of DNA from unknown origin) or if samples are unidentifiable. The scientist will then sequence the barcode gene and compare it to the reference library and will eventually be able to tell the species. Those barcodes can be informative in biodiversity studies but by no means substitute taxonomists, which are still needed to describe and identify species when no DNA is available.

A monograph of the Gymnoblastic or Tubularian hydroids by George James Allman, published in 1870. I found this book in the library of the Tjärnö laboratories in Sweden. Allman was a pioneer in hydrozoan research and described many species. Nowadays it is much easier to access original descriptions since many book are available online. You can find a PDF* of this book in the Biodiversity Library. Picture credits: Lara Beckmann

Also, the DNA does not help us when we have no reference we can map the specimen to in order to determine the species. That is why this master project also aims to create a barcode-library for the species in the family Hydractiniidae.

What I really like about this project is that it contributes to our basic understanding of the diversity in our oceans – in this case even in two completely different environments: the water column as well as the seafloor.

Even if hydractiniids are just a little part of the ecosystem, they play their role and influence the ocean in their own way. Also, my work is super diverse and I need to be an allrounder in many respects: trying to find species descriptions I search and read taxonomic literature from the 19th century (coming in Latin, German, English, Swedish or French). Then I work in the laboratory where I combine traditional working methods like drawing, microscopy or photography with modern techniques from DNA sequencing to computational science and bioinformatics.

I love this kind of work, and it is great to contribute just a little bit to reveal the mysteries of our oceans.


– Lara

You want to learn more about hydrozoans and why it is important to study them? Read more about it in my blog article for Ecology for the Masses (link).

Also, keep up with the activities of NorHydro (link to project home page) here in the blog, on the project’s facebook page (link) and in Twitter with the hashtag #NorHydro.

*Link to pdf of A monograph of the Gymnoblastic or Tubularian hydroids by George James Allman

Brattström baby, HYPCOP goes offshore!

Last days of November HYPCOP spend two days (26th & 27th) offshore. We had the possibility to join some sampling efforts of NorHydro and others on the research vessel Hans Brattström.

Research Vessel Hans Brattström ready early in the morning, photo Cessa Rauch

This vessel is owned by the University of Bergen and operated by the institute of Marine Research (IMR, Havforskningsinstituttet).

H. Brattström is used 200 – 230 days a year along the West coast of Norway. It has the capability of operating different sampling gear, which makes it useful for multiple projects, studying a variety of marine organisms, from fish, to worms, jellyfish, and yes, also copepods!

On the first day HYPCOP joined NorHydro consisting of Luis Martell (UiB) and Joan Soto Angel (Sars):

NorHydro team and HYPCOP; from ltr Cessa Rauch, Luis Martell and Joan Soto Angel, photo Cessa Rauch

Plankton net being lowered in the ocean with some early morning sun, photo Cessa Rauch

 

 

The main sampling gear consisted of a large plankton net that was slowly dropped to 660m, 245m and 128m depth.  We sampled close to Bergen in Raunefjord, Krossfjord and Fanafjord.

Sampling for jellyfish needs to be done with caution, with the net going up to fast, the animals will just fall apart because of the pressure. So, a depth of 660m can take up to an hour and more before we could see the results.

 

 

Joan Angel Soto scanning the shore for birds, photo Cessa Rauch

During the waiting times we didn’t let our time go to waist, with binoculars we scanned the air and shore for birds.

After waiting for some time, the plankton net was brought back on board and contained, besides jellyfish and other pelagic planktonic dwellers, many million copepods. Mostly consisting of a few species. One of the species had a distinguishable blue egg sack, this is Paraeuchaeta norvegica (Boeck, 1872). This species is an active predator that feeds on other (smaller) copepods by rapidly jumping on them and catching their prey with their large maxillipeds (mouthparts).

 

 

The second day HYPCOP joined head engineer Bjørn Reidar Olsson (UiB) and PhD student Miguel Meca (UiB)

HYPCOP (Cessa Rauch left) joining Miguel Meca (middle) and Bjørn Olsson (right), photo Cessa Rauch

They were looking for shark teeth and polychaetes (marine worms) respectively and used the grab, which is perfect for benthic copepod sampling. The grab is basically a big metal clamshell that collects sediment from the seafloor. Working with grab samples gets dirty very quickly, you have to wash through the sediment to find your animals.

The grab with Cessa Rauch (HYPCOP left), Miguel Meca (middle) plus operator Bjørn Frode Grønevik (right), photo Bjørn R. Olsson

Most of the sediment was filtered out in order to find our copepod friends. Although less plentiful in comparison to the plankton net sampling the previous day, we still found some copepods hiding in the dirt. At moment of this writing, the the copepod species we collected have not be named yet, however, the last months we have been experimenting with barcoding the first batch of 60 different specimens. We had a 43% success rate. Usually, marine invertebrates have a success rate between 40 – 70%, so it was still within the margin, but not with a lot of enthusiasm. HYPCOP will spend the remainder of 2020 and the beginning of 2021 in the laboratory figuring out what the culprit of this low success rate could be.

For HYPCOP this will be the last blog before the Christmas holidays and the New Year. Therefore, we want to take the opportunity to wish you happy holidays and hope to see you around in 2021 with from us more copepod news to share!

-Cessa

Follow HYPCOP @planetcopepod

Instagram, for pretty copepod pictures https://www.instagram.com/planetcopepod/

Twitter, for copepod science news https://twitter.com/planetcopepod

Facebook, for copepod discussions https://www.facebook.com/groups/planetcopepod

See you there!

Fieldwork at Sletvik Fieldstation!

From Monday 12th of October till Monday the 19th a bunch of different projects funded by the Norwegian taxonomy initiative travelled up North together to meet up with researchers from NTNU in the NTNU Sletvik field station.

Front of Sletvik fieldstation main building, photo credits Nina T. Mikkelsen

Sletvik fieldstation is NTNU owned and is a short drive from Trondheim. The Germans built the station during the Second World War. Ever since it has been used as a town hall, a school and a shop. In 1976 the NTNU University took over the building and transformed it into a field station, which it remains ever since. The entire station contains of two buildings that has room for a total of 75 people (Before Corona). The main building has a kitchen, dining and living room plus a large teaching laboratory, a multilab and two seawater laboratories. Besides it has bedrooms, sauna, laundry rooms, and showers, fully equipped! The barracks have additional bedrooms and showers, all in all, plenty of space.

 

From the Natural History Museum of Bergen, 5 current running projects would use the NTNU fieldstation facilities for a week in order to work on both fixed as well as fresh material. Besides HYPCOP (follow @planetcopepod), we had Hardbunnsfauna (Norwegian rocky shore invertebrates @hardbunnsfauna), Norhydro (Norwegian Hydrozoa), Norchitons (Norwegian chitons @norchitons) and NorAmph2 (Norwegian amphipods) joining the fieldwork up North!

Lot of material needed to be sorted, photo credit @hardbunnsfauna / Katrine Kongshavn

 

At the Sletvik fieldstation, a lot of material from previous fieldwork was waiting for us to be sorted.

For HYPCOP we wanted to focus mostly on fresh material, as this was a new location for the project. And not just new, it was also interesting as we have never been able to sample this far north before.  Almost every day we tried to sample fresh material from different locations around the fieldstation

Cessa and Francisca on the hunt for copepods, photo credits Katrine Kongshavn)

On top of that we aimed to sample from different habitats. From very shallow heavy current tidal flows, rocky shores, steep walls, almost closed marine lakes (pollen called in Norwegian) and last but not least, sea grass meadows

Different habitats give different flora and invertebrate fauna, photo credits Nina T. Mikkelsen

Sampling we did by either dragging a small plankton net trough the benthic fauna or the most efficient way, going snorkeling with a net bag

Ready for some snorkeling with Cessa and August, photo credits Torkild Bakken

Benthic copepod species tend to cling on algae and other debris from the bottom, so it is a matter of collecting and see in the laboratory whether we caught some copepods, which, hardly ever fails, because copepods are everywhere!

Copepods are difficult to identify due to their small nature, differences between males, females and juveniles’ and the high abundance of different species. Therefore, we rely heavily on genetic barcoding in order to speed up the process of species identification. So, after collecting fresh material, we would make pictures of live specimens to document their unique colors, and then proceed to fixate them for DNA analyses.

Yet unidentified copepod species with beautiful red color, photo credits Cessa Rauch

Winter Wonderland! Photo credits Cessa Rauch

The other projects had a similar workflow so you can imagine, with the little time we got, the Sletvik fieldstation turned into a busy beehive! One week later we already had to say goodbye to the amazing fieldstation, and after a long travel back (even with some snow in the mountains), we finally arrived back in Bergen where unmistakably our work of sorting, documentation and barcoding samples continued!

If you are interested to follow the projects activity, we have social media presence on Twitter (@planetcopepod, @hardbunnsfauna, @norchitons), Instagram (@planetcopepod, @hardbunnsfauna, @norchitons) and Facebook (/planetcopepod /HydrozoanScience).

 

-Cessa

Sea slug day 2020; Jorunna in the spotlight

Today we celebrate Sea Slug Day! ✨

The day coincides with the birthday of Terry Gosliner, who has discovered one-third of all known sea slug species (more than a 1000!). Here’s a link to how October 29th became #SeaSlugDay.

And what better way to celebrate it than introducing a new species to the world. Today it will all be about the Jorunna tomentosa species complex that our master student Jenny Neuhaus studied for the last two years.

Jorunna tomentosa, picture Cessa Rauch

Jorunna tomentosa is known to occur in a wide variety of colour patterns, which tossed up the question whether we are actually looking at a single species at all, or maybe dealing with cryptic lineages.

The colour diversity of Jorunna tomentosa, picture by Anders Schouw, Nils Aukan, Cessa Rauch, Manuel A. E. Malaquias

Jenny compared specimens from Norway, Ireland, Spain, Azores and South Africa, both genetically as well as anatomically. She used different gene markers like COI, 16S & H3 to check how these morphotypes compare with each other and evaluate the meaning of genetic distances. But she also did an elaborate morpho-anatomical study to look for differences between these colour patterns. Together with Dr. Marta Pola in Madrid, they dissected the different J. tomentosa specimens and looked at parts of the digestive (radula & labial cuticles) and the reproductive systems. These are all key to help unraveling putative different species and characterize them.

About Jorunna tomentosa

Jorunna tomentosa has an oval-elongate body shape with different colours varying from grey-white to cream-yellow and pale orange. They can reach a size up to 55 mm and occur at depths from a few meters down to more than 400m. they feed on sponges of the species Halichondria panicea, Haliclona oculata and Haliclona cinerea. J. tomentosa can be found from Finnmark in northern Norway, southwards along the European Atlantic coastline, the British Isles, the French coast, Iberian Peninsula, Mediterranean Sea up to Turkey, and the Azores and Canary Islands,. Besides the species has even been recorded from South Africa.

Before Jenny studied J. tomentosa, the various colour morphs were regarded as part of the natural variation of the species. By combining molecular phylogenetics with morpho-anatomical characters Jenny investigated the taxonomic status of the different colour morphs of J. tomentosa.

Jorunna sp. nov.?

Jenny sequenced 78 specimens of which 60 where successful for using in the final phylogenetic analyses. Her results supported a new Jorunna species, and a possible case of incipient speciation in J. tomentosa with two genetic lineages morphologically undistinguishable.

From left to right Jorunna spec. nov. Jorunna tomentosa lineage A and down Jorunna tomentosa lineage B

The new Jorunna species was based on material collected from Norway (Kristiansund, Frøya & the North Sea). Jorunna spec. nov. has a distinct colour pattern of cream-yellow with dark small dots (plus, as important; major differences in the radula and reproductive system).

Jorunna spec. nov.

It has been our pleasure to have Jenny here as a student, and she has done excellent work. Last year she won best student poster award last year with her work on Jorunna tomentosa at the World Congress of Malacology in California, USA. Most recently, Jenny defended her thesis on October 26 and passed with an A for her great work – congratulations from all of us at the Museum!

-Cessa Rauch

Sea slugs of Norway Instagram: @seaslugsofnorway

Sea slugs of Norway Facebook: www.facebook.com/seaslugsofnorway

Sea slugs of Southern Norway; farewell but not goodbye!

A note from the Norwegian Taxonomy Initiative project (artsprosjekt) “Sea Slugs of Southern Norway” (project home page), which ran from 2018 to the end of April 2020.

Dear all,

The Sea slugs of Southern Norway project reached its terminus at the end of April, with sending the last reports of our collection and research efforts to Artsdatabanken (the Norwegian Biodiversity Information Centre).

What we have been able to build up these last two years is of immense importance for the scientific collections of the Natural History Museum of Bergen (University of Bergen)  and for (Norwegian) biodiversity research.

Sea slugs of Southern Norway managed to collect over 1000 lots covering 93 different sea slug species, of which 19 are new for Norway and a few new to science (we are working on it!).

Below are photos of the species that were collected at different sampling events.  The photos are made either by the researchers associated with the project, or by the amazing team of citizen scientists.

Look at these beauties!

This would absolutely not have been possible without the special effort of our knowledgeable citizen scientists, and we would like to use this opportunity to name a few that were extraordinarily productive during the last years and provided the project and the Museum with valuable samples; Nils Aukan, Roy Dahl, Viktor Grøtan, Heine Jensen, Tine Kinn Kvamme, Runa Lutnæs, Ole Christian Meldahl, Jenny Neuhaus, Bjørnar Nygård, Anders Schouw, Erling Svensen, Cecilie Sørensen, Mona Susanne Tetlie, Anne Mari with Ottesen, Mandal Dykkerklub, Hemne Dykkerklubb, Slettaa Dykkerklubb, SUB-Studentes Undervannsklubb Bergen, Larvik Dykkerklubb, Sandefjord Dykkerklubb, and all the others that made big and small contributions.

A big thank-you to all contributors!

Would you like to know more about the citizen scientists part of the project? Check out this paper (starts on page 23) by Cessa and Manuel: Sea Slugs of Southern Norway: an example of citizens contributing to science.

Mandal team

One of the core components of the projects success was our outreach effort on all kind of social media platforms. During these two years these platforms got much more traffic than we initially thought; apparently we have many Norwegian sea slug fans, within and outside of Norway!

Therefore we decided to continue with our outreach efforts to keep everyone engaged and up to date about these wonderful animals in our ocean backyard, but with some minor adjustments. Some of you might have already noticed a few changes during the last days on the Facebook page  and our Instagram account. From today onward, the social media pages will cover sea slugs of all of Norway, and is now named accordingly. We also welcome a new admin to the facebook group: Torkild Bakken of NTNU University Museum. Welcome Torkild, the more expertise the better, so we are very happy to have you onboard!

We encourage everyone in this community to continue to be active and share your findings and knowledge with other.

Let’s carry on enjoying the wonderful world of sea slugs of Norway!

 

-Cessa & Manuel

 

Research Internship – Francesco

In the last part of 2019 Francesco Golin collaborated with us as an intern in project NorHydro. Francesco is a student at the University of Algarve, where he is enrolled in the International Master of Science in Marine Biological Resources (IMBRSea). We asked him about his internship and this is what he told us:

During the 2019 autumn semester I joined Luis Martell and Aino Hosia in project NorHydro as a research intern. My research contribution was aimed at finding how many species of the hydrozoan genus Euphysa are present in Norwegian waters, and how to define them morphologically and genetically. Euphysa is a common genus with 22 accepted species, but many of them are not easy to tell apart from each other, which is why we decided to implement an integrative approach for species delimitation including morphological and molecular analyses.

Some of the species of Euphysa occurring in Norway. From left to right: Euphysa aurata, Euphysa flammea, and Euphysa sp

Working on board during the cruise

My first mission as an intern was collecting some samples of Euphysa and other gelatinous organisms. Luckily, the opportunity to do so presented itself during the student cruise associated to BIO325, a course in which I participated as part of my studies at UiB.

During this cruise I used a light table to spot the tiny jellyfishes brought on board by the Multinet, then I placed them on a Petri dish and took pictures of them with a camera attached to a stereomicroscope, before transferring them to an Eppendorf tube filled with ethanol.

All these elements (the pictures of each organism, the associated sampling data, and the samples themselves) are needed for species delimitation of hydromedusae. The pictures are used to compare the morphology of different individuals and to identify important diagnostic characters (unfortunately, ethanol-fixed jellyfish are not useful for morphological analysis), while the ethanol-preserved samples are used to obtain DNA sequences.

The light table used to spot the gelatinous zooplankton

Some siphonophore parts are very transparent, and thus they are some of the most difficult animals to spot in plankton samples.

The hydrozoan Aglantha digitale (left) was very abundant in all my samples. Other cnidarians, such as this anthozoan larva (right) were also present.

My second mission consisted on gathering the original descriptions of the different species of Euphysa. This information is necessary if we want to understand what makes each species different, and will come handy when analyzing the individuals and their pictures collected on the field. Talking about species boundaries, I had the opportunity to attend a course on “Molecular Species Delimitation” offered by the University Museum. In this course I learned how to perform the analysis of DNA sequences for species delimitation, using some common software (MEGA and R) for this purpose. These are important tools that will allow us to assess the diversity of Euphysa in Norway, and together with the morphological analyses these data will help us determine if new species have to be described.

Now the semester has ended and my internship is over. Nevertheless, I hope my help was meaningful, as I want to continue being a part of this research project in the future. I will keep myself updated with the changes in the taxonomy of Euphysa, so I’m sure I will be able to join NorHydro again when I’ll come back to Bergen!

-Francesco

Guest researcher: Eric

Eric, from the Federal University of ABC, visited the University Museum in November. We asked him about his time in Bergen examining some of the least common species of siphonophores in the collections and this is what he told us:

My name is Eric Nishiyama, and I am a PhD student from Brazil. The main focus of my research is the taxonomy and systematics of siphonophores, a peculiar group of hydrozoans (Cnidaria, Medusozoa) notorious for their colonial organization, being composed of several units called zooids. Each zooid has a specific function within the colony (such as locomotion, defense or reproduction) and cannot survive on its own.

Fig_1. I had the opportunity to examine both ethanol- and formalin-fixed material from the museum. For morphological analyses, specimens preserved in formalin are preferable because ethanol-fixed individuals are usually severely deformed due to shrinkage.

Understanding how zooids evolved could provide major insights on the evolution of coloniality, which is why I am looking at the morphology of the different types of zooids. In this sense, siphonophore specimens available at museum collections provide valuable information for visiting researchers such as myself.

During my short stay at the University Museum of Bergen in November, I was able to examine a few siphonophore samples deposited at the museum’s collections. By examining the specimens under a stereomicroscope, and using photography and image processing tools, I was able to gather a lot of information on the morphology of several species.

Fig_2. Documenting the morphology of the nectophores of Rudjakovia plicata (left) and Marrus or-thocanna (right) was particularly interesting because these species are not commonly found in museum collections.

Fig_3. Other ‘unusual’ siphonophores that I was able to examine were Crystallophyes amygdalina (left) and Heteropyramis maculata (right).

Fig_4. Some large nectophores of Clausophyes preserved in formalin.

The data obtained will allow me to score morphological characters for a phylogenetic analysis of the whole group, and hopefully will help me revise the group’s taxonomy.

– Eric