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Tell-Tail Adaptations For Respiration And Rapid Escape In A Freshwater Oligochaete (Lumbriculus Variegatus Mull.), Charles D. Drewes

Journal of the Iowa Academy of Science: JIAS

The aquatic oligochaete, Lumbrimlus variegatus (Order Lumbriculida; Family Lumbriculidae), utilizes a combination of postural and anatomical specializations that enhance gas exchange across the dorsal surface of posterior segments as these segments lay exposed at the air-water interface. Predator avoidance by exposed posterior segments is enhanced by neurobehavioral mechanisms involving a well-developed lateral giant nerve fiber system that mediates rapid escape withdrawal of the worm's tail in response to shadow or mechanosensory stimuli.

Climatic Influences On Annual Variations In Water Transparency In Lake West Okoboji, Roger W. Bachmann

Journal of the Iowa Academy of Science: JIAS

Secchi disk transparencies, chlorophyll a concentrations, and total phosphorus concentrations were studied in Lake West Okoboji, Iowa, in the summers of 1971-7 3 and 1987-89. The average summer Secchi disk transparencies varied from a low of 2.5 to a high of 5.5 m during the study. The variations in the transparency of lake West Okoboji from year to year seem to be related to climatic factors such as the amounts of spring precipitation in the watershed and probably reflect changes in the annual inputs of plant nutrients. There is some indication that climatic conditions that cause the period of deep …

Diatoms (Bacillariophyceae) From The Excelsior Fen-Complex, Dickinson Co., Iowa, With The Description Of Two New Taxa, Charles W. Reimer

Journal of the Iowa Academy of Science: JIAS

This paper presents a summary list of the presently known diatom flora of the Excelsior Fen-complex and a description of two new taxa: Navicula incompta var. incurva Reim. var. nov. and Stauroneis bovbjergii Reim. sp. nov. Notes on some physico-chemical parameters of the habitat and on the ecology of the taxa are included.

Plant Parasitic Fungi Of Four Tallgrass Prairies Of Northern Iowa: Distribution And Prevalence, Lois H. Tiffany, Judy F. Shearer, George Knaphus

Journal of the Iowa Academy of Science: JIAS

Throughout the 1980's, most intensively during the past five years, collections of fungal parasites of prairie plants have been made at various times of the growing season from four prairie preserves, Cayler, Freda Haffner Kettlehole, Hayden, and Stinson prairies, in northern Iowa. A total of 216 species of parasitic fungi were collected on 129 prairie plant hosts. Ninety-nine of the fungi were not previously documented from Iowa. Also, fungus species previously reported were found on 72 host species not included in earlier records.

Index For Volume 97

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Gene Transfer In Crop Improvement - An Introduction And Overview, Robert M. Goodman

Journal of the Iowa Academy of Science: JIAS

The application of recombinant DNA technology to plant breeding promises important applications in agriculture and advances in many plant science disciplines. Gene transfer at the molecular level can be routinely accomplished in an increasing number of plant species. For many of the world's important crops, new methods or refinements of proven methods will be needed and are being developed. Experience with gene regulation in transgenic plants is accumulating in many laboratories around the world. The action of any particular gene cannot be predicted precisely without reference to the genetic background in which it acts, but, qualitatively speaking, the cis-acting elements …

Book Review: Fragile Giants: A Natural History Of The Loess Hills, Kenneth D. Carlander

Journal of the Iowa Academy of Science: JIAS

The Loess Hills, which are a special feature of the eastern bank of the Missouri River in Iowa and northern Missouri, have been cited by Dean Roosa, Iowa's State Ecologist, as a "world treasure and ... our best-kept secret." These Hills are mounds of finely ground soil, "glacial flour," deposited by dust storms after the glaciers receded 31 to 12 thousand years ago. Loess is rather widely distributed in Iowa, but the extensive deposits (often over 200 feet deep) on and against the eastern wall of the valley left a rolling, wave-like, terrain which on erosion leaves vertical banks of …

Characteristics Of Channel Catfish Populations In Streams And Rivers Of Iowa With Varying Habitats, Vaughn L. Paragamian

Journal of the Iowa Academy of Science: JIAS

From 1983 co 1985, more than 1,000 channel catfish (Icatalurus punctatus) were sampled with rotenone from 50 streams and rivers in Iowa to assess differences in population densities, standing stocks, viral statistics, age and growth, and habitat use Catfish densities ranged from 5 fish/ha in sites on the South Skunk and Upper Iowa Rivers to more than 4,400 fish/ha at a site on the Thompson Fork of the Grand River. Standing stocks ranged from a low of 0.1 kg/ha on a site on the South Skunk River to a high of 467 kg/ha on the East Fork of the Des …

A Survey Of The Benthic Macroinvertebrates Of The Big Spring Basin, Iowa, Jack O. Kennedy, John G. Miller Iii

Journal of the Iowa Academy of Science: JIAS

Benthic macroinvertebrates were collected in the Big Spring Basin, located in northeastern Iowa, from May through October 1988. The purpose of the study was to develop baseline information on the benthic organisms present in the basin. A total of 167 taxa including seven species of leeches, five genera of snails, three genera of clams, one crayfish genus and over 150 taxa of aquatic insects were identified with the majority of the organisms having been reported in Iowa previously. Benthic organisms not usually encountered in Iowa include the planarian, Cura formanii; the isopod, Lirceus; the beedes, Enrxhrus, Hydrophilus, and llybius; the …

Computed Normal Range Of Iowa Statewide July Precipitation, H. C. Vaughan, D. S. Sheets, G. R. White

Journal of the Iowa Academy of Science: JIAS

Iowa summer rainfall distributions are examined to identify small-scale anomalies. Examination of extremely wet and dry summer months shows that large rain amounts fall mainly in small, cellular areas for both extremely wet and dry months. These configurations result from individual rainfall events. Analysis of the distribution of mean July rainfall across the state reveals significant anomalous wet and dry regions that contrast with the background, east-west rainfall gradient. Because of the skewed nature of summer rainfall distributions, the median value is used to represent a more realistic expected rainfall amount for any given year. Some parts of the stare …

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Special Issue Photo: Richard V. Bovbjerg, Director Of The Iowa Lakeside Laboratory 1963-1989

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Changes In A Prairie Bird Population From 1940 To 1989, Neil P. Bernstein, Kristine K. Baker, Sherry R. Wilmot

Journal of the Iowa Academy of Science: JIAS

We repeated a bird census of a prairie/field community that was done by Kendeigh (1941) in 1940. Changes in the bird populations were compared with changes in vegetation, agricultural land use for the county, and trends in urbanization. Grassland birds did decline in abundance due to causes similar to those cited in other studies. The increase in forest and edge nesting species was more unusual to this study, and probably correlated with the woody succession that had occurred.

Time To Metamorphosis As A Function Of Larval Size In A Population Of Ambystoma Tigrinum Salamanders Consisting Of Cannibal And Typical Morph Phenotypes, Michael J. Lannoo, Michael P. Sweet, Nancy M. Ladehoff, Edmund S. Fangman, William B. Collins

Journal of the Iowa Academy of Science: JIAS

Salamander larvae of the species Ambystoma tigrinum are dimorphic in northwestern Iowa. In addition to common typical morphs, there exist rare, specialized cannibal morphs, which are induced environmentally by crowding. Cannibal morph phenotypes are characterized morphologically by their large size, proportionately large heads and hypertrophied vomerine teeth, and behaviorally by facultative cannibalism. During metamorphosis amphibians are particularly sensitive to predation. To help understand why cannibal morphs are uncommon, we have raised cannibal and typical morphs in isolation and under crowded conditions to compare the timing and duration of metamorphosis between these morphs. Results show that larger larvae, most of which …

The Cladocera Of Lake West Okoboji, Iowa - Revisited, Kenneth L. Lang

Journal of the Iowa Academy of Science: JIAS

Seven stations, established in 1968 to sample Cladocera, were sampled again, using the same methods, in 1988. Seven species, all of them in low abundance, are new records for Lake West Okoboji. In 1988, there was little difference 1) in the ranking of the stations relative to abundance of cladocerans, 2) the distribution and abundance of the species by habitat-type, 3) the seasonality of the predominant species in the specific habitats, 4) the temporal patterns of the number of species and total cladoceran abundance in the specific habitats, compared to 1968. On the average there were more species but lower …

Holocene Vegetational Changes In Eastern Iowa, R. G. Baker, C. A. Chumbley, P. M. Witinok, H. K. Kim

Journal of the Iowa Academy of Science: JIAS

Pollen and plant macrofossil analysis from three sites along an east-west transect in southeastern Iowa provide evidence for Holocene vegetational development. Colo Marsh at the west end of the transect is relatively complete, with a late-glacial spruce zone ending about 11,500 yr B.P.; a deciduous forest zone from about 11,500 to 8300; a prairie zone from 8300 to 4500, and prairie with oak from 4500 to presettlement times.

Sediments from the site at the Indian Creek Nature Center, midway in the transect, date only from about 6000 to 1600 yrs B. P. This site also was dominantly prairie from 6000 …

A Summer Course In Invertebrate Developmental Biology At Iowa Lakeside Laboratory: A Unique Experience, Carol W. Schutte, Dale J. Witt, Nicole Y. Janosek, Douglas E. Robinson, Edwin C. Powell, George G. Brown

Journal of the Iowa Academy of Science: JIAS

The course, "Developmental Biology of Selected Invertebrates'', has been offered in alternate years at Iowa Lakeside Laboratory (Ill) on Lake West Okoboji, Dickinson County, Iowa, since the first summer session of 1983. This course has taken advantage of the great diversity of invertebrates found in the Ill area and has demonstrated to students and faculty alike the exciting phenomena and principles of developmental biology. The course is continuously evolving as new experiments and observations are discovered with each offering of the course.