Category Archives: HYPNO

Hydrozoa course 2022 edition – as told by our MSc student Ana González

Last month, our project NorHydro (together with ForBio Research School of Biosystematics and project MEDUSA) organized a course on diversity, systematics and biology of Hydrozoa at the Marine Biological Station in Espegrend. Fifteen participants from 9 different countries came all the way to Bergen to learn more about these intriguing animals, share their ideas and projects, and start new collaborations. We asked one of the youngest members of the group –our highly motivated student Ana González– to share with us her thoughts about the course and her experiences with her MSc project. This is what she had to say:

When I started my Master’s Degree of Marine Ecology at the University of the Balearic IslandsI already knew about the existence of hydrozoans, but I had no idea how interesting these animals actually were. After some discussions, a lot of reading, and a fair amount of looking at pictures of hydroids and hydromedusae, I decided to work with these inconspicuous invertebrates for my MSc project under the supervision of Dr Luis Martell (University Museum of Bergen) and Dr. Maria Capa (University of the Balearic Islands). My project aims to evaluate whether we can use the benthic communities of hydrozoans as bioindicators of anthropogenic impact on the easternmost coasts of Mallorca Island, in the Mediterranean Sea.

Me on a sampling day looking for benthic hydrozoans at the marine reserve of Cala Gat (top). A closer view of the hard substrates I sample in the marine reserve (bottom left). The common hydroid Monotheca obliqua growing on Posidonia oceanica (bottom right). Picture credits: Maria Capa and Ana González.

Coastal areas are an attractive place to live, and these habitats provide ecosystem services that contribute greatly to the economy of the world, but a bad management of them can generate important damages and drastic changes in the ecosystem. One way to monitor environmental impacts in these habitats is by observing the response of their biological communities, so for this project I decided to study the assemblages of benthic hydrozoans in two opposite sites with different levels of anthropogenic impact: a harbor and a marine reserve. Moreover, I am comparing the communities in different seasons of the year, and I will analyze the assemblages growing on hard substrates (like rocks) and also those growing on a very important Mediterranean soft substrate: the endemic seagrass Posidonia oceanica.

Some hydroids common in my study area are those belonging to genera Clytia (family Campanulariidae, left), Sertularella (family Sertularellidae, middle), and Aglaophenia (family Aglaopheniidae, right). Picture credits: Ana González.

At the beginning, working with benthic hydrozoans was very challenging for me since the specimens I find are easily overlooked if one is not searching carefully for them. But the more time I dedicate to observe these organisms, the more curious I became about their identity and dynamics, and the easier it was to recognize them in the samples. However, identifying hydrozoans is a difficult task and I realized early that I needed some help, so I was very happy when the opportunity arose to apply for the course “Diversity, Systematics and Biology of Hydrozoa” in Bergen. There, I had the chance to meet some of the leading scientific experts in the field that helped me understand better the taxonomy and ecology of these animals. I couldn’t have imagined how much I was going to learn during the different activities of the course, but at the end these organisms were able to catch my attention and time flew between lectures, sampling trips, and laboratory work. One aspect of the course that I particularly enjoyed is the fact that it brought together participants with different trajectories in science, and everybody was happy to share their experiences in the world of hydrozoan science.

We had all kinds of weather during the course: rain, sun, wind, and even snow! Picture credits: Lara Beckmann and Joan J Soto Àngel.

We had the chance to sample on board the UiB research vessel Hans Brattström and we collected several planktonic and benthic hydrozoans in the fjords around the Marine Station. After each sampling event, we went back to the lab to sort the samples, find the hydrozoans and identify them to species. The plankton samples were usually the first ones to be processed, since hydromedusae are quite fragile and they tend to suffer morphological damages after being sampled with a net. We tried to identify all specimens to species level, with the aid of the stereomicroscopes and scientific literature with identification keys that the curse provided. The benthic samples were placed in aquariums to keep the organisms alive and then each of us had the opportunity to observe the specimens in our own stereomicroscope.

A sampling day on board of RV Hans Brattström. Top left: deploying the plankton net. Top right: a full cod-end with plankton sample. Middle right: students and teachers ready to leave the pier. Bottom: benthos sampling with the triangular dredge. Picture credits: Lara Beckmann, Sabine Holst, Luis Martell

Top right and left: students and teachers at the laboratory, identifying hydrozoans. Bottom left: searching for hydromedusae and siphonophores in the plankton sample. Picture credits: Sabine Holst and Lara Beckmann.

All together, we were able to find and identify more than 40 species from all the main groups of hydrozoans, including siphonophores, trachylines, leptothecathes, and anthoathecates. Working with hydromedusae was new for me and I discovered that observing them was more challenging than identifying the polyps, but it was also interesting in its own way. The hydrozoans that caught my attention the most were the polyps from the suborder Capitata, because their morphology is very different from the hydroids that I have observed in my MSc project so far. Capitate hydroids don’t have a protective theca, they possess tentacles that end up in a ball of nematocysts (so-called capitate tentacles), and they are absent from almost all my samples from Mallorca, which are instead dominated by hydroids belonging to the Order Lepthothecata.

Top: Colony of Sarsia lovenii (Anthoathecata: Corynidae) with gonophores (i.e. reproductive buds on the polyp body). You can also see the capitate tentacles, which end in a ball of nematocysts and are typical for suborder Capitata. Bottom: Colony of Clava multicornis showing also gonophores on the polyp body, but with filiform (non-capitate) tentacles. Picture credits: Lara Beckmann (top), Joan J. Soto Àngel (bottom).

My interest for hydrozoans, the great set of experts we had as teachers, and the charismatic animals that we collected were the perfect combination for me to have an incredible experience in this course. I think that courses like these are an excellent opportunity for beginners to learn with experts from different parts of the world. Interacting with all of these amazing people was very rewarding at both cultural and scientific levels, and this whole experience motivated me to keep on studying these interesting animals that are a part of the complex functioning of our oceans.


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!


Follow HYPCOP @planetcopepod

Instagram, for pretty copepod pictures

Twitter, for copepod science news

Facebook, for copepod discussions

See you there!

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

Door #7: New shipment of tissue samples for barcoding

In the upper right corner is a “plate”: the microplates with 96 wells where we deposit small tissue samples that are to be processed at the CCDB lab in Canada for NorBOL

On the third day of Christmas,
we sent eleven microplates away:
one plate cnidarians (A)
two with worms a-wriggle (B)
two plates of insects (C)
three plates crustaceans (D)
two (and a half) plates of mites (E)
and a half-plate assorted a-arthropods (F)!

Ahem. Yes.

As Endre explained in the fifth post of the calendar, collecting, identifying, documenting and keeping specimens used for DNA barcoding is an important part of what we do here at the invertebrate collections. Our mission in the NORBOL consortium is to produce DNA-barcodes, particularly for marine fauna in Norwegian waters and to make these barcodes available with open access to records and metadata in the BOLD database. These samples contribute to the building of a validated reference library of the genetic barcodes of the species found in Norway. You can search for different taxonomic groups here to see if they have been barcoded from Norwegian territory: Search NorBOL

The process is fairly straight forward (at least on paper!): Animals are collected and identified. Those species relevant for barcoding are selected, and a specimen (=1 animal) is chosen to be barcoded. We take a small tissue sample from the specimen, and keep the rest of the animal as the barcode voucher; if the need should arise to check if it really is what we initially thought, it is crucial to be able to go back and check the animal again. The tissue samples are collected in wells on a plate like the one pictured above, and the information about the animals – where they were collected, who collected them, what species they are, who identified them and so on is uploaded to BOLD together with images of the animals.

Representatives for the tissue sample plates that we just shipped off. Thank you Steffen, Anna and Per for contributing the terrestrial animals and images! Photos: L. Martell, A. Seniczak, S. Roth, K. Kongshavn. Illustration: K. Kongshavn

On Monday we shipped a new batch of plates – as (attempted) illustrated in song above.

Included is material from several of the Norwegian Taxonomy Initiative projects (artsprosjekt) that are happening at the University Museum of Bergen. We are coordinating the efforts on marine life, but are of course also facilitating the NorBOL barcoding of other organisms that take place at the UMB.  There are animals from NorAmph (Norwegian Amphipoda), Hydrozoan pelagic diversity in Norway (HYPNO), Orbatid mites, and the insects found associated with nutrient rich marshes in Hedmark in this shipment.

We have also prepared several plates of Crustaceans collected and identified by the Norwegian marine mapping programme Mareano – one of the great contributors of material to the collections.

Now we wait for the lab to process them, and for the genetic sequences to be uploaded to BOLD – fingers crossed for many interesting results!


Door #2: A glimpse of Hydrozoan anatomy

Hydroids and hydromedusae are abundant and widespread, but they can be difficult to identify, in part due to the overwhelming amount of terminology used to describe their polyps, colonies and medusae. The diversity of shapes and life cycle strategies in Hydrozoa is in fact so high that it is almost impossible to find a single set of descriptive terms for all species, and different glossaries have been developed for closely related families, sometimes genera, and also for the different stages in the life cycle of the same organism. To further complicate things, the terminology we use for the characterization of hydrozoan morphology has been adapted in many cases from other fields of science (like botany and geometry), and some of the words ended up with very different meanings depending of the organism we are looking at.

But if you are interested in these fascinating creatures, fear not! We at the invertebrate collections have thought about giving you a little visual aid in the form of four plates including some of the basic structures of hydroids and hydromedusa (courtesy of artsprosjekt HYPNO and upcoming artsprosjekt NORHYDRO).

Figure 1: Thecate polyps, like the ones of Aglaophenia harpago, are protected by rigid structures called “thecae” into which the polyp can retract. In many species they live all together forming colonies. Credit: Joan J. Soto Àngel and L. Martell.

Figure 2: Unlike their “protected” relatives, athecate polyps (e.g. those of Pennaria disticha) lack the skeletal protection of the theca, but can also form large colonies with many polyps. Credit: Joan J. Soto Àngel and L. Martell.

Figure 3: The hydromedusae produced by thecate polyps are called leptomedusae, and can be recognized by the development of gonads in the radial canals (among other characteristics). From left to right and top to bottom in the picture are three species present in Norwegian waters: Tiaropsis multicirrata, Modeeria rotunda, and Tima bairdii. Credit: L. Martell and A. Hosia, HYPNO project.

Figure 4: Anthomedusae (hydromedusae produced by athecate polyps) usually have the gonads developed in the manubrium. From left to right and top to bottom in the picture are Leuckartiara octona, Rathkea octopunctata, and Sarsia tubulosa. Credit: L. Martell and A. Hosia, HYPNO project.

Hopefully these images can be used as a starting point for the uninitiated, and why not? perhaps also as a source of inspiration for cool marine-related presents for the season!

-Luis Martell and Joan J. Soto Àngel

JESS! It’s World Jellyfish Day!

November 3 is World Jellyfish Day, and it is the perfect opportunity to celebrate the gelatinous creatures of the world by sharing experiences and plans with friends and colleagues. We at the Invertebrate Collections take every chance to share our love for jellies, which is why Aino and I were particularly happy to participate in the Jellyfish Research in Svalbard (JESS)-Workshop held last week in Tromsø (22-23 October).

Some examples of Arctic jellies. From left to right, in the top row: Catablema multicirratum, Beroe abyssicola, Botrynema ellinorae, Euphysa flammea; bottom row: Dimophyes arctica, Sminthea arctica, Bathykorus bouilloni, Aglantha digitale. Photos: HYPNO

Loved or hated, jellyfish are the kind of animals that either mesmerize beachgoers or make them go straight out of the water. Fortunately, all participants at the JESS Workshop belonged to the first category of people, and we had a very nice and productive meeting discussing methods, state-of-the-art, challenges, and opportunities of working with jellyfish in Arctic waters.

Happy jellyfish hunters in Tromsø

The workshop covered sessions on sampling, data management, ecology, and diversity, including an interesting discussion on how to obtain more (and better quality) jellyfish data from current plankton monitoring protocols. It was an international meeting (20 participants from more than 10 different countries) neatly organized by the University of Tromsø, but it still felt a lot like a bunch of friends getting together to talk about one fascinating subject, which is something I really enjoyed.

Sampling protocols and data curation were some of the most discussed topics during the JESS Workshop. Photos: Joan J. Soto Àngel

All that talking about feeding and predation made us hungry!

While the JESS Workshop was not exactly held on November 3rd, the spirit of commemoration of our gelatinous neighbors was present during the entire event. Celebrating World Jellyfish Day may be a rather recent activity (I could not find any reference of the first time this date was observed, but most likely it only started a couple of years ago), but being fascinated by the movement, color and shapes of jellyfish is certainly not a new thing. There has always been a lot of mystery surrounding the gelatinous inhabitants of the sea, so in a way it was only natural for the origin of the date dedicated to jellyfish to be as much of an enigma as the animals themselves. Mysterious or not, don’t miss the chance to celebrate your local jellies today!

Aino Hosia and Sanna Majaneva did a superb job organizing the JESS Workshop and making us feel at home in Tromsø: thank you so much for that! Many thanks as well to all the participants and speakers for the motivating talks and discussions.

Further reading
What could be better than adding some jelly-related reading to the celebration of World Jellyfish Day? I personally love the classics, so I would always recommend Sir Arthur Conan Doyle’s “The Adventure of the Lion’s Mane” for a case of a peculiar encounter with the beautiful Cyanea capillata. Enjoy!

– Luis

Keeping an eye open for mud jellies

Working on a team makes for the best discoveries in science, and we at the HYPNO and NorAmph artsprojects know it well, especially after we stumbled upon a large number of the elusive mud jellyfish Tesserogastria musculosa in one of our joint sampling trips to Raunefjord (you can read Christine’s account of our sampling here, in Norwegian).

Live specimens of mud jellyfish (Tesserogastria musculosa) collected in Raunefjord. Foto: L Martell

We were able to compare our specimens with the holotype (i.e. the original specimen upon which the description of the species was made, pictured above), thanks to a loan from the Natural History Museum of the University of Oslo. Collaboration between museums make science happen! Foto: L Martell

Mud jellyfish can be very abundant, but they are also easily overlooked, and only a gentle way of collecting animals will reveal its presence on a benthic sample. These hard-to-catch benthic jellyfish are so fragile that many previous surveys of the bottom of the fjords may have missed them because the jellies were simply too damaged to be identified at any level, but thanks to the careful processing of the samples and an expert eye we were able to obtain living specimens in good shape. This finding led to the evaluation of all the records of the species in the world, obtaining the first genetic data (including the DNA-barcode) for the species and genus, and finally to a redescription and a joint publication (available here:

Getting the sample and carefully separating the animals. Fotos: AHS Tandberg (left), L Martell (right)

Searching for (and finding!) many jellyfish. Fotos: AHS Tandberg

Mud jellyfish are the only species in genus Tesserogastria, which takes its name from the square-shaped stomach of the animals (Tesserogastria comes from ancient Greek τέσσαρες “four, square” and Latin gaster “stomach”). The specific name musculosa (Latin for “muscular”) was given to them because they look quite sturdy, with extremely well developed muscles around the opening of the “bell”. They are not the typical free-swimming and pulsating jellyfish, as they prefer to live in muddy bottoms, where they use their tentacles to walk around (they really don’t like to swim) until finding a place to sit and wait for dinner (which is usually some small crustacean). We still don’t know many things about this species because mud jellyfish are tiny and live on the bottom of the sea far away from the surface, but now that a new population has been discovered in Western Norway we will have the opportunity to investigate more on its behavior and body structure, perhaps answering some questions such as why do these jellies need very strong bell muscles if they don’t swim very often, or how the species is related to the other crawling jellyfish species from the North Atlantic.


Guest Researcher: Joan

Dr Joan Soto from the University of Valencia (Spain), visited us at the museum during August/September 2017 to collaborate with HYPNO on the mysterious issue of linking hydroids and their medusae. We asked him about his experience, and got the following:

Joan, ready to go jelly-hunting under the blue sky!

Joan, ready to go jelly-hunting under the blue sky!

Imagine a caterpillar and its butterfly described as different species by the scientific community. Now think on how confusing it would be if everybody kept calling them with different names over centuries. Well, this is the case of many hydroids and their corresponding medusae!

Hydrozoans, together with other well-known animals such as corals, anemones and jellyfishes, are included within the Phylum Cnidaria. Most hydrozoans are metagenetic, which means that they alternate between asexual (the polyp, usually benthic) and sexual (medusae, usually pelagic) stages in their life. Since the early works by Linnaeus in the mid-18th century, the very first scientists who showed interest in hydrozoans specialized primarily in a single stage of their life cycle, often neglecting the other, and even those courageous scientists who accepted the challenge of studying both groups were unable to discover the correspondence between such different animals as the polyp and the medusa.

Nowadays, in the era of molecular tools, new techniques are revealing that things are not what they seem, neither do they look like what they really are. Thanks to project HYPNO, several links between polyps and medusae have been found, with the subsequent adjustment in their ID (a.k.a. their scientific name), but that is not all! New evidences are bringing to light that some hydrozoans, even if they are morphologically identical to each other, in reality belong to different species, a fact known as “cryptic species”.

Both of these phenomena may be involved in the taxonomic confusion surrounding the hydroid Stegopoma plicatile and the medusa Ptychogena crocea, the former a worldwide reported species, the latter a Norwegian endemism. How can a medusa be so restricted in distribution while its hydroid lives everywhere? Perhaps now we know the answer thanks to molecular tools: Stegopoma plicatile may represent a complex of species, hiding a misunderstood diversity, and similar S. plicatile hydroids may produce different Ptychogena medusae. In other words, perhaps the polyp does not have such a wide distribution, and records from other parts of the world should be re-examined in detail, paying special attention to the tiniest and easily overlooked details of its morphology. But of course this is a job only for very patient detectives…

Hydroids of Stegopoma plicatile (like this one) from all over the world look very similar to each other, but may produce very different medusae.

Hydroids of Stegopoma plicatile (like this one) from all over the world look very similar to each other, but may produce very different medusae.

These beautiful medusae of Ptychogena crocea collected in Korsfjord were sexually mature. You can see the four gonads as folded masses of yellow tissue in each jellyfish.

These beautiful medusae of Ptychogena crocea collected in Korsfjord were sexually mature. You can see the four gonads as folded masses of yellow tissue in each jellyfish.

Thus, this was the objective of my recent visit to the Bergen University Museum. An outstanding month surrounded by enthusiastic scientists, amazing landscapes, restricted doses of sun, and upcoming challenges: we trust that current and future analyses combining both molecular and morphological taxonomy will lead to settle the correspondence of Stegopoma hydroids with other Ptychogena-like medusae from all over the globe, or even to the description of new species to science!

Deploying the net with help of the crew from RV "Hans Brattstrøm"

Deploying the net with help of the crew from RV “Hans Brattstrøm”

Team-work during the sampling makes everything a lot easier!

Team-work during the sampling makes everything a lot easier!

The amazing crane of the RV "Hans Brattstrøm" allowed us to efficiently hunt for jellyfish at the fjords.

The amazing crane of the RV “Hans Brattstrøm” allowed us to efficiently hunt for jellyfish at the fjords.

This is what our samples look like when we finally get to look at them on board

This is what our samples look like when we finally get to look at them on board


Meeting a famous gelatinous neighbour: Bathykorus bouilloni

Every now and then, a hydrozoan species will make the headlines because of the problems it creates for humans in a particular location. Hydrozoan jellyfish may bloom unexpectedly, transforming the water into a gelatinous soup, stinging people and fish in the process, while some hydroids have a tendency togrow  massively in places where they are not wanted. There are others that end up in the news because they produce some unusual protein, or have a peculiar life cycle that could lead to important findings in the fields of medicine or ecology.

Then there is Bathykorus bouilloni, a hydrozoan jelly that has gotten some media attention due to its resemblance to an extremely famous movie character.

This is the original photograph by of a live specimen included in the description of the species, next to a pic of its look-alike. Photo of the jelly: Kevin Raskoff

This is the original photograph of a live specimen included in the description of the species, next to a pic of its look-alike. Photo of the jelly: Kevin Raskoff

This jellyfish was described in 2010 by Dr. Kevin Raskoff, who gave it its appropriate name. Bathykorus is a combination of Bathy (from bathus, meaning depth or deep in Greek) and korus (also from Greek, meaning helmet), and it refers to the deep-sea habitat of the species, as well as to the helmet-like shape of the bell (like that of an intergalactic villain). The word bouilloni in the name of this critter is a tribute to Dr. Jean Bouillon (1926-2009), one of the most prolific authors in Hydrozoan biology in the 20th century.

The species has been known to science only for some years, and indeed very few people may have seen it alive, but this does not necessarily mean that it is an uncommon animal: in fact, it may be extremely abundant in some places and is perhaps one of the most common species living at certain depths in the Central Arctic Ocean.

Caption: the peach-coloured spots in this medusa are most likely the remnants of its last meal. Photo: Aino Hosia

The peach-coloured spots in this medusa are most likely the remnants of its last meal. Photo: Aino Hosia

The wide circular mouth of this animal (a characteristic shared with many other jellyfish in the Order Narcomedusae) is best seen from above. Photo: Aino Hosia

The wide circular mouth of this animal (a characteristic shared with many other jellyfish in the Order Narcomedusae) is best seen from above. Photo: Aino Hosia

We at the HYPNO project are happy to have found this charismatic species off Svalbard, and even more so when it was possible to barcode it through NorBOL!



Antsulevich, A. E. (2015). Biogeographic and faunistic division of the Eurasian Polar Ocean based on distributions of Hydrozoa (Cnidaria). Journal of the Marine Biological Association of the United Kingdom 95(08): 1533-1539.

Raskoff, K. A. (2010). Bathykorus bouilloni: a new genus and species of deep-sea jellyfish from the Arctic Ocean (Hydrozoa, Narcomedusae, Aeginidae). Zootaxa 2361(1): 57-67.

Sognefjorden cruise May 2017

After our week with SponGES on R/V Bonnevie, Luis and I had a night back in Bergen before we headed out on our second spring adventure: a four day cruise (still onboard Bonnevie) of Sognefjorden, the longest (205 km) and (deepest 1308 m) fjord in Norway.

The cruise, led by Prof. Henrik Glenner from the Institute of Biology, UoB,  was a multi-purpose one, with the majority of the projects being linked to the Norwegian Taxonomy Initiative (Artsprosjekt):

We collected material for the ongoing project that is investigating and mapping the barnacle fauna (Crustacea: Cirripedia) in Norway, which a special focus on the strange, parasitic barnacle Anelasma squalicola that is found on the shark Etmopterus spinax (velvet bellied lantern shark/svarthå).

The material we collected will also serve as an addendum to the project on Species inventory and nature type mapping of Sognefjorden, which was recently concluded.

As for the University Museum, Luis was onboard collecting pelagic and benthic Hydrozoa for the HYPNO-project, whilst I was on the hunt for more species for DNA-barcoding through NorBOL (the Norwegian Barcode of Life). We have also re-sampled some polychaete type localities from the 1970’s, and attempted to retrieve more material from stations where we have found new species in more recent material (we need more specimens before we can formally describe them).

In addition, we had two Danish researchers onboard that were studying the bioluminescence and eye development of the starfish family Brisingidae. The story told in images:

We should maybe also add "one of the most gorgeous" to the description of the fjord

We should maybe also add “one of the most gorgeous” to the description of the fjord

Velvet belly lanternshark, Etmopterus spinax

Velvet belly lanternshark, Etmopterus spinax

Henrik and Christoph sorting a shrimp trawl catch on deck

Henrik and Christoph sorting a shrimp trawl catch on deck

Eager pickings in the trawl catch

Eager pickings in the trawl catch

Not all trawl samples go according to plan... this one, taken in the open sea, ended up sampling *a bit* deeper than intended, so we got a lot of benthic animals - and mud. So. much. mud.

Not all trawl samples go according to plan… this one, taken in the open sea, ended up sampling *a bit* deeper than intended, so we got a lot of benthic animals – and mud. So. much. mud.

Most novel sampling gear yet? Collecting velvet belly lanternshark by monkfish!

Most novel sampling gear yet? Collecting velvet belly lanternshark by monkfish! (caught in the “benthic” trawl)

The brisinga sea stars are very fragile - and live deep down.

The brisinga sea stars are very fragile – and live deep down.

We amanged to get some not-too-damaged specimens with a small trawl

We manged to get some not-too-damaged specimens with a small trawl

The plankton net going our for collecting

The plankton net going our for collecting

Luis an Marie studying a plankton sample

Luis an Marie studying a plankton sample



For some reason, my samples seems to involve inordinate amounts of mud - good thing I had good helpers to work through it all!

For some reason, my samples seems to involve inordinate amounts of mud – good thing I had good helpers to work through it all!

Cruising in a postcard!

Cruising in a postcard!

Sadly, plastic pollution was prevalent in Sognefjorden as well - here's a soda bottle from a sample taken at 911 m depth

Sadly, plastic pollution was prevalent in Sognefjorden as well – here’s a soda bottle from a sample taken at 911 m depth

And here are som eof the plastic that we ended up with from our sampling, most of it from over 1000 meters depth.

Here is some of the plastic that we ended up with from our sampling, most of it recovered from over 1000 meters depth.

Our final night of the cruise was spent in the mud and the sunset - it's starting to become a recurring theme!

Our final night of the cruise was spent in the mud and the sunset – it’s starting to become a recurring theme!

Once again, thank you so much to the crew on Bonnevie for all their help!

Once again, thank you so much to the crew on Bonnevie for all their help!