Termite Symbionts


Richard Howey's HomePage

This page is devoted to a few of the most bizarre micro-critters in the micro-world.  These are protists which live in the gut of termites and without which the termite would starve to death.  Termites can't digest cellulose and so are dependent upon the organisms in their intestines to digest wood particles and transform them into sugars and starches which the termites can metabolize. These extraordinary creatures have not been thoroughly studied and there are still a significant number of undescribed species. Here is a sampling with a few comments about some of their structure.

 This organism is Trichonympha campanula and is one of the more common and best studied denizens of the termite gut. We'll take a closer look at its structural detail a bit later. For the moment, notice that it is clearly a complex micro-organism with long flagella covering most of the surface, a distinct nucleus, and a structure at the anterior end called the rostrum.

 This one is named Streblomastix strix and is, as you can see, very different from Trichonympha. Perhaps the most remarkable feature of Streblomastix is the extraordinarily long flagella. Below are two additional views.

In addition to the long flagella, the body is spirally striated and quite elastic and contractile as you can see when you compare the middle picture with the other two. 

Another intriguing symbiont has an undulating membrane and when active it looks almost like a miniature chainsaw. 

This is Trichomitopsis.  Below is another view.

All of the larger flagellates which I examined appeared to have a striated membrane which is evident in both images. In the top image, you can see, on the right, some of the flagella which are distinctly shorter than in the other two organisms we've considered.

The next three images are of organisms which I was not able to identify definitively.

This organism almost certainly belongs to the Hypermastigida given the exceptionally large number of flagella. 

Notice that on this specimen, although the flagella are very numerous, they are considerably shorter than those in the other examples we looked at.

This one appears to have groups of flagella which are arranged in tufts.

Now let's take a closer look at some of the features of Trichnympha.

Here we get a clear view of the ovoid macronucleus which is approximately in the center of the organism. 

This image clearly shows the nucleus, the striated character of the membrane and the rostrum or "cap" at the anterior end.  

Yet another view.  Notice at the posterior end, to the left, there is clear space surrounding the "body".

    Returning to the first image with which we started this page, I want to point out a few more details.  Note once again, the clear area at the posterior end.  This is of special importance, because it is here that feeding takes place. If we look at the previous image which shows the detail of the rostrum, there is nothing there that suggests a cytosome (mouth). Trichonympha feeds by engulfing wood particles through this clear space by forming structures rather like pseudopodia. In the image above this one, you can see the irregularity of shape of this portion of the membrane. In the image immediately above, you will also be able to see that this area is free of flagella. In the previous image, it appears that there are flagella there, but these are simply very long ones extending down and they are, in fact, "anchored" higher up on the membrane. 

    The yellowish particles in the lower half of the organism are wood particles and are extremely numerous, packing up the entire lower half of the body.