A bizarre deep-sea siphonophore

April 17, 2015 • 10:00 am

I originally made a typo in the title, calling this a “deep-see” creature, but in fact that’s what it is! The video and info comes from IFL Science!and shows a bizarre deep-sea species of siphonophore.

Siphonophores are in fact one form of what we normally called “jellyfish,” a group that actually comprises diverse creatures in the phylum Cnidaria.  This form falls into the class Hydrozoa along with hydroids and colonial “jellyfish” like the Portuguese “Man O’ War” (Physalia physalis). Like the Man O’ War, this beast, spotted by a remote vehicle operating in the depths, is not really what we usually consider a “jellyfish,” as it’s colonial: the “individual” is really a colony of diverse and specialized individual cells (“zooids“) that have become integrated into a miniature cooperating society. Creatures like this stretch the notion of what biologists consider an “individual.”

At any rate, this siphonophore (if that’s what it is; I doubt they captured it), is certainly a species new to science. And, as I always say, the deep sea is so remote, and individuals so sparsely distributed, that there are certainly tons of bizarre species down there that we don’t know a thing about.

Look at this thing!:

And the facts from IFLS!:

Recently, a team from the Nautilus Live expedition piloting a remotely operated vehicle (ROV) happened upon one of the most fascinating-looking lifeforms in the world: a rare, purple siphonophore roving through the ocean’s depths. Even the experienced deep sea explorers, well-acquainted with the marine animals, had a hard time accepting that what they were seeing was really real.

Amazingly, although this appears to be a single jellyfish-like animal, it is in fact a roving colony made up of thousands of individual organisms, called zooids, each contributing to the whole. However, more than just its otherworldly shape, this specimen’s purple coloring is said to be rather unusual as well.

Deep Sea News writer R.R. Helm calls it a “shocking shade”, remarking that this footage truly stands out.

h/t: Ant

121 thoughts on “A bizarre deep-sea siphonophore

  1. WEIRD!!
    I’m fascinated by the deep ocean. It is an alien world right here on this planet.
    I wonder if technology will ever allow marine biologists to have a decent look at all the critters down there?
    Also, is a colonial species like this an example of symbiosis, or does that term only refer to two different species?
    Please don’t stop with the science posts. I don;t always understand everything, but I usually learn a lot.

    1. “I wonder if technology will ever allow marine biologists to have a decent look at all the critters down there?”

      As with the trend of most technological advances, I wouldn’t be surprised given enough time and funding. Think how far we’ve come from the Trieste in 1960 that reached Challenger Deep and in 2012, James Cameron’s Deepsea Challenger which performed the same feat. 50 years and the technology in 2012 seems to come from a different planet. In another 50 years, who knows?

      1. The tech for getting people (or cameras and roboticised arms – much easier!) to multiple-kilometre depths is pretty much off the shelf these days. Provided you choose the right shelves to shop at. An ROV spread that can get down to 3km water depth is a few megabucks only, and just a few tens of thousands a day service charges (equipment rental and wages). you do need a substantial boat to put it on and crew it, but … well, that’s a fixed cost you’re going to have for any such exploration.
        The big problem is that there aren’t many such boats, or ROV spreads, and the ocean is big. Oh, and water is less transparent than air.
        We’re still finding unknown species of mammals on dry land.

    2. Not a symbiosis – the different parts of the colony all develop from one fertilized egg and are all genetically identical (same way your liver and your legs developed from the same fertilized egg and have the same genotype).
      Lots of cnidarians can clone themselves this way to make copies of the basic unit or zooid – many sea anemones do this, it’s how corals make coral reefs. But siphonophores can make several different kinds of basic units in the same colony. The long rod on the left that looks symmetrical has tiny tubular or cup-shaped zooids that resemble a swimming jellyfish, and these ‘swim’ while attached to the central rod to propel the colony through the water. The furry part on the right has many units with long tentacles (hence the fuzziness) that feed. Looks like most of the tentacles are bunched up, maybe because the colony has been bumping along the muddy bottom. Normally the tentacles would be extended to catch food, and they can be very long (many meters). The swimming zooids don’t have a mouth, but the feeding zooids do, and they’re all connected to each other by a continuous gut. The feeding zooids catch prey, and feed all of the non-feeding zooids that do other things (swim; defend the colony; have sex).

      1. Wow, that is just amazing. I have to thank you for teaching me something I didn’t know about coral reefs. I used to spend as much time as possible with my grandparents who lived in the Florida Keys. From 8 to about 13 or 14 I think I spent as much time wearing fins and a mask as I did in my school clothes. If you’ve never dived or snorkeled a coral reef, I highly recommend it.

            1. I would like to dive around the Azores. I have seen amazing footage from the area on various documentaries.

            2. If you have been limited to the FL coastline, you will be pleased to know that just to your east, is the Bahamas. Fabulous diving. You can take a live-aboard cruise and get in 4 or 5 dives a day. Also check out the Cayman Islands south of Cuba. Wonderful coral there.

        1. If you’ve never dived or snorkeled a coral reef, I highly recommend it.

          It is pretty phenomenal, particularly if you’ve got light and even life on your dive. And visibility. Optional extras, but they do make the experience more varied.

          1. Feynman, Sagan, Dawkins…proud to say I came up with that independently, too. But then, I suppose most WEITians did.

      2. This is very cool, but it’s never been clear to me why an animal composed of genetically identical clones of various types that share all their tissue layers, including a single digestive system, is called a ‘colony’. It’s obviously a pretty special sense of the word that doesn’t carry most of the connotations either of an imperial outpost or an assemblage of nesting seabirds. Frankly, it seems about as disingenuous as declaring a corporation to be a ‘person’.

  2. Amazing creature(s)! I have to believe this is a so-called “living fossil” in the sense that it represents a stage in early evolutionary history when there were no animals complex enough to have well defined organs. The components all have the same genotype but at the same time are independent animals arranged in functional subgroups. At some point this type of creature would have become so tightly integrated that the different functional parts would be true organs and organ systems.

    1. Amazing creature(s)! I have to believe this is a so-called “living fossil” in the sense that it represents a stage in early evolutionary history when there were no animals complex enough to have well defined organs.

      It’s as much a living fossil as a coelacanth, or a just-evolved strain of Ebola, or a Placozoan – it’s a representative of a species whose ancestors have been evolving and adapting to changing environments for hundreds of millions of years. There’s no such thing as a “living fossil”.
      As Michael says above, there are quite distinctly organised parts to this creature. If I were to try writing this up from the perspective of a palaeontologist, I’d see at least 4 different types of tissue, organised into several distinct organs.
      “Soft, squidgies” like this don’t fossilize as well as coelacanths – which managed about 90 million years of cryptic evolution between Macropoma in the Early Cretaceous and the extant Latimeria – but I could anticipate something like this fossilising in conservat laagerstaate (exceptional preservation rocks). Not very often, but it’s got the potential.

      1. Ya. That’s why I prefixed “so called” and quoted “living fossil”. I still think it’s a useful metaphor.
        I guess my question really is: have there been studies (perhaps of the DNA) which could assign the kind of organization of these creatures a place in evolutionary history that would suggest that organs evolved from colonial species?

        1. That’s a big question. Certainly there’s a lot of activity in the “EvoDevo” (evolution and development) sector, but development does seem to be unsurprisingly complex (you’ve got all the complexity of the adult anatomy, AND the complexity of assembling it with all the bits in the right place and in the right sequence. Think of not just the blueprint for a car, but also for the machinery to assemble the car.
          If we knew all of what went on in developing a complex animal, then disentangling the genetics wouldn’t be that much of a problem. But we’re a long way from being there.

          1. “But we’re a long way from being there.”
            That’s what keeps it interesting. Better than to say ‘God did it’ and then go out for pizza.

        1. Hmmm, interesting.
          I’m packing the rig bag at the moment … do I have weight for SP 286 (Vickers-Rich, P. and Komarower, P. (eds) The Rise and Fall of the Ediacaran Biota. Geological Society Special Publication 286, 195-222), or shall I just snarf the PDFs?
          Annoyingly, I’ve got that one in dead tree mode, but not electronically. Soon fix that.

          1. Fixed that. I remember reading several of the SPs articles a year or so ago. The Ediacaran has always been interesting.

  3. Friday is purple day in my lab, so this is the official lab animal this day. I initially thought that the ‘animal’ was the two parallel structures and that it was dragging a ‘fish’. But the ‘fish’ was just the rest of its body. Does anyone know how a colonial animal controls differentiation of individuals to make the different structures?

    1. Does anyone know how a colonial animal controls differentiation of individuals to make the different structures?

      Squidmaster, I’d like to introduce you to the entire field of EvoDevo. EvoDevo, shake tentacles (or an appendage of choice) with Mr Squid.

  4. This is so cool! I’d never heard of siphonophores before today! My tablet and I have learned a new word. Now to find out more about what it means. 🙂

  5. Prof. Coyne,

    Will you please tell us the proper pronunciation of “Cnidaria”?

    Do you try to make a sound for the “C”?

    1. My palaeo lecturers did try to pronounce the initial “c” – knye-dar-ia with an almost-sneeze in the initial syllable.
      Without access to Classical Greek scholar, I’d accept either pronunciation. And if I did find a Classical Greek scholar, I’d find a couple more and go for a majority opinion.

      1. The problem with your proposal is that the only Classics scholars ’round here would wind up getting sidetracked arguing over the proper orientation for hanging toilet paper rolls….


        1. The word derives from the Greek “Knidos”, which I believe means “stinging nettle” – a reference to the stinging ability of jellyfish and their relatives.

      2. As a Classics graduate with an ancient language background, I’d go with the hard “C” and the “N” pronunciation. However, the way Classicists pronounce something & the accepted pronunciation are often two different things.

        1. Classicists fight!!!!
          [reaches for ….. well there should be popcorn, but there is only beer.
          In the wordt of SgtMaj Saddup, ”
          Oh dear
          What a pity.
          Never …. mmind..

    1. I cautiously add that even if one could separate one from the rest and were it to survive, I do not think it would carry on beyond its life. The different zooids are specialized for feeding, swimming, or reproduction. The different units are specialized clones.

    1. No, everything in the colony arises from a single fertilised egg – just as all of us reading this bl…website do.

      The fertilised egg develops into an embryo, which then becomes a functioning individual organism. The difference from “unitary” organisms like ourselves is that the founding organism then buds off identical copies of itself, which remain physically connected and therefore able to function cooperatively. Think of it as if you were able to bud multiple “Siamese twin” copies of yourself, which all stayed joined and worked together for the common good. This is what’s termed “modular” construction in organisms that are able to do this.

      This siphonophore is not fundamentally different from corals, zoanthids, sea fans or other colonial cnidarians which are able to form colonies by budding. The main difference is that in corals etc., all the modules (zooids or polyps) in a colony are usually physically identical and all do the same things. In the siphonophores, there is “division of labour”, with different members of the colony being physically specialised for different tasks – there are bell-like swimming zooids, feeding zooids, reproductive zooids, and others. Nevertheless, all the members of the colony are genetically identical, and all are derived from one founding individual.

      The reproductive modules in the siphonophore colony will produce eggs or sperm, which will combine with gametes from another colony to produce the next generation.

      An amazing creature, but not quite as alien as it looks at first glance!

      1. To me the interesting question is how they coordinate their behavior. I gather the individual zooids lack brains. So the behavior of the colony as a whole presumably emerges from simple behavioral repertoires on the part of the zooids, coordinated by chemical signals between them.

        Perhaps there’s an analogy with eusociality in insects.

        1. The swimming zooids have nervous system connections to each other. They swim by jet propulsion like a tiny jellyfish, and ‘jetting’ can be coordinated through the neuronal connections so that all of the swimming zooids jet at the same time. They can swim at high speeds for short distances (escape swimming).

          1. Thanks.

            Seems to me then that given that the zooids share a gemone, a gut, and a nervous system, a rather strong case can be made for considering the “colony” a single organism with a somewhat eccentric developmental program.

            1. In this case, yes, the siphonophore colony is functionally and genetically equivalent to a single unitary organism (like ourselves).

              The lines between genetic and functional individuals become blurred in the case of some other colonial cnidarians such as branching, twig-like corals, where fragments of a colony can break off, be transported by currents, and end up a long distance away from their parent colony. Then you can end up with multiple, spatially separate colonies, all sharing the same genotype, but with quite independent destinies – some will survive, grow and flourish, others will die. Clonal organisms of this kind are potentially immortal. Some coral colonies are thousands of years old, and in theory there seems to be nothing to stop them from happily cloning themselves for ever more.

              1. @Dave – do you teach this stuff? I just finished my invertebrate zoology course for the year. Am enjoying your posts.

              2. That does sound like ‘colonial’ behaviour, so I suppose the extension of the term to more integrated beasts like the one in the video makes more sense now.

            2. Yeah for sure – individuals but with unusual development! Somebody up-thread asked about the developmental program and I don’t think anything is known about that in siphonophores because big, planktonic etc. But in other hydrozoans the polymorphic colony has similar division of labour among the types of zooids, plus the colony is small, benthic, and hardy so can be grown in the lab. Paulyn Cartwright and her students have worked on the gene expression differences between the different types of zooids.

              BMC Genomics 2014, 15:406 doi:10.1186/1471-2164-15-406

              1. Yes, I do teach this stuff – Marine Zoology and Deep-Sea Biology specifically, so it’s part of my job to drone on about these things at great length!

        2. A hive of bees. Yes, that’s a good metaphor. How do we do the research? Maybe the DNA harbors the legacy. Maybe the bees DNA contain siphonophore genes.

      2. Thanks for the explanation.
        Jerry has already raised the question, but in case you missed it, any idea what makes the zooids individual animals?

        1. It’s easier to understand why the zooids are individual animals (in the functional sense) if you imagine a colony where all the units (zooids/polyps) are identical. They all have the complete set of organs and tissues required to sustain themselves and carry out all the necessities of life – food capture organs, a mouth, gut, muscle fibres or tissues, gonads, excretory system, etc., etc. Many colonial corals, bryozoans, sea squirts and other sessile invertebrate groups are built like this. If you experimentally snipped off one individual from the colony it could potentially survive, feed, and eventually give rise to a new colony.

          The siphonophores, in contrast, show a much higher level of integration and specialisation among units of the colony. Zooids are physically specialised for different functions, to the extent that many of them probably wouldn’t be able to survive if excised from the colony. However, they are quite clearly derived from much simpler, less integrated colonial hydroid ancestors, and within the group there’s a continuum from relatively simple colonies with only a few zooid types, to much bigger and more complex ones with much more specialisation. The same thing can be seen among the bryozoans (I used to study them)- some species have only one jack-of-all-trades zooid type, others show varying levels of zooidal polymorphism (to use the technical term)and functional specialisation.

          So, the zooids in a siphonophore colony are “individuals” in a developmental terms, even though they’re genetically identical to their colony-mates, and may not be able to survive in isolation.

          Hope that makes things a bit clearer!

          1. Yes, I think it’s clearer and appreciate your efforts.
            But, just to make sure I got it, and please excuse me if this is a silly question, are they considered individual organism for “historic” reasons, because of what they developed from, while they in fact resemble organs in other animals?

            1. I guess my question would be: in what sense do you think they resemble organs? They may be functionally specialized, but (as I understand it) structurally and developmentally they resemble free-swimming jellyfish.

              1. For me (I have no background in biology beyond high school, and that was too many years ago) they resemble organs in that unlike, say, corals, they have no independent existence.

            2. It’s not a silly question at all. I started studying colonial invertebrates way back in 1982, so I’ve been steeped in the literature, terminology and scientific conception of them for a long time. It’s easy to forget that what seems quite clear to me isn’t necessarily obvious to everyone, and that these organisms are actually quite unfamiliar to most people.

              Your suggestion that the zooids are considered individual animals for “historic reasons” is actually quite a good way to conceptualise it. Again, if you imagine a colony where all the units are identical and unspecialised(say, a coral), each unit is basically equivalent to the original, non-colonial ancestral species that must have existed in the distant past. Corals are basically just colonial sea anemones that secrete a hard, stony skeleton. A single coral polyp (= zooid, different terms are used in different groups of animals) looks like a solitary sea anemone, has all the same structures, and does all the things a sea anemone can do. The coral polyp just happens to live surrounded by thousands of identical copies of itself, all formed by asexual budding, and all joined together in a common sheet of tissue.

              The siphonophores have just taken things further by going in for zooidal specialisation in structure and function – but each unit of the colony is still equivalent (technically, “homologous”) to a single hydrozoan polyp – think of the Hydra that can be found in freshwater ponds, if you’re familiar with that animal. The very remote ancestor of siphonophores probably looked and behaved something like that.

              Again, hope this makes things a bit clearer still!

              1. Dave, thanks for all your patience in answering all our elementary questions on this topic!

                The really interesting question that I don’t see anybody having asked yet…is how this colonial organism compares with what I’m assuming must have been our own very ancient ancestor in the dim and distant past.

                Shirley, there must have been some similar stage between single-celled organisms, colonies of single-celled organisms, and naked apes?

                And what’s the evolutionary relationship between these and us? Is that the point on the tree where our branches merge, or do you have to go even farther back to single-celled organisms? Is colonialization a more recent development in these species than in our lineage, or have they been “stuck” there for half a billion years?

                …and so on, alas….


            3. Ben Goren’s question is my own. How does the history of colonial organisms fit with the origin of critters with organs? Have the relevant genomes been sequenced?

          2. Dave wrote “…Zooids are physically specialised for different functions, to the extent that many of them probably wouldn’t be able to survive if excised from the colony….”

            Correct me if I am wrong, but isn’t that an indirect way of saying that those specialized zooids are comprised of terminally differentiated cell types that cannot (readily) revert to gametophytic “blanks slate” form?

            1. I’m a bucket-and-spade ecologist rather than a specialist in developmental biology, but venturing out of my field I would say that your summary sounds about right.

              I await correction by someone knowing more about cell biology and genetics!

      3. But then how is that different from us who have different tissues to do different things? Is it because rather than starting an organ from a single cell the organ itself is the individual? I can almost see a difference there …

        1. Think of it as a spectrum with specialized tissues at one end and worker bees at the other. Organs are at the tissue end of the spectrum, while zooids are closer to the worker-bee end. Like worker bees, each zooid has its own internal developmental program, whose timing is largely independent from its neighbors, and new zooids can be budded at need from a mature parent. Unlike worker bees, zooids don’t detach from their parent, but draw nourishment from it throughout their lives.

  6. I believe the scientific name of this one is Erenna richardi (sorry, I don’t know how to do italics!)

    I did a couple of lectures last year on Cnidarians, and featured this one in the section on siphonophores.

    1. For italics enclose the text you want to italisize with the following “tags”.


      Except replace the square brackets with the corresponding “less than” and “greater than” symbols.

  7. Again makes it rather obvious that any extraterrestrials we might (though certainly won’t) encounter will be at least as alien and bizarre as this…whatever-the-hell-it-is. They most emphatically won’t be something the females of which Shatner will want to shag.

    Hell, they might not even have genders, though that does seem to be a popular evolutionary strategy….


              1. Wait — the prokaryotes already have the Bomb? When did that happen!?

                Any day now, we’ll wake up to reports of an expanding mushroom cloud over the nucleus of the eukaryotic capital city….


      1. I know (very loosely) a local mycologist through the CFI group. He tried to explain fungal mating types in one particular species or something to me once. Ow, my head. 🙂 We’ve got it simple! (Even with all the variation of human sexuality.)

    1. All the siphonophores are hermaphrodites. I can’t remember if that sort of thing turned Kirk’s crank?

      1. I seem to recall that what really…cranked Kirk’s crank…was drop-dead gorgeous Hollywood actresses wearing exotic makeup and skimpy costumes. And, really…can you blame him? I mean, who wouldn’t want to make out with Nichelle, just to pick one random example?


          1. [Shudder]
            That got awfully close to a goatse moment.
            (Yes, I do have a goatse.cx email address. Once I heard of the idea, I didn’t really have a lot of choice in the matter.)

    1. No depth info on the video presented. The NautilusLive.org website gives the depth limits of their current spread of ROVs as 4km.

  8. As ever, I am stupefied at the variety of the natural world and the lengths of exoticism that its products will go to to make a living. Many thanks for this fascinating article: like others here, I intend to try to understand more than I do at present about siphonophores!

  9. I never tire of seeing videos of this amazing purple boa bearing a serrated saber. This video was taken last year, wasn’t it, the first of this purple specimen?

  10. Dear HDPT, And people think I am strange! (I hope you can watch this in full-screen view. Is lunch still on next Sunday? (tomorrow week). Best wishes, HH Dr John Hayman 20 Florence Ave, Kew, VIC, 3101.

    phone & fax 03 98175706 mobile 0400 173 408 hayman@johnhayman.net

  11. Since no one has mentioned it yet, I thought some might be interested in a large, “coffee-table style” book called The Deep, by Claire Nouvian, subtitled The Extraordinary Creatures of the Abyss. Minimal text, though useful, and superb pictures.

    1. Yes, Nouvian is a lovely book. A more texty volume on the deep sea, but still with plenty of pictures, is “The Silent Deep” by Tony Koslow – also well worth a read.

  12. Far from being an new species unknown to science, it’s very likely (as identified by another commentator) to be Erenna richardi, first identified in 1904. A specimen found in 1908 had blackish pigments which would likely give rise to the color seen in the video. The species is rare, as in we haven’t come across it often, but then more humans have stepped on the moon than have been to the deepest parts of the ocean, and we’ve onle visited (in person or remotely ) a few percent of the ocean floor. In fact, the vast majority of the hard surface of this planet we call home has yet to be visited by us.

    The average depth of the abyssal plains of the ocean is a tad under 4 km, not very remote really. Hard to get to for humans, yes, and a devilish environment for almost any kind of human made equipment. And organism abundances are not that low, lower than the terrestrial environment certainly, but it can still be quite bustling down there as is evidenced by the many tracks seen in the sediments. If you want to see what it can be like, search for videos of baited benthic landers, the feeding frenzy is disturbing in the extreme.

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