The following observations refer specifically to the tank labeled with the following code, top to bottom: Red C, Red L, Blue P, stored in laboratory section 004, Wednesday 11:15. This tank includes pond water from Container # 1 (Tommy Schumpert Pond, Seven Islands Wildlife Refuge, Kelly Lane, Knox Co. Tennessee. Partial shade exposure. Sheet runoff around sink hole. N35 57.256 W83 41.503 947 10/12/2008) with some existing algal plant life, along with Plant B (Utricularia vulgaris L. A flowering, carnivorous plant. Collection from: Greenhouse in White Avenue Biology Annex. The University of Tennessee. 1400 White Ave. Knox Co. Knoxville TN. Partial shade exposure N 35o57' 33.45" W083o55' 42.01". 932 ft 10/13/2008). The associated Blog for this tank, noting more complete observations is available online at <http://microcosmicgod.blogspot.com/ >.
Upon initial observation immediately following tank setup on 15 October 2008, the water appeared quite clouded to the unaided eye, but a wide variety of living organisms were evident under 10X magnification in the binocular compound light microscope. Especially notable upon this first observation were many small flagellates, ciliates and rotifers throughout the tank. Also noted were several apparent insect larvae and one large egg-bearing female Macrocyclops near the plant Utricularia vulgaris, the common bladderwort identified by several bladder-shaped green leaves.
One week later, on 22 October 2008, the tank had lost at least 30% of the original moisture, which was replaced by dropper with distilled water. This observation yielded several desmids, identified by the greenish colors, distinctive rod or “cucumber” shapes and the nuclei at restricta (<http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/index.html>). Another Macrocyclops was sighted, identified as an adult male due to the fully developed appendages and lack of egg sacs (). The Macrocyclops albidus is a copepod crustacean and is discussed in further detail in the following section. Several algae were also noted upon this observation but had not yet been classified.
The third observation on 29 October 2008 occurred five days after a single pellet of Atison’s Betta Food had been added to the tank (McFarland). Most of the previously noted organisms were still present, but several new species were also evident. Of particular note was the ciliated protist Vorticella, several of which were attached by stalks to the stems of Utricularia (Corliss 273). When disrupted by movement, the bell-shaped body of the organism closes quickly and a structure called the myoneme coils the stalk like a spring, making the organism appear much smaller, presumably as a deterrent to predators (<http://www.microscope-microscope.org/applications/pond-critters/protozoans/ciliphora/vorticella.htm>). Also noted were a large number of rapidly moving Paramecium ciliates identified by their cigar shape and peristomata (), as well as a substantial number of new growth crosiers on the carnivorous plant Utricularia.
The following week, on 7 November 2008, a variety of diatoms were noted near the bottom of the tank, identified by their golden and green color and strikingly symmetrical shapes (Raven 275). Also noted was the emergence of a Chlorophyte alga, branching prolifically throughout the tank (Raven 391). In addition, several small areas included Spirogyra, identified by the unique spiral shape of the chloroplasts in thin branching filaments (Forest 89).
On the final day of observation, 14 November 2008, a notable change in plant life had occurred. While Utricularia remained vibrant, the alga Stigeoclonium nanum had become prolific throughout the tank, and many small rotifers and ciliates seemed attracted to its “branches” (Forest 87). Meanwhile, the now plentiful Macrocyclops seemed to favor the protection or environment of Utricularia (both discussed in detail in the following section).
Classification and Results
Special consideration was given in this study to two microorganisms that commonly coexist in nature. Utricularia macrorhiza, the common Bladderwort, and Macrocyclops albidus, the copepod commonly known as Cyclops, are both abundant in freshwater ponds in the southeastern United States, with the Bladderwort regularly supplying shelter for Cyclops (http://www.fcps.edu/islandcreekes/ecology/copepod.html).
Both organisms regularly prey on insect larvae, especially mosquitoes, and have been the subjects of several studies involving their possible uses as natural pesticides in mosquito control in tropical and sub-tropical climates. The Blog associated with the classroom study in this project (<http://microcosmicgod.blogspot.com/ >) includes references and links to an ongoing study at the University of Florida, in which the copepods are cultivated in used tires filled with stagnant water and then studied for their effects on mosquito populations (<http://fmel.ifas.ufl.edu/COPEPODS.HTM>). The Bladderwort, a carnivorous flowering aquatic plant, has also been studied for its possible use in mosquito control, but concern remains among scientists that Utricularia itself may in fact become an uncontrollable genus if intentionally cultivated in areas rich in mosquito larval food sources, because of its widespread rhizomes its and ability to asexually reproduce by fragmentation (Taylor 182). Following are brief discussions about both of these organisms, including taxonomy, life cycles and descriptions. Additional photographs and graphic displays are posted and their sources cited at (<http://microcosmicgod.blogspot.com/ >).
Utricularia vulgaris L.
The taxonomy of Utricularia is somewhat vague, with some dissention among scientists as to the species represented here. In general, however, Utricularia vulgaris and Utricularia macrorhiza are so similar in most respects that they may be considered together for the purposes of this study (Figure 1) ().
DOMAIN
Eukarya
KINGDOM
Plantae, the Plants
PHYLUM
Magnoliophyta (Angiosperms, the Flowering Plants)
CLASS
Magnoliopsida, the Dicotyledons
Subclass Asteridae
ORDER
Scrophulariales
FAMILY
Lentibulariaceae – Bladderwort family
GENUS
Utricularia
SPECIES
Utricularia macrorhiza, Utricularia vulgaris
Figure 1 Utricularia Classification
Collected from the greenhouse at the White Avenue Biology Annex, this carnivorous flowering plant is also known as the common Bladderwort. The plant consists of a network of underwater stems called rhizomes equipped with oval, bladder-shaped leaves (Figures 3, 4). Above the water’s surface, Utricularia produces delicate yellow flowers similar in appearance to snapdragon flowers, and reproduces sexually as a dicot angiosperm (<www.rook.org/earl/bwca/nature/aquatics/utriculariamac.html>). The bladders, long thought to provide floatation for the underwater portions of the plant, actually act as traps for small prey. When the tiny, cilia-like hairs at the bladder opening sense motion, the bladder closes, trapping inside any insect larvae or other small organisms with the misfortune of swimming past. Once the prey is inside, Utricularia secretes enzymes to slowly break down the matter into forms which can be ingested and used as nutrition for the plant. Thus, this carnivorous plant is able to gain nutrients not only through photosynthesis but also through this complicated digestive process. Utricularia reproduces sexually as an Angiosperm (Figure 2), and is additionally able to reproduce asexually through fragmentation.
Figure 2 Life Cycle of Utricularia (Adapted from Angiosperm Life Cycle by Sarah Pena)