You know how people can be going along, minding their own business, and then they see some cute big-eyed puppy and they go "Awwwww," and their hearts melt, and then it's all a big sloppy mushfest? I felt that way the other day, as I was meandering down some obscure byways of the developmental biology literature, and discovered the dicyemid mesozoa … an obscure phylum which I vaguely recall hearing about before, but had never seriously examined. After reading a few papers, I have to say that these creatures are much more lovable then mere puppy dogs. Look at this and say "Awwwww!"
Light micrograph of Dicyemid japonicaum rhombogen. AX, axial cell; C, calotte; IN, infusorigen; P, peripheral cell.
O dicyemid mesozoan, how do I love thee? Let me count the ways.
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The dicyemids are all parasites: specifically, parasites that live in the renal sacs of benthic (primarily) cephalopods. They take up residence inside the kidneys of cephalopods, attaching themselves to the renal tubules or the crypts (folds) of the sac with a specially shaped set of anterior cells called the calotte, and then they live there, bathed in octopus urine, from which they extract all the nutrients they need.
It's a beautifully specific lifestyle in a very narrow environment; they occupy a niche that is populated only by other dicyemid mesozoans.
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That niche is a kind of natural laboratory for evolutionary experimentation. The different species (there are over 100 total known so far) each vary in the shape and size of the calotte. There is of competition between the different species for different sites of attachment to the renal sac, and species with similar calottes are not found coexisting in a single sac, except when certain other species are also present. It's like there's a whole simple ecosystem flourishing in octopus urine, jostling about in some fascinating interactions.
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They have a wonderfully intricate life cycle, and the name comes from the fact that the adults come in two forms, the nematogen and the rhombogen. This is not analogous to two sexes: the nematogen reproduces asexually by creating vermiform embryos, while the rhombogen makes a different kind of embryo, the infusiform.
Life cycle of the dicyemids. The dashed line indicates an unknown process involved in the infection of a new cephalopod and development into adult forms. In vermiforms (nematogen, rhombogen, vermiform embryo), a large axial cell is surrounded by peripheral cells. Four to ten anterior peripheral cells (propolars and metapolars) form a calotte. The other peripheral cells are diapolars. Two posterior diapolars are somewhat specialized as uropolars. The development of infusorigens, gametogenesis around the infusorigen, and development of two types of embryo all proceed within the axial cell cytoplasm. AG, agamete; AN; axial nucleus; AX, axial cell; C, calotte; DI, developing infusiform embryo; DP, diapolar cell; DV, developing vermiform embryo; IN, infusorigen; MP, metapolar cell; PA, parapolar cell; UP, uropolar cell.The vermiform embryo (which is small, perhaps a few hundred micrometers long) grows up to be a larger nematogen or rhombogen, which are as much as a few millimeters long. The nematogen incubates more vermiform embryos in the cytoplasm of the axial cell, a characteristic long cell around which peripheral cells are arrayed. It releases these embryos into the renal sac; this is the tactic to rapidly populate a host with progeny. Under certain conditions, such as crowding, some of the vermiform embryos develop into rhombogens, which are functionally just like the nematogens, but differ in their reproductive apparatus. Rhombogens build infusorigens inside their axial cells, which produce haploid gametes that fuse to create the infusoriform embryos. The infusoriform embryos are the autonomous form that are not dependent on parasitizing cephalopods, and which are freed as the octopus urinates to swim about and seek out new hosts. Once they settle in to a new renal sac, they restart the whole process.
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Dicyemids have a very simple body plan. They are eutelic, which means that the adult form has a species-specific number of cells, which varies between 10 and 40. You can see the body plan in the diagram above: a central axial cell which forms the elongated, wormlike shape of the animal and contains the reproductive cells; a cap of cells called the calotte which is responsible for attachment; and a surrounding set of ciliated cells that have the job of absorbing nutrients from the urine. That's it; that's all it takes.
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These animals have gorgeous embryos with species-specific patterns of cell division; individual cells can be named and have specific developmental fates. This is a pattern we also see in another classic model system, the nematode.
(click for larger image)
The late-stage vermiform embryos of four species of dicyemids. Scale bar represents 10 µm. Cilia
are omitted. Other abbreviations: AG, agamete; AX, axial
cell; DP, diapolar cell; MP, metapolar cell; PR, propolar cell; PP, parapolar cell; S, syncytium; UP, uropolar cell.
Microcyema vespa: (a) a late-stage embryo (sagittal optical section) note an agamete (5a2) in the cytoplasm of
an axial cell (5a1); (b) a late-stage embryo (sagittal optical section); (c) formed embryo (sagittal optical
section) pairs of 6B11, 6B12, and 6B21 cells form a syncytium (S) that is more conspicuously stained with
hematoxylin.
Conocyema polymorpha: (d) a late-stage embryo (sagittal optical section) note an agamete (6a2)
incorporated in the cytoplasm of an axial cell (6a1); (e) a late-stage embryo (lateral view); (f) formed embryo
(lateral view) pairs of 4B11 and 5B21 cells form propolar cells (PR) that are more conspicuously stained with
hematoxylin.
Dicyema apalachiensis: (g) 13-cell stage note an anaphase gure of 4B12 cell and a metaphase
gure of 4B12 cell; (h) 15-cell stage the 5B111 and 5B121 pairs form the propolar cells (PR), while the 5B112
and 5B122 pairs form another type of polar cell, the metapolar cell (MP); (I) formed embryo (lateral view)
propolar cells and metapolar cells are more conspicuously stained with hematoxylin.
Pseudicyema nakaoi: (j)
22-cell stage note a metaphase gure in 4B12 cell the plane of this division, in contrast to the divisions of
4B12 pair (Fig. 2g), are oblique to the anterior-posterior axis, and as the result, cells of the propolar tier alternate
with cells of the metapolar tier; (k) a late-stage embryo (lateral view); (l) formed embryo (lateral
view) propolar cells and metapolar cells are more conspicuously stained with hematoxylin. -
Did I mention that they have species-specific patterns of development? Yes, I did, and it's worth mentioning again. The lineages of the different forms can be followed, and what's seen are divergences generated by varying the number of cell divisions — that is, these animals have an evolutionary history of generating novel forms by a relatively simple process of changing the regulation of embryonic mitoses.
(Click for larger image)
Developmental processes of vermiform embryos in several species of dicyemids. The developmental patterns and cell lineages from the agamete (AG) to 7-cell stage are identical among the species. The
numerals in the bottom row represent cell number stages in the development. Arrows in the developing embryos
indicate daughter cells that were produced by the proceeding division. (a) Microcyema vespa; (b) Conocyema
polymorpha; (c) Dicyema apalachiensis; (d) D. acuticephalum with 16 peripheral cells; (e) D. acuticephalum
with 18 peripheral cells; (f) D. japonicum; (g) Pseudicyema nakaoi. -
Now here's the part that really tickles the imagination: you might be wondering where these strange creatures came from. The cells are linked together by classic gap junctions; they produce the extracellular matrix molecules fibronectin, laminin, and collagen; it even has an Antp-like Hox-like gene, a member of a family not found in cnidarians; the evidence suggests that these beasties are descended from fairly elaborate ancestors. Comparison of 18S rDNA shows the dicyemids nested within the triploblastic metazoa, with some fuzzy results (we're talking looooong branches here) suggesting affinities with the lophotrochozoans, like the flatworms.
(Click for larger image)
Maximum-likelihood tree showing the phylogenetic position of the dicyemids among 28 representative eukaryotic groups. The tree was obtained using the fastDNAML algorithm with a transition/
transversion ratio of 1.48, which gave the best maximum-likelihood score (In likelihood = - 11909.45548).
Branch lengths are proportional to the scale given in substitutions per sequence position. Because of the
long computation time (more than 12 h per replication), bootstrapping was not performed.What all that means is that the ancient ancestor of the dicyemids was probably a full triploblast, an animal with three embryonic tissue layers (endoderm, ectoderm, and mesoderm) and some kind of coelom, or body cavity. This is a lineage that threw all that away, and stripped itself down to a bare minimum, a single axial cell surrounded by an absorptive layer of cells. That's all it needed to thrive in a very confined environment.
After saying how much I like these wonderful little creatures, though, I have to make a confession: there isn't a single organism you can't come to love if you get to know it well enough. That's one of the joys of biology, that there is this never ending stream of fascinating characters, every one of them a star.
Furuya H, Hochberg FG, Tsuneki K (2001) Developmental patterns and cell lineages of vermiform embryos in dicyemid mesozoans. Biol Bull 201:405-416.
Furuya H, Hochberg FG, Tsuneki K (2003) Reproductive traits in dicyemids. Marine Biol 142:693-706.
Furuya H, Tsuneki K (2003) Biology of dicyemid mesozoans. Zoolog Sci. 20(5):519-32.
Katayama T, Wada H, Furuya H, Satoh N, Yamamoto M (1995) Phylogenetic position of the dicyemid mesozoa inferred from 18S rDNA sequences. Biol Bull 189:81-90.
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AWWWWWWWWWWWWW!
Yeah, PZ, it was cute because you didn't see it lodged in your kidney.
Context matters.
Glen D
http://tinyurl.com/2kxyc7
Yeah, I get the coolness of the specificity ... but "Happiness is a warm parasite" is an uphill sale ... you might want to think about finding something else to rhapsodize about ... I'm just saying, is all ...
Regards,
Bob Felton
It takes a biologist to make these two statements about the same organism.
Something new! Never painted one of these little beasties. Wonderful introduction PZ, but I should say that my adopted puppies all came WITH 2 or 3 extra phyla at no cost!
Ain't it the truth?
I was wondering why "dicyemid" mesozoans, instead of just mesozoans sans adjective, but a quick google shows another, apparently only distantly related, but similarly reduced group of parasites, the orthonectids. They also seem pretty cool!
Context is key. Imagine a huge colony of these parked in Ken Ham's bladder. Awww, how cute. :-)
They take up residence inside the kidneys of cephalopods....and then they live there, bathed in octopus urine, from which they extract all the nutrients they need.
That's taking "water sports" to a whole new level!
That's taking "water sports" to a whole new level!
And again urolagnia rears its calotte on this blog.
Note well: the multicellular embryo develops inside a cell of its parent...now that's cool!
Imagine a huge colony of these parked in Ken Ham's bladder.
Given that it's Ken Ham we're talking about, wouldn't Trichinella be more apropos?
And that reminds me of something that's been bugging me: what does one call a group of tapeworms? A colon-y?
If I may get pedantic about the phylogeny, these guys are shown grouping (by long branches indeed!) with a myxozoan, an acoel flatworm, and a nematode--none of these are lophotrochozoans AFAIK. Dugesia is the lophotrochozoan flatworm in that tree.
I believe I once met someone by the name of Dicyemid Japonicaum at a eukaraoke bar....(ba dum dum chick). I'm sure it was just a fluke...(wah wah waaaaah)
Since Carl has chimed in, perhaps Cuttlefish will favor us as well.
MicroRNAs Help Zebrafish Regenerate Fins
I'm curious. You refer to these as "parasites", a term I usually associated with a relationship that harms the host. To my naive eye, this looks like a commensal relationship. If the octopus still needed that, it shouldn't have excreted it.
I have to say that these creatures are much more lovable then mere puppy dogs. [...] they live there, bathed in octopus urine
Puppy dogs are happy to bathe us in puppy urine. That must count for something.
The dashed line indicates an unknown process involved in the infection of a new cephalopod and development into adult forms.
Could they be transferred during sex? It would seem unlikely that such an animal would have either the sensory or ambulatory skills to actively find another host or could be released in the huge numbers required to accidentally find a host if they just leaked into the environment during excretion.
How common are they? Are they ubiquitous?
I'm wondering where I can find one to keep as a pet!
Toad! DUDE! Don't pee into the wind and NEVER EVER correct a tenured PhD in Biology ABOUT biology... Perhaps you should have wickied "parasite". As for the "If the octopus still needed that, it shouldn't have excreted it..." remark -poor logic dude, dogma has no place here.
So that's what I was sensing! As discomfort was commencing,
Inflammation in my kidneys as I swam in the abyss
Was where parasites were feeding, and (in both their ways) were breeding,
And now Myers, metaphorically, joins in to take the piss.
A biologist, his duty is to rhapsodize their beauty
But a little sensitivity is all a 'pod can ask!
Yes, I get that it's exciting--I can see that in his writing--
Guess I only wish he didn't take such pleasure in the task.
"O dicyemid mesozoan", while inside my pain is growin'
"Let me count the ways I love you", like this parasite is heaven
Then the dude proceeds in counting, while my agony is mounting,
And he doesn't stop until he's all the way to fucking seven!
jsn: Perhaps I had the humility turned down too low, or perhaps I should have made my question explicit. I shall try again.
The posting refers to these as parasites. To me, that word implies negative impacts on the host. Not being a biologist, my naive view is that it is consuming something that the octopus is excreting. I expect that PZ has chosen his words carefully, and the "commensal" term has appeared on these pages before. This makes me curious. And so, the questions: "Are we using the word 'parasite' in its strictly formal meaning, as the benefiting member of a relationship that harms one party, and if so, what is the mechanism by which this harm is done? Alternatively, as we using the word 'parasite' in its more colloquial meaning, as a creature living inside another?"
Now, for me, trapped within my own thought processes, it's "obvious" that I was asking these questions. Thank you for pointing out that my meaning may not have been clear to some or all of the persons who do not reside within my cranium. I'm still interested in the answers to the questions. This isn't an attack on our host, it's an attempt by me to learn more.
Nono, he's right. I don't see why these are considered parasites -- aren't they commensals? I don't think the octopus is harmed by 'em, is it?
And these are pretty cute, alright. ALMOST as cute as tardigrades.
I'm not a Biologist so it just looks like a booger to me.
Given that these little guys live in the EXCRETIONS of cephalopods, i.e. stuff that they don't need, do they actually count as parasites, or is this just a very, very, VERY close commensal relationship? ("We're not married to this squid, we're just shacking up in it.")
Oops, my bad. I understood that commensal relationship was under the aegis of parasitism. (Is my face red) Hosts with the most, y'know? As for losing the little buggers now and then, it's gotta happen sometime.
Sorry, the cold medicine has made me a bit punchy. I'll go away now...
Welcome, PZM, to the wonderful world of parasites!
But only if you don't get to know it too well. There's any number of organisms I'd only want to know in the abstract rather than by, for instance, hosting it.
Very cool. That's almost enough to makes me wish for the end of my sabbatical so I can get back to teaching Invertebrate Biology. Almost.
I thought this sounded familiar...
>>>The infusoriform embryos are the autonomous form that are not dependent on parasitizing cephalopods,
Hmm. So... what do they DO while they're atonomous little hairy things out in the big vast ocean? Do they just float there in suspended animation, waiting to be breathed into a cephalopod?
And people said -I- was crazy for loving horseflies...
And people said -I- was crazy for loving horseflies...
Wee parasite: Aww!
Urolagnia: Eww!
Calotte: Lawl!
Indeed not. Myxozoans aren't even triploblasts, they're cnidarians. The phylogeny is from 1995, so this -- a clade for all long branches -- is exactly what we should expect.
When did people stop discussing whether long-branch attraction ever occurs in real life or is just a theoretical problem...?
SQUEEEEEEEEEEK!!! :-}
Bride of Shrek, but it's such an elegant little booger, or bugger, as the case may be.
I don't know much about cephalopod kidneys.
In normal human kidneys, a blood filtrate goes in and after a complex series of processes, urine comes out.
If an organism were positioned in the ureter or bladder, in an way that was not mechanically harmful, and it subsisted on "what the human meant to excrete anyway", that is, final urine, it might be termed a neutral parasite or quasi-commensal, I guess.
But if it were positioned higher up relative to the process and exploited molecules or ions that would have been resorbed, it would be a parasite, and potentially a quite harmful one.
Presumably, the position of these critters relative to how "complete" the cephalopod urine is has a similar implication.
To use grossly anthromorphic language, I'm tempted to say that they must absorb something that "the octopus really wanted" and would have resorbed.
@ #2. Well gee, Glen D.
How 'bout them little fellers that live among the roots of our eyelashes? Worm-like critter, I understand. They aint' never bothered me none. They ever bother you?
'Course, if I think about it in a certain way, it does give me the heebie-jeebies. ;->
This statement logically includes Bill Dembski, Stalin, George W. Bush, etc, all of whom are organisms.
Dicyemid mesozoa world domination plan:
1: A/Sexual reproduction
2:
3: Infection of Cephalopod host
4:
5: Profit
"there isn't a single organism you can't come to love if you get to know it well enough"
I'm drawing the line at Cheney
Jeez, you people are weird...!
But a good education is not just vocational training. Don't chase after the dollar signs but make sure you will be doing something rewarding in many ways.
All this talk about urine and parasites, and I can't believe no one's brought up the candirú yet.
Travel tip for anyone heading to South America--don't pee in the Amazon[1]. You'll thank me later.
[1] Herman JR. Candirú: urinophilic catfish. Its gift to urology. Urology. 1973 Mar;1(3):265-7.
PZ, you could sell me cholesterol!
PS - I'd love to know the derivation of the name of one of these beasties, Dicyema apalachiensis. I've been to Appalachia, and I sure don't remember seeing any octopodes anywhere there.
#34 Dave,
From what I can tell the myxozoans qualify as transitional forms. In this case transitional between one slime mold kingdom, and the animal kingdom. The process of evolution does have a way of complicating things.
Just remember, sponges do have cnidarian larvae, while urochordates have chordate young.
Whoa, was that Jay Hosler? Man, between him, Cuttlefish, and Carl Buell, there's a lot of creative artist types hanging around here.
I was actually rereading Clan Apis for the nth time yesterday. Still one of my all-time favorite graphic novels.
Looking forward to hearing more about the effects they have on their hosts. :)
I dunno. I think rotifers will always hold that special place in my heart for microscopic organisms. Perhaps it's proximity, knowing they're around in nearby ponds.
We don't have a lot of cephalopods and their "little helpers" in Toronto. Oh, except on Spadina Ave. There, you big money for those for lunch.
Mmmmm, dicyemid mesozoa. Needs ketchup.
Oops, my bad. I understood that commensal relationship was under the aegis of parasitism.
commensalism and parasitism are types of symbiosis; the other common type being mutualism (both benefit).
there are also amensal relationships that organisms can have with each other, where one organism negatively impacts the other, while experiencing a neutral effect (or positive) itself.
allelopathy between plants would be an example.
@48,
If you want fresh squid strips you get to cook yourself, as well as fish and meats, including ox tongue (only on dinner menu), go to Grill Time on Yonge St, just north of College on the west side. A carnivore's paradise, all you can eat (and cook at the grill embedded in the table) for excellent prices. Lunch is under $10, dinner not much more and includes more variety.
This is where we had the single PharyngulaFest in Toronto. Great fun!
#50:
I missed a PharyngulaFest in Toronto? Gah. I think I know where Grill Time is.
Any new meet-ups planned, Snakelass? We can send photos, and PZ will be all jealous he couldn't come (until he sees all the big crusty snowdrifts).
Gen. 1:20 - And God said (to himself I guess), "Let the water teem with living creatures. And don't forget a hundred or so parasites for the octopus pee."
#11 - How about "a measure of tapeworms"?
Ian, English or metric? Does it vary by coast?
Aw is right. I got tingly too after reading this. Awesome Pz!!!
The real question is, how does the tapeworm communicate the size of the object? I assume you swallow it. Does the tapeworm imprint the size on it before, um sending it on its way?
Halanych 2004 has dicyemids as lophotrochozoans with references to various papers. The orthonectids are tentatively placed as triploblasts basal to the deuterostome/protostome divergence.
Fascinating reproduction method. Can someone please give me more information about how it produces gametes and offspring within its axial cell?
Do they use their cells the way we use whole organs?
In gamete production does a nuclear and plasma membrane form around the new set of chromosomes _inside_ the axial cell? And how does the parent cell undergo mitosis and meiosis without having its DNA halved?
How do the offspring develop inside the cell without interfering with or damaging the parent cell's structures? Are they stored in vacuoles?
And finally how are they "born"? Exocytosis?
Many thanks in advance :D
Stefan there is a phenomenon in biology called a syncitium, a cell with more than one nucleus. Some invertebrate embryos, like Drosophilla (fruit flies) go through a phase in early development where the whole embryo is a syncitium, the cell walls going up later. All your skeletal muscle cells are syncitia, long tubes with multiple nuclei formed from the fusion of individual cells. Once fused in muscle nuclei can duplicate independently of one another and those in different parts of the cell, like at the ends and under the nerve synapse make different sets of proteins etc.
The cells that line the interface between embryo and mother in the placenta are syncitia too. In fact they resemble what happens when some types of viruses invade cells, and lots of our endogenous retroviruses are active during development, including in the placenta and one hypothesis is that we might owe the transition from marsupial to placental mammals at least in part to a viral infection. Of such raw materials does Nature select.
So what Dicymids do is nothing special, biologically speaking.
I have waxed poetic about these little guys in introductory biology courses (and invertebrate zoology too). I use them as the poster child that evolution is under no obligation to evolve from the simple to the complex.
My question is are they regarded as parasites or commensals?
Presumably as the load increases they negatively impact kidney function, but what is the harm of siphoning off a little urine otherwise? If they are like most parasites, I suspect that they spend part of their life cycle either in another body part of their host or molluscs and/or fish serve as an intermediate host. Since the job market for octopus and mollusc epidemiologists is tight, the world may have to wait for an answer.
I had no idea that a multicelluar organism could consist of so few, yet so specific cells. I guess it shows how little interest I ever had in biology before coming here.
This actually makes me want to discover a new species of these critters, just so that I can name it Peezedii.
But the closet I've ever been to dicyemides is dicyanamide.
Presumably as the load increases they negatively impact kidney function,
that would make them amensal.
either way though, it doesn't look like they fit the definition of parasite.
(#59)
I have to disagree--growing a multicellular propagule with complete cell membranes within a single cell is not at all the same thing as a syncitium or coenocyte, and as far as I know (not all the way) it's unique. Stefan's questions are good ones.
A closer analogy might be zooxanthellae--complete cells that live within the cells of cnidarians, giant clams, etc. Still not the same thing.
Thanks Andreas (#57) for the phylogeny update.
#46 Alan Kellogg: I don't think that's right about myxozoans. I thought, as David said, that they are degenerate cnidarians. Urochordate and sponge larvae don't enter into it.
bathed in octopus urine, from which they extract all the nutrients they need
Ah sure, nice work if you can get it. We earn our bread in the sweat of our brow, but some organisms are living the life of Riley!
Thalarctos @43, not to blow me own horn, but I mentioned the candiru ages ago in comments on this very website. And linked to photos. Those of you who know what a candiru is will understand what the photos involve, and will give Google Images a wide berth. Those of you still swaddled in innocence; if you must go to Google Images, don't do so right after lunch.
BTW, if one is in candiru-infested waters and absolutely must piss: Redmond O'Hanlon recommends sticking a bit of window screening into a cricket box or "cup" and placing this impromptu apparatus afore the candiru's entry-port. Never had the chance to test the idea empirically, but any Pharyngula readers who find themselves in the Amazon basin are encouraged to report their findings.
"the adult form has a species-specific number of cells, which varies between 10 and 40"
"they have species-specific patterns of development"
"a wonderfully intricate life cycl" "the adults come in two forms, the nematogen and the rhombogen."
That's it. Now I'm in love.
The life cycle thing is awsome ! that beat boring spermatophytes and gametophytes!
beatS
Sorry.
The last sentence is true, but in a quite different way than you think. Your information is outdated by a few years. Try to find PZ's post on Buddenbrockia. It's amazing.
(And BTW, we're more closely related to the mushrooms than to the slime molds. Slime molds are Real True Amoebae, aka Amoebozoa.)
------------
The spermatophytes are the seed plants. You mean sporophytes.
Thanks for the reference, Andreas. Skimming it now for reading in depth later, I'm pleased to see several references to the work my intro to vert embryology prof did on the subject. You go, Billie Swalla! I remember her telling our lecture class about it when it just came out; that's some big questions they're working on.
And Mrs. Tilton, I tip my calotte to you for knowing about the candirú, and sharing the informational bounty. But it's not any big surprise that you do--by now I know very well that urological person, and I can always trust urinalysis of the situation.
ouch!
and:
ouch!!
Sven,
when it's about the candiru, "ouch" is very much the operative term.
Thal,
but, yes, ouch.
[sung to the tune of Harry Belafonte's great hit "Matilda," while shaking maracas and generally dancing around in a conga-line-like fashion}
Can-di-ru! (chicki chicki chicki)
Can-di-ru!
Candiru, swim up me urethra
When I pee in Pe-ru
(Women over forty!)
(I'll be out of town, but you can slip my Molly under the door.)
You noticed comment 43? It's spelled candirú because it's stressed on the last syllable. To become the next Cuttlefish, you need to work harder. (Or just choose another tune for the same text.)
David @72,
when in need of prosody that fits the pronunciation, Rolf Harris is yer only man.
Pull me candiru out, sport!
Pull me candiru out.
It's so long since I've peed, sport,
And it's starting to bleed!
All together now!
I am, of course, unworthy to touch the hem of Cuttlefish's mantle. But as long as we are immortalising South American nasties, perhaps s/he will have a stab at the chupança.
Perhaps better diction would help your advocacy. 'Twould be better to state, "After reading a few papers, I have to say that these creatures are much more lovable *than* mere puppy dogs."
actually, Belafonte stresses that third syllable pretty strongly--it's dat calypso beat mon.
OIC.
-------------------------
What help does it need?
He means that if PZ enunciated more clearly, he might maintain the distinction between "than" and "then" in writing more easily.
Coming from a part of the US where "pen" and "pin" are homonyms, I can see his point.
Indeed not. Myxozoans aren't even triploblasts, they're cnidarians. The phylogeny is from 1995, so this -- a clade for all long branches -- is exactly what we should expect.
When did people stop discussing whether long-branch attraction ever occurs in real life or is just a theoretical problem...?
SQUEEEEEEEEEEK!!! :-}
The last sentence is true, but in a quite different way than you think. Your information is outdated by a few years. Try to find PZ's post on Buddenbrockia. It's amazing.
(And BTW, we're more closely related to the mushrooms than to the slime molds. Slime molds are Real True Amoebae, aka Amoebozoa.)
------------
The spermatophytes are the seed plants. You mean sporophytes.
You noticed comment 43? It's spelled candirú because it's stressed on the last syllable. To become the next Cuttlefish, you need to work harder. (Or just choose another tune for the same text.)
OIC.
-------------------------
What help does it need?