Category Archives: Mollusca

Sea slugs from Vestfold

Larvik & Sandefjord 22.10.2019 – 27.10.2019

From October 22 to October 27, Sea slugs of Southern Norway crossed the Hardangervidda mountain pass to pay a visit to Larvik Dykkeklubb (LDK) and Sandefjord Dykkeklubb (SDK). Vestfold, in particularly the Larvik area, was a thorn in the side for the sea slug project. With fieldwork and collection trips covering most of the Hordaland area (Bergen, Espegrend), Rogaland (Egersund), Mandal (Vest-Augder), Drøbak (Oslofjord area) a lot was left to be discovered still for Aust-Agder and Vestfold. Therefore, a visit to Vestfold was very high on our bucket list.

With Winter just around the corner, we decided to squeeze in a short fieldwork trip to Larvik just before the end of 2019. Me and Anders Schouw drived from Bergen to Larvik with our rented caddy to meet up with Tine Kinn Kvamme and members of the LDK. On Tuesday morning, after packing our mobile laboratory in the car, we drove off to Larvik. In the early evening we arrived at the LDK, there we were welcomed by Lene Borgersen from LDK, who facilitated access to the clubhouse for sorting sea slugs during our stay. That evening was also a club members evening, and I took that opportunity to give a presentation about sea slugs and the Sea slugs of Southern Norway project

It was a great evening talking about sea slugs with interested club members while eating pizza! The next day Tine, Anders and I met up with LDK member Mikkel Melsom, who joined to help on our hunting for sea slugs

Picture 2. Some sea slugs from Larvik; from left to right; Limacia clavigera, Edmundsella pedata, Diaphorodoris luteocincta, Tritonia hombergii, Tritonia lineata and Cadlina laevis. Photo credits Anders Schouw

Later that day we met up at the SDK clubhouse with Stein Johan Fongen, where I had the opportunity to once again talk about sea slugs this time to the SDK members. This was a very special evening because among the audience, besides SDK members, we also had students from Sandefjord videregående skole (Sandefjord High School)

Sea slug presentation for students of the Sandefjord videregående skole and Sandefjord Dykkeklubb members. Photo credits Tine Kinn Kvamme

In the following days several members of the SDK also joint us collecting sea slugs. Despite the fact that October is known for being not an ideal season to find sea slugs (most species are observed during Winter and (early) Spring) we still somehow ended up with hours of sorting work at the Larvik clubhouse

Cessa Rauch & Anders Schouw sorting sea slugs in the Larvik clubhouse. Photo credits Tine Kinn Kvamme

Overall, we collected 21 different species, all newly registered specimens for the project with regard to this part of the country. It would be great to see what the species abundance would be during a sea slug season like February or March!

Overview of the species collected at Larvik and the Sandefjord area

Besides sea slugs and enthusiastic club members, another highlight of the week was a visiting seal at SDK! On our last day of fieldwork, a young seal was very bold and decided to rest close to the clubhouse in the harbor. It let people come up really close, which was great for making cute seal pictures. Cherry on the cake, in my opinion!

Young seal in the harbor close to the Sandejord Dykkeklubb. Photo credits Anders Schouw

On Sunday the tree of us had to say goodbye, Tine would go back to her hometown Oslo and Anders and I would cross the snowy mountains again back to Bergen. It was a short but sweet visit and great opportunity to meet members of Larvik and Sandefjord dykkerklubbs. I therefore want to thank LDK and SDK for their interest, enthusiasm and help for the few days Anders, Tine and I were around. I surely hope we will meet again next year, and find many more sea slugs. And of course, thanks to Anders and Tine for helping again, hope we can share many more sea slug adventures together

Left to right; Tine Kinn Kvamme, Cessa Rauch and Anders Schouw in front of the Larvik Dykkeklubb were most of the ‘lab’ work was done. Photo credits Lene Borgersen

More sea slugs: 

Do you want to see more beautiful pictures of sea slugs of Norway? Check out the Sea slugs of Southern Norway Instagram account; and don’t forget to follow us. Become a member of the Sea Slugs of Southern Norway Facebook group, stay updated and join the discussion! Hunger for more sea slug adventures, check our latest blog posts.

Explore the world, read the invertebrate blogs!

– Cessa

World Congress of Malacology 2019: 10 – 17 August 2019

On August 10, four delegates from the University Museum of Bergen made their way to Monterey Bay California, USA.

Attending the World congress of Malacology 2019, from left to right; Jenny Neuhaus, Justine Siegwald, Manuel Malaquias & Cessa Rauch

This year the World Congress of Malacology took place at the Asilomar conference grounds in Pacific Grove, Monterey. Monterey Bay is well known among many marine biologists due to its world-famous aquarium and aquarium research institute (MBARE), many marine protected areas (7; including the Asilomar State Marine reserve, close to where the conference was held), Hopkins Marine Station of Stanford University, Steinbeck Center (although located in Salinas, close enough to make it count). The latter was named after the famous marine biologists John Steinbeck and Ed Ricketts from the Monterey County; Among other works they contributed to marine biology with their famous books ‘The sea of Cortez’ and ‘Between Pacific Tides’. All in all, Monterey Bay seems like an exciting place to be for us marine biologists.

The World Congress of Malacology was organized and chaired by the famous Terry Gosliner (Terry described more than 1000 species of sea slugs!) a senior curator of the California Academy of Sciences. About 300 participants contributed to a very lively and busy scheduled week

Some of the participants of the World Congress of Malacology 2019

Registration for the conference started on Sunday the 11th of August, but Monday was the real kick off of the program with fabulous keynote speakers such as Geerat Vermeij, David Lindberg, Susan Kidwell, etc.. During the poster session Jenny Neuhaus and Cecilie Sørensen, two of our master students working in close collaboration with the Museum project Sea Slugs of Southern Norway have presented their preliminary results. Unfortunately, Cecilie could not join us due to time constraints, and the poster was presented by Cessa

Justine presenting her work on Scaphander

On Tuesday we had a crammed agenda with multiple speakers talking at the same time, divided over the different halls in a variety of sessions. It was a busy day of running around trying to catch those talks one were most interested in. Justine had her talk in the Systematics session about her PhD research on Scaphander titled; First global phylogeny of the deep-sea gastropod genus Scaphander reveals higher diversity, a possible need for generic revision and polyphyly across oceans. It received a lot of attention and numerous questions afterwards, it was great to see how her research was perceived with so much curiosity and enthusiasm.

Wednesday we had a day off filled with several excursions. Jenny went to the whale watching trip, Justine went to spot marine mammals and Cessa to a trip along the coast to meet and greet the Californian red giants. The trips were all well organized and a very nice break off the week as the many presentations and sessions made the days long and intense. The whale watching trip took place in Monterey Bay and Jenny was lucky enough to observe the mighty blue whale, Balaenoptera musculus, plenty of humpback whales (Megaptera novaeangliae), and several sunfish (Mola mola) swimming at the surface. It was an incredible experience for her to be able to watch the animals thrive in the great Pacific Ocean.

Whale-watching with Jenny Neuhaus in Monetery Bay

Cessa walking in between the Californian red giants

 

The trip to South Monterey was along the California’s rugged coastline and provided one of the most spectacular maritime vistas in the world. It has peaks dotted with the coast redwoods that go all the way to the water’s edge. The trip took you to Pfeiffer Big Sur State Park where we got the opportunity to walk through the redwood forest. Along the way we stopped at numerous scenic vistas, it was definitely a memorable day .

 

On Thursday, all well rested, we had another hectic day full of presentations, this time it was Cessa’s turn, she would talk about the ‘Sea slugs of Southern Norway project as an example of citizen science’ (Picture 8. Cessa presenting the sea slugs of Southern Norway project). It was placed in the citizen science session and many that attended had questions about citizen science which constituted a great opportunity to share our experience acquired during the last year of our project.

Cessa presenting the sea slugs of Southern Norway project

Friday, on the last day of the conference, Manuel had his talk about the phylogeny and diversity of the Indo-West Pacific gastropods Haloa sensu lato (Cephalaspidea: Haminoeidae): Tethyan vicariance, generic diversity, and ecological specialization. This was part of the recent collaborative work his previous PhD student Trond Oskars

Manuel Malaquias presenting his and Trond’s work on the phylogeny of Haminoeidae

Jenny Neuhaus won the best poster award for her research on Jorunna tomentosa

 

The day was closed off with a big dinner and the award ceremony. Prizes were handed out to the best student’s oral and poster presentations. Jenny was awarded by the Malacological Society of London the prize for the best student poster. This was a very exciting way to end a successful conference trip!

 

 

 

-Cessa & Jenny

Success in the South; fieldwork in Mandal

From May 20th to 27th the sea slugs of Southern Norway team headed South to Mandal to pay a visit to the Mandal dykkerklubb and try to find more enthusiastic citizen scientist to join the sea slug project. We had a few special guests invited for the week and the team consisted of Cessa Rauch, Manuel Malaquias, Anders Schouw, Erling Svensen, Nils Aukan, Tine Kvamme and Heine Jensen. In Mandal the head of the club Erling Tønnessen would be there to help us around and organize club activities for collecting the sea slugs.

The first day basically consisted of traveling to Mandal and setting up our “hyttes” for a week of sea slug hunting. As usual we underestimated the amount of space needed to bring our ‘mobile’ lab to the camping site in Mandal. Even though a station wagon theoretically fit a family of five plus luggage, it was barely enough space for a family of sea slug hunters with their equipment.

Picture 1. We accomplished to fit everything in this rental car, picture Cessa Rauch

We ended up with a challenging Tetris game and me being squeezed between microscopes and jars in the back seat, still, no complaints! At least I was spared for driving the long hours from Bergen all the way to Mandal, that every local would be able to fix in less than 7 hours, we managed to take 12. I guess the car was heavy loaded! Manuel did a fantastic job while Anders and me where dozing off. Eventually we managed to arrive safely in Mandal and there we were greeted by our team of citizen scientists that helped us out through the week. They as well had to travel from all corners of the country; Kristiansund, Egersund, Oslo and Sarpsborg. It was quite special to arrive all together in Mandal with only one thing in our minds; finding sea slugs!

The next days in collaboration with the local Mandal dykkerklub and their fantastic club boat equipped with a lift to get people in and out of the water, we operated most of the sampling activities. After a day out collecting we would all go back to our cabins and start photographing and registering the samples.

Even though late spring is supposedly not the best season for collecting sea slugs, due to low abundance of the different species, together we were still able to collect 47 different species!

Picture 4. Overview of the species collected during fieldwork in Mandal

On our last day of the expedition, the Mandal dykkerklubb organized an evening social gathering for their members in which we had the chance to give a presentation about sea slugs and the project, and to give away a few sea slug sampling kits to all those interested.

Picture 5. Cessa and Manuel presenting the sea slugs of Southern Norway project, picture Erling Svensen

Picture 6. Interested dive members of the Mandal dykkerklubb showing up to learn more about sea slugs and having a good time, picture Erling Svensen

With every fieldwork trip we get more experienced in the organization and execution of the event and this is definitely paying off in the diversity of species we manage to collect. We were not able to register so many species before as with this fieldwork trip to Mandal. This was by far the most successful expedition and together with the joined efforts off all the excellent citizen scientist we formed a real professional sea slug team!

Picture 7. Group picture of the expedition members on board of the Mandal dykkerklubb boat, left to right; Heine Jensen, Erling Svensen, Anders Schouw, Cessa Rauch, Tine kinn kvamme, Nils Aukan and the expedition leader Manuel Malaquias in front, picture Erling Svensen

At the moment we are waiting for the first DNA barcode results in order to confirm the species diversity we found that week. An update will follow; but Manuel and I would like to take this opportunity to gratefully acknowledge all the efforts and interest of our team members of that week and the good times we had together! Hope to meet you all again soon during yet another sea slug hunt! Tusen takk!

-Cessa

Door #19: Photosynthetic vs solar-powered sea slugs

I think we can all agree that sea slugs are amazing creatures. Some species contain toxins that are useful for cancer research and others are photosynthetic! There are a few species of sea slugs that have the ability to photosynthesize. But beware; the ability for them to do the thing that plants and algae are good at (photosynthesis), doesn’t always mean they are solar-powered. And I will explain you in the next few lines what I mean with that.

There are two families of sea slugs known to have a few species within them that can photosynthesize; it’s within the family of Facelinidae and the family of Sacoglossa.

Within the family of Facelinidae we have the genus Phyllodesmium; and all species in this genus are considered solar-powered, meaning that they get a part of their daily energy intake via photosynthesis. At the moment the theory goes that they are able to do so as they contain photosynthetic zooxanthella stolen from their feeding source (soft corals), and they continue to ‘farm’ these zooxanthellae in their own bodies. The species Phyllodesmium longicirrum masters this trade and is best known as the solar-powered Phyllodesmium

Solar-powered Phyllodesmium longicirrum by Jason R. Marks

The other family does things quite differently but nevertheless as impressive; those are the Sacoglossa.

A few representatives of the photosynthetic sea slugs within the Sacoglossa

Unlike Phyllodesmium, they don’t farm zooxanthella but they steal the photosynthetic cell organelles (chloroplasts or plastids) from the algae they feed on; also known as kleptoplasty (Kleptes (κλέπτης) Greek for thief). Approximately 140 years ago these sea slugs were first described by de Negri and de Negri, who discovered that these sea slugs were green colored due to foreign ‘bodies’ that were reminiscent to those known from plants. It took at least another 100 years before the ‘granule bodies’ were identified to be chloroplasts from the algae the slugs feed on. Sacoglossa are also known as sap-sucking sea slugs because of the way they eat their algae; at first, the sea slugs pinch a whole in the algae wall with their special teeth, called the radula. Then they suck out the cytosolic content of the algae (hence the name sap sucking sea slugs). Finally, the cytosol content is being digested in the digestive tract that perforates the entire body and within some species the chloroplasts are being sequestered and continue to photosynthesize in the animal’s digestive cells

Sap-sucking slug sequestering chloroplasts from the algae it feeds on (figure from Rauch et al. 2015)

Although the sea slugs are famous for their ability of stealing chloroplasts, they only represent a minority within the Sacoglossa. In fact, only 6 out of 300 described species, can keep the chloroplasts fully functional for long term, or long-term retention species; that is the chloroplasts are photosynthetic active for longer than 21 days after sequestration. The gross majority are either short term retention species (with functional chloroplasts up to 14 days or more) or cannot retain the chloroplasts at all (called non-retention species). This means that the chloroplasts are immediately being digested like the rest of the algae content.

So why are Sacoglossa photosynthetic but not solar powered like Phyllodesmium? Well this is because numerous studies observed how the sea slugs died as soon as they were being starved (meaning they couldn’t eat their algae food anymore) even though they had photosynthetic active chloroplasts in their cells. Besides, based on CO2 fixating measurements, it turned out that 99% of the sea slug has to live from normal ingested food, like all other animals do. This could very well explain why only 6 out of the 300 described species are able to sequester chloroplasts long-term, and apparently for reasons other than carbon fixation!

The take home message is that this case of photosynthetic and solar-powered sea slugs is a great example of how good science is about resisting the pull of easy conclusions. When something seems right at first, it should still be testified!

Furthermore
Interested in photosynthetic sea slugs? You can read more in the following papers that are also used as source for this blog:

  1. A sea slug’s guide to plastid symbiosis (2015) J De Vries, C Rauch, G Christa, SB Gould, Acta Societatis Botanicorum Poloniae 83 (4)
  2. Why it is time to look beyond algal genes in photosynthetic slugs (2015) C Rauch, J Vries, S Rommel, LE Rose, C Woehle, G Christa, EM Laetz (…), Genome biology and evolution 7 (9), 2602-2607
  3. On being the right size as an animal with plastids (2017) C Rauch, P Jahns, AGM Tielens, SB Gould, WF Martin, Frontiers in plant science 8, 1402
  4. Mitochondrial Genome Assemblies of Elysia timidaand Elysia cornigera and the Response of Mitochondrion-Associated Metabolism during Starvation (2017) C Rauch, G Christa, J de Vries, C Woehle, SB Gould, Genome biology and evolution 9 (7), 1873-1879
  5. The ability to incorporate functional plastids by the sea slug Elysia viridisis governed by its food source (2018) C Rauch, AGM Tielens, J Serôdio, SB Gould, G Christa, Marine Biology 165 (5), 82

Would you like to see pictures of sea slugs that you can find in Norway? Check out the Sea slugs of Southern Norway Instagram account,and don’t forget to follow us!
Become a member of the sea slugs of Southern Norway Facebook group, stay updated and join the discussion.

Explore the world, read the invertebrate blogs!

Door #17: Sea bunnies of Norway?

Some years ago, in 2015, the internet was taken a storm by the sudden rise of the so-called sea bunnies. It all started with a video taken the year before by a SCUBA diver in Japan who filmed the little creatures crawling around the seabed:

The species seen in the video is called Jorunna parva, and are since then worldwide unofficially known by the adorable pet name ‘sea bunny’ as it has a ‘fur’ like exterior with tiny upright ‘ears’ and a fluffy tail like bunnies do. The ‘fur’ is actually created by bunches of tiny rods, called the caryophyllidia. The caryophyllidia are arranged around little knots that are often dark coloured, which create the illusion of black dots on the animals. The seemingly ears are the animals rhinophores, that function as chemical receptors that make the animal able to detect its environment in search of food and other sea bunnies. Its tail on the back are actually its gills to extract oxygen molecules from the surrounding water, the ‘fluffier’ it is, the bigger the surface area, the easier it is to diffuse oxygen from the water. This sea bunny is small, often less than 2.5 cm, and can be found throughout the Indo-Pacific; from South Africa to Central Pacific. They have, like many sea slugs do, a high degree of colour polymorphism in the species, with colours varying from white with black dots, to yellow and even bright orange:

Different colours of Jorunna parva, aka the sea bunny (photo credits on image)

Unfortunately, our sea bunny J. parva is only short-lived and just lives from a few months up to a year, but at least during its short life it doesn’t need to worry about predators. They are very toxic, because of the food they eat, which are sponges. All dorid nudibranchs (the group of slugs J. parva belongs to) are toxic because of their diet, and these toxins are often used in cancer treatments for people. Who would have thought that sea bunnies would be lifesavers, besides  being cute? But is the word sea bunny only referring to this particular species called J. parva? A quick search on the internet definitely tells us otherwise, it seems people refer to sea bunnies when they talk about any other dorid nudibranch with a fluffy and round appearance.

So, the question remains, do we have any sea bunnies in Norway? And the answer is yes, we do!

Sea bunnies of Norway (click to enlarge!)

And they are absolutely great and adorable to encounter underwater. Let us make a list of the sea bunnies of Norway, so we know what species we are talking about. Sea bunnies of Norway are; Doris pseudoargusGeitodoris planataJorunna tomentosaRostanga rubraCadlina laevis, Aldisa zetlandicaAdalaria loveniAdalaria proximaOnchidoris muricataOnchidoris bilamata,
Onchidoris pussilaOnchidoris depressaAcanthodoris pilosaDiaphorodoris luteocincta and I personally would draw the line at Goniodoris nodosa, as the other Goniodoridae don’t resemble that much the typical sea bunny characteristics. What do you think? Which species do you think are missing in this list, or which species should be left out?

I think it is time to take over the internet with our sea bunnies of Norway!

 

Furthermore
You want to see more beautiful pictures of sea slugs of Norway!

Check out the Sea slugs of Southern Norway Instagram account; and don’t forget to follow us.
Become a member of the sea slugs of southern Norway Facebook group, stay updated and join the discussion.

Explore the world, read the invertebrate blogs!

-Cessa

Door #16: Basic anatomy of the sea slug

Haminoea sp, photo by M. Malaquias

“Sea slugs” include both the by far most famous nudibranchs, and groups such as the Sacoglossa (sap-sucking slugs, more about these later in the calendar!) and Cephalaspidea (the bubble snails), amongst others. These latter ones often do have shells – but reduced ones, too small for the animals to completely retreat into, like this Haminoea:

Nudibranchs, however, are the “naked” snails: Their name “nudibranch” comes from the Latin nudus, naked, and the Greek βρανχια, brankhia, gills. They don’t have a shell, but this wasn’t always the case. In their early larval life stage, they actually have a shell, but when settling down and transforming from zooplankton into adults, they lose the shell. The loss of the shell in adults might be responsible for the amazing diversity we see in body forms present in sea slugs.

So, in this basic anatomy of sea slugs we will focus mostly on the body forms of nudibranchs, but all other sea slug orders are not far off from this anatomy, if you know the basics of nudibranchs, you can extrapolate to the other orders as well. So here we go!

Nudibranchs are roughly divided in two type of body forms; the dorid nudibranchs and the aeolid nudibranchs.

Two basic body types found within the Nudibranchia; the dorids and the aeolids. (Illustration: C. Rauch)

The dorid nudibranchs have a thick mantle that extends over their foot. In some species the surface of the mantle is covered with tubercles than can vary in different sizes, numbers and shapes. This gives them often a rigid body that offers some protection.  In most of the dorids it is the mantle that contains toxins to defend themselves, the toxins are extracted from their food sources.

Aeolid nudibranchs have mantles that are covered with finger-like extensions called cerata. The cerata are very special as they contain branches of the digestive tract, and in some species, this is also visible! The tips of the cerata contain special organs called the cnidosacs. Cnidosacs store stinging cells (called nematocysts). These are obtained from their food source which are often cnidarians like hydroids, sea-anemones and soft corals. The cnidosacs are activated when the nudibranchs feel threatened and the stinging cells will be discharged!

All sea slugs have rhinophores. On the head of all sea slugs you can find a pair of sensory tentacles called the rhinophores. They detect smell and taste and in most of the dorid nudibranchs the rhinophores can be retracted into a basal sheath. Sea slugs know all kind of shapes of rhinophores which are a very important tool for identification of the species.

Diversity of sea slug rhinophore shapes

Besides a pair of rhinophores many nudibranchs also have a pair of oral tentacles, one on each side of the mouth. They are most likely involved in identifying food by taste and touch.

Sea slugs also need to breathe oxygen. They do this via the surface of their entire bodies, but their main reparatory organ are their gills. Dorid nudibranchs have often a feather like structure encircling their anus on the back of their body (the branchial plume). Some dorid species can also retract their gills into a pocket. Within the aeolid nudibranchs the cerata act like gills by diffusing oxygen from the surrounding water. The cerata are sometimes branched in order to increase the surface area, also here, like the rhinophores, different species can have different forms of cerata.

Diversity of aeolid cerata shapes

-Cessa

Door #12: Meet the chitons!

Some molluscs, like snails, clams, mussels and octopuses are familiar to most people, but others are more unknown. Among these are the flattened, shell-bearing chitons (skallus/leddsnegler in Norwegian). They are commonly found clinging to rocks in the intertidal zone, and can be found all along the coastline. Many species can be colourful, with stripes, dots and zigzag lines ornamenting the shell plates.

Tonicella marmorea, a common species of chiton in Norway. Photo N. Mikkelsen

The scientific name, Polyplacophora, translates to “bearer of many plates”, and refers to the eight hard shell plates covering the animal. The shell provides protection from predators, and the organization of the shell into eight separate plates also provides flexibility— if disturbed, some species can roll up into a ball like a hedgehog. Surrounding the shell is a tough girdle, which in many species is covered in scales or spines, which also serve to deter any predators.

On the underside, the chiton has a muscular foot that is used for movement and for attaching firmly to the rocks that they live on. They rasp food, like encrusting algae and animals, from the substrate with their radula, a tongue-like structure with several rows of tiny teeth. The teeth are often reinforced with minerals to make them extra durable for scraping on rocks.

The underside of the chiton Tonicella marmorea. The muscular foot can be seen the centre. The gills are seen around the foot to the right. The head with the mouth can be seen on the left side. Photo N. Mikkelsen

Chitons are found in habitats from the intertidal down to depths of several thousand meters, usually on stones or rocky surface. Some species have adapted to other habitats. One of the species we find in Norway is even specialized to live on large sponges in the deep-sea. This chiton grazes on the sponge, and in the process gradually digs out a depression in the sponge perfectly fitted for the chiton to sit in.

Hanleya nagelfar, a chiton that lives on sponges. Photo N. Mikkelsen

Chitons are a very old animal group, with fossil dating back 500 millions years. In fact, their body plan even still bears resemblances to the animals that were among the ancestors of the variety of molluscs in existence today. The chiton’s way of life is apparently an evolutionary successful recipe!

The next time you walk along the seashore, take a close look at a rock and you might find some colourful chitons!

-Nina

Door #10: The Molluscan Forum 2018 in London

Special 20th anniversary 22.11.18
The Malacological Society of London
Conference talk about citizen scientists

A few weeks ago, Manuel Malaquias, Justine Siegwald and me travelled to London in order to attend the 20th anniversary conference of the Malacological Society of London, UK. This society is dedicated to research and education on molluscs. Although based in London (as the name refers to), the society is internationally orientated and welcomes all members interested in the scientific study of molluscs. The society was founded in 1893 and registered as a charity. One of the many activities of the society is to organize meetings and symposia, and this year it turned out to be a 20th anniversary of the molluscan forum!

It was an incredible interesting day with a lot of inspirational posters and talks. My mission for that day was to present our ‘Sea slugs of Southern Norway’ project with the emphasis on how citizen scientist made this project a success. I wanted to share with the audience how citizen scientists with the right approach could be the future for many scientific studies.

Cessa presenting at the Molluscan Forum, 22th of November 2018

But first let us have a look into the meaning of citizen science. According to the Oxford English Dictionary, citizen science is scientific work undertaken by members of the general public, often in collaboration with or under the direction of professional scientists and scientific institutions. The term was first coined during the nineties in the United States of America. Since than it has grown in popularity, with multiple projects in the world that rely on the input of data generated by the general public. Some big and well-known examples are eBird, with roughly 411K users, Nasa Globe with 640K users, iNaturalist, with almost 1 million users and OPAL with 930K users and counting.

Increase of popularity of citizenscience projects per year, Nature 2018

Since the beginning of this year we put a lot of effort in setting up a network of volunteers and underwater photographers. We got many good people willing to contribute to our project and most them are located in the South of Norway, but we also have a few located more further up North in Norway. Currently we have around 150 members directly and indirectly involved in helping us with our project. We try to involve our citizen scientist in the project as much as possible and one way is by reaching out to them via several social media platforms. For example, in our Facebook group community members can participate in discussions about species descriptions and share their findings etc. But we also have an Instagram account that functions as a pocket field guide for followers. Besides we try to keep everyone up to date about the project by regular posting blogs.

Cessa showing the different social media platforms used in the project during the Molluscan Forum

But our key element in this project definitely goes to the assembly and design of our sampling kits. These were designed specially for our citizen scientists in order to make collecting easier, more accessible and more standardized for everyone. By trying to standardize the collecting steps with so-called instructed sampling kits we minimized the errors that could occur during sampling of the data. The sampling kits contain plastic jars for the samples, fixative, preprinted labels and a USB flash drive with enough space for high-resolution pictures and a preset excel file that only needs filling in.

Example of the content of a citizen science sampling kit designed for the Sea slugs of Southern Norway project

We noticed that this approach worked out and the data quantity and quality increased as well the recruitment became easier. When we look at all the Norwegian sea slug records from the museum collection since the 19th century, it consists of roughly 1400 records. In just over six months time we see that the contribution of the citizen scientists covers almost half of that.

A comparison of the amount of records collected by citizen scientists since this year compared to our museum collection

Eubranchus farrani species complex, one species or multiple?

The material that is sent in by the citizen scientists is at the moment being studied by us. We have two master students who will start working in January on a variety of taxonomic challenges by studying the different geographical material.

 

An example of this is Eubranchus farrani species complexes that have different color morphotypes from different geographical locations. Do we deal here with one species or multiple?

Stay tuned for a follow up!

Furthermore
Sea slugs of Southern Norway recently got its own Instagram account! Perfect for on the go if you would like to quickly check some species, click here https://www.instagram.com/seaslugsofsouthernnorway/ and don’t forget to follow us.

Become a member of the sea slugs of southern Norway facebook group, stay updated and join the discussion; https://www.facebook.com/groups/seaslugsofsouthernnorway/

Explore the world, read the invertebrate blogs!

-Cessa

Door #3: Mollusc hunting around the world

The study of molluscs (malacology) has a long tradition in Norway. Despite the nearly 50,000 species dwelling in the world oceans and seas, a number only barely supersede by the arthropods, new species continue to be discovered and our understanding of the relationships and systematics of molluscs to change.

At the Natural History Museum of Bergen, the study of molluscs is focal, and research is carried out on various aspects of their diversity, morphology, ecology, systematics, evolution, and biogeography, using state of the art methods like DNA barcoding, molecular phylogenetics, and electron microscopy. Understanding the patterns and processes that drive present diversity in the oceans is one of our main goals and our research foci are framed within several “big questions”: How many and how can we differentiate between species? How do species originate in the oceans? Why some regions in the oceans are more diverse than others? Are mechanisms responsible for the patterns of diversity in the deep-sea the same as in shallow ecosystems?

Our quest for answers necessitate the continuous collection of new specimens and the exploration of remote geographies. We conduct regular fieldwork around the world including Norway, through numerous projects and partnerships.

Here are some snapshots from recent fieldwork from Manuel & team:

Working during October 2017 together with Professor João Macuio from the University Lurio (Pemba, Mozambique) in Nangata Bay (Nuarro, Mozambique) on a survey of the sea slug diversity inhabiting this pristine coral reef area and on an assessment of the structure and conservation status of the population of the threatened giant clam species (Tridacna maxima). Left image: Manuel Malaquias and João Macuio photographing sea slugs at the Nuarro Research Center.

João Macuio measuring underwater the total length of a specimen of the giant clam Tridacna maxima

Working in remote places requires often some capacity to improvise and during a fieldtrip to Taiwan while in the Penghu islands we had to convince the manager of our hostel to let us set up a field-lab in the garage among his gear and pet-cage!

Manuel and Trond Oskars, PhD candidate at the Museum, searching for molluscs during May 2017 at mangrove systems near the city of Kaohsiung, Taiwan

In the Penghu islands we had the opportunity to work in the field together with students from the National Penghu University of Science and Technology, here depicted in the right image helping collecting sea slugs along a water stream lined by few mangrove bushes.

After a three weeks fieldtrip to Vamizi island in the Quirimbas archipelago, north of Mozambique during May 2015, we were finally brought to shore at Palma village near the border with Tanzania where we had to do some final sorting and organization of samples under the curious eyes of the local villagers (Manuel Malaquias and Yara Tibiriça from the Zavora Marine Lab in Mozambique).

Fieldwork during May 2018 in the Oslo fjord as part of the project “Sea slugs of southern Norway” funded by Artsdatabanken. Left image: part of the team working through the catch of the day at the Tolboden Course Center in Drøbak, University of Oslo (left to right: Cessa Rauch, Manuel Malaquias, Torkild Bakken, Anders Schouw)

You can read more about some of these expeditions by exploring the posts found here (workshops) and here (fieldwork).

Manuel

NorBOL and BOLDsystems course Trondheim 17th-19th of October

Travelogue from Cessa Rauch

Today the weekly event of MolluscMonday and the annual SeaSlugDay (29th of October) coincide!Bunch of sea slugs to celebrate sea slug day, collected in Askøy

What better way to celebrate it with another blog! Much has happened again since the last blog in August, in which we went on fieldwork in Askøy by joining the ladies of the jentedykketreff to find sea slug species in the Bergen area. We officially started to barcode our first specimens, got two new master students that will also work on the project by looking into a variety of topics (diversity of sea slugs in Hordaland, population genetics of Polycera quadrilineata and taxonomy of the genus Eubranchus).

In this blog I will share with you how we are uploading our slugs to the World Wide Web with help of the Barcode of Life data system and how the Norwegian Barcode of Life is helping us getting this done by organizing an informative course in Trondheim.

First step in trying to decode our precious species
The sea slugs of Southern Norway project is a two-year project funded by Artsdatabanken (The Norwegian Taxonomy Initiative) with the aim of mapping the biodiversity of sea slugs along the Southern part of the Norwegian coast

Sea slugs of Southern Norway being eaten by Doris pseudoargus

The focal area stretches from Bergen, Hordaland, all the way down to the Swedish border. In May, July and August of this year the project successfully completed its first fieldwork trips with an additional of 500 new registered museum specimens that cover roughly 90 sea slug species. The species names are attributed based on morphological characteristics, but several species exhibit amazing colour polymorphism, possibly hiding cryptic diversity.

Moreover, we cannot discard the possible occurrence of alien species with similar morphotypes to the native fauna. Therefore, we will need to DNA barcode our specimens to either confirm or change the species names credited to our collected specimens. Besides it will give us an overview for the relatedness of the sea slugs to one another and unravel maybe new species!

In order to successfully sequence 500+ specimen the project collaborates with the Norwegian Barcode of Life project (NorBOL). NorBOL is a network of Norwegian biodiversity institutions and individual scientists that coordinates the establishment of a library of DNA sequences (barcodes) of the fauna and flora of Norway. These barcodes)will be submitted to the open access database BOLD (Barcode of Life Data System), as part of the global Barcode of Life initiative and the International Barcode of Life project (iBOL).

Barcode of Life Data System course
Barcode of Life Data System (BOLD) is a globally orientated online workbench and database that supports the assembly and use of DNA barcode data, and is open access to the scientific community and public. At the moment it holds a record of 6235000 barcodes; 194000 of those are animal species, 67000 plant species and 21000 fungi and other species. The BOLD system is an amazing tool to work with for those interested in biodiversity research. Initially it can be a little overwhelming to fill in all available data into Excel file after Excel file, as this is mandatory and needs to be uploaded first to the system before any sequencing can be done. Especially for those who have many specimens to work with. But afterwards the reward is very fulfilling as you, in an instant, can see distribution maps, trees and images of all the specimens uploaded.

Distribution map from Google earth with collected sea slugs from the Oslo area

Image library of all the collected sea slugs

It is the perfect tool for digitizing, analysing, storing and accessing your genetic and image library data from everywhere anytime. BOLD system standards for uploading actual specimen data are pretty high, the quality of what you can find on the platform is good, but in order to keep these standards great, NorBOL organizes special multi day courses for users in order to guide them through all the steps and features of the BOLD system. This year the course was organized by the NorBOL National coordinator NTNU in Trondheim.

It would take three full days of getting together with fellow participants and going through all the steps necessary in order to start a successful project in the BOLD platform. This year it took place from 17th till 19th of October and as such, me, Anna and Per travelled that Wednesday the 17th very early in the morning to Trondheim. The course was well attended with participants traveling from all over Norway and even from its neighbouring country Sweden. The first day consisted mainly of introduction talks and familiarizing ourselves with the many new abbreviations; NorBOL, BOLD, iBOL (et cetera).

It was a nice experience to meet and talk to other biologists working on such interesting topics, varying from flies, mites, sponges, jellyfish, worms, variety of plants, etc. Everything was taken care off, we could check in to our hotels and in the evening, we had a dinner together with the organizers and participants. The next two course days we were asked to work with our own brought specimens. The days consisted of registering the specimens, filling in as much data per specimens as possible. After finishing and uploading the first datasets, it was time to make pictures of every species, before sampling them for DNA barcoding tissue. Almost all participants brought a 96 wells plate worth of specimens so you can imagine the work that was put into getting everything finished in such a short amount of time.

Sea slug tissue in a 96 well plate ready to be shipped for barcoding

The course was an excellent way to get used to the different steps necessary in order to make the submission process a success. And it was very helpful that at any given moment we could ask the course organizers for advice during the preparations of the datasets and the submission.

All the participants were very excited about the course and happy they attended, it was nice meeting new people and as for someone that moved to Norway, a good opportunity to finally also see Trondheim, with its amazing large Cathedral, a real eyecatcher

 

 

Sea slug goals
The goal for the sea slugs of Southern Norway project is to barcode all, or at least as much as possible, collected specimen, in order to attribute species names to them, expose cryptic species, maybe find new species and look out for invasive and or alien species. Thanks to this course the first 95 species will be barcoded soon and be added to the image library that we already managed to set up (Image 8. Screenshot of the project page of sea slugs of Southern Norway in the BOLD system workbench).

Screenshot of the project page of sea slugs of Southern Norway in the BOLD system workbench

We are very much looking forward for the first results to be accessible and to analyse the data; keep an eye on the invertebrate blogs because for sure the follow up of this story is going to be pretty exciting.

Acknowledgements
I would like to thank Aina Mærk Aspaas for the coordination of the course, Katrine Kongshavn to help out with my first introduction to NorBOL and the BOLD system workbench and Anna Beata Seniczak and Per Djursvoll for being great colleagues during the course and lovely companions in discovering Trondheim together as real Bergen tourists!

 

Furthermore
Sea slugs of Southern Norway recently got its own Instagram account! Perfect for on the go if you would like to quickly check some species or just want to look at pretty pictures; click here, and don’t forget to follow us.

Curious about what we have been doing so far,  read about it in our blogs on the invertebrate website;
First fieldwork blog Drøbak may 2018;
Second fieldwork blog Haugesund July 2018;
Third fieldwork trip august 2018

Become a member of the sea slugs of southern Norway facebook group, stay updated and join the discussion; https://www.facebook.com/groups/seaslugsofsouthernnorway/

Why is it SeaSlugDay today? Read more about that here!  (link goes to Echinoblog)

Explore the world, read the invertebrate blogs!

-Cessa