Archive for July, 2010


Thursday, 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…


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…


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.

Good Stuff

Saturday, 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.


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,



Friday, 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,