Category Archives: 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

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

NorHydro in South Africa: the 6th International Jellyfish Blooms Symposium

The 6th International Jellyfish Blooms Symposium was the last big academic event in 2019 attended by team NorHydro, and we were very happy to have presented our project in such a relevant meeting!

Team NorHydro at the 6th Jellyfish Blooms Symposium, from left to right: Maciej Mańko (University of Gdansk – Poland), Aino Hosia (UiB – UMB), Joan J. Soto (UiB – Sars Center), and Luis Martell (UiB – UMB).

In many ways, the Jellyfish Bloom Symposium (JBS) is the most important meeting of scientists working with medusozoans in the world. Professionals from different countries, backgrounds and lines of research meet every 3 years in this symposium to present their results, discuss new findings, and chat with colleagues about the state of knowledge in the group. So of course our Artsdatabanken project NorHydro had to be present, especially after a session focused on polyps was announced for this particular edition. The importance of polyp stages – the object of study of NorHydro – is now widely recognized in jellyfish biology, and understanding the ecology and diversity of polyps has become a key point in the study of jellyfish blooms.

This time, it was the turn of the University of the Western Cape, Iziko South African Museum and the Two Oceans Aquarium to host the JBS, which was held in Africa for the first time.

Iziko Museum was the venue for the oral presentations and poster sessions. The way to the auditorium was marked by jellyfish but we still had to pass under the vigilant eyes of a giraffe.

The city of Cape Town provided a beautiful setting for discussions on gelatinous matters and sharing of jellyfish-related stories, and we even got to see some of the local hydrozoans from the surroundings, both in the aquarium and in the sea.

Not everyone was happy with the high concentration of jellyfish researchers in Table Mountain. Photo: Joan J. Soto Àngel

We were lucky to see some hydrozoans by the sea. Several specimens of the siphonophore Physalia physalis (top left) and the anthoathecate Velella velella (top right) were stranded in Diaz Beach, near the Cape of Good Hope (bottom).

The oral presentations and poster sessions covered many subjects on jellyfish biology, not only the dynamics of polyps but also the relationship between jellyfish and humans, the role of jellyfish in the ecosystem, and the diversity of medusa, ctenophores and salps.

Overall, the participation of NorHydro in the JBS was very succesful. We received positive feedback about the results presented, and people were very interested in our upcoming activities, particularly the course on hydrozoan biology and diversity (read more and apply here).

All the participants of the 6th Jellyfish Blooms Symposium

NorHydro was so warmly welcomed that we are already looking forward to sharing more about the hydrozoans of Norway in the next JBS in 2022!

– Luis

Keep up with NorHydro in Facebook and in Twitter with hashtag #NorHydro.

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

Field season’s end

Sletvik field station, October 15th-23rd 2019

We wanted to make a write-up of the last combined fieldwork/workshop we had in 2019, which was a trip to the marine field station of NTNU, Sletvik in Trøndelag, in late October. From Bergen, Luis (NorHydro), Jon, Tom, and Katrine (Hardbunnsfauna) stuffed a car full of material, microscopes, and drove the ~12 hours up to the field station that we last visited in 2016.Beautiful fall in Trøndelag

There we joined up with Torkild, Aina, Karstein, and Tuva from NTNU university museum, students August and Marte, and Eivind from NIVA. We also had some visitors; Hauk and Stine from Artsdatabanken came by to visit (if you read Norwegian, there’s a feature about it here), and Per Gätzschmann from NTNU UM dropped by for a day to photograph people in the field.

Most of the workshop participants lined up Photo: Hauk Liebe, Artsdatabanken

During a productive week the plan was to work through as much as possible of the material that we and our collaborators had collected from Kristiansand in the South to Svalbard in the North. Some of us went out every day to collect fresh material in the field close to the station.The Artsprosjekts #Sneglebuss, Hardbunnsfauna, NorHydro, and PolyPort gathered at Sletvik, and with that also the University museums of Trondheim and Bergen. Of course we were also collecting for the other projects, and the museum collections.

One of the things Hardbunnsfauna wanted to do whilst in Sletvik was to pick out interesting specimens to submit for DNA barcoding. This means that the animals need to be sorted from the sediment, the specimens identified, and the ones destined to become barcode vouchers must be photographed and tissue sampled, and the data uploaded to the BOLD database. We managed to complete three plates of gastropods, select specimens for one with bivalves, and begin on a plate of echinoderms, as well as sort through and select quite a few crustaceans and ascidians for further study.

Collecting some fresh material was particularly important for NorHydro because the hydroids from the coasts of Trøndelag have not been thoroughly studied in recent years, and therefore we expected some interesting findings in the six sites we managed to sample. We selected over 40 hydrozoan specimens for DNA barcoding, including some common and widespread hydroids (e.g. Dynamena pumila), some locally abundant species (e.g. Sarsia lovenii) and exceptionally rare taxa, such as the northernmost record ever for a crawling medusa (Eleutheria dichotoma). We also used a small plankton net to catch some of the local hydromedusae, and found many baby jellyfish belonging to genus Clytia swimming around the field station.

Plan B when the animals (in this case Leuckartiara octona) won’t cooperate and be documented with the fancy camera; bring out the cell phones!

It was a busy week, but combining several projects, bringing together material spanning all of Norway, and working together like this made it extremely productive!

Thank you  very much to all the participants, and to all the people who have helped us gather material so far!

-Katrine & Luis

Invertebrates in harbours

Harbours and marinas are interesting places to look for marine creatures. These environments are usually teeming with life, but a closer look often reveals that their communities are strikingly different from the ones living in adjacent natural areas. Piers and pontoons offer new surfaces for many algae and animals to grow, and the maritime traffic of large and small boats allow for an intense movement of organisms, making harbours some of the preferred spots for newcomers (what we called introduced species) to settle. Many surprises can be expected when sampling for invertebrates in these man-made habitats, which is why our artsprosjekt NorHydro teamed up with project PolyPorts (based at the NTNU University Museum) to explore the hidden diversity of worms and hydroids in the Norwegian harbours.

I was very happy to collect polyps in sunny Southern Norway.

Last year, PolyPorts sampled extensively in some of the main Norwegian harbours (including Oslo, Bergen, Trondheim, and Stavanger); but for this year’s sampling season our two projects headed first south (to the harbours and marinas of Sørlandet), and then west (to Bergen).

In the south, we sampled several ports and marinas from Kristiansand to Brevik (including Lillesand, Grimstad, Tvedestrand, and Risør, thus covering a large portion of southern Norway). In Vestlandet we concentrated our efforts in the area of the port of Bergen, Puddefjorden and Laksevåg, as well as Dolvika.

 

Although it could be surprising that heavily trafficked (and sometimes quite polluted) harbours support a high diversity of invertebrates, this was actually the case for every single port we surveyed.

All our sampling areas had pontoon pilings and mooring chains covered in colourful seaweeds and animals, and reefs of native and introduced mussels and oysters that provided a home for sea squirts, skeleton shrimps, bryozoans and hydroids. For NorHydro, perhaps the most surprising result came from the brackish areas that we analyzed, where large populations of Cordylophora caspia were found. This species is not native to Norway and had not been observed in so many Norwegian localities before, making for an interesting finding to explore even further through the analysis of DNA.

– Luis

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

Many hands (plus some tentacles and legs) make light work

In the last months, our project NorHydro has been very busy with sampling trips and outreach; we have been collecting hydroids in Southern Norway, presenting our results in festivals, and hunting for hydrozoans inside mythical monsters as well as around Bergen, the project’s hometown. All of these activities sound like a lot of work, and they certainly take a fair amount of time and effort, but the good thing is that NorHydro has never been alone in its quest for knowledge of the marine creatures: on the contrary, this has been the season of collaborations and synergies for our project!

At the end of August, for example, we attended the marine-themed festival Passion for Ocean; where we shared the stand of the University Museum of Bergen with a bunch of colleagues, all working on several kinds of marine creatures, from deep sea worms and sharks to sea slugs and moss-animals. It was a great opportunity to talk to people outside academia (including children!) about our work at the museum, and also to show living animals to an audience that does not venture too often into the sea.

Our stand at the Passion for Ocean festival was incredibly popular with the public – we feel like most of the 5-6000 people who attended P4O must have dropped by to talk to us! Photos: K. Kongshavn and M. Hosøy

Although most of the people in Bergen are familiar with jellyfish, very few of them would know that most jellies are produced by flower-looking animals living in the bottom of the ocean, so the participation of NorHydro was met with a lot of surprise and curiosity. The festival was a big success (you can read a more about the experience in the Norwegian version of the blog), and hopefully we will get the chance to join again next year.

 

 

 

Later on, in September, we set off for a field trip to the northerly area of Saltstraumen, in the vicinity of the Arctic city of Bodø. For this trip NorHydro was again in collaboration with the UMB-based project “Hardbunnfauna” (Jon and Katrine represented the hard-bottom dwelling invertebrate fauna scientists) and also with Torkild Bakken (from NTNU University Museum, with his project “#Sneglebuss”). For me, Saltstraumen was definitely an exciting place to go; the strong currents of Saltstraumen have been the cause of death of too many sailors and seamen in the past, so in the collective mind the area has become some sort of man-eating whirlpool similar to the Mediterranean Charybdis… I don’t get to sample inside a mythological creature very often! Underneath the water though, Saltstraumen is teeming with life.

Saltstraumen looks stunning and inviting when seen from the coast.

Sampling the littoral zone within the Polar Circle

During this trip, we were prepared to sample in the littoral zone (and we did), but more importantly we were lucky enough to meet several enthusiast citizen and professional scientists that were diving in the area and shared with us some of their observations.

We were treated to extremely nice underwater pictures of invertebrates by Bernard Picton and Erling Svensen, and all the participants in the activities of the local diving club (Saltstraumen Dykkecamp) were very keen in providing us with suggestions, animals, images and impressions that made our sampling trip a total success.

 

The area was dubbed as a “hydroid paradise” (likely due to the strong currents that favor the development of large hydrozoan colonies), and many new records and even perhaps new species are present in the region.

For those of you that know Norwegian, you can read another interesting account of our trip here, and there is even a small service covering our adventures filmed by the regional TV channel NRK Nordland here.

The TV service is worth a look to see the beautiful underwater images of the Norwegian coast even if you’re not familiar with the language!

– Luis

Royal hydrozoans and noble snails at Her Majesty the Queen of the fjords

As part of our continuous quest for hydrozoans and snails, we (Luis and Justine) recently embarked on a trip to the mighty Hardangerfjord on board the RV Hans Brattström. This is an area that we at the museum are keen to explore, since there have not been many sampling efforts in Hardanger in recent years, at least not after the joint survey carried out in the years 1955–1963 and in which Hans Brattström himself (the scientist, not the ship) took part. The Hardangerfjord has changed a lot since the 1960s, developing into one of the major fish-farming regions of Norway while at the same time retaining its touristic and agricultural vocation, so it is very interesting to come back and see if and how the invertebrate communities have also changed.

Our trip started with warm summer temperatures and clear skies…

…but it quickly turned into a more ‘typical’ western Norwegian weather. Fortunately we were prepared for the rain!

The Queen of the fjords, as Hardangerfjord is sometimes known, is the second longest fjord in Norway and the fourth longest in the world, which means that we had quite a lot of ground to cover in our two day-trip if we wanted to have at least a brief look at the diversity of habitats and animals living in its waters. For this trip, we settled for a sampling scheme involving 9 stations distributed in the middle and outer parts of Hardanger, and we decided to leave the innermost part of the fjord for a future occasion. We looked at the animals living in the bottom of the fjord (benthos), the water column (plankton) and also deployed a couple of traps in order to catch specific critters. We explored rocky sites, sandy bottoms, muddy plains and kelp beds, and found an interesting array of animals in all our samples.

The samples came from the deployed amphipod traps, triangular dredge, and plankton net.

Some of the animals we saw (most of them were actually returned to the sea):

Without any doubt, the highlights of our trip were the snail Scaphander lignarius and the hydrozoans Eudendrium sp. and Laodicea sp. The colonies of Eudendrium sp. were relatively abundant in shell- and rock-dominated bottoms, but their small size and not reproductive status prevented us from identifying them to species level right away. For a correct identification, we now have to look closely at the stinging cells (nematocysts) of the hydroids, and of course we will also try to get the DNA barcode of some of the specimens. Unlike Eudendrium sp., which lives in the bottom of the sea, our specimens of Laodicea sp. were swimming around in the water column. This species is interesting because previous DNA analysis have shown that, although they look like each other, different species of Laodicea coexist in Norwegian waters, so we are looking forward to obtain the DNA barcode of the jellies from Hardanger to compare it with the sequences we have from other parts of Norway.

. A polyp of Eudendrium sp. (left) and the hydromedusa of Laodicea sp. (right)

Scaphander lignarius was quite the surprise finding. We really wanted to collect some individuals, but our hopes were not very high and we were mostly convinced that we would not see any during our trip. Luckily for us, there were several of them happily crawling around the mud in two of our stations! S. lignarius is one of the few representatives of the Scaphandridae family in Norway. This family of bubble snails is of particular interest to us to study the biogeography and speciation process of invertebrates in the deep sea on a worldwide scale, since members of the family are distributed all around the world, and most tend to inhabit depths below 500m. Sampling some of them will definitely help that project!

Two views of Scaphander lignarius

All around, this was a quite successful sampling trip, with many specimens collected to be added to the Museum Collections, and which will be very useful to many different research projects!

– Justine and Luis

PS: You can find more updates on our Artsdatabanken project NorHydro here in the blog, on the project’s facebook page and in Twitter with the hashtag #NorHydro.

 References and related literature about the survey of the Hardangerfjors in 1955–1963

Braarud T (1961) The natural history of the Hardangerfjord, Sarsia, 1:1, 3-6.

Brattegard T (1966) The natural history of the Hardangerfjord 7. Horizontal distribution of the fauna of rocky shores, Sarsia, 22:1, 1-54.

Lie U (1967) The natural history of the Hardangerfjord 8. Quantity and composition of the zooplankton, September 1955 – September 1956, Sarsia, 30:1, 49-74.

NorHydro in Japan: chronicles of the 9th Workshop of the Hydrozoan Society

Team NorHydro at the 9th Hydrozoan Society Workshop, from left to right: Joan J. Soto (UiB – Sars Center), Aino Hosia (UiB – UMB), Marta Ronowicz (IOPAN – Poland), and Luis Martell (UiB – UMB). Picture: Mitsuko Hidaka

Earlier this summer, the small Japanese cities of Enoshima and Shimoda became the chosen scenario for the celebration of the 9th Workshop of the Hydrozoan Society, one of the most important meetings of hydrozoan scientists in the world.

We were constantly amazed by the beauty of Japanese writing, and were happy to receive name tags with our names in katakana. During the workshop we also learned some important hydrozoan-related words in Japanese

 

This workshop is held every 3-4 years, and it offers everyone attending the opportunity to present his or her results, discuss new findings, collect some samples, and meet with other specialists in the group. Our Artsdatabanken project NorHydro is all about hydrozoans, so of course we could not miss this important event!

 

 

Selecting Enoshima and Shimoda as the venues for the workshop was a very fortunate decision. These cities are located in the area of the historically important Sagami Bay, where numerous studies of hydrozoans have taken place and from where many species of hydroids and hydromedusae have been described, which helped make this meeting a commemoration of previous hydrozoan studies in Japan.

Several renowned marine biologists, including Uchida, Yamada, and the late Emperor Hirohito dedicated their time and effort to study the hydrozoans of Sagami Bay, so during the workshop we felt like we were following their steps while collecting animals and comparing results.

The workshop included several different activities.

In Enoshima we visited the aquarium (just like Emperor Hirohito did many times) and we got to know the facilities where hydromedusae are kept and raised.

In Shimoda we went on and into the water to look for hydroids, hydromedusae and siphonophores that we then identified at the laboratories of the Shimoda Marine Research Center of Tsukuba University.

Also in Shimoda we sampled at the local aquarium, and it was in this city where the talks and poster sessions were held.

The workshop started with a visit to Enoshima Aquarium…

All in all, the participation of NorHydro in the workshop was very productive. We came back home with more than 30 samples that we will analyze and use to answer some questions that we are currently working on (did you know, for example, that the Japanese specimens of Nanomia bijuga may actually belong to a different species? We’ll see what our results suggest about this!).

We also received very positive feedback about the works we presented during the meeting, and we established some important collaborations with other hydrozoologists.

Some of the critters we observed during our time in Japan:

An even more exciting result of our participation was that the presidency of the Hydrozoan Society has now come to Norway, and NorHydro will be in charge of organizing the next Hydrozoan Society Workshop here in Bergen!

The Norwegian delegation, prepared for organizing the next Hydrozoan Society Workshop

– Luis

PS: Pictures of all the activities during the workshop can be found on the official facebook page of the Hydrozoan Society, and the entire event was tweeted with the hashtags #9HSworkshop, #HydrozoanSociety and #NorHydro.

 

Some hydroids, four naturalists, and a small island in the North Sea

NorHydro partner (and hydrozoan expert) Joan J. Soto Àngel from the Sars International Centre for Marine Molecular Biology went in a sampling trip to Kinn to collect benthic hydroids. Here is an account of his experience in this trip:

Kinn is a small grassy island on the western Norwegian coast. Today it is a quiet, peaceful place with only a few inhabitants, but in the past it was an important fishing town and the center of the cultural and religious life of the area, as evidenced by its imposing medieval stone church (Kinnakyrkja). The island is also a place of historical relevance for biologists, since it is intimately tied to the life and discoveries of one of the most prominent naturalists of the XIX century, Michael Sars, who worked as a priest in Kinnakyrkja for many years.

Here I am, ready to sample! The island behind is Kinn, easy to recognize thanks to its characteristic cleft silhouette. Picture: Cessa Rauch

The islands in the area face the ocean and are rather exposed, so the vegetation is not particularly tall, but the waters are teeming with life. Picture: Joan J. Soto

The XIX century Norwegian naturalist Michael Sars. Picture from Wikicommons (public domain)

Sars described many species inhabiting the waters around Kinn and also made key observations about their distribution and life cycle. Indeed, he was the first to discover that jellyfish and polyps are in fact different stages of the same animals!

This finding led him to be recognized as an outstanding zoologist of his time. Even now, ca 200 years after, his extensive work is regularly consulted by researchers of many fields. Like me and the other participants of the Artsdatabanken project NorHydro, Sars was fascinated by the group we call Hydrozoa, which is why it was very interesting for our project to join a sampling trip of the University Museum of Bergen in the same waters where he sampled and described many hydroids, hydromedusae and siphonophores.

Because Sars was also interested in other critters of the sea besides hydrozoans, it was only natural to make this sampling trip a joint, collaborative effort. In our case, three marine scientists were involved, each representing a different project: I was in charge of the hydrozoans for NorHydro, while Anne Helene Solberg Tandberg focused on amphipods (NorAmph2) and Cessa Rauch concentrated on sea slugs (Sea Slugs of Southern Norway). But we did not limit ourselves to our favorite animal groups; we also sampled some poychaetes, bryozoans, ascidians and echinoderms for two other projects based at UMB, Hardbunnsfauna and AnDeepNor. In addition, while we sampled extensively the waters around Kinn, we also stopped in the way to the island and back and collected some animals in two other localities in the coast of Sogn og Fjordane. Our efforts paid off and, despite some windy weather, we came home with many specimens to analyze and samples to sort.

Three more contemporary naturalists working for different projects: Joan (left, NorHydro), Cessa (middle, Sea Slugs of Southern Norway), and Anne Helene (right, NorAmph2). Picture: Joan J. Soto

For the hydrozoans, the majority of samples consisted in colonies of hydroids belonging to the families Sertulariidae, Haleciidae and Campanulariidae. This was not surprising as Sertulariidae (sensu lato) is the largest and most diverse family in all Hydrozoa, and their conspicuous colonies are relatively easy to recognize and collect. The haleciids are represented in Norway mainly by species of Halecium, whose colonies are among the largest benthic hydrozoans of the country. As for the campanulariids, particularly those belonging to genera Obelia, Laomedea and Clytia, they are common inhabitants of rocky and mixed bottoms all around the world, and are especially conspicuous when growing on macroalgae such as kelp. To correctly identify some of these specimens, we will look closely at their morphological characteristics and will also employ molecular techniques of DNA analysis. Hopefully this approach will help us understand the diversity of benthic hydroids living around Kinn, and will allow us to determine whether the species that we encountered are the same that Sars studied.

Dynamena pumila was one of the most conspicuous species of hydroid that we collected in this trip. It belongs to the speciose family Sertulariidae.

We were very lucky to have the help of the crew of RV Hans Brattström. This is how the command center of the boat looks like!

You’ll find the results of these and other NorHydro’s analyses here in the blog as we progress, and more updates on the project can be found on the Hydrozoan Science facebook page and in Twitter with the hashtag #NorHydro.

– Joan


References and related literature about Michael Sars

Tandberg AHS, L Martell (2018) En uimodstaaelig lyst til naturens studium. Yearbook of the University Museum of Bergen: 17 – 26.

Sars M (1835) Beskrivelser og Iagttagelser over nogle mærkelige eller nye i Havet ved den Bergenske Kyst levende Dyr af polypernes, acalephernes, radiaternes, annelidernes, og molluskernes classer. Thorstein Hallagers forlag, Bergen.

Windsor MP (1976) Starfish, jellyfish and the order of life. Issues in Nineteenth-Century Science. Yale University Press, New Haven. 228 pp