Category Archives: Uncategorized

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!

Scavengers in the ocean

Lysianassoid amphipods from a trap in Raudfjorden, Svalbard. Photo: AHS Tandberg

Most animals are sloppy eaters. They have their favourite piece of food that they go for, and then they leave the rest. This allows for others to pick up where others leave. One of the laws of ecology is that “there is no such thing as an empty ecological niche”. That can be translated to “where there is a food-source (or a place to live) someone or something will use that food-source (or place to live). And that gets us to the sloppy eaters out there, and not least the animals picking up after all the sloppy eaters.

From the pigeons crowding under your cafe-table for your panini-crumbs to the rats in our sewers, our “local scavengers” tend to be animals we feel slightly uncomfortable around. Is it different with the scavengers we dont see so often? It does not seem that way. Vultures  are not the most popular birds, even the word “vulture” has a negative connotation – and we mainly use it in its non-bird meaning.

How about the scavengers of the sea? As on land, we have many different animal-groups that can be classified as scavengers. Many of the marine scavengers are invertebrates (even if some fishes also scavenge). Let us look at the scavenging Lysianassoid amphipods. Are these as little loved in our world as the rats and vultures seem to be?

A typical lysianassoid amphipod. Photo: AHS Tandberg

Lysianassoid amphipods can mostly be distinguished from other amphipods by their “telescope-like” antennae: a very fat inner article with the two next looking like a collapsed old fashioned radio-antenna; two short rings. We know that the antennae of crustaceans are often used to “smell” things in the water – food or mates or possibly even enemies. It is not thought that the radio-antenna-shape of the Lysianassoid antenna specifically has to do with being a scavenger, as other amphipods and indeed several other crustaceans not having such an antenna are also scavengers. But most Lysianassoids have that antennae, and it makes for an easy first-sorting for the scientist. (Getting further – towards a genus, or even species name on the other hand, is not so easy).

Other general traits in most Lysianassoids, are the smooth exterior, and their high swimming abilities. Both are good if you need to get to some leftover food-source fast, and to “dive” into the food-source while not getting stuck through the entry.

Leftovers of bait (polarcod) after 24 hrs in the trap. Not much left for dinner… Photo: AHS Tandberg

And this is where many Lysianassoids loose out when it comes to human appreciation. They seem to love to scavenge on fish caught in fishnets and traps, and both professional and hobby fishers don’t like to share their catch. We dont think it is very appetising to find our fish-dinner “infested” by non-fish. I am quite sure the scavengers being pulled up with their lovely find of dead or dying fish also are not pleased with having to share their dinner with us.

Lysianassoid scavenging amphipods are the focus of our NBIC-financed project NorAmph2. Here, we will collect and register what different species are present in Norway, and we will try to barcode them. These are quite tricky animals to identify properly, but luckily we have teamed up with the best lysianassoid-expert we know – Tammy Horton from the National Oceanography Centre in Southampton, UK.

We use baited traps to collect: put some lovely, smelly fish out there and see who comes to dine. So far, we have collected from Svalbard in the north to Kong Haakon VIIs Hav in the south, and from the intertidal to the deep. They are often many, and the size-variation is great. We look forward to continuing finding out what species we have, and to see if what morphologically seems one species really is (only) one species genetically. (This previous blog-post (in Norwegian) tells the story about one scavenging amphipod that turned out to be 15 (or maybe even more!) separate species)

Anne Helene

Door # 8: The DNA-barcode identification machine

In a previous blog post I explained briefly how DNA-sequences are produced for the DNA-barcode library. Now I will show how the BOLD database can be utilized to identify species from sequences.

Some of the equipment used to produce DNA-sequences in our lab.

Say you have access to a lab that can produce DNA-sequences and you have a sample of a crab you cannot identify because some of the key characters are on body parts that have been broken and lost. You produce a DNA-sequence from the “barcode-gene” and open the identification engine in BOLDSYSTEMS.org.

Internet start window for the BOLD identification engine where you paste your unknown DNA sequence into the bottom blank window. (Click on picture to expand)

Having submitted your query to BOLD, you wait for some seconds for results. In this example BOLD returned the following window.

Example of results from a query to the BOLD identification engine. (Click on picture to expand)

The results window lists the top matches in terms of sequence similarity, and in this case we have 100 % similarity match with the crab Atelecyclus rotundatus. There is also an option to display the results as a TREE BASED IDENTIFICATION. When clicking on the option tab, the closest hits are clustered in a so-called Neighbour Joining Tree. In the window below you see parts of the tree where our unknown DNA-sequence has been joined to a group of other sequences in BOLD that have been deposited as Atelecyclus rotundatus barcodes by other biodiversity labs.

Part of TREE BASED IDENTIFICATION of an unknown DNA sequence (in red). We see that the unknown clusters with with other sequence of Atelecyclus rotundatus. The nearest neighbour branch is Atelecyclus undecimdentatus. (Click on picture to enlarge.)

The species page for Atelecyclus rotundatus gives us more information about this crab and about its records in BOLD.

Species page for the individual we identified with the BOLD identification engine. (Click picture to enlarge.)

If in fact your sequence was produced from an unknown crab, this identification seems convincing. But sometimes you should think twice about search results, and this will be the topic of a future blog post.

-Endre

PhD thesis defence

On June 7th Nina Therese Mikkelsen presented her thesis ” Phylogeny and systematics of Caudofoveata (Mollusca, Aplacophora)” for a public audience.  She was questioned by the opponents dr Mikael Thollesson, University of Uppsala, and dr Suzanne Williams, The Natural History Museum of London, and did an excellent performance explaining the results of her studies.

WoRMS is presenting ten astounding marine species of the last decade (2007-2017)

Marivagia stellata, the starry sea wanderer Galil & Gershwin. Photo by Shevy Rothman. CC-BY-NC-SA

As part of the celebration of the first decade of WoRMS – the World Register of Marine Species, ten of the most astonishing new species from the big old blue is given a special presentation here.

 

Artwork of Ramisyllis multicaudata by Sarah Faulwetter

Click your way over and read about the Deep-sea lyre sponge – Chondrocladia lyra, the Palauan primitive cave eel – Protanguilla palau, the Deep-sea acochlidiacean slug – Bathyhedyle boucheti, the Tree syllid worm – Ramisyllis multicaudata, the Starry sea wanderer jelly – Marivagia stellata, the The Hoff crab – Kiwa tyleri, the Squidworm – Teuthidodrilus samae, the Jesse Ausubel’s ‘terrible claw’ lobster – Dinochelus ausubeli, the  ‘living fossil’ octocoral – Nanipora kamurai, and the Scaly-foot snail – Chrysomallon squamiferum. 

Photo by David Shale, CC-BY-NC-SA

Chrysomallon squamiferum, Scaly-foot snail. Photo by David Shale, CC-BY-NC-SA

Link: Ten astounding marine species of the last decade (2007-2017)

Door # 21: A tale of three fading buck-goats

“Julebukken” – the Yule Goat. 

A goat made of straw has commonly been observed among the paraphernalia that people put on display around Christmas times in the Nordic countries. Ask people what they symbolize and I bet that the majority would say just “Christmas” without having a further explanation at hand. It is very likely that the Yule Goat is a remnant from the pagan celebrations of the December solstice. The mythological origin of the Yule Goat is unclear (see Gunnell 1995).  It is probably of mixed origin because cultural evolution is often syncretic, – a blend of beliefs, mythologies, and practices from different sources and “ethno-folkloristic schools of thought”.  It has been speculated that the straw figure of the Yule Goat reflects some sort of pagan vegetation god ruling over grain growth and who required particular human attention around the winter solstice.

"Julebukk" - a common Christmas decoration.

“Julebukk” – a common Christmas decoration.

Others have associated Yule Goat with the Germanic thunder-god Thor, because he used two bucks to pull his chariot over the sky. Thor must have been an environmentally friendly god because these bucks were used as a food resource in Valhalla and if only he took great care to keep the bones and the skin, he could revive fully reincarnated goats the next day. The idea of a resurrected goat was dramatized in folk rituals of Nordic small communities by people who reenacted the death and revival of the Yule Buck in songs and theater performed on house visits by a ragged assembly of masked people. The central character in these folkloristic plays was a person either wrapped in straw or hides and carrying a goat head, sometimes also a hammer (like Thor). Right up to the mid nineteenth century, plays like these were practiced in Scandinavia. The traditions have several characteristics in common with Halloween and the Yule Buck masquerade apparently is a tradition that now seems to be fading and to be replaced by Halloween celebrations. In both cases there is an underlying theme of temporary breakdown and restoration of cosmological and moral order when cyclic time has gone the full circle. A small scale version of this idea is also at work around midnight, – the ghost hour. The Cristian tradition has tended to associate goats with naughty behaviours of all sorts, particularly in terms of sexuality. Goats were also at times associated with mythological creatures like Pan and with the Devil.

The Star Buck

The Babylonians divided the sky in 360 parts, but ancient astronomers also used twelve 30 degrees sectors of the sky to reference the positions of celestial bodies on the ecliptic, – the track that the sun appears to follow through the year.  Like the classic analogous clock with twelve sectors marking divisions of the day and night the zodiac is a clock for the earth’s revolution around the sun.  Because the rotation axis of the earth is tilted, the sun appears to draw an S-shaped path around the Earth.  From a northern perspective the maximum of the path is the summer solstice. The minimum is the winter solstice, when the zenith of the sun is farthest away from the Arctic and the days are shortest on the Northern hemisphere. The exact time for the solstice is not easy to determine, but ancient astronomers found that the winter solstice took place when the sun was in the sector of the star constellation called Capricornus. Claudius Ptolemy, who is known as the prime authority of  pre-Copernican cosmological texts, wrote in Book 1 chapter 11 of his very influential Tetrabiblos :

“For the sun turns when he is at the beginning of these signs and reverses his latitudinal progress, causing summer in Cancer and winter in Capricorn.”

Capricornus is Latin for “goat horn” and Capricorn is sometimes depicted as a goat, sometimes as half goat, half fish. Because the “turning point” of the sun at winter solstice was once at an imaginary latitude circle drawn through Capricornus, we say that the sun is turning at the Tropic of Capricorn. However, due to the swaying of the Earth’s rotation axis, winter solstice is no longer in Capricorn and the Tropic of Capricorn has also moved away so that, paradoxically, the Tropic of Capricorn is now passing through Sagittarius . When the Julian calendar took effect 45 years BC the solstice was celebrated on 25th of December, but apparently winter solstice was already about to leave Capricornus in the direction of Sagittarius.  Historians of astronomy think that Capricornus was already a marker of seasonal time about 2000 years BC.

The sun in Capricornus seen from Rome 45 years BP according to Stellarium.

The sun in Capricornus seen from Rome 45 years BP according to Stellarium.

 

The sum at winter solstice in 2016 seen from Rome according to Stellarium.

The sun at winter solstice in 2016 seen from Rome according to Stellarium.

Although much speculation has been put forward about the origins of Yule Buck, I suspect that the role of the goat in the sky has been undervalued when trying to understand the conducts and traditions of people in the Nordic countries around the winter solstice. Surely, the teaching of Ptolemy must have diffused somehow to ordinary people during the Medieval Ages. After all, Capricorn was the messenger of a better existence to come, if one could only sustain over the winter.

Resurrecting a goat
Goats that stood model for the Capricorn have been part of the human environments since long before they were painted on cave walls in Ardeche at the foot of the Pyrenees about 30000 years BC. Archaeological material from Jordan indicates that goats were domesticated already 7000 BC as one of the first of the ruminant species. Wild goats are members of the genus Capra and are distributed with several species over the Eurasian and African continents. Most of the wild goats are now regarded as more or less threatened species due to hunting pressure and habitat loss. In Spain the so-called bucardo goat was declared extinct in year 2000, when the last individual was hit by a falling tree in Oresa National Park.

The extinct subspecies of the Pyrenean Ibex. (Source Wikipedia)

The extinct subspecies of the Pyrenean Ibex. (Source Wikipedia)

An international group of biotechnologists set up experiments to resurrect the bucardo, which is considered as a subspecies of the Pyrenean Ibex, Capra pyrenaica. It is perhaps not likely that these scientists were inspired by the Nordic myth about Thor and his perpetual buck-goats. Nevertheless, they had already taken skin samples from the last living female the year before she died. With the frozen cells from the skin they had cellular nuclei with goat genome and also a plasma membrane with small amounts of cytoplasma. With a technique similar to the one that was pioneered by the Roslin Institute in Edinburgh to clone the sheep Dolly, they replaced the cell contents of domestic goat eggs with somatic cell material from the dead ibex. Then they implanted the manipulated eggs into many substitute mothers of both domesticated goats and of females of the Spanish ibex. Only one of the embryos survived long enough to be released by cesarean section and it died only a few minutes after birth. Despite this and similar failed efforts to reconstruct extinct evolutionary lineages, it is still claimed by scientists who are involved in this business that such methods hold promise for rescuing rare and endangered species. But without making claims of being a specialist in conservation genetics I ask myself: how is it possible to save a species when all of the genetic variability in the population is lost. This may have been a problem already before the population went extinct because the sets of genes that run the immune system and code for the proteins that protect the body from foreign molecules, the so-called major histocompatibility complex, had already been observed to lack variability. Then of course, in the case of the extinct Pyrenean ibex there is also another problem that would be a major impediment in the reconstruction of a natural population. It is a problem of the missing Y-chromosome. Goat Y-chromosomes would be necessary to have functional males of reconstructed goats. Basically this is a problem that has also puzzled thinkers with respect to the child that allegedly was born by a virgin on the solstice 2000 years ago. Did he have a chromosome set from the father?

Merry solstice, Christmas, and Happy New Year!

EW


More reading

Folch, J. et al. (2009) First birth of an animal from an extinct subspecies (Capra pyrenaica pyrenaica) by cloning. Theriogenology 71:1026–1034.

Gunnell, T. (1995) The Origins of Drama in Scandinavia. Boydell & Brewer Ltd.

Hinson, R. (2015) Goat. Reaction Books, London.

Lee, K. (2001) Can cloning save endangered species? Current Biology 11 (7): R245-R246

 

And we teach

In the practice part of the regular UiB Phylogenetics course (BIO332) we also invite participants from other Nordic universities who are members or associates of ForBio, the Research School in Biosystematics. This time we had guests from the University of Iceland, the University of Tromsø, the University of Nordland, the Norwegian University of Science and Technology, the University of Oslo, Uppsala University, and University of Copenhagen.

Computer practice with tools for phylogenetic analysis. UiB 2015

Computer practice with tools for phylogenetic analysis. UiB 2015

More about… Fieldtrip to Mozambique – hunting for seaslugs

Chromodoris africana (Zavora, Inhambane). This species is part of a complex in need of revision where other "species" imaged here are also part of (e.g. Chromodoris hamiltoni, Hypselodoris regina, Chromodoris elisabethina)

Chromodoris africana (Zavora, Inhambane). This species is part of a complex in need of revision where other “species” imaged here are also part of (e.g. Chromodoris hamiltoni, Hypselodoris regina, Chromodoris elisabethina)

Chromodoris cf. elisabethina (Zavora, Inhambane)

Chromodoris cf. elisabethina (Zavora, Inhambane)

On the 27th January we left the subtropical latitudes and moved into the tropics where we established our base-camp in the town of Vilanculos overlooking the Bazaruto Archipelago Natural Park – a string of six islands surrounded by coral reefs. Regrettably a spiral of bureaucracy and administrative complications made impossible to obtain the necessary collecting permit to sample in the pristine reefs of the Natural Park. Alternative good sampling sites were not that easy to find and the weather conditions also didn’t help much with strong winds and some rain, resulting in a very choppy sea. We decided to move back south one day before scheduled and spend two days in the village of Paindane with great tidal and inshore reefs housing an extraordinary diversity of slugs. Here we sampled both at night- and day-time and was impressive to see the faunal differences between these two periods of the day.

Heading for snorkeling during spring tide in a tidal reef in Zavora.

Heading for snorkeling during spring tide in a tidal reef in Zavora.

On the 2nd February we travelled back to the village of Zavora where we had meet for the beginning of the campaign. We spend the last three days sampling in Zavora a truly hot spot for marine slugs; the diversity in the tidal and subtidal reefs exceeds anything I have experienced before. My colleagues from the Zavora Marine Lab have already registered the occurrence of nearly 200 species in these reefs and even so we managed to add to the list a few more!

Sorting the catch on the beach in Vilanculos with the Bazaruto Natural Park on the back scene

Overall, about 80 species were collected during our fieldtrip but the identification of several of them requires now detailed study and will integrate ongoing projects at the Natural History Museum of Bergen.

Chromodoris tennentana (Zavora, Inhambane)

Chromodoris tennentana (Zavora).

Hypselodoris nigrolineata (Zavora, Inhambane)

Hypselodoris nigrolineata (Zavora, Inhambane)

Hypselodoris nigrostriata (Zavora, Inhambane)

Hypselodoris nigrostriata (Zavora, Inhambane)

Goniobranchus cf. tinctorius (Vilanculos). This is part of another complex of species in need of systematic study

Goniobranchus cf. tinctorius (Vilanculos). This is part of another complex of species in need of systematic study

 

Nembrotha purpureolineata (Zavora).

Nembrotha purpureolineata (Zavora).

Flabellina rubrolineata (off Benguerra I, Bazaruto archipelago).

Flabellina rubrolineata (off Benguerra I, Bazaruto archipelago).

Protaeolidia cf. juliae, a cryptic nudibranch on its prey species of sea-fan coral.

Protaeolidia cf. juliae, a cryptic nudibranch on its prey species of sea-fan coral.

Micromelo undatus (Zavora). Presently at the University Museum we are revising the systematics of this species regarded as cosmopolitan but likely made up of three or four morphologically very similar lineages.

Micromelo undatus (Zavora). Presently at the University Museum we are revising the systematics of this species regarded as cosmopolitan but likely made up of three or four morphologically very similar lineages.

On the road

On the road between Vilanculos and Paindane at 90km/h…!