Social and Behavioral Sciences Commons^™

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.