Why?

July 22nd, 2010

It is time for my usual and periodic rant about the idiocies apparent in the coral reef aquarium hobby.  The particular thorn-in-the-paw that has set me off this time is one of the usual ones that have been beating around the scientific blogosphere over the last year or so; specifically, the lack of scientific literacy amongst the public – or in my case, the particular subset of the public that I sometimes interact with – the average aquarists I try to advise, or work with, or write for.  I have to throw in a caveat here; there are a fair number of very good aquarists, who can actually look up articles, and act upon what they read.  However, they are a small subset of the total number, and are the exceptions rather than the rule.  If you count yourself amongst this group, and have actually read something in the peer-reviewed literature, I hope the rest of this diatribe does not offend you.

I suppose I may be guilty of one on the mistakes I warn my readers about, that being making unwarranted generalizations.  Still…  It seems like trying to introduce common good husbandry based on scientific knowledge practices to the majorit of this group of folks is a useless task.

Nothing I propose is based on anything other than scientifically determined facts and good common sense, buttressed by those facts.  Most of the time following the suggestions would save a lot of money.  In all cases, it would result in healthier, longer-lived animals.  And after 15 years of doing this, I think I could count on the fingers of one hand the number of people who regularly correspond with me who seem to “get it.”  And, even though there are probably more, the fact of the low numbers is damned discouraging.

 The Aquarium Advice Form Of Gresham’s Law

 Gresham’s law in economics states that “Bad money drives out good.”  Basically, if two types of currency circulate simultaneously, and their exchange rates are governed by law, the artificially overvalued money tends to drive the other, artificially undervalued, or “the more valuable or good,” money out of circulation.  In the aquarium hobby world, it is the artificially overvalued advice, mostly advertisments, but some other advice as well, drives out or submerges the artificially undervalued advice, that based on scientific evidence.

One probably shouldn’t take this analogy too far, but it works pretty well on the short run.  Advice that is overvalued is that which is continually trumpeted by advertisements.  This advice is everywhere in short bursts, it is easily learned, and it is often repeated by people who don’t know how to test or evaluate it or probably more correctly, don’t care to test or evaluate it.  As we all know, continual exposure to a patent falsehood claimed to be true will result in that falsehood being accepted as the truth by the majority of the audience exposed to the repeated message.  This was discovered and explicitly stated by Joseph Goebbels, and has been exploited by every propagandist since then.  Of course, it was probably intuited by every natural-born scam artist since the first travelling caveman sold defective obsidian on his way through an ancient valley.  And it continues to be inuited today, and exists well in the advertisements aimed at aquarium hobbyists. 

The undervalued advice in my example, scientifically determined knowledge, requires the recipients to think about it and to implement it often in the face of an overwhelming amount of contrary advice.  That is hard to do, particularly when the recipients are today’s typical Americans who have never had any training in how to evaluate ideas or claims, and whose knowledge of science and the scientific method have been formed by shows such The X-Files. 

There are numerous examples of how idiotic advice seems to rise to the top in the aquarium hobby, but my favorites for today are the use of strontium and iodine as additives in aquaria.

Strontium is a known coral poison affecting calcium metabolism.  It has been demonstrated to reduce calcium transport across the coral’s surface membranes, and that is definitely not a good thing.  Fortunately, it doesn’t kill corals outright, and the the concentrations found in natural sea water, evolution has given corals the ability to detoxify it.  Still, adding it to an aquarium, to “boost” coral growth is not a really sterling example of the intelligence of the average reef aquarist.

Then there is the addition of iodine.  This material, often added in one of the many formulations called Lugol’s solution, is an essential material, in very small amounts.  The amounts necessary in a reef aquarium are so tiny as to be effectively unmeasurable.  Excess amounts of iodine are amazingly lethal.  Like many budding scientists who worked in freshwater systems, I learned about Lugol’s solution in my limnology classes, where it was used as a preservative. 

Yeah, that’s right.  A preservative, a material used to kill organisms and make them so toxic that nothing could eat them. 

Good stuff, to be adding to one’s aquarium, to be sure.  Especially as it is impossible to hobbyists test for iodine in aquaria as it has exceptionally complicated chemistry and no cheap test kits are available.  But that doesn’t matter, as you see, we all know that iodine is essential for crustaceans.  Particularly because it is necessary for crustacean molting.

Necessary for molting in crustaceans… You know, crustacean molting has been investigated in great detail by arthrophysiologists for as long as there have been scientific arthropod studies.  This is well over 100 years, and there is an amazing body of literature about the chemical aspects of molting in crustaceans.  Litereally, there are thousands of articles.  Turning to the Advanced Search in Google Scholar to get an estimate of the number of articles turned 11,800 hits, about 210 of these articles contain a mention of iodine.  A few of those discussing iodine inside the molting fluid and in the water outside the animal, along with all other ions the researcher could measure, but most of the mentions of iodine were as a component of various testing chemicals, not normally found in the animal but used as a reagent to indicate some other factor.

The sum total of articles mentioning iodine in any of its many forms as being necessary for molting was…   

Wait for it…

Zero.

One would think that if iodine were necessary for crustacean molting, there would be a plethora of articles describing its action.  There are for every other necessary chemical, such as 3,820 for phosphate, 3,210 for copper, 2,680 for iron, 2,520 sulfate, 4,080 for calcium.  Iodine zip…   Search engines turn up a lot of false positives, and depending on how one queries for iodine, hits can be found.  But, when those articles are examined, NONE of them discuss iodine as a necessity for molting. 

 Negative evidence is, of course, difficult to deal with.  The old saw, “Absence of evidence is not evidence of absence,” remains as sharp as ever.  Still, one would think that somewhere along the line, if iodine were a requirement for arthropod molting, some researcher over the last century would have found it.

Anecdotal stories from aquarists seems to indicate that iodine supplementation seems to cause some changes in molting.  My suspicion, my very strong suspicion, is that iodine poisons the molting process and causes premature molting.  Repeated iodine forced -molts result in premature death.   At the very least.  Now, I would love to be shown to be wrong.  But, I am not going to hold my breath waiting for such evidence to appear.

Below are some references about strontium in corals, they are all worth reading.  It is particularly enlightening to read the first two, and then the rest.  The first one tells how increasing strontium causes increased growth in corals.  The second one tells how that growth was an artifact of the experimental system.  The first one is used by incompetent aquarists to support their supposition about adding strontium.  These aquarists are incompetent because they didn’t read the next article.  And the subsequent ones.  

Of course if you want to read an article in the scientific peer-reviewed literature detailing with the necessity of iodine in crustacean molting.  You will have to find it.  I couldn’t.  

On the other hand, the aquarium version of Gresham’s law is alive and well, just check out any aquarium vendor and their online advice about iodine and strontium.

More later…

Cheers,

Strontium References:

Swart, P. K. 1980. The effect of seawater chemistry on the growth rates of some scleractinian corals. In: R. Tardent and P. Tardent (Editors). Developmental and Cellular Biology of Coelenterates. Proceedings of the Fourth International Coelenterate Symposium. Interlaken. pp. 203-208.
Swart, P. K. 1981. The strontium, magnesium and sodium composition of recent scleractinian coral skeletons as standards for paleoenvironmental analysis. Palaeogeogrraphy, Paleoclimatololy, Paleoecology. 34:115-136.

Chalker, B. E. 1981. Skeletogenesis in scleractinian corals: the transport and deposition of strontium and calcium. In: S.C. Skoryna (Ed.) Handbook of Stable Strontium. Plenum Press. New York, pp. 47 63.
Ip, Y. K. and P. Krishnaveni. 1991. Incorporation of strontium (90Sr2+) into the skeleton of the hermatypic coral Galaxea fascicularis. Journal of Experimental Zoology. 258:273-276.
Wright, O. P. and A. T. Marshall. 1991. Calcium transport across the isolated oral epithelium of scleractinian corals. Coral Reefs. 10:37-40.
Greegor, R. B., N. E. Pingitore, Jr. and F. W. Lytle. 1997. Strontianite in coral skeletal aragonite. Science. 275:1452-1454.

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Good Stuff

July 3rd, 2010

I have been going from a bare bones, sorta, tank back to something that is an approximation of a natural system.  My aquarium is nothing I would call a reef tank a the present time, more like the emulation of a habitat someplace near a reef.  In other words, no stony corals, yet.  And probably not for a long time.  For the last couple of years my system has mostly been focused on maintaining my research animals.  And it had been an adequate system, as far as it went, it just wasn’t the most aesthetic aquarium of all times.  In fact, it was pretty much the other extreme.  To a large extent, this condition was due to my health problems, which finally seem to be fading a bit.  I simply didn’t have the time to maintain it properly.

So…

I have been in the process of converting my aquarium into a more attractive system designed to maintain and support my research beasties of the present, my Diodogorgia colonies.  Now, like any good scientist, I don’t want to spend any more time than is absolutely necessary in this exercise.  I am NOT one of those aquarium hobbyists who spends all waking hours puttering around his/her system.  Nope.  I want to put the animals in the system, and sit back and enjoy it as I can, relaxing… Not working.

My research has shown that Diodogorgia colonies need strong, and more-or-less laminar currents to feed well.  It just can’t capture prey very well in either particularly slow currents or stagnant situations, nor in strong currents that are irregular, the type of water flow generated by so-called wavemakers, and oscillators.  So I have created a Diodogorgia gully along one side of my system with the wall of the aquarium being one side, and live rock being the other.   At one end of the aquarium, I have three relatively powerful powerheads to create the current.  I can’t, in this situation, use propeller type pumps, because the ones I have create a noise in the tank that irritates my spouse – apparently anywhere in the house (and, it is a noise I can’t hear, sigh…)  .  So…  a compromise, but it seem to be working so far.

Yesterday’s event of notice was the arrival of a shipment of sand bed and “maintenance” critters from Indo-Pacific Sea Farms.  I been periodically purchasing this type of critter from this vendor for over ten years, and other than the fact that some of the animals are misidentified (more about that below), I have nothing but good things to say about the operation.  The animals arrive in good order, ALWAYS.  The animals arrive in labeled bags, ALWAYS.  And the animals are reasonably priced, ALWAYS.   

Yesterday, I got a shipment of “bristle worms” – amphinomids or fire worms, the classic scavengers, some of their “Mama Mia” worms – these are cirratulid worms, not terebellids as it states on the webpage.  See this online article to tell the diffence between the two types of worms.  Nobody in the hobby, as near as I can tell, actually sells terebellids, but many folks misidentify cirratulids as terebellids.  Folks,  the presence of a lot of tentacles isn’t the sole diagnostic characteristic for a terebellid, those tentacles have to arise from a specific body region and the whole worm has to have the proper morphology.   Similarly with the cirratulids.  These two types of worms are NOT hard to tell apart. 

This is one of the cirratulids I got from IPSF. They do well in a good sand bed and are great detritivores.

I also got some mini-stars, small brittle stars, and some of the the “miracle mud,” some sediment containing real microscopic sediment critters, as a recharge for my sand bed.  This latter stuff is what live sand should be when it is sold, but other than IPSF, I don’t know of any vendor that actually sells it.

Finally, I finished off my order with some good grazing snails, three of the Trochus IPSF sells, and an order of grazing columbellids.  Although IPSF calls the latter Strombus maculata, they are clearly not a strombid.  However, that misidentification doesn’t get in the way of their grazing abilities, which are truly awesome.  These little snails are probably a species of Euplica, but that is really not important.  And here is an article that discusses the differences between the columbellids and the conchs (= strombids).  Again, they are not hard to tell apart, and the columbellids are really the best grazing snails in the business; additionally, they survive far better in reef tanks than do strombids.

This is one of the columbellids added to my system. See the linked article for differences between these animals and conchs (strombid snails).

Finally, and the thing that makes IPSF a REALLY great place to buy from, is that all of this stuff is aquacultured.  They raise it all.  YES!!!!  A marine aquarium animal vendor that is doing business like it should be done.   I had a heck of a good time yesterday adding all of these animals and a few other things, some algae, besides to my tank.

Until later,

Cheers.

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Macroalgae(s)

July 2nd, 2010

Any recent visitor to my “expert” forum on the Marine Depot site may have noticed a new posted note about feeding – and about the language.  More to the point, not just about the language, but about the use of words that seem on their way to becoming ubiquitous amongst reef aquarists.  These are  the “invented” words that form from unfamiliar terms, such as “algae,” giving rise to algaes (sic) by itself, or in the combined forms:  micro- and macro-algaes (sic).  The case that pushed me over the edge this particular time was zooplanktons (sic), supposedly – I think – as a plural word for a zooplankter, a single zooplankton entity.   However, I will point out, I couldn’t discern from the sentence where it was used, what the writer meant.   Arrgh!!!

Ah, isn’t illiteracy wonderful? 

The marine aquarium hobby is an expensive undertaking, this generally means that two types of people become hobbyists:  those who can easily afford it, and those whose interest in the animals/hobby is so great that they make all sorts of sacrifices to participate.  As one might expect there are relatively few of the latter folks, although in many cases, when one can identify them, they often are amongst the more knowledgeable of hobbyists.  The point of this statement is that to be able to afford such a hobby, one often has to have a well-paying job, and following this train of thought to full derailment, such jobs are often domain of people that have a so-called ”good” education. 

So… why are so many of these people illiterate?   

For that is what the misuse of the these simple terms implies.  Either the people have not been exposed to fact that the plurals of many words are not made by simply plopping an “s” down at the end of the word, or they are not aware of such strange tools as “dictionaries.”   I suppose the problem is that these folks read or hear the term and become aware of some sort of meaning for it from the context wherein they find it.  And, away we gooooo……

Probably the word in this regard that captures most people is “algae.”  People see the word and kinda, sorta, somehow get a warm, fuzzy, or cold, slimy, idea of what algae means; all the time not realizing that algae is a plural term.  More than likely this is because the original user of the word, hasn’t a clue about the word, either. 

It is really interesting, and more than a little disheartening, to read something one of these people writes and to realize that they don’t have a frigging clue as to what any single alga is.  Let alone what many algae are.  They have no conception that algae are not plants – but, hey, don’t try to pin them down on what a plant is, either.   You really don’t want to know what they think it is.

The marine coral reef aquarium hobby is by some sort of necessity technical.  It has to be, there are no common names for many of the organisms, and most of the techniques for maintain the organisms verge on being complicated culture methods requiring more than a little bit of scientific or technical background.  While there are many aquarists who are very well versed in the sciences or engineering, there are unfortunately quite a large number of wannabes who just don’t have a clue about what they need to do to keep their organisms alive, or for that matter what their organisms even are (oh, they may use a name, they just don’t realize what the name implies).  The sad part of all of this is that they, in most cases, already have the organisms as they have purchased some critters and some equipment because of some smooth-talking salesperson.   Generally, the budding aquarist seems to think they have something like a gold fish (hey, the fish they have is golden… that make it a gold fish, right?).  And the equipment they purchase, instead of being a set of expensive devices specifically tailored toward keeping these strange creatures alive, is simply a series of “black boxes” of unknown and unknowable function.  All our aquarist has to do is to follow some simple instructions, and their animals will be thriving.

Sigh.  It is hard to tell who is more to blame here;  the clueless individual or the mercenary salesman.

One would like to think that people don’t view these beautiful living things as disposable, but all too many of them have the asinine  philosophy that animals are put on Earth for man’s benefit, another unfortunate piece of garbage thought spawned by our dominant religions superstitions.  In this case,  who cares if one doesn’t know how to take care of the animals properly, it is no big deal.  One would like to think that people would try to learn about keeping these organisms before they purchase them – and to the credit of many, they do.  But far too many don’t.  These are the people who can’t read enough to know that they don’t know what one alga does, let alone what many algae mean in the context of a marine aquarium. 

And so it goes, and questions will arise about microalgaes, and phytoplanktons, and…

I will beat my head against the wall, ’cause it will feel SOOOO good when I stop.

Until later,

Cheers,

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Movies, Movies, and More Movies…

June 30th, 2010

The Diodogorgia project continues, of course, and right now, I am in the throes of making the final adjustments to the 180 movies I made last week of the polyps feeding in 16 and 24 cm/sec currents.   There is often quite a bit of massaging that is necessary to bring the “raw” movie upto easily viewable condition.  I convert it from a QuickTime movie to a Windows one, then generally, I have to brighten it up, and sharpen it slightly.  Additionally, I also put a title on it.  All of this takes time, even if each movie is only 40 seconds of raw material.

Fortunately, the process is straight forward and easy, it just consumes some time.   Actually, for 180 movies, it consumes a LOT of time.   But that process will be done shortly.  Then I will do the analyses that I do, and soon… I hope by the beginning of the second week of July, I will actually be able to getting to the nitty and gritty of some actual writing.

Or more likely, making some more illustrations for the manuscripts and presentations.  With the MACNA presentation coming up in September, I need to be getting going on having that prepared.  I REALLY don’t want to go in that conference with a half-assed presentation.  Particularly, of this stuff!!!

So… back to work,

More later,

Cheers!!!

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And, So It Goes…

June 22nd, 2010

The Diodogorgia feeding experiment ”saga” continues.   Yesterday, I did the first two sets of supplemental experimental feeding observations.  I made about 90 movies watching polyps under both 16 cm/sec and 24 cm/sec laminar flow currents.   I did about 45 movies under each speed, and I hope that they show some good captures or attempts, and such.  I think they did, but it is really hard to tell by watching on the view screen of my little camera as I am taking the pictures.

Today, I will be duplicating the effort, but I will use turbulent flows.  Getting all of these data is great, but of course, it does – in one sense – slow me down, as I have to process and analyze all the movies.  That involves adjusting the brightness and contrast, if I can, to make viewing easier.  Also, I label the movies and such, so that I won’t make mistakes about what I am watching.  With over 500 movies, it is easy for my feak and weeble mind to get confused on occasion.  And then I have to analyze them for actual content.  Gonna take a while!!!

Still and all, even though this sets me back a bit on my schedule, it really is of no consequence – because the schedule is all of my own making.  I want to have the best project I can have, given some reasonable constraints of cost, time, and effort, and these new movies certainly help correct some early errors.   I took the original movies under these conditions as the first ones for this aspect of the project, and I really didn’t know how many I needed nor under orientations were best.   After looking at movies from all the other speeds, I have  a really honed appreciation of what I need.  I just hope that these will fit the bill.  

Doing this aspect of the project was an interesting process.  Initially, I had no intention of working on the question of exactly how do the animals captured their food.  The primary question was simply, “Was there a difference in the rate of capture between animals in laminar flow and turbulent flow situations?”  Additionally, I thought it would be interesting to see if the differences, if any, changed as the velocity of the current changed, so there was the additional question, “Was there a difference in the prey capture rates between animals in laminar and turbulent flows at different current velocities?”  These were questions driven by animal husbandry concerns; primarily, “What does a marine aquarist have to do to maintain these or similar animals in good conditions in an aquarium?”

In the process of doing those experiments, I thought it would be useful to have some movies of Diodogorgia polyps capturing Artemia, simply as visual aids for presentations.   However, once I had a couple of good movies of prey capture, the REAL question became evident:  Just How DO Diodogorgia polyps capture prey?  Frankly, the question actually has a much larger significance, because when I was reading references about gorgonian feeding, it became evident that the process was really a “black box” phenomenon. 

People have done experiments – a very few – about feeding in gorgonians, and have found feeding rates for some species, but there is no general model of how the polyps actually work to catch prey.  There are some data and ideas for other octocorals, primarily the lumpy leather corals, such as Sinularia and Alcyonium, but nothing for gorgonians such as Diodogorgia, where the polyps have to be projected up into the currents.  In most of the previous experiments, it simply is assumed that the polyps work to capture food, no thought seems to be given to the processes involved. 

And, if you think of it, prey capturing in such a small animal under the normal conditions it encounters has to be an amazing process.  The animal has to encounter the prey item, assess it, and capture it all the while in a strong (relative to the size of the polyp) current.   If you consider the dimensions of a small – tiny even - gorgonian polyp, and how long it takes a food particle (a tasty zooplankter, or a yummy particle of bacterial goo) to pass through the space around the polyp, all of the decisions about the food capture have to be made in small factions of a second.  All by an animal with no brain and, at best, a rudimentary nervous system.

This is really neat stuff, I think.  

When I get all done, I hope I have done a good enough job at this project that the people who review and read my work, think it is a neat project as well.

Until sometime later,

Cheers,

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Of Course…

June 17th, 2010

It was going too well; my Diodogorgia research that is.  I am just about done with the original set of feeding movies.  I am in the last batch, those where the animals were feeding in currents of 24 cm/sec.  And I am not finding any feeding events on the films.  I did pretty well at the lower velocities, but at 16 cm/sec and 24 cm/sec, the animals just do not seem to be feeding at all.

The do seem to be shaking a lot more than they should.  These two “movie runs” were done early in my project and, I suspect, I didn’t have the colonies oriented properly in the chambers resulting in too much vibration and that, in turn, meant that the didn’t feed much.  Here is one of the few good feeding episodes that I managed to capture.  It is a big movie and takes a while to load, please have patience. :-)

Nauplius Capture at 16 cm per second, Laminar Flow

Fortunately, I just ordered two more Diodogorgia colonies, I was going to set them up to try to keep them in my reef tank.  They arrived yesterday.  So, I think I will be cutting one of them down to the size that fits into my apparatus, and I will be doing another couple of experimental runs.  If all goes well, I will be able to complete the movie making within a couple of days, but the evaluation and analysis will take several weeks. 

ARRRGH!!!!  I thought I was getting done with this part of it!!!! 

Oh well, at least I can remedy the problem.

Eye candy

The bird below is a western tanager.  They normally live in the mountains around here, and we get them at our feeders as transients when they are migrating though.  This year, for some wonderful reason, probably shelled peanuts in one feeder, they have stayed.  I counted 12 males in one feeding aggregation a couple of days ago.

Western Tanager male on the roof of a feeder out my office window in Wilsall, Montana.

Until next time,

Cheers,

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Brief Updates/Diodogorgia research

May 10th, 2010

Since my last post I have been working intensively on examining the videos for my research project on Diodogorgia feeding. This has really been a HOOT!!!  Lotsa fun!

I am actually getting data!  What I never let on was that there was always a possibility that I would have no useable data from the videos.  After all these were taken by a very “jury-rigged” apparatus.  Well, judging from what I have seen so far (and as of yesterday, I had looked at 89 videos), it must have been a pretty good jury, indeed, that did the rigging.  The images are surprisingly clear, and I am being able to see all that I want/need to see.  Not only that, but I also am getting enough instances of the polyps capturing prey that I should be able to do some pretty good statistics about the process.  Of course, the caveat at this time, is that I have only examined in detail those captures at the 2 cm/sec current velocity.  I still have 4 cm/sec (which I will start looking at today), 8 cm/sec, 16 cm/sec, 24 cm/sec and 32 cm/sec.  However, given that I used the same technique to make videos for all of them, I don’t a priori see any reason why I should not be getting good images from those speeds.

Incidentally, I took a lot of trial recordings at the 24 cm/sec current conditions before I took the slower ones, and made sure the video techniques worked for those higher velocities.  So… I really don’t foresee any problems with the videos, themselves. 

Of course, the videos may show that my hypothesis is not valid – but, I think if that is the case, they will show that clearly and unambiguously. :-)

I am pushing to get these videos to be looked at ASAP, so that I can start on the statistics and subsequently the writing of the final articles – including my presentation at MACNA 2010.    However, the most important target is one or more articles for the peer-reviewed professional press.  I think it will be a real coup to be able to publish something in a good journal, and to be able to say in the Acknowledgements section that the work was NOT done at any university and was NOT supported by any federal $$$.  

I will not post any of the actual feeding videos for the time being.  I haven’t yet discovered a way to internally label the videos, and without some things like ”arrows” to point out what is happening, they don’t seem to show much.   If I find the time to dissect a movie and put labels and titles in it, I will defiitely post it.

Facebook

I have  deleted my facebook account.  I am not really sure what I expected when I set up an account there a year or so ago, but whatever it was, didn’t happen.  It didn’t develop into something that I found useful or terribly enjoyable, so given the probems with Facebook’s privacy issues, etc., it seemed prudent to bail.   If anybody who reads this, also was a Facebook “friend,”  – -  Well… Sorry about that.   Really, the bottom line is that I guess I am simply too antisocial for the facebook milieu.

Just a short note this morning, so until later…

Cheers!!!!

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Pre-Iridiana, A Found World

April 25th, 2010

Early in the last century Sir Arthur Conan Doyle wrote about Professor Challenger, a “scientist” who found bits and snatches of the world of dinosaurs still living, most famously, on plateaux in the Amazonian jungle. There he found living pterosaurs, dinosaurs,  and all manners of strange and wonderfully monstrous animals. Alas – maybe – the animals that Doyle wrote about vanished from the living world in the aftermath of an impact of a rather small asteroid with the Earth, some 65.5 million years ago. During the vast span of intervening years, the Earth has changed. Very dramatically!! The world of the dinosaurs really was not the world of man, but it has only been in the last couple of decades have we been truly able to realize how different these two worlds were from one another.

Until recently, except for the foolishness of the massive floods and perfect gardens found in some of the religious mythologies of the world, if people thought about what the world was like in the distant past, they visualized it pretty much as the world they saw around themselves.   As a scientific viewpoint developed in the nineteenth century, particularly within the basic science of geology, there were many acrimonious debates between those individuals who contended that all changes were gradual and based on the same or similar processes as were seen in action today, the uniformitarianists, and the catastrophists, who contended that many calamitous changes, mostly floods of a truly biblical nature, radically altered and changed both the landscape and the life on it. By the beginning of the 20th century, the catastrophists were pretty much considered to be all wet, and uniformitarianism carried the day, the week, the month, the year, the decade, the generation… but not quite the century.

By the beginning of the 21st century, thanks to some brilliant insight, and a lot of hard work, it had become clear that although the world’s environments had stayed rather consistent for long periods, there have been times of drastic change, after which literally everything, from climate to biota, changed. For most folks, the most notable of those drastic changes was the one that ended the domination of the world’s bioata by the larger non-avian dinosaurs, the Cretaceous epoch, about 65.5 million years ago. Although, by far and away, not the largest of these mass extinction events,  the devestating changes triggered by the impact of a small asteroid off shore of the northern presumptive Yucatan peninsula were damaging enough;  resulting in wholesale changes in the Earth’s biota, virtually every large terrestrial animal species went extinct, along with many marine species.  Subsequent changes in the Earth’s climate resulted in today’s world; a much different globe than that the larger dinosaurs dominated.

Although this event, the Cretaceous/Tertiary Mass Extinction, closed the door on the non-avian dinosaurs, it allowed mammals, more-or-less by default, to adaptively radiate and come to dominate the world.  Nonetheless, the extinction event, while it changed the biota, did not wipe away the evidence of the world that had existed.  That world holds, for many people, particularly evolutionarily oriented biologists, a fascination due the awesomely different biosphere that was present.  

About a month ago, I received as a gift, the book titled, The Cretaceous World, by Peter Skeleton and his coauthors. Over the last few weeks I have been enjoying learning about that long gone world. Very well-written, and exceptionally well-illustrated, the book is designed as a text, but unlike many texts, this one is as alive as the inhabitants of the world it describes are not. Pulling together geological, oceanographic, and biological data, much of it gathered in the last few years, the authors create a world that is awesome in its differences from the present one. From discussing in detail forests at the latitude of Pt. Barrow, Alaska, to describing ferocious storms in the central Tethys seaway, along with the immense deserts of the equatorial latitudes, the authors take the reader on a memorable mental tour of a long-lost world.

I have so enjoyed this book that I want to tell people about it.  In a way, it is the most wonderful type of science fiction, although I am certain the authors would not appreciate that description.  However, they describe in detail a world that changed over the 80 million year history of the Cretaceous, a world based on very hard, and very good science, and have assisted the reader to clothe this world with their mental images.  We really will never know what the Cretaceous world looked like, nor will we ever find out much about the vast majority of the animals that lived there (because they were invertebrates and didn’t fossilize), but we have a good basis for knowing the world itself.  So, what we see in our mind’s eye may be “science fictional,” but it is the hardest of science fiction, that based on and consistent with all the facts.  This world would not be the benign, kind and friendly world of  Jurassic Park.  Humans in the Cretaceous would find the climate oppressive, the flora unfamiliar, the oceans utterly strange, and full of dangerous reptilian predators, although those are not discussed in the book.  And, in general, the megafauna positively frightening and exceedingly dangerous; Cretaceous Park would be a great place for a well-prepared scientist to visit, but you really wouldn’t want to live there. 

The animal life, however interesting, is not the center of the discussion.  While putting the story together for their students, the authors have really given the rest of us a rare glimpse of an alien World, from a geologist’s perspective.   We become aware of the almost familiar orientation of the continents,  but the huge oceanic areas render the land masses of those continents much smaller than what is experienced today.  While the continents are tectonically moving, they haven’t – yet – encountered each other in the massive collisions that have characterized the last 50 million years.  There are not a lot of impressive mountains.  Lots of hills, to be sure, but nothing like the Himalayan plateau, and the Alps are in the future as well.   Coral reefs are the dream of the cnidarians’ future, but – Wow!, this is the world of the Clamrades!  There are huge expances of clam beds comprised of, in many cases, huge clams.  What most geologists don’t really seem to flash on, the author’s of this tome missed it as well, is the amount of biomass that must have existed planktonically in the shallow seas.  These seas were not the clear blue seas of today’s coral reefs, they were gorpy, green, and thick with life.  The huge carbonate “platforms” of the Cretaceous had to feed on something, and clams have a lot higher metabolic rate than do corals. 

And the temperatures!  Baby, it’s hot out there!!!  Diving in the shallow equatorial seas would kill a scuba diver.  There would be no way to dump the body’s excess heat, and any exertion at all would be lethal.  Rather like diving in the hottest extremes of the Persian Gulf today, one could not spend a lot of time in those oceans.  One probably wouldn’t want to, though, as humans could have been considered to a good snack for some of the mosasaurs and other swimming arrays of teeth; LARGE swimming arrays of teeth, that dominated those seas. 

The  Cretaceous world that the authors describe in detail, really for the first time, is in effect, like an extrasolar world, only one that is 65.5 million light years away in space and time.  This world would be a great star of documentaries, although you couldn’t pay me enough to go film the action; nonetheless, I would love to see it.

Enjoy the book and learn about a wholly new place, the Olde Earth.

Until later, 

Cheers!

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Diodogorgia Research Progress!!

April 18th, 2010

Finally!!  After about two years of somewhat diligent work (slowed by bouts of various illnesses), I have finished the primary editing of all of the movies I have made during the experimental flow chamber phases of my Diodogorgia nodulifera research.  That means I examined about 970 files, including over 32 Gbytes of movies.  Next, – and probably within a week – I will start actually quantitatively looking at the movies and enumerating how the animals feed in various current regimes and various velocities.

 Artemia Entrapment And Capture Slowed Down

In this movie, watch how a Artemia, or brine shrimp, nauplius is captured and eaten by a single polyp of a small Diodogorgia colony.  The movie’s speed is slowed to only 1/4th normal, so that the food capture will be clearly visible.  Note how the tenacles move.  Note the motion of other particles in the water flow.  And realize when you look at this that each polyp under natural conditions probably has to consume between 4 and 10 naupliar-sized objects each day-every day to survive.

The above movie gives an idea of what I will be seeing with all of these movies, albeit it is a bit clearer than most of the actual research footage.  I will watch where the Artemia (baby brine shrimp – the small orange blob in the movie) enters the polyp’s crown of tentacles, and where it implacts the tentacle(s) that it hits.  Then I will also watch what the tentacle does and the trajectory of the nauplius.  Finally, I will note whether or not the nauplius is eaten.

Then I will compare similar actions across all current velocities tested: 2 cm, 4 cm, 8 cm, 16 cm, 24 cm and 32 cm per second, in both laminar flow and turbulent flow.  I expect to be able to describe the most efficient means of food capture by the gorgonian.  Then I will be able to propose a protocol to maintain these animals – and perhaps some other azooxanthellate soft corals –  in an aquarium.  Also, such information will be useful in determining the animals food under natural conditions.

The enumeration should go pretty rapidly, he says… probably foolishly.  In any case I hope to have a lot, if not all, of these data gathered by late summer so that  I may use these data for my talk at MACNA 2010, in Orlando, this coming September.

Until next time,

Cheers, Ron

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It Happened One Night

April 3rd, 2010
    
It Happened One Night…2nd Edition.

This is the second version of this essay, the first one was destroyed when my blog had to be wiped as a result of being hacked, see the previous post for details.  I did not keep a record of the images that I had placed in the previous version, so if you read the previous version and had a favorite image, and it is not here, please contact me and I will see what I can do about inserting it. 

A couple of squid near the breeding assemblage

About 25 years ago I was teaching Marine Invertebrate Zoology at the Bamfield Marine Station (the name has been since changed to the Bamfield Marine Science Centre), a university-run marine teaching and research laboratory facility.  This facility is located on the shores of Bamfield Inlet, a small embayment on the south side of Barkley Sound near the southwest corner of Vancouver Island.  That particular year the course ran from late April until early June and was supposed to be a total immersion course – the students lived, breathed, ate, slept, and dreamed about invertebrates.  In this year, by late May, I was casting around for something of special interest for the students to work on, something above and beyond the “standard” course offerings.   

For about a week, we had been seeing a few squids swimming near the water’s surface next to the dock.  This was unusual, so I decided to go diving and see if I could see what they were up to.  These animals were Loligo opalescens, the “Pacific Market Squid” harvested in huge numbers near Monterey, California for calamari.  At the time, the southern populations were pretty well known, but not much was known about the northern populations. The local lore was that the squids, occasionally, would spawn in the inlet.  If spawning was to occur, I thought it would be nice to document this for a couple of reasons.  First – it would be ultimately cool to be in a squid spawning aggregation.  Second – I thought I might get some nice images that I could use in lectures.  Third – I thought I might be able to interest a few of the students in doing some actual research on some small aspect of the spawning.  All-in-all, if I could carry it off, it would be a win-win-win situation.  The only problem was trying to predict when the  animals would spawn, and then coming up with a scientifically valid short research project.   

Prior to this one particular morning, we had been seeing a few scattered squids near the surface in the inlet.  These surface-swimming animals were fully-grown, about 30 cm (1 foot) long, and bright white, so they were quite evident in the dark water of the inlet.  About 10 o’clock, after my lecture for the day was over, I wandered down to the dock, and noticed that the squids were present in larger than “normal” shoals, maybe up to 30 to 50 animals in each fast moving school, so I thought this would be worth a look.  I asked around and found a dive partner and dock tender, and we plopped ourselves in the water about 30 minutes after 10 AM.  To document our dive, I took along my underwater camera system, which consisted of an Olympus OM-2 in an Ikelite housing, with two strobes attached; one triggered by the camera and the other slaved to the first one.  The film was Kodachrome-64, my film of choice for underwater photography.  

Solitary Loligo opalescens

Dropping down to the bottom, at a depth of about 17m to 18 m (55-60 ft), we found a small mass of squids in a frenzy of activity.  As a result, I started my personal frenzy of activity taking some images.  It soon became evident that a couple of individuals were spawning, but that most of the animals were just “interested” observers, squid voyeurs, I guess.  I documented a solitary female spawning and depositing her egg capsules.  I presumed copulation had already taken place, as I saw no obvious mating activity.  I had seen movies of some squid spawning aggregations, and it was obvious that what we were watching was not a normal spawning event.  However, I thought it might be a precursor to the “real” action.       

Solitary Female Loligo opalescens Spawning. Note The Extruded Egg Capsule Between Her Arms.

Solitary Female Ovipositing. Note Egg Capsule Between Her Arms.

Same Individual As In The Previous Figure. Note The Egg Capsule.

Egg Capsules Deposited By The Single Female Over The Course Of Her Spawning

Egg Capsules Produced By The Single Female Over The Course Of Her Spawning.,

For about a week the people of the village of Bamfield had been catching squid by jigging for them near the government-owned docks in town.  So, after seeing the events off of the laboratory dock, I thought that there might be a small mass spawning event occurring near the dock in the upcoming evening.  It would be a “small” event simply because the area was constrained.  The inlet was not wide and was relatively shallow, about 18 m (60 ft) deep at its maximum in that area.  I arranged for another dive buddy and boat tender and we went down to the town docks about 10:30 pm to do our dive.  As usual, I took my camera system along to document interesting “happenings.”   

When we arrived at the scene, the fishermen already there said that jigging was “slow.”  Squids were visible, but sparse, and not many had come into the area where the fishermen were.  To avoid upsetting the fishermen, we dove well away from them.  This also prevented us from being “jigged.”  Having a sharp squid jig tear open and flood one’s (very) expensive dry suit can really ruin the experience of the moment!   

When we first got into the water, few Loligo were around, but within a couple of minutes they started to aggregate around us, probably attracted by our diving lights, and the large pile of rocks on the bottom nearby.  At first there were just a few solitary individuals, then a few doublets, and then quartets, and then … large groups; Too large and too fast to count.  All of a sudden the action began.   

Although the spawning aggregation appeared terribly chaotic, with thousands – yes, thousands – of Loligo jetting around from all directions and bumping into each other and us, after a bit of observation, it became clear that what appeared to be an unruly affair was really quite well “choreographed.” 

From the outside in…   

The animals approached the spawning site alone or in small groups of up to about ten individuals.  As they approached they had normal coloration; brown to reddish brown tones predominated on the bodies and the arms’ outer surfaces.    

A Squid Pair Above The Main Spawning Site

A Quartet Of Squid Approaching The Spawning Site.

At the outermost region of the spawning site, about 5 to 6 m (15 to 20 feet) above it, the individuals were actively fighting with one another to find a mate.  Females were “attacked” by males that wished to mate with them, and often two or more males fought each other for each female.  This was a brutal, winner-take-all, competition!  Skin was ripped off and the combatants used their beaks to rip pieces of flesh from their opponents.  The females were NOT passive participants in this rough foreplay; they were actively fighting as well.  Presumably, the strongest, most fit male prevailed.  During this activity, both males and females were white.  They did not flash or change colors.   

Mating/Foreplay Damage Making the mate choice - maybe... Lots of action here.

Foreplay - but getting near the final choice of mates. Note the bite damage on the male (lower animal).

Precopulation - "Foreplay" - Two Males and One Female

Loligo opalescens foreplay or copulation well above the egg deposition site

 As the combat continued, the participants got closer and closer to the bottom, and eventually one male prevailed.  He got into the oviposition position; holding the female from behind and below, with his eight arms wrapped around her.  Copulation, the transfer of a spermatophore (sperm packet) from the male to the female, occurred once this posture was stabilized.  The animals were now about 3 m (10 feet) above the bottom.  Once he was securely holding his mate, the male’s color pattern changed from pure white all over, to having a white body and reddish-brown tentacles.  The female remained totally white.  Once this color pattern was established all other males avoided the pair, and ceased jostling the resident male for possession of his female.  I suspect the color pattern change was THE signal that mating had occurred and that this particular female was no longer available.   

Mated Pairs Depositing Egg Capsules.

After the male’s color changed, he did all of the subsequent swimming for the pair.  He moved the female to the oviposition site and began to push her into the mass of egg capsules that were already at the site.  As they approached the site, the female extruded and formed an egg capsule which was held in her arms.  Once the male pushed her into the egg capsule mass, or onto any other acceptable area, the female wrapped the distal, adhesive and ropelike, end of the egg capsule around anything, such as other egg capsules, a sunken twig, a rock, a diver’s mask strap, which would hold it in place.   

The egg deposition frenzy, overall there were hundreds of pairs of squid at this one small site.

Egg Capsule Deposition

Frenzied action a couple of meters above the main egg capsule mass

Spawning pairs and the main egg capsule mass.

  When first formed, these egg capsules were about the size of one’s little finger, but they became larger as they absorb water.  From subsequent studies, part of the project we later did, I found that each egg capsule in this region contained about 150 eggs, sequestered within a series of protective – and toxic – membranous coverings.  I was unable to count the number of egg capsules produced by any specific single female, the situation was just too chaotic for that.  In the California areas other studies found that each female produced about 20 capsules.  If the same number was produced by these northern Loligo, each female would deposit about 3000 eggs in her one night stand.  

Newly deposited egg capsules

Egg Masses The Day After Spawning. The Masses Are About A Meter Thick.

After the final capsule was deposited, the male released the female and they both slowly departed the area.  The males seemed to be a bit more active and I surmised that at least some of them might try to mate again, as each one produces numerous spermatophores, and they only use one per female.  However, the action was so frenzied that I was unable to follow any given squid more than a few seconds, so it is possible that one shot was all the males had.  The females appeared to be totally spent; they swam erratically and weakly.  They often travelled only a short distance prior to settling to the bottom and dying.  The males probably swam a few more hours, at best, but they, too, don’t survive long.  Individuals of both genders are badly injured by the experience.   

New Egg Capsules, The Day After Deposition, My Dive Partner For Scale.

During the flurry of spawning activity predators made their appearance.  In the area where I was diving these predators were seals and California sea lions which would come blasting through the spawning masses biting up squid as they went.  Fortunately, they decided big ugly divers in rubber suits didn’t match their search image of calamari.  In other areas, larger sharks, such as blue sharks, will also come into the spawning squid schools, but, blissfully, I didn’t see any of those in the aggregations I dove in. 

After the spawning was over, the bottom was littered with egg capsule masses and dead or dying squid.  Over the week following the spawning, some of my associates and students and I did some diving to make measurements of the squid egg masses.  Scattered all over the bottom, from just below lowest low water to beyond diver depth, were small individual egg capsule aggregations.  Each of these covered about 0.3 square meters, (about 3 square feet) and there were about 1.3 of them per square meter (10 square feet).  I collected some of these aggregations, and found that each contained, on the average, about 1,940 capsules.  Each capsule contained about 150 eggs, meaning each capsule mass was the result of 194 squid pairs, and contained 291,000 eggs.   

Dead squid the morning after the spawning event.

Mass of dead squid, the morning after.

 We did diving surveys to determine the extent of the night’s spawning activity.  This particular night’s spawning aggregation extended along about 11 km (7 miles) of the southern edge of Barkley sound.  The largest egg mass we found in a quantitative survey area was 69 square meters or 742 square feet, however, we saw some much larger egg masses.  Unfortunately, these were seen during the spot surveys for determining the whole area covered by the spawning aggregation, and we could not return to them.  We estimated the largest measured spawning aggregation was result of 24,000 spawning pairs of Loligo, and based our quantitative measurements of small egg mass abundance we estimated that during that one night of spawning, in the Bamfield area, over 64,000,000 squids spawned!   

Urticina corieaca, a sand dwelling anemone, and squid corpses. It normally would eat squid, but was sated the next morning.

 Loligo opalescens eggs take about six weeks to hatch in that region, and some of the egg masses were followed for that length of time.  After hatching, the remnants of the membranous egg coverings were still noticeable on the bottom for another several weeks in places.  As long as the egg capsule membranes were intact, nothing was seen eating the eggs.  Stupidly, I did not wear gloves during my initial examination of the egg capsules and the eggs when I was tearing and cutting open the egg capsule membranes.  After a few minutes of handling the membranes my fingers lost feeling, and a few minutes after that my hands became numb and immobile.  The area of numbness continued to expand until finally my arms became numb up to the elbows.  It took about 2 to 3 hours before the feeling slowly returned to my arms and hands.  Obviously, whatever is in the membranes would be effective at deterring predation.  In over 100 diver hours of examining the capsule masses, no animals were seen eating the eggs, although we saw many animals positioned on or in the masses.  If egg capsules were torn or cut open underwater, red rock crab individuals, Cancer productus, rapidly approached and started eating the eggs or developing embryos, further illustrating the protective function of the capsular membranes.  The long decay period for the membranes after the squids had hatched also indicated that the membranes contained either or both antifungal and antibacterial agents.   

A sunflower star, Pycnopodia helianthoides, on an egg capsule mass. The star was not eating them.

Old egg capsules, near hatching. They absorb water and are about three times the size they were when deposited.

During the several weeks it takes them to hatch, other animals in the area seem to consider the toxic egg capsules as "just part of the habitat."

 Reference:   

Shimek, R. L., D. Fyfe, L. Ramsey, A. Bergey, J. Elliott, and S. Guy.  1984.  A note on the spawning of the north Pacific market squid Loligo opalescens(Berry, 1911) in Barkley Sound, Vancouver Island, Canada.  Fishery Bulletin.  82:445-446.   

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