The blog has been quiet over summer – but we’ve been busy!
The #AnnelidaCourse2017 came to an end, and happy participants went back to their home institutions with a lot of new knowledge, a increased contact network, and many new friends.
a) Students working in the lab; b) Picking interesting animals from the samples onboard R/V Hans Brattström; c) Animals to be studied; d) Group photo of most of the participants; e) Detailed study and drawing of a specimen; f) Field work onboard R/V Aurelia Fotos: K.Kongshavn (a,b,e), G. Kolbasova (c), G.Jolly (d), S. Rosli (f)
Heaps (HEAPS!) of samples have been cataloged and labeled, DNA-sequencing has completed on the shipment we sent in June and we’re working on analyzing the results, and samples from the cruises we particpated on have and are being sorted.
Labels need to be..
..matched to samples..
..and samples stored securely
The next shipment of animals to be barcoded through NorBOL is being assembled – of marine invertebrates from our collections, one plate of polychaetes and one plate of isopods have been prepared, and we plan on completing a few more plates before shipping in October.
Isopods for barcoding – these have all been collected and identified by the MAREANO project. Photo: K.Kongshavn
We will also get contributions from several of the Norwegian Taxonomy Initiative projects (Artsprosjekt) that are running, and a plate with insect samples made by the students of BIO233 (I was down there today giving them an introduction to barcoding, NorBOL and the BOLD database) – hopefully we’ll get good results on all of it.
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):
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
Velvet belly lanternshark, Etmopterus spinax
Henrik and Christoph sorting a shrimp trawl catch on deck
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.
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.
We manged to get some not-too-damaged specimens with a small trawl
The plankton net going our for collecting
Luis an Marie studying a plankton sample
Plankton
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!
Sadly, plastic pollution was prevalent in Sognefjorden as well – here’s a soda bottle from a sample taken at 911 m 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!
Once again, thank you so much to the crew on Bonnevie for all their help!
I wanted to write a bit more abou the SponGES cruise, as we are currently entering Sognefjorden on the second spring cruise Luis and I have managed to sign up for (what a job!).
SponGES took us to Korsfjorden, Bømlafjorden, west of Bømlahuken and finally past Fedje and back to Bergen. We ended up with ~70 stations, using grabs, Agassiz trawl, plankton net, RP-sledge and ROV. For the most part the gear performed admirably, though we had some mishaps (and an epic final station, key word being MUD – Anne Helene will have more to say about that one).
The first grab of the new cruise is going down, so I have to be quick; here’s SponGES in pictures (not recorded: lots of laughs and horrible songs)
Call that a sponge?
Now THIS is a sponge!
Pretty, pretty Norway!
True stowaway – (s)he hitchhiked to Bergen after blowing onboard
We don’t have much internet out here, so updates will be sporadic – but here’s the tale of the first half of the two cruises that the Invertebrate Collections people have stowed away on this spring. The current cruise is part of the SponGES-project that is being coordinated by the University of Bergen, Norway (prof. Hans Tore Rapp).
We are currently midway in the six-day cruise (26th of April to 2nd of May), and are presently to be found at 59°63,000 N, 04°42,000 E – there are mountains on one horizon, and open ocean on the other. After a night of muddy (clay-y) sampling, the majority of us are relaxing and eagerly awaiting lunch, whilst some of the sponge-folks are huddled inside the big, blue container on the deck, surveying the sea floor with the ROV Aglantha (occasionally cherry-picking sponges with fancy scoops).
The ROV Aglantha, inside the Blue Box, and sponge-capturing device
At present we are at station #33; it has been three busy days so far! This is the first trip for all of us on the “new” R/V Kristine Bonnevie (formerly known as “Dr. Fritjof Nansen”, but that name has passed on to the new Nansen vessel), and we’re thoroughly enjoying it. The crew is amazing, the food is delicious, and the samples keep coming – what’s not to like? Even the weather has been good to us most of the time – though we have sprouted quite a crop of anti-seasickness patches onboard by now!
#bestoffice
We had to take a break to admire this
Shenanigans on deck
In addition to the ROV, we are using van Veen grabs, Agassiz trawl, plankton net, and RP-sledge to collect fauna. We also stumbled across hundreds of meters of lost fishing line when diving with Aglantha – the operators were able to catch an end of it, and it was dragged onboard to be discarded properly. The rope was heavily colonized by sponges, hydrozoa and mussels, so we got a “bonus sample” from that – and we got to clear away some marine pollution. Win/win!
Old Fishing line being removed – and samples taken from it!
My main incentive for being onboard is to secure ethanol-fixed (=suitable for DNA work) material from locations that we have either none or only formaldehyde fixed. This will then become part of the museum collections – and we will have fresh material for DNA barcoding through NorBOL.
Ready to dive in!
The art of washing grab samples – get rid of the mud, keep the animals intact!
Scooping up top sediment from grabs for analyses
Incoming trawl
Sampling in the sunset
The samples we are collecting are gently and carefully treated on deck before being bulk (i.e. unsorted) fixated in ethanol. There is lab space onboard, but we don’t have the time to do much sorting here. It will be exciting to see what we find once we get back to the lab and begin sorting it!
Lab facilities onboard
But before we get to that, we have three more days with SponGES, and then we go on to the next cruise, which will also be with Bonnevie – this time we’re heading up and into the Sognefjord.
This 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)
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!
Ready to start the workshop! Photo: AH Tandberg
The beaver was here! Photo: AH Tandberg
Ed found the bison! Photo: AH Tandberg
What way should we take? Amphipodologists out of their natural habitat? Photo: AH Tandberg
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.
Lauren and Anne-Nina hard at work. Photo: AH Tandberg
Wims microscope after a sample is done.. Photo: Christian Bomholt (www.instagram.com/mcb_pictures)
Lauren after getting the identification right. Photo: AH Tandberg
Ed at work with a nice sample. Photo: AH Tandberg
Lauren examines the specimen while Anne-Nina and Tammy checks the literature. Photo: AH Tandberg
“the Anne-table” in the amphipod lab. Photo: Christian Bomholt (www.instagram.com/mcb_pictures)
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.
A large amphipod comes out of the jar! Photo: Christian Bomholt (www.instagram.com/mcb_pictures)
Cleippides quadricuspis. Photo: AH Tandberg
Amphipods sorted and identified. 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).
The field-station is ready for easter. Photo: AH Tandberg
The coolest easter-chickens in Spala. Photo: AH Tandberg
Easter-prepared coffee! Photo: AH Tandberg
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.
It certainly does not take a great leap of imagination to get from these Isopoda collected by the MAREANO programme to various science fiction monsters!
click to embiggen!
I just completed photographing and tissue sampling 95 specimens that will be submitted for barcoding through NorBOL – we’ll send them to the CCDB-lab in Canada for sequencing, and upload the metadata and sequences in the BOLD database – fingers crossed for successful sequencing!
A whale recently had to be put down by wildlife management after it had repeatedly beached itself on the island of Sotra outside of Bergen. It was found to be a Cuvier’s beaked whale (Ziphius cavirostris), a species with apparently no official previous records from Norway. The University Museum of Bergen therefore wished to include the whale skeleton in its collections (and future exhibitions, once the remodelling completes).
Arriving at Espegrend
The whale was transported to the Marine Biological Station of Espegrend, and a team of five people from the museum set to work collecting measurements of the whale, taking tissue samples for DNA-barcoding though the NorBOL-project, collecting ectoparasites, and doing photo-documentation.
Collecting measurements
We then began removing the blubber and muscle tissue off the whale so that the bones can be further treated (they contain a lot of oil which needs to be taken care of once the soft tissue has been removed), before the skeleton can be mounted for display.
Starting the work of removing blubber and muscles
Little did we know that what had so far been a local news matter would soon go viral…
Sadly, it became clear during the autopsy that the whale had been ingesting massive amounts of plastic – as much as 30 plastic bags, and many smaller pieces of plastic. The whale was emaciated, and we believe that the plastic had gathered in such an amount in its stomach that it had created a plug, stopping the digestive process.
The plastic in and from the whale stomach (photos: T. Lislevand, H.Glenner/C.Noever)
The images of all the plastic spread out on the ground became a potent reminder of the tragedies that marine pollution is creating, and has sparked a renewed debate on how we can limit the amount of micro- and macro-plastic that end up in nature.
The news of the whale’s stomach content became international news
What should the Cuvier’s beaked whale have been eating?
Occurring as solitary animals or in small pods, and preferring the deeper open waters, the Cuvier’s beaked whale is not an easy animal to study. We do know that the species have a more or less cosmopolitan distribution, and that it holds the world record for longest and deepest dive for any mammal: one was recorded diving down to 3000 meters.
What data we do have on the species diet comes from beached individuals, and suggests that the species may be a fairly omnivorous predator. From the limited number of Cuvier’s beaked whales that have been examined for stomach content, there are regional differences in the diet, but it seems to consist mainly of cephalopods (squid and octopuses), deep sea fish, and medium sized crustaceans (Santos og andre 2001).
Above are the suckers on the arm of a giant squid, Architeuthis. Below are scars on the skin of a sperm whale. Photo: E.Willassen
The cephalopods appear to be the dominant food source, but this interpretation may be influenced by the longevity of the hard parts of a cephalopod in the stomach.
The tough beaks of a cephalopod consist of chitin, and is used for tearing prey to pieces. Chitin is also found in the suckers of many cephalopods. The beaks can be used to identify the cephalod groups based on their size and shapes. Animals such as jellyfish would be much harder to document as part of the diet, as they would be digested much more rapidly and completely.
We don’t know how well resolved the information produced by the animal’s echo-location is, but it is conceivable that the plastic reflects signals in a way similar to the natural food of the whale, and is therefore “caught” and eaten.
Cephalopod beak, drawing by J.H. Emerton (from Wikimedia commons)
We did find some cephalopod beaks in between the plastic in the whale stomach – so far we have not had the time to attempt to identify these, but we will.
Amongst the plastic there are some cephalopod beaks (dark brown) and a bivalve shell (top left). Photo: C. Noever
The University Museum have extensive cephalopod collections, and long traditions for working with this group – from Dr. Jakob Johan Adolf Appellöf who began working here in 1890, to the material collected in the MAR-ECO project.
MAR-ECO workshop on cephalopoda
From the work of Santos et al 2001 we know that the following species are in the diet of European Curvier’s beaked whales, and are probably amongst the things our whale should have been eating:
Tewuthowenia megalops. Photo: Richard E. Young during MAR-ECO-cruise 2004.
Teuthowenia megalops is an odd squid that floats around in the open water with a propulsion system based on ammoniumchloride that the animal produces by digesting protein. The name “megalops” hints to the huge eyes, which also contain three light producing organs (chromatophores). The species seems to be common in deep water in the north Atlantic (Vecchione et al. 2008). For more information, see Wikipedia.
Mastigoteuthis agassizi
Mastigoteuthis agassizii was originally registered in whale stomachs as Mastigoteuthis schmidti, but from the work on the MAR-ECO project, three species of Mastigoteuthis were considered to all be M. agassizii. Some ambiguity remains about the species of this genus of oceanic squid with a broad distribution in the world’s oceans in depths ranging from 500 to 1000 meters. They have diurnal migration, and may be found hunting closer to the surface at night.
Taonius pavo seen ventrally (above) and dorsally. Illustration from Wikipedia.
Taonius pavo
This little squid is not very well known. It has been recorded from the Atlantic Ocean, but it may have a broader distribution. In this link you will find a video from the Bahamas at 850 m depth where the animal releases bio- luminescent “ink” to confuse a predator and escape.
Histioteuthis bonelli Photographed by Richard E.Young during the Mar-Eco-cruises in 2004
Histioteuthis bonelli, drawing by Ernst Haeckel.
Histioteuthis bonnellii has several names in English, one of which is “umbrella squid”. The name is due to the skirt-like membrane between the arms – when it splays its arms it resembles an umbrella. We don’t know much about the biology of H. bonellii, except that it has several close relatives in the world oceans, and that what has hitherto been considered one species (H. bonellii) may well turn out to be several species.
Todarodes sagittatus
Todarodes sagittatus, the European flying squid, is one of the ten-armed cephalopods that may irregularly occur in schools along the Norwegian coast. T. sagittatus is subject to fisheries.
Vampyroteuthis infernalis
Vampyroteuthis infernalis – the vampire squid is a deep-sea squid with eight arms and a skirt-like mantle between its arms. It also has moveable wings on its body that it can use to manoeuvre with. The name “vampire squid” is not quite true – this is no blood sucker, but it traps organic material from the water masses using long, sticky threads. If threatened, it can invert the “skirt” over its head, resembling a hedgehog. It also has light producing organs towards the back of the body, and can create clouds of bioluminescence. Even with all these defences, it may end up in the stomach of a Cuvier’s beaked whale.
Pelagic crustaceans and deep sea fish are also amongst the recorded prey from Cuvier’s beaked whales. Amongst these we find the fairly large and shrimplike Gnathophausia, found within the order Lophogastrida, which has been studied extensively at the University of Bergen. We also found a bivalve shell in the stomach of our whale, which as far as we are aware of has not been recorded as part of their diet previously.
Plastic or food?
It may seem strange that the whale should ingest large amounts of plastic – why would it do that? If the whale primarily finds its pray by echolocation in the pitch black of the deep sea, it may well be that it is unable to differentiate between the reflected signal from a sheet of plastic, and that from one of its usual prey animals.
Unlike the sperm whales that hunt cephalopods in a similar way, the beaked does not have teeth to grab its pray. Instead they use a suction to ingest the food. Perhaps it is this feeding mode that becomes very unfortunate for the whales in a natural environment with an incredible amount of human garbage.
Today we present two more of Arne Nygrens gorgeous photos, that he made during our week in the field in Sletvik (central Norway). The subjects in both of these are polychaetes from the family Phyllodocidae, the paddleworms.
First up is a stunning Phyllodoce citrina collected from shell sand at about 60 m depth. The animal is approximately 6 cm long.
Phyllodoce citrina, Photo by Arne Nygren CC-BY-SA
The next one, Paranaitis sp. n. is actually a new species for science, which came as a pleasant surprise. This is a fairly well-studied group, and the locality Galgenes is one that has been sampled regularly – yet there it was! It is rather unusual to find species where one can so immediately recognize that they are something new; usually we need many specimens, and a combination of detailed studies of morphology and genetic work – but this one is possible to distinguish straight from morphology, as it was lacking eyes. The specimen is about 1.5 cm long.
Last year we had a calendar post about the Heart of the Museum – our type collections.
To recap, a species’ type is “…the objective standard of reference for the application of zoological names. When a new species or subspecies is described, the specimen(s) on which the author based his/her description become the type(s) (Article 72.1). In this way names are linked to type specimens, which can be referred to later if there is doubt over the interpretation of that name.
Consequently types are sometimes referred to as “onomatophores” which means name bearers.”
The location – sampling site – from which the type specimen is described is known as the type locality.
Michael Sars (image from Wikimedia)
As you have probably noticed, polychaetes (bristle worms) are a focus group in our lab, and several species have type localities close by.
The biologist and theologian Michael Sars (1805-1869) lived in the Bergen region for many years. He was a prolific taxonomist, naming 277 species of marine taxa according to the World Register of Marine Species (WoRMS).
Consequently there are quite a few species that have their type locality within easy daytrip-distance by ship for us.
On the hunt with R/V “Hans Brattstrøm”
One such locality is Glesvær, where Michael Sars described several new species in his work of 1835: Beskrivelser og Iagttagelser over nogle mærkelige eller nye i Havet ved den Bergenske Kyst levende Dyr af Polypernes, Acalephernes, Radiaternes, Annelidernes og Molluskernes Classer* (“Descriptions and Observations of some strange or new animals found off the coast of Bergen, belonging to the Classes …”).
The polychaete Amphicteis gunneri (Ampharetidae) is one of these species. It was first described by Michael Sars as Amphitrite gunneri (the species name is an homage to Johan Ernst Gunnerus (1718-1773) who was an active scientist within botany and zoology, as well as the bishop in Trondheim, and one of the founders of Det Kongelige Norske Videnskapers Selskap) in the publication above. Here are his original illustrations of the species:
Amphicteis gunneri by M. Sars (1835)
We have previously submitted several specimens of Amphicteis gunneri for DNA-barcoding through the NorBOL-project – and found that specimens that according to the keys in the literature should all come out nicely as A. gunneri in fact end up in several barcode-based groupings (BINs), meaning that they genetically different from each other. Then we need to unravel which one is the true A. gunneri, and decide what to do with the others. In such cases, material from type localities is invaluable. By sending in specimens identified by resident taxonomists as A. gunneri from the type locality, we hope to figure out which BIN represent A. gunneri, and which represent potentially new species.
We were also able to photograph live specimens showing the nice coloration of this worm. Fixed specimens lose this colour and become uniformly yellow/white (no dots).
Amphicteis gunneri collected at type locality. Photo: K.Kongshavn
Today, I thought I’d introduce to you to a cool group of animals that is ubiquitous in the oceans (including the Norwegian seas), but unfamiliar to most people. Siphonophores (“kolonimaneter” in Norwegian) belong to cnidarians, a group that includes corals, anemones, hydroids and jellyfish, and is characterized by the presence of stinging cells used in prey capture. All siphonophores are predatory, and use their stinging tentacles to catch small crustaceans or, in the case of some species, even small fish.
The most (or only) familiar siphonophore for the majority of people is probably the highly venomous Portuguese Man O’War (Physalia physalis), which can be spotted floating on the surface of the ocean or stranded on beaches. However, it is not really representative of the group as a whole, as most siphonophores live in the water column of the open ocean rather than its surface. There are around 200 described species of siphonophores.
The most fascinating feature of siphonophores is their peculiar body plan. While siphonophores may appear to be a single animal, they are in fact a colony of physiologically connected and genetically identical but morphologically diverse individuals called zooids that have specialized to carry out different tasks for the colony. Siphonophores belong to the class Hydrozoa (“polyppdyr” in Norwegian), which covers two basic body plans: the polyp/hydroid and the medusa.
Schematic of a physonect siphonophore. From http://www.siphonophores.org (CC-by-nc-sa)
The various zooids comprising a siphonophore colony can also be divided into these main groups. For example, the zooids used for swimming, called nectophores, are medusoid, while the feeding zooids, or gastrozooids, are polyp-like. The siphonophore colony can also include specialized defensive, protective and reproductive zooids. All the zooids forming a colony arise by budding from a single fertilized egg. The different zooids are specialized to the degree that they cannot function as individual animals any more, and are only able to perform their specific tasks as parts of the siphonophore colony.
Anterior nectophore, posterior nectophore and eudoxid of the calycophoran siphonophore Dimophyes arctica – a common species in Norwegian waters. Photos by Aino Hosia (cc-by-sa)
The zooids, for example the swimming nectophores, vary in appearance between species, and can be used for species identification. In addition, the various types of zooids in the colony are arranged in a strict species specific pattern, providing the intact colonies of each species with their particular appearance. While the individual zooids are generally small, millimeters to centimeters in size, some siphonophore species, like Praya dubia, may have colonies that reach 40 m in length! Siphonophore colonies generally have a zone of one or more (up to several dozen) swimming nectophores at the front, used to pull the colony through water. Behind this nectosome is the siphosome, which contains the feeding, reproductive and other zooids in a repeating pattern, each iteration of which is called a cormidium. In some species (suborder Calycophorae), these cormidia are released as small free-living reproductive colonies called eudoxids. Unfortunately, siphonophore colonies are extremely fragile and tend to fall apart during standard plankton sampling with nets, leaving behind a bewildering array of small bits and pieces – part of the reason they are relatively poorly known to most people.
Colony of physonect siphonophore Physophora hydrostatica, aka hula skirt siphonophore. Photo by Aino Hosia (cc-by-sa)
Intact siphonophore colonies are beautiful, but often utterly alien in appearance. It is interesting to consider where to draw the line between an individual and a colony. While we as individuals have specialized organs to carry out our various bodily functions, siphonophore colonies are made up of specialized interdependent individuals or zooids similarly carrying out their specific tasks.
As part of project HYPNO we are charting the diversity of pelagic hydrozoans, including siphonophores, in Norway. There are ~15 species observed in Norwegian waters, and some, particularly Dimophyes arctica, Lensia conoidea and Nanomia sp. are extremely common components of marine plankton. However, siphonophores are primarily noticed when they become a nuisance: For example, mass occurrences of Muggiaea atlantica and Apolemia uvaria have in the past killed large numbers of farmed fish in Norway, with resulting losses to aquaculture companies.
