************************************************* INSECTS AND MICROORGANISMS ************************************************* ******************************** INSECTS ******************************** __________ QUESTION: Are there any type of bugs or creatures that fly in the air in Antarctica? ANSWER from Diane Stoecker In the area around McMurdo Sound, there aren't any flying insects. However, there are springtails and mites that live under rocks in the dry valleys. Every once in a while, a fly will show up in a building in Antarctica (in three years I've only seen one). The flies must have come on cargo shipped to Antarctica. People gather around the fly and watch it, because it is so unusual in McMurdo to see one. If the fly leaves the building, it dies from the cold almost immediately. At more northern (warmer) parts of Antarctica, such as the Peninsula region, there are some flying insects in the summer. In McMurdo, there is one type of flying bird, skuas, that are only there in the spring and summer. In more northern parts of Antarctica, there are more types of flying birds, including petrels, fulmars, gulls and terns. All the birds depend on the sea for their food. __________ QUESTION: What kind of insects do you have in Antarctica? How do they adapt to the wind and cold, and are they endangered? ANSWER from Michael Castellini on January 26, 1995 Actually, there are no insects on most of the continent. It is simply too cold and there is no place for them to live (it's all ice) and nothing to eat (no plants). On the side of the continent near South America where it is warm enough to rain, there are some small areas of moss, grass, etc. Here you will find some small spiders, mites, etc. But you are right, it is generally much too cold for insects to live in the Antarctic. Best of all, no mosquitoes! ****************************************** MICROORGANISMS ****************************************** ************************ BACTERIA (ANAEROBIC) ************************ __________ QUESTION: Since Martian soil in the area of the Viking landings is very chemically reactive and inhibits the growth of organic compounds, the best chance for any organic growth is in the Martian glaciers. Is there is any anaerobic bacteria in Antarctica, and if so, what type and strain? ANSWER from Diana W. Freckman First, life on Mars could exist in the form of cryptoendolithic rocks, that is rocks that from the outside appear to have no oxygen; but in fact, oxygen does exist inside rocks, as does unicellular algae and a fungusÑi.e., a whole ecosystem within a rock! And there is a lot of work being done on that aspect here in the McMurdo Dry Valleys. Secondly, there are questions about where the Viking sampled and whether the few samples really represent all of Mars. If you have a vast landscape like Mars or the McMurdo Dry Valleys which have been used by NASA as analogs to Mars, where and how do you choose your one or two places out of the vast landscape to sample! Sampling Mars for life is a lot like saying, "Oh, there is California, I will sample 2 places: one the Mojave desert, one in the Sierra Nevada Mountains," and surprise, no people! But, if you had more knowledge about where to look, you might choose your sampling spot as L.A. or Sacramento! My point is that just because Viking only sampled a few places doesn't mean that the whole surface will represent those two samples. If Mars is similar to early Earth, could not bacteria exist by other metabolic pathways than anaerobically? We know from research in the oceans that bacteria have adapted to living in high-sulfur, no oxygen environments. Could this have happened? What about organisms that we know about today, from our studies in the Dry Valleys, that totally shut down their metabolism when the environment becomes toxic/changed? They allÑnematodes, rotifers, tardigrades (all invertebrates)Ñcan exist for many many years, and when the environment changes, they become active, while cryobiotic (frozen life) can exist in liquid nitrogen, in a vacuum. Now to your real question! Certainly there are anaerobic bacteria here, in lakes, in very wet areas with algal mats, etc. I unfortunately cannot tell you their strain or name without doing a literature search, and I am off to the field again. **************************************** PHOTOSYNTHESIS AND THE FOOD CHAIN **************************************** __________ QUESTION: What happens to the food chain for penguins during the long months of mostly darkness? How do the producers photosynthesize in darkness and extreme cold? ANSWER from Diane Stoeker on February 2, 1995 During the Antarctic winter when it is dark, there is no photosynthesis. The "plant"-eating zooplankton live on algae that grew during the summer. Lots of zooplankton also used recycled food, bacteria and detritus from the spring-summer bloom. The zooplankton in turn are eaten by fish. Both the fish and larger zooplankton are eaten by penguins. Also penguins are fat, and store food thay ate during the summer as fat. For example, male Emperor penguins fast for 3-4 months during the winter while they are incubating their egg. They may lose up to 45% of their body weight during this time. For life in the water, temperatures are not very different in winter and in summer, always just at about the freezing point of sea water. But the colder temperatures in winter are a problem for penguins. On land, they often huddle together to conserve heat. *********** PLANKTON *********** __________ QUESTION: How long do most plankton live? ANSWER from Diane Stoecker on December 6, 1995: Plankton includes all the organisms in the water column that can't control their movements against the movement of big waves, strong currents, etc. They go where the water goes. The plankton includes very big organisms, such as jellyfish, which have been known about for a longtime, sailors and fishermen must have noticed them from when people started to go down to the sea. However, most plankton are smaller; the copepods and other animal plankton were a major focus of study in the 1800s. Darwin observed algal and protozoan plankton through a microscope on the voyage of the Beagle in the 1800s. Some of the smaller algal, protozoan and bacterial plankton have only been discovered in the last 10 years! The life span of plankton generally depends on their size. Most of the larger animal plankton live several months, but some may live more than a year. For the one-celled plankton, it isn't possible to give a life span, because they reproduce by dividing in two, so how old is a cell? However, the one-celled plankton divide every few hours to every few days, depending on the species and the growth conditions. *********** PROTOZOA *********** __________ QUESTION: How many if any different forms of protozoa are there on the South Pole? ANSWER: On February 12, 1995 Katy McNitt answered: There are no native protozoa at the South Pole. The only critters here right now are the 28 winterovers, plus any parasites we happen to have living in/on us, plus maybe a slug or two that might have traveled here with our vegetables! The good part about the sterility of this place is that food doesn't spoil so quickly, and we rarely get sick during the year. But next October, when the new crew arrives with all of their new germs, our immune systems might have a hard time adjusting! We call this the "crud," and it's not much fun. *************** TARDIGRADES *************** __________ QUESTION: What is a tardigrade and what microorganisms are researched? ANSWER from Jeff Merrell on January 25: Tardigrades are more commonly known as "water bears." They are microorganisms; however, they are multicellular (like us)Ñnot 'single-celled' like many of the creatures that you can view through a microscope. A tardigrade typically has 4 pairs of short legs which it uses to walk along underwater surfaces like rotting plant debris. Tardigrades also have the amazing ability to 'hibernate' (called cryptobiosis) in which they can survive extreme heat, exposure to highly toxic chemicals, drying out, etc., which would kill an active individual. Some other very interesting microorganisms for you to study are rotifers, choanoflagellates, ciliates, and dinoflagellates. ****************************************** NEMATODES AND PARASITES ****************************************** ********************** PARASITES IN THE ICE ********************** __________ QUESTION: What kind of parasites are in the ice? ANSWER: from Diane Stoecker, Research Scientist, on February 2, 1995 Most of the organisms actually living in the ice are one-celled. There are probably viral and one-celled parasites also, but this hasn't been studied. In the water under the ice, some of the fish and zooplankton have parasites. ANSWER: From Jeff Merrell, Research Scientist, on January 23, 1995 Even though we have looked at microorganisms in the ice using an epiflourescence microscope, we have not detected any parasites. However, that certainly does not mean that parasites don't exist in the ice. Maybe as we learn more about the organisms that live in the ice through continued research, we will begin to find parasites among them. Remember that if nematodes live in Antarctica, anything is possible. ************* NEMATODES ************* __________ QUESTION: How far down does a nematode go in the soil? Does anything eat nematodes? ANSWER: From Jeff Merrell on January 13, 1995 Here are some interesting facts about nematodes. - Nematodes live in the soil as well as within the sediment at the bottom of lakes and even the ocean! They can occur in numbers as high as billions in a clump of soil, and as high as 10 million nematodes per square meter in ocean sediment. - Some things that eat nematodes include: amebas, mites, spiders, certain fungi, worms, and even other nematodes! __________ QUESTION: How much does a nematode weigh? ANSWER from Polly Penhale at McMurdo The average nematode here in the McMurdo Dry Valleys of Antarctica is about 0.6 mm long, 0.03 wide and weighs about 0.55 micrograms.