by Richard L. Howey, Wyoming, USA
Can you believe that anybody would actually pay money for termites? Well, I did, and I’m very glad that I did. Mind you, it wasn’t the termites per se that enchanted me into making this bizarre purchase—although they are indeed intriguing in their own right—no, it was the extraordinary protist fauna living in the gut of the termites that motivated this particularly outlandish acquisition. Yes, Virginia, you can buy termites from biological supply houses. People ask me: “What do you want with termites?” and after I patiently explain, they look at me as though I were mildly retarded and give me the inevitable caution: “Well, don’t let them loose in your house!”
These strange beasties are among the most complex protists around anywhere. They used to be classified as flagellated protozoa, but with the new revolution in taxonomy, they are doubtless undulipodiated protoctista scattered around several phyla, but more of that on some other occasion. These creatures are symbionts and parasites and the symbionts are essential for the survival of four of the five families of termites and also for certain of the woodroaches. Over the years, I have seen photographs and drawings of these organisms, but I decided it was finally time to have a look for myself.
The most evident organism in the specimens I have is Trichonympha; it is a large (about 200 to 300 microns) hypermastigote, which means it is one of the long-haired hippies of the protist world.
Figure 1. Trichonympha campanula. Here you can get a good sense of the general body construction. Note the arrangement of the flagella and their abundance. At the anterior end, the rostrum is clearly visible and in the mid-section, you can see the distinctive nucleus with its “halo”. In the posterior section, one can see wood particles with a slight birefringent effect from the Nomarski DIC.
The anterior end consists of a sort of “nose cone” called a rostrum, which has long, abundant flagella. The midsection is wider and has an abundance of medium length flagella which get very long at the end of the midsection and extend beyond the posterior end which is a wide blunt extension without flagella and which is soft and sticky. It is here that the ingestion of wood particles takes place! You’ve all heard of an upside-down cake; well, this is an upside-down critter. It “feeds” at the posterior end, but its morphology, arrangement of flagella, and hydrodynamics, dictate that the rostrum leads the procession when Trichonympha is swimming. However, getting a general sense of its shape is no easy, obvious task, since it possesses a highly flexible membrane which allows it to behave like a contortionist, especially under a cover glass. So, the situation is this: Trichonympha is a large, highly flexible, very active multi-flagellate of odd construction, which under a cover glass, presents the observer with multiple views, some of which it is hard to believe are really perspectives of Trichonympha.
Figure 2. Close-up of T.campanula. Here the rostrum and the flagellar arrangement are even clearer.
Figure 3. This is an image which I like, even in spite of the illumination problems, because it show 3 different views of Trichonympha campanula, giving a hint of its protean character.
Its relationship to the termite is intriguing. The particular termite I obtained is Zootermopsis sp. The Trichonympha must have wood, since this is its source of carbon; Zootermopsis must have Trichonympha living in its gut, since it cannot digest wood (cellulose), so this fascinating interdependence has developed. Trichonympha ,and other symbionts in termites and woodroaches, produces the enzyme cellulase which “digests” cellulose. In this process, sugar and starch by-products are produced by the flagellates which the termites can then metabolize. I have done some video-taping of Trichonympha as well as capturing some digital still images, but I feel I have barely scratched the surface in examining these creatures. I have tried to preserve a few in glutaraldehyde as well [CAUTION: Poisonous and a potential carcinogen]. In the meantime, I have been carefully feeding and watering my termites, so that I can continue my examinations.
A second, and also highly intriguing, organism found in Zootermopsis is probably Trichomitopsis termopsidis. (The biological supply house had it listed as another genus which seemed unlikely and on contacting them, I was informed that this had been a matter of heated discussion and that probably my designation was correct.) It is considerably smaller than Trichonympha and averages about 30 to 120 microns and like Trichonympha is very active. I haven’t yet had the time or the means to carefully examine this organism, but I suspect that it has a series of small undulating membranes which spiral down the length of the body which, combined with its odd locomotion, give it the appearance of a miniature chainsaw as it swims.
Figure 4. Trichomitopsis termopsidis. This is the organism which I described as looking like a miniature chainsaw. It is very active, moving not only horizontally, but in a vertical plane as well, making it difficult to photograph. Although this image is rather blurry, you can see the membrane formed along the flagella.
Figure 5. Another image of T. termopsidis.
It also seems to have an axostyle, but to determine that will require further observation. Both Trichomitopsis and Trichonympha require cellulose for their survival.
In this intestinal jungle, there are many other very small protists zipping around and, of course, there is an active bacterial population as well. Another sizeable, distinctive, elusive, and bizarre polymastigote which is to be found is Streblomastix strix (which could also be the name of a punk rock band).
Figure 6. Streblomastix strix. This is a real challenge to photograph since, not only is it highly active, highly contractile, and flexible, it also has an uncanny knack for not being in the right position whenever one tries to photograph it. As you can see, the anterior end is tubular and it attaches to the intestinal wall of the termite. There are spiral ridges down the body which are not visible here. The length of the flagella is remarkable as can be seen in this image.
Figure 7. Another image of S. strix.
Polymastigotes, as against hypermastigotes like Trichonympha, can be thought of as middle-aged hippies who are going bald, but what tresses survive are waist-length or longer. In other words, polymastigotes have distinct bundles of long flagella, but are not covered with them. This creature is going to require a lot of work to study. It is very active, elastic, and so highly contractile that it can extend by a factor of 10 from about 30 microns in length to over 300 microns! This organism does not digest cellulose, so one wonders what it’s doing in this environment. The answer seems to lie in a tube-like extension at the anterior end which has a special apparatus for attaching itself to the gut wall of the termite. Since they occur in rather large numbers, it seems likely that they are a relatively benign parasite. At first Trichonympha and Trichomitopsis were so absorbing that I didn’t notice Streblomastix, but when I did, I was quite taken with it, as the flagella are in a very long bundle, but they are also rather difficult to see in the living organism.
I suspect that there are many insects which harbor an unusual fauna in their intestines and relatively few have been studied with this in mind. However, the woodroaches, termites, and even some cockroaches present a group of micro-environments of extraordinary complexity, both in their own right as environments and in terms of the diversity and intricacy of the organisms which inhabit them. Eric Gravé has a section devoted to these organisms in woodroaches and termites in his wonderful little book Discover the Invisible: A Naturalist’s Guide to Using theMicroscope. He has some very interesting photomicrographs illustrating that many of these organisms are still unidentified.
The Grisly Preparation Of The Flagellates For Observation
This is not an exercise for the faint-of-heart and while it may seem rather brutal to some, I hope no one will be inclined to initiate a movement for termite rights. I open the jar in which the termites are housed and, using a small pair of mosquito hemostats, seize a specimen firmly just behind the head, move it to a Syracuse watch glass into a small pool of insect saline and using a very sharp scalpel, behead the termite. This insures that this critter won’t be feasting on my furniture. Termites make a fascinating subject for the study of biomechanical behavior. Even after decapitation and disembowelment (yes, that’s that next step), various muscle and nerve bundles continue to function and I have come back, after over an hour, to find the antennae still moving on the head and muscular contraction in the separated intestine. (This does make one have second thoughts about the guillotine!)
After the beheading, I take a pair of forceps to hold the thorax and use a dissecting needle to pull out and puncture the gut to release the symbiotic (and parasitic) flagellates, spirochetes (and according to Gravé—micro-fungi). This is why it is crucial to carry out this procedure in insect saline—namely, in order to create as hospitable an environment as possible for the flagellates. Insect saline is easily prepared and consists simply of a 0.6 % solution of ordinary table salt (NaCl) and it is best to use non-iodized salt. Place a drop of saline on a clean slide and then transfer some of the flagellates (you will be surprised at their abundance) from the watch glass. Add a cover slip and you’re ready for a remarkable adventure.
After seeing the extraordinary intestinal flagellates, you may decide that you would like to have a supply of termites to allow you to study them for more than a week or so. My original sample came in a plastic jar with holes punched in the metal lid and through the heavy paper liner. There was also a circle of fine mesh netting slightly larger than the diameter of the jar and the lid screws down over it as an extra precaution. The jar contains small bits of wood and some crumpled paper, providing food for the termites and also allowing them to have a primitive “nest”. I strongly recommend using a sturdy transparent plastic jar rather than a glass one, because if you drop a glass one on the floor or accidentally knock it against the wrong surface, it may break and termites can move very quickly. So then, you’ll have to call an exterminator and your spouse might just put you on the list of pests he or she wants eliminated from the house.
So, I took a plastic jar of the same general size, punched holes in the metal lid and through the cap liner, put in some bits of wood, some crumpled bits of paper and added 2 or 3 cc. of artesian water. If you use wood from your lumber pile, make sure it hasn’t been treated to protect it against things like fungi and termites. The best is to take some bits of a decaying log or lacking that some old wood shavings. As far as paper is concerned, the cheaper the better, but don’t use news print. News print not only has the problem of inks, but has clearly been treated with special chemicals to make the inks come off on your hands and clothes with the slightest contact, making you look as though you had just been shoveling coal. I tear off some small pieces from a cheap tablet, the paper of which has had minimal chemical treatment, crumple them up and place them in along with the wood chips so that the jar is about half full. Then I moisten the paper and wood slightly and am ready to make the transfer. This part of the procedure, I carry out on the cement driveway, so that if a termite does manage to escape, I can manage either to retrieve it or stomp it. So far, none have escaped and I transfer some of the paper from the old jar to the new one along with about half of the termites. Instead of fine mesh netting, I cut a circle of kitchen cheesecloth as a cover under the lid. If you use a lid with a liner, you must be sure that each time you replace it, the air holes in the metal cap and the liner are aligned or simply take a dissecting needle and run it through the 6 or 8 holes each time. It is important to insure an adequate supply of air and moisture, so every 2 or 3 days, I add a bit of water to the jars with a Pasteur pipet. I did this subculturing after about a week and a half, hoping to keep them going for another week until my friend and fellow microscopist from a neighboring city could get over to see the flagellates. In the end, I managed to keep them going for about 3 months.
My thanks again to my fair lady wife, not only for proofreading, but for tolerating termites.
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