Waters (141) made a thorough review of stream drift, particularly with regard to insects, in the Annual Review of Entomology (141), providing an excellent survey of the historical development within this special field of running water ecology. This review gives an interpretation of the phenomenon of drift and its function in running water, as well as a presentation of the relevant literature up to 1972. The context in which I take up these problems is one concerning stream drift as a chronobiologic phenomenon. The starting point for this presentation consists of a number of independent studies, performed in various parts of the world, which have shown that stream drift occurs with a diel rhythmic pattern. This finding is based on the extensive investigation of Tanaka (125) in a Japanese stream, Waters (134) in Minnesota, Muller (75) in central Europe, Elliott (23, 25-27, 29, 31, 33) in the British Isles, and Levanidova & Levandov (63, 64) in eastern Siberia. The 24 hr cycle with its continuously changing light-dark periods (depending on the time of year and latitude) causes, directly or indirectly, variations in the physical and chemical factors in running water. It also governs the development and locomotory processes of unicellular algae and the development and behavior of various aquatic invertebrates (including insects) and fish. Stream drift and those activities that underlie it have been found to possess a time-regulated component in running water ecosystems. The above investigations, which have appeared in the last ten years, show that the invertebrates in running water are able to perceive the differentiated day and night length. The duration of activity is positively correlated to the length of the periods of light or darkness.

Stream Drift as a Chronobiological Phenomenon in Running Water Ecosystems

Phytotelmata (Greek phyton + telm = plant + pond) are small bodies of water held by leaves or flowers of plants or in tree holes. Communities containing algae, protozoa, insect larvae, and other aquatic organisms are found in pitcher plant leaves, in leaf axils of the bull rush, Scirpus, and the teasel, Dipsacus, and also in tree holes in temperate latitudes. By far the greatest development of phytotelm community size and diversity, however, is in the wet tropics, where almost all major groups of freshwater organisms are represented. Phytotelmata and their analogs are useful tools in the study of several important ecological processes, especially those of dispersal, colonization, species interaction, and founder effects. These processes combine to produce the community structure and equilibrium number of species. Phytotelmata (including their bottle and beaker analogs) and their communities are useful for investigation of these ecological processes. They are small, numerous, amenable to experimentation, exist in various degrees of isolation, un-. dergo ecological processes rapidly, and are relatively simple but have real ecological significance because they have evolved for a long time. A possible disadvantage is that these communities are considerably simpler than many others and therefore may not display some of the more complex interactions important in the function of some larger communities. Most of the papers concerning phytotelmata resulted from the amazement of finding "hanging aquaria" in the tree tops and from curiosity concerning the kinds of aquatic organisms inhabiting these plant-held waters, and they led to considerable speculation concerning the nature of dispersal mechanisms of the aquatic biota. The taxonomic literature is of secondary importance to the purposes of this paper. In summary, however, the kinds of organisms which are found in phytotelmata include: bacteria, fungi, algae (blue-greens, greens, euglenoids, desmids, diatoms), protozoa (flagellates, amoebae, ciliates), platyhelminths (various turbellaria), rotifers, gastrotrichs, nematodes, oligochaetes,

https://www.jstor.org/stable/info/2096936

Phytotelmata: Biota and Community Structure Determination in Plant-Held Waters

Biofuels made from algae are gaining attention as a domestic source of renewable fuel. However, with current technologies, scaling up production of algal biofuels to meet even 5 percent of U.S. transportation fuel needs could create unsustainable demands for energy, water, and nutrient resources. Continued research and development could yield innovations to address these challenges, but determining if algal biofuel is a viable fuel alternative will involve comparing the environmental, economic and social impacts of algal biofuel production and use to those associated with petroleum-based fuels and other fuel sources. Sustainable Development of Algal Biofuels was produced at the request of the U.S. Department of Energy.

Sustainable Development of Algal Biofuels in the United States

The objective of this investigation was to provide new and more detailed information on the life history and ecology of Neoperla clymene, through an intensive study of the species in the Brazos River, Texas.

/pdf/the-life-history-and-ecology-of-the-stonefly-neoperla-3y4cc0tkib.pdf

The Life History and Ecology of the Stonefly Neoperla clymene (Newman) (Plecoptera: Perlidae)

Given their dormancy capability (long-term resistant stages) and their ability to colonise and reproduce, microscopic aquatic animals have been suggested having cosmopolitan distribution. Their dormant stages may be continuously moved by mobile elements through the entire planet to any suitable habitat, preventing the formation of biogeographical patterns. In this review, I will go through the evidence we have on the most common microscopic aquatic animals, namely nematodes, rotifers, and tardigrades, for each of the assumptions allowing long-distance dispersal (dormancy, viability, and reproduction) and all the evidence we have for transportation, directly from surveys of dispersing stages, and indirectly from the outcome of successful dispersal in biogeographical and phylogeographical studies. The current knowledge reveals biogeographical patterns also for microscopic organisms, with species-specific differences in ecological features that make some taxa indeed cosmopolitan with the potential for long-distance dispersal, but others with restricted geographic distributions.

https://link.springer.com/content/pdf/10.1186/s40462-019-0155-7.pdf

Long-distance passive dispersal in microscopic aquatic animals.

Fifteen of 16 species of aquatic insects studied, including 5 aquatic Hemiptera, 5 caddisflies, 1 stonefly, 2 dobsonflies, and 2 mayflies, were found to be transporting 27 genera of viable small aquatic organisms. Three corixids carried 5 genera of blue-green algae, 11 green algae, 1 yellow-green alga, 2 protozoans, and fungi. Eudorina, representing colonial volvocalean algae, was found for the 1st time on field-exposed aquatic insects. The suitability of the Corixidae and Notonectidae as passive dispersal vehicles for small organisms is discussed. Only 1 of 6 caddisflies studied carried algae and protozoans, but that species, Hydropsyche orris Ross, carried 10 genera. Organisms taken in casual samplings of Plecoptera, Megaloptera, and Ephemeroptera are indicated. Excluding fungi, Chlorella was the most common viable form being carried, followed by Bodo, Nannochloris Chloroccoccum, and Microcystis, in order of frequency of occurrence. Unidentified fungi and Fusarium were carried by more than 75% of the 16 insects sampled and occurred in more than 50% of the 112 culture samples.

Dispersal of Algae, Protozoans, and Fungi by Aquatic Hemiptera, Trichoptera, and Other Aquatic Insects

The relative importance of aquatic and terrestrial beetles as passive overland dispersal vehicles for viable algae and protozoans is elucidated. Twenty-three species of aquatic beetles, representing the families Haliplidae, Dytiscidae, Gyrinidae, and Hydrophylidae, collected aseptically during overland flights, carried 101 different genera of algae, 20 protozoans, 1 rotifer, and unidentified fungal spores and/or mycelia. Of the 204 inoculae (“washings”) made with these beetles, 193 developed populations of algae and/or protozoans. Six of the remainder contained only fungi; only 5 were negative. Sixteen species of terrestrial beetles, representing the families Cicindelidae, Carabidae, Cebrionidae, Meloidae, Scarabaeidae, Trogidae, Cerambycidae, and Curculionidae carried 50 different genera of algae, 15 protozoans, and unidentified rotifers, nematodes, and fungi. Seventy-six of the 93 inoculae developed populations represented by combinations of these organisms. Fifteen inoculae contained only fungi; 2 were negative. The average number of genera of algae and protozoans per individual for all 23 aquatic beetle species was 5.8. The 16 species of terrestrial beetles carried an average of 3.0 genera of algae and protozoa.

Larry E. Milliger

Papers

Dispersal of Algae, Protozoans, and Fungi by Aquatic Hemiptera, Trichoptera, and Other Aquatic Insects

The Passive Dispersal of Viable Algae, Protozoans, and Fungi by Aquatic and Terrestrial Coleoptera