Tag Archives: marine invertebrates

Sled test for copepods

R.P. sled onboard R/V. H. Brattström

Happy new year to everyone! We managed to start 2021 with a day at sea, testing the R.P. sled for collecting benthic copepods from greater depths . January 27 we went out with research vessel Hans Brattström, crew and research scientist Anne Helene Tandberg who also turns out to be a true sled expert! She would join HYPCOP to teach how to process the samples from the R.P. sled on the boat.

 

 

 

 

Anne Helene Tandberg (left) joining HYPCOP (Cessa Rauch right) for teaching how to use the sled.

But first, what is an R.P. sled and why is it such an important key in the collection of copepods? The R.P. sled is an epibenthic sampler. That means that it samples the epibenthic animals – the animals that live just at the top of the (soft) seafloor – and a majority of these are often small crustaceans. The “R.P.” in the name stands for Rothlisherg and Pearcy who invented the sled. They needed to collect the juveniles of species of pandalid shrimp that live on the sea bottom floor. These animals are very small so a plankton net was necessary to collect them; a ‘normal’ dredge would not quite cut the job. They needed a plankton net that could be dragged over the bottom without damaging the net or the samples and also would not accidently sample the water column (pelagic); and so, the R.P. sled was born. This sled was able to go deeper than 150m, sample more than 500m3 at the time and open and close on command which was a novelty in comparison to the other sleds that where used in those days (1977). The sled consists of a steel sled like frame that contains a box that has attached to it a plankton net with an opening and closing device. The sled is heavy, ca. 150kg, and therefore limits the vessel sizes that can operate it; the trawl needs to be appropriately equipped including knowledgeable crew. It is pulled behind the vessel at slow speed to make sure the animals are not damaged and to make sure it does not become too full of sediment that is whirled up.

 

 

Sieved animals from the decanting process

So off we went with r/v Hans Brattström pulling the heavy gear at ca. 700m depth with 1 knot and a bottom time of 10 minutes sampling the Krossfjorden close to Bergen. It was a beautiful day for it with plenty of sun and calm seas. The crew handled most of the sled, leaving sorting the samples up to HYPCOP under the guidance of Anne Helene. Which is not as straight forward as it may sound! The process of filtering the samples after collecting them from the sled is done by decanting, which you can see in this movie from an this blog (in Norwegian) from earlier.

Decanting set-up for R.P. sled samples

Decanting means separating the mixture of the animal soup from the liquid by washing them in a big bucket, throw the liquid through a filter and collect the animals.

Sieved animals from the decanting process

This all needs to be done with care as the animals are often very small and fragile. After collecting, the most time-efficient and best preservation for the samples is to fixate them immediately with ethanol, so they don’t go bad while traveling back to the museum.

Fixating collected animals with technical ethanol

For collecting copepods we use a variety of methods; from snorkeling, to scoping up water and plankton nets, but for greater depths and great quality benthic samples the R.P. sled will be the most important method. We thank Anne Helene for her wisdom and enthusiasm that day for showing HYPCOP how to work with such interesting sampling method

 

We got some nice samples that will be sequenced very soon so we can label them appropriately. Although this first fieldwork trip off the year was mainly a teaching opportunity, we still managed to sample two stations with plenty of copepods and lots of other nice epibenthic crustacea, and Anne Helene is especially happy with all the amphipods she collected during the day. So for both of the scientists aboard this was a wonderful day – sunshine and lovely samples to bring back to the lab!

Some fresh copepods caught with the R.P. sled

– Cessa & Anne Helene

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

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

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

See you there!

When amphipodologists meet.

It generally happens every two years. The event may be seen as a natural phenomenon – or maybe rather  a cultural phenomenon. I am sure it looks strange if observed from outside the community. A lot of people of all ages and affiliations meet up in places most of us usually did not even know existed, and we have the best week of our work-year.

Happy friends meeting in Trapani. (all photos: AH Tandberg)

Happy friends meeting in Trapani. (all photos: AH Tandberg)

The bi-annual International Colloquium on Amphipoda (ICA) is without doubt the scientific meeting I look most forward to.  Every time. The fun, the science, the amphipods, the friendships, the coffee, the familiar banter, the late nights and early mornings, the discussions – all in an atmosphere of friendship.

The Polish Amphipod-t-shirt edition 2017. (photo: AH Tandberg)

The Polish Amphipod-t-shirt edition 2017. (photo: AH Tandberg)

The first day of any ICA could be mistaken for a family-gathering – or the opening credits of any film about best friends. The room resounds of “oh – finally – there you are!”, “how are the kids/grandkids?”, “I missed you this last hour! Thought maybe you got lost since you weren’t here immediately” and not least “Come, let me give you that hug I promised!” Ten minutes later everybody will be organised by the large Polish group for some gathering or fun – and the rest of us are trying to find out how we can get one of the cool group-t-shirts the Łodz-group have concocted this year. Or maybe we should rather go for one of the other cool t-shirts picturing amphipods?

We do talk amphipods, of course. The incredible variety of the group (of animals – as well as people) opens up for a wide spectre of research-questions and approaches, and meetings allow time to learn from each other, get inspired, start new collaborations and share samples and ideas.

Most important: the science of amphipods. Loads of interesting talks and posters! (all photos: AH Tandberg)

Most important: the science of amphipods. Loads of interesting talks and posters! (all photos: AH Tandberg)

 

Those getting to the poster-session fast enough win the crochet amphipods... (photo: AH Tandberg)

Those getting to the poster-session fast enough win the crochet amphipods… (photo: AH Tandberg)

This years ICA was held in Trapani, Sicily – where prof Sabrina LoBrutto on a short one year notice had organised the meeting. The three days we met were packed with more than 60 talks, more than 60 posters and loads and loads of happy amphidologists. With the University situated right across the road from the beach, and a lunch hour long enough for both a coffee and a swim/sample search the friendly atmosphere stretched to drying towels on the railings of the university-hall and sea-salted hairstyles for many after lunch.

Keeping the atmosphere friendly: Beach, coffee and icecreams (all photos: AH Tandberg)

Keeping the atmosphere friendly: Beach, coffee and icecreams (all photos: AH Tandberg)

 

The scientifically helpful Japanese amphipod t-shirt. (now the rest of you should notice the morphological differences between the families). (photo: AH Tandberg)

The scientifically helpful Japanese amphipod t-shirt. (now the rest of you should notice the morphological differences between the families). (photo: AH Tandberg)

We always try to publish the Amphipod Newsletter to coincide with the ICA. You can download the newsletter both from the World Amphipoda Database and the Biodiversity Heritage Library (both places also have back-issues available for downloads). One of the features of the newsletter is a bibliography of amphipod-related literature, and a list of new taxa. Since last AN we have 79 new species, 14 new genera and 12 new families! Every AN includes an interview with one of the amphipodologists – this year you can get to know Wolfgang Zeidler and his Hyperiidea better.

The next ICA? In two years we meet in Dijon, France! I am already excited – and maybe there will be mustard-coloured t-shirts in honour of the location (or burgundy-coloured t-shirts)?  What I know already, is that it is going to be like meeting family.

Anne Helene

AmphipodThursday: IceAGE-amphipods in the Polish woods

img_2610This adventure started 26 years ago, when two Norwegian benthos researchers (Torleiv Brattegard from University of Bergen and Jon-Arne Sneli from the University in Trondheim) teamed up with three Icelandic benthos specialists (Jörundur Svavarsson and Guðmundur V. Helgasson from University of Iceland and Guðmundur Guðmundsson from the Natural History Museum of Iceland) to study the seas surrounding the volcanic home of the Nordic sages. 19 cruises and 13 years later – and not least lots of exciting scientific findings and results the BioICE program was finished.

But science never stops. New methods are developed and old methods are improved – and the samples that were stored in formalin during the BioICE project can not be used easily for any genetic studies. They are, however, very good for examinations of the morphology of the many invertebrate species that were collected, and they are still a source of much interesting science.

Participants of the IceAGE workshop. Photo: Christian Bomholt (www.instagram.com/mcb_pictures)

Participants of the IceAGE workshop. Photo: Christian Bomholt (www.instagram.com/mcb_pictures)

The dream about samples that could be DNA-barcoded (and possibly examined further with molecular methods) lead to a new project being formed – IceAGE. A large inernational collaboration of scientists organised by researchers from the University of Hamburg (and still including researchers from both the University of Iceland and the University of Bergen) have been on two cruises (2011 and 2013) so far – and there is already lots of material to look at!


This week many of the researchers connected with the IceAGE project have gathered in Spała in Poland – at a researchstation in woods that are rumoured to be inhabited by bison and beavers (we didn´t see any, but we have seen the results of the beavers work). Some of us have discussed theories and technical stuff for the papers and reports that are to come from the project, and then there are “the coolest gang” – the amphipodologists. 10 scientists of this special “species” have gathered in two small labs in the field-station, and we have sorted and identified amphipods into the wee hours.

It is both fun and educational to work together. Everybody have their special families they like best, and little tricks to identify the difficult taxa, and so there is always somebody to ask when you don´t find out what you are looking at. Between the stories about amphipod-friends and old times we have friendly fights about who can eat the most chocolate, and we build dreams about the perfect amphipodologist holiday. Every now and then somebody will say “come look at this amazing amphipod I have under my scope now!” – we have all been treated to species we have never seen before, but maybe read about. We also have a box of those special amphipods – the “possibly a new species”- tubes. When there is a nice sample to examine, you might hear one of the amphipodologist hum a happy song, and when the sample is all amphipods but no legs or antennae (this can happen to samples stored in ethanol – they become brittle) you might hear frustrated “hrmpfing” before the chocolate is raided.

 

Isopodologists (Martina and Jörundur) visiting the amphipodologists... Photo: AH Tandberg

Isopodologists (Martina and Jörundur) visiting the amphipodologists… Photo: AH Tandberg

The samples from IceAGE are all stored in ethanol. This is done to preserve the DNA for molecular studies – studies that can give us new and exciting results to questions we have thought about for a long time, and to questions we maybe didn´t even know we needed asking. We can test if what looks like the same species really is the same species, and we can find out more about the biogeography of the different species and communities.

The geographical area covered by IceAGE borders to the geographical area covered by NorAmph and NorBOL, and it makes great sense to collaborate. This summer we will start with comparing DNA-barcodes of amphipods from the family Eusiridae from IceAGE and NorAmph. They are as good a starting-point as any, and they are beautiful (Eusirus holmii was described in the norwegian blog last summer).


Happy easter from all the amphiods and amphipodologists!

Anne Helene

Literature:

Brix S (2014) The IceAGE project – a follow up of BIOICE. Polish Polar Research 35, 1-10

Dauvin J−C, Alizier S, Weppe A, Guðmundsson G (2012) Diversity and zoogeography of Ice−
landic deep−sea Ampeliscidae (Crustacea: Amphipoda). Deep Sea Research Part I: 68: 12–23.

Svavarsson J (1994) Rannsóknir á hryggleysingjum botns umhverfis Ísland. Íslendingar og hafiđ.
Vísindafélag Íslendinga, Ráđstefnurit 4: 59–74.
Svavarsson J, Strömberg J−O,  Brattegard T (1993) The deep−sea asellote (Isopoda,
Crustacea) fauna of the Northern Seas: species composition, distributional patterns and origin. Journal of Biogeography 20: 537–555.

Door #15 Twinkle, twinkle, little animal?

Yesterdays door of this calendar introduced the bioluminescent animals of the deep sea.
In the parts of the ocean where sunlight reaches (the photic zone), production of ones own light is not common. This is because it is costly (energetically), and when the surroundings already are light, the effect is almost inexistent. An exception to this is the use of counter-illumination that some animals have: lights that when seen from underneath the animal camouflages them against the downwelling light from above.

But what then with the ocean during the polar night? Last Thursdays blog told the story of the dark upper waters during the constant dark of the arctic winter, and how the quite scanty light of the moon is enough to initiate vertical mass movements. Another thing we see in the dark ocean is that processes that at other latitudes are limited to the deep sea come up nearly to the surface during the polar night.

So – in the Arctic winter we don´t have to use robots and remote cameras to observe biioluminescent animals: we can often observe them using normal sport diving equipment or even from above the surface. A very recent study (Cronin et al, 2016) has measured the light from different communities in the Kongsfjord of Svalbard during the polar night. They found that going from the surface and down, dinoflagellates produced most light down to 20-40 m depth, the lighting “job” was then in general taken over by small copepods (Metridia longa). Most light was produced around 80 m depth.

Bioluminescent dinoflagellates shining through the winter sea ice in Kongsfjorden. Photo: Geir Johnsen, NTNU

Bioluminescent dinoflagellates shining through the winter sea ice in Kongsfjorden. Photo: Geir Johnsen, NTNU

It is possible to recognise different species from the light they make; a combination of the wavelength, the intensity and the length of the light-production gives a quite precise “thumbprint”. If we know the possible players of the system in addition, an instrument registering light will also be able to give us information about who blinks most often, at what depths, etc. Cronin and her coauthors have made a map of the lightmakers in the Kongsfjord.

Bioluminescence profiles from Kongsfjord. Figure 3 from Cronin et al, 2016

Bioluminescence profiles from Kongsfjord. Figure 3 from Cronin et al, 2016

This is all well and good, but the next question is of course WHY. There can be several uses for light, and we can bulk the different reasons into 3 main groups: Defense, offense and recognition.

Different strategies for Bioluminescence. Fig 7 from Haddock (2010), redrawn for representation of the Polar night bioluminescence by Ola Reibo for the exhibition "Polar Night"

Different strategies for Bioluminescence. Fig 7 from Haddock (2010), redrawn for representation of the Polar night bioluminescence by Ola Reibo for the exhibition “Polar Night”

 

The bioluminescent cloud from an escaping krill. Kongfjorden, during the Arctic polar night. Photo: Geir Johnsen, NTNU

The bioluminescent cloud from an escaping krill. Kongfjorden, during the Arctic polar night. Photo: Geir Johnsen, NTNU

Defence has already been mentioned above: the counterillumination against downwelling light is helping an animal defend itself against predation. Some will leave a smokescreen, or even detach a glowing bodypart while swimming away in the dark, and others blink to startle the enemy or to inform their group-mates that an enemy is getting close.

 

 

Offense is mainly to use the light to get food (this is typical angler-fish-behaviour), and recognition is very often about flirting. Instead of flashing your eyelashes at your your chosen potential partner, you flash some light at him or her…

Thursdays are about amphipods in this blog, so here they come. Bioluminescent amphipods are present mainly in the hyperiid genera Scina (a Norwegian representative of this genus is Scina borealis (Sars, 1883).) Hyperiids are amphipods that swim in the free watermasses, like most other bioluminescent animals.

The bioluminescent amphipod Scina borealis (Sars, 1893). The added stars indicate where the bioluminescence occurs. Original figure: G.O.Sars, 1895.

The bioluminescent amphipod Scina borealis (Sars, 1893). The added stars indicate where the bioluminescence occurs. Original figure: G.O.Sars, 1895.

Crustacea use more different ways to produce bioluminescence than most other groups – this points to a possibility that the use of bioluminescence has evolved several independent times in this group. So the copepod Metridia longa will use a different chemical reaction than the krill, and the amphipods use again (several) different reactions. Some research on the bioluminescence of amphipods was undertaken already in the late 1960s, where P Herring collected several Scina species and kept them alive in tanks. There he exposed them to several luminescence-inducing chemicals and to small electrical shocks, to see where on the body light was produced and in what sort of pattern. He reported that Scina has photocytes (lightproducing cells) on the antennae, on the long 5th “walkinglegs”, and on the urosome and uropods. They would produce a nonrythmical rapid blinking for up to 10 seconds if attacked, and at the same time the animal would go rigid in a “defence-stance” with the back straight, the antennae spread out in front of the head, and the urosome stretched to the back. This definitely seems to be a defence-ligthing, maybe we should even be so bold as to say it would startle a predator?

Anne Helene

Literature:

Cronin HA, Cohen JH, Berge J, Johnsen G, Moline MA (2016) Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports/Nature 6, article 36374 (DOI: 10.1038/srep36374)

Haddock SHD, Moline MA, Case JF (2010) Bioluminescence in the Sea. Annual Review of Marine Science 2, 443-493

Herring PJ (1981) Studies on bioluminescent marine amphipods. Journal of the Marine biological Association of the United Kingdoms 61, 161-176.

Johnsen G, Candeloro M, Berge J, Moline MA (2014) Glowing in the dark: Discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology 37, 707-713.

Door #11 Invertebrately inspired art?

Scientific illustrations today are usually formed within quite strict limits. We use photographs or drawings of small details, and these are all connected to one specific specimen that preferably is to be found in a scientific collection.

But can other approaches also help us? The artist Pippip Ferner has long found her inspiration in nature, and especially the (marine) invertebrates. Maybe her pictures can inspire us to examine other details in our study-animals? Maybe a picture can inspire you to think more about nature, the sea, or invertebrates – their lives and lores? These are not pictures that are meant to be scientifically accurate, but rather fabulations inspired by the wild things that happen when evolution gets to do as it pleases…

Some of Pippis drawings are inspired from scientific drawings, both old and new, some are from animals we have looked at together.

Here are some of Pippips pictures from this year, and the animals that inspired them. These three pictures were chosen to be part of the Evolution and Art section of the international science conference Evolution this summer in Austin, TX.

"Tunicate anatomy" (c) Pippip Ferner

“Tunicate anatomy” (c) Pippip Ferner

Pippip says about this first picture:

“A scientific illustration of a TUNICATE is the inspiration for this work. Tunicates are sort of last stage before vertebrates. Clues for this is found in the larva that has a notochord, comparable to the spine of vertebrates. It has cerebral vesicle equivalent to a vertebrate’s brain, sensory organs that includes an eyespot to detect light and an otolith, which helps the animal orient to the gravity.
Fascinated by the thought of this “slimy blob” having many features similar to humans resulted in this quite complex outcome. The overload of insistent lines has given the tunicate quite a sophisticated system.”

Komodo National Park sea squirt (Polycarpa aurata). Photo: Nick Hobgood (wikipedia)

Komodo National Park sea squirt (Polycarpa aurata). Photo: Nick Hobgood (wikipedia)

On the left is a photo of a live tunicate. This photo is from Indonesia, but tunicates are common to find also in our colder waters. They can be solitary as this one, or colonial – where several tunicates form a colony together by budding, so that one large colony basically has the exact same DNA. Most tunicates are sessile (they sit attached to one place), but some live floating around in the water. The best known of these pelagic tunicates are the salps of the southern oceans.

 

Internal anatomy of a tunicate (Urochordata). Adapted, with permission, from an outline drawing available on BIODIDAC. (Wikipedia)

Internal anatomy of a tunicate (Urochordata). Adapted, with permission, from an outline drawing available on BIODIDAC. (Wikipedia)

A scientific illustration of a tunicate in a Biology textbook will look something like this:

 

 

 

 

 

 

Moving to other invertebrates, Pippip has worked with clams:

"Bivalve anatomy" (c) Pippip Ferner

“Bivalve anatomy” (c) Pippip Ferner

“In this image I question how the clam lives in symbiosis with other species as its shell gets weaker due to climate changes. The drawing might resemble the results of some kind of scientific inquiry with references to the anatomy of a clam (bivalve).
In my work I let my own artistic evolutionary process make the clam into something more abstract.”

(If you wait until door # 22, there might be a story that relates to bivalves that live with others…)

This is a Ctenophore, a comb jelly:

"Comb jelly anatomy" (c) Pippip Ferner

“Comb jelly anatomy” (c) Pippip Ferner

“The starting point of this work was a detailed illustration from biologist Ernst Haeckel’s (Artforms in Nature) of a comb jelly/ctenophorae. The comb jelly differs from other jellyfish with more sophisticated nervous system with both synapses and individual muscle cells.
The outcome of this drawing is a tribute to the beauty of the structure of this organism.”

Jelly fishes anf Comb jelly fishes. Illustration: Ernst Haeckel, Kunstformen der Natur 1904, plate 27

Jelly fishes anf Comb jelly fishes. Illustration: Ernst Haeckel, Kunstformen der Natur 1904, plate 27

Ctenophores are predatory planktonic jellies. The special thing about them, according to our Jelly-specialist Aino, is that they have a rotational symmetry. The diagnostic feature of comb jellies are their comb-rows that they use for swimming. The photos above represent the three groups of comb jellies – all of them are present in Norway.

 

To the right is the Haeckel-picture she started from, and here is a film of Comb jellies from the Chicago Shedd Aquarium.

 

 

 

Pippip, Anne Helene and Aino

 

 

Door #8: the ups and downs of a marine werewolf?

When we think about what drives the ecosystems, much of the initial responsibility is put on the sunlight. This is mainly because of the photosynthesis, and thus the basic pieces of almost all food-webs, but light is also important for the animals. Many animals use visual cues to find food, and whether you search for food or do not want to become food, the presence (or absence) of light will help you.

Themisto sp swims up into the dark night. Photo: Geir Johnsen, NTNU

Themisto sp swims up into the dark night. Photo: Geir Johnsen, NTNU

Seawater is a pretty good stopper of light. We don’t need to dive far down before we are in what we consider a dark place, and less and less light finds its way the deeper we come. We tend to call the depths between 200 and 1000 m “the twilight zone”: most light stops way before 200m and the last straggling lumens give up at 1000m.

Most places on earth has a daily division between a dark and a light period: night and day. This is the ultimate reason for what is often called “the largest motion on earth”: Millions of zooplankton hide out in the darker parts of the water column during the day, and then move up to feed on the plants living in the light-affected parts of the water during the night (when predators will have a hard time seeing them). This daily commute up and down is called Diel Vertical Migration (DVM).

Themisto sp among the many smaller particles. (The light in this picture is from a flash). Photo: Geir Johnsen, NTNU

Themisto sp among the many smaller particles. (The light in this picture is from a flash). Photo: Geir Johnsen, NTNU

But what about the waters north of the polar circle? These areas will for some time during the winter have days when the sun stays under the horizon the entire day – this is “the Dark time” (Mørketid). At higher latitudes, there will be several days, or even weeks or months when the sun is so far below the horizon that not even the slightest sunset-glow is visible at any time. In this region, we have long thought that the Dark time must be a dead or dormant time.

 

The acoustic signals that gave the first indications of LVM. Figure 2 from Last et al 2016.

The acoustic signals that gave the first indications of LVM. Figure 2 from Last et al 2016.

We could not have been more wrong! It turns out that during the polar night, the DVM moves from being on a 24 hr cycle (sunlight-induced), to a 24.8 hour cycle! What is now the driver? The moon !(The lunar day is 24.8 hrs). Another thing that shows us that the moon must give strong enough light that predators can hunt by it, is that every 29.5 days most of the zooplankton sinks down to a depth of 50m: this falls together with the moon being full. Researchers have started to call this LVM (Lunar-day Vertical Migration) to show the difference to the “normal” DVM. There are of course lots of complicated details such as the moons altitude above the horizon and its phase that influences the LVM, but in general we can say that during the polar night (the Very Dark time), the “day” as decided by light has become slightly longer than normal.

The full moon, photographed by the Apollo 11 crew after their visit. Photo: NASA, 1969

The full moon, photographed by the Apollo 11 crew after their visit. Photo: NASA, 1969

Themisto - the werewolf. Note that the whole head is dominated by eyes - this is a visual hunter! Photo: Geir Johnsen, NTNU

Themisto – the werewolf. Note that the whole head is dominated by eyes – this is a visual hunter! Photo: Geir Johnsen, NTNU

Some of the larger animals taking part in the LVM are the amphipods Themisto abyssorum and Themisto libellula. They are hunters – so their reason to migrate up in the water column is not the plants, but the animals eating the plants; their favourite food are copepods of the genus Calanus. These are nice and quite energy-rich small crustaceans that eat the microscopic plants in the upper water column. We have sampled both Themisto-species in the middle of the winter (january), and their guts were filled to the brim with Calanus, so we know that they continue hunting by moon-light. They are such voracious hunters that some researchers have started to call them marine werewolves: the moonlight transforms them from sedate crustaceans to scary killers…

 

But, if they are the hunters, why do they spend so much time in the deep and dark during the lighter parts of the day? The hunters are of course also hunted. Fish such as polar cod (Boreogadus saida),  birds such as little auk (Alle alle) and various seals like to have their fill of the Themisto species. So – life has its ups and downs, and the dance of hunter and hunted continues into the dark polar night…

Anne Helene

Literature:

Berge J, Cottier F, Last KS et al (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters 5, 69-72.

Berge J, Renaud PE, Darnis G et al (2015) In the dark: A review of ecosystem processes during the Arctic polar night. Progress in Oceanography 139, 258-271.

Kintisch E (2016)  Voyage into darkness. Science 351, 1254-1257

Kraft A, Berge J, Varpe Ø, Falk-Petersen S (2013) Feeding in Arctic darkness: mid-winter diet of the pelagic amphipods Themisto abyssorum and T. libellula. Marine Biology 160, 241-248.

Last KS, Hobbs L, Berge J, Brierley AS, Cottier F (2016) Moonlight Drives Ocean-Scale Mass Vertical Migration of Zooplankton during the Arctic Winter. Current Biology 26, 244-251.

Door #1 Gammarus wilkitzkii – closer than Santa to the North Pole?

We greet December with our 2016 edition of the invertebrate advent calendar, and will be posting a new blog post here every day from today until the 24th of December! Be sure to check in often! All posts of this year’s calendar will be collected here: 2016 calendar, and all of the post in last year’s event are gathered here in case you would like a recap: 2015 edition. First out is Anne Helene and a Northern amphipod:

December is over us, the Advent Calendar from the invertebrate section lets you open the first door today, and many children (both small and slightly older) are eagerly awaiting the answer to their letter to Santa Claus. Mr Claus is supposed to live on the North Pole, and many letters addressed there have been coming through different post-offices the last months.

Many of us are wondering if Santa Claus might be a Species dubius (a species it is slightly doubtful exists), but if he exists, his homestead is becoming endangered. We are seeing a rapid decline of the Arctic sea ice (here is a video from NOAA showing the extent and age of the icecap from 1987 to 2014), and this will undoubtedly have a large effect on the Earths climate.

A polar bear mother and cub walking on the top of the sea ice. Photo: AHS Tandberg

A polar bear mother and cub walking on the top of the sea ice. Photo: AHS Tandberg

In addition to the theoretical possibility of Santa, there are several true and precious species that depend on the sea ice for their life. Most probably think about polar bears and seals now, but there is an even more teeming abundance of life right under the ice, many of them live as the sea ice is an upside-down seafloor. The largest animal biomass of all the many invertebrate species connected to the sea ice (we call these sympagic species), comes form the amphipod Gammarus wilkitzkii Birula 1897.

Gammarus wilkitzkii is the largest of the invertebrates that hang out (literally) under the ice; they can reach almost 3 cm length. They are whitish-grey, with red-striped, long legs. The hind legs have hooks that allow them to easily attach to the sea ice, and hanging directly under the ice instead of swimming saves a lot of energy for them. This behaviour is so necessary to them that if we keep them in an aquarium, they need something to hang on to – be it the oxygen-pump, a piece of styrofoam, the hand of a researcher or the edge of the lid. There are a few observations of swimming G. wilkitzkii sampled from the middle of the water-column, but this seems to be specimens that have lost their hold in life – we do not think they can live long swimming around (that would take too much energy).

A male (white) Gammarus wilkitzkii holding a female (yellow) Gammarus wilkitzkii. The male is also holding on to the sea-ice with his hind legs. Photo: Bjørn Gulliksen, University of Tromsø and UNIS.

A male (white) Gammarus wilkitzkii holding a female (yellow) Gammarus wilkitzkii. The male is also holding on to the sea-ice with his hind legs. Photo: Bjørn Gulliksen, University of Tromsø and UNIS.

Being such large animals, and in such large abundance, G. wilkitzkii are preyed upon mostly by diving sea-birds, but they have also been found in the stomach-content of harp-seals and to a small degree the small and stealthy polar cod. Most of these animals are mainly found in what we call the marginal ice zone – where the sea ice meets the open water. This is also the place where G. wilkitzkii can find most of its own food: algae, other small invertebrates and ice-bound detritus.

A diver under the sea ice. Photo: Geir Johnsen, NTNU

A diver under the sea ice. Photo: Geir Johnsen, NTNU

G. wilkitzkii is also found in great quantities under the multi-year ice, where it probably leads a safer life. Being at the edge of the ice presents a problem: this is the ice that melts during the summer, and that will force the amphipods to move further into the ice as its habitats disappear. The underside of the ice is not a flat field – it is a labyrinth of upside-down mountains and valleys, with several small and large caves. Many nice hiding-places, but if you swim or crawl along the ice-surface, the distance is longer than we would measure it on the top of the ice.

Where the ice is thin, or where there is no snow covering the ice, some light will shine through. This means that the edge of the ice normally lets a lot more light through than the multi-year ice. We dont know what this does for G. wilkitzkii, but they have eyes that are of similar size and shape as the other species in the genus, so they possibly use their eyes for hunting for food or checking for enemies.


G. wilkitzkii is an animal that is accustomed to a tough life. The sea temperature right under the ice normally lies around -1.8ºC, (so below what we think of as “freezing”) this is because of the high salinity of the water. As sea-water freezes, the salt leaks out, and flows in tiny brine-rivers trough the ice and down into the water below.  They have specialised their life cycle to fit with the available food – so that their young are released when there is much food to be found, and they can live up to 6 years reproducing once every of the last 5 years, probably to make sure at least some of their offspring survive.

We have 24 more days before we find out if Santa “exists”, though this might not give us the answer to him having become a climate-refugee. Hopefully, we will have to wait much longer to find out what will happen with the many ice-dependent invertebrates, but becoming climate-refugees might not be easily accomplished for them.

Anne Helene

Literature:

Arndt C, Lønne OJ (2002) Transport of bioenergy by large scale arctic ice drift. Ice in the environment – Proceedings of the 16th IAHR International Symposium on Ice, Dunedin , NZ. p103-111.

Gulliksen B, Lønne OJ (1991) Sea ice macrofauna in the antarctic and the Arctic. Journal of Marine Systems 2, 53-61.

Lønne OJ, Gulliksen B (1991) Sympagic macro-fauna from multiyear sea-ice near Svalbard. Polar Biology 11, 471-477.

Werner I, Auel H, Garrity C, Hagen W (1999) Pelagic occurence of the sympagic amphipod Gammarus wilkitzkii in ice-free waters of the Greenland Sea – dead end or part of life-cycle? Polar Biology 22, 55-60.

Weslawski JM, Legezinska J (2002) Life cycles of some Arctic amphipods. Polish Polar Resarch 23, 2-53.

Biodiversity Valentines

This gorgeous polychaete (Bristle worm) is from the family Serpulidae, it was identfied as a Pomatoceros triquetes during the students' course in marine faunistics

This gorgeous polychaete (bristle worm) is from the family Serpulidae, it was identified as a Pomatoceros triquetes during the students’ course in marine faunistics (Photo: K.Kongshavn)

Release the Kraken!

Oh, dear… this challenge:

Please share your love of biodiversity this Valentine’s Day with the hashtag #bdvalentine.

Have fun and help raise awareness of biodiversity and conservation!

We’ll be on Twitter and Facebook celebrating all day on Friday, February 12th with “Biodiversity Valentines.” Tweet your best biodiversity-themed Valentine message with the hashtag #bdvalentine.  You can borrow from our growing Facebook gallery of #bdvalentine images here:  https://goo.gl/dZkQdS .

Get your creative juices flowing (and your creative and communications folks brainstorming)!  We’ll retweet and create a gallery of your images all day on Friday, February 12th.

At JRS, we’re working to increase the use of biodiversity data and information services for conservation and sustainable development in Africa.  We love biodiversity data.  Join in with your #bdvalentine!

ticked into our in-box from the JRS Biodiversity Foundation a couple of days ago, and we decided to give it a spin.

Now, biologists seem to gravitate towards punny (and occasionally funny) humour, and there’s been an avalanche of submissions and suggestions on what we could post.

Here’s a selection of submissions from the Invertebrate collections, we hope you’ll enjoy them!

Interspecies <3 between Laonice sarsi and L. bahusiensis (photo:T. Alvestad)

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This little Cephalopod was collected by MAREANO. (Photo: K.Kongshavn)

This little Cephalopod was collected by MAREANO. (Photo: K.Kongshavn)

This cuttlefish was encountered in an Aquarium, and thus does not reside in our collections! They belong to the class Cephalopoda, which also includes squid, octopodes, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone. Despite their name, cuttlefish are not fish but molluscs. (Photo: K.Kongshavn)

This cuttlefish was encountered in an Aquarium, and thus does not reside in our collections! They belong to the class Cephalopoda, which also includes squid, octopodes, and nautiluses. Cuttlefish have a unique internal shell, the cuttlebone. Despite their name, cuttlefish are not fish but molluscs. (Photo: K.Kongshavn)

IMG_2773

Not a local species! Jelly fish do not have a independent circulatory system, nor do they have structured organ systems, brain, or breathing apparatus.

isopod_stack

A friendly (?) Isopod from the Cirolanidae family.

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ZMBN_106092_4

Uncini bristles from a Euclymene (Maldanidae) polychaete

Uncini bristles from a Euclymene (Maldanidae) polychaete. The picture is taken with an Scanning Electron Microscope (SEM) at our local SEM lab. The scale bar is 2 µm, or 0.002 mm, so these are truly TINY structures.

crabby.tif

Here’s an Ebalia sp. that we have barcoded through NorBOL.

Here's a Urticina eques (Photo: K.Kongshavn)

Here’s a Urticina eques (Photo: K.Kongshavn)

A Crossaster papposus collected for NorBOL together with the local student dive club SUB (Photo: K.Kongshavn)

A Crossaster papposus collected for NorBOL together with the local student dive club SUB (Photo: K.Kongshavn)

A marine snail in the family Naticidae (Photo: K.Kongshavn)

A marine snail in the family Naticidae, also known as moon snails or necklace shells. These snails are predators, mainly feeding on Bivalves (Photo: K.Kongshavn)

We could not resist, even though it's a vertebrate (Photo: K.Kongshavn)

Look at that face! We could not resist including him(?), even though it’s a vertebrate (Photo: K.Kongshavn)

(Photo: K.Kongshavn)

apologies for the ear worm!

Well, we sure had fun – we hope you did too!

Make sure to check out other contributions to the hashtag #bdvalentine on Twitter and Facebook.

Berthella sideralis, a rarity finally documented alive and barcoded!

The Pleurobranchidae sea slug species Berthella sideralis was described by the Swedish malacologist Sven Ludvig Lovén in 1846 based on specimens collect at Bohuslän, in southern Sweden not far from the city of Gothenburg. This species has hardly been mentioned in the literature after its original description, and no images of life species are to our best knowledge available in books, research papers or even web platforms – until now!

A synthesis of the morphological features of B. sideralis can be found in Cervera et al. (2010) who studied in detail two specimens collected during 1930’s in Trondheimfjord as part of a phylogenetic study of the genus Berthella.

Recently, in late November 2015 during a Museum scientific cruise – there is a blog post about this day of field work here – we collected one specimen in Hjeltefjorden (around Bergen) at 220 meters depth using an RP-sledge. This specimen is here documented and was recently genetically barcoded as part of our effort to barcode the Norwegian marine fauna through the NorBOL project.

A live specimen of Berthella sideralis. Ths scale bar i 5 mm. Photo: K. Kongshavn

A live specimen of Berthella sideralis. The scale bar i 5 mm. Photo: K. Kongshavn

Berthella sideralis is only known from Sweden and Norway. In Norway it has been reported between Bergen and Finnmark.

Reference: Cervera, J L., Gosliner, T. M., García-Gómez, J. C., & Ortea, J. A. 2010. A new species of Berthella Blainville, 1824 (Opisthobranchia, Notaspidea) from the Canary Island (Eastern Atlantic Ocean), with a re-examination of the phylogenetic relationships of the Notaspidea. Journal of Molluscan Studies, 66: 301–311.

-Manuel & Katrine

Door #9: Delving into the DNA

From the pre-PCR lab

From the pre-PCR lab

The four PCR-machines lined up

The four PCR-machines lined up

We are very fortunate in that we have a modern DNA lab available «just down the street» from us, as the University Museum is part of the shared Biodiversity laboratories (BDL) structure.

The BDL is a formalized cooperation between three research groups at Dept. of Biology (Marine biodiversity, Geomicrobiology and the EECRG), and two of the research groups at the University Museum. One of the senior engineers if this lab is a Museum employee, and from time to time we are also able to hire in other collaborators for specific projects.

 

 

 

Pipetting

Pipetting samples onto one of the plates that we fill with DNA-extracts

 

For the past couple of months we’ve had a technician – Morten – working on resolving some of the challenges that we run into when we work on COI barcoding of marine invertebrates.

Unlike many of the other groups that this method works exceedingly well for (like the Diptera), we are experiencing difficulties in obtaining DNA barcodes from a significant proportion of our samples.

IMGP0775-001We are currently focussing particularly on the Polychaeta (bristle worms), as this is the group we have submitted the majority of samples from in both our major barcoding projects: MIWA (Marine Invertebrates of Western Africa) and NorBOL (Norwegian Barcode of Life).

 

Morten has been working on obtaining DNA from the more problematic species, by troubleshooting and tinkering on various aspects of the ways we extract and amplify genes.

Basically there are more or less standardized ways of obtaining DNA, and these methods normally works well. Unfortunately (for various reasons) this is not always the case, and this is where we have to alter the protocols to see if we can find a way to retrieve the sample DNA from the specimens.

So far it looks quite promising; we’ve been able to fill in some of the most important “blanks” in our datasets – and we’re not done yet!

– Morten & Katrine