D URING the summer of 1950 a number of living specimens were collected during studies on temperature regulation in Alaskan mamma1s.l These animals were brought back to Wisconsin and maintained in captivity, a number being still alive more than two years after capture. Since an adequate diet is often essential for successful maintenance, some systematic observations on food preference in terms o...

Šupraha, L. 2016. Phenotypic evolution and adaptive strategies in marine phytoplankton (Coccolithophores). Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 1427. 54 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9689-0. Coccolithophores are biogeochemically important marine algae that interact with the carbon cycle through photosy...

Three major primary parasitoids of the diamondback moth, Plutella xylostella (L.), are found in the Cameron Highlands, Malaysia. Cotesia plutellae (Kurdjumov) was discovered in the early 1970s, Diadegma semiclausum (Hellén) and Diadromus collaris (Gravenhorst) were introduced in the mid 1970s from New Zealand and Australia. Field studies in the early 1980s showed that C. plutellae was the domin...

We analyzed blood lead concentrations and prevalences of ingested lead and steel shot in 93 ring-necked ducks (Aythya collaris) at Catahoula Lake, Louisiana. Blood lead concentrations were higher for immatures than for adults, but did not differ between sexes or between randomly collected and hunter-shot birds. Blood lead concentrations were elevated (> 0.20 ppm) in 18 of 31 immatures (58%) and...

The biogeographical history of major groups of bees with worldwide distributions have often been explained through hypotheses based on Gondwanan vicariance or long distance dispersal events, but until recently these hypotheses have been very difficult, if not impossible, to distinguish. New fossil data, comprehensive information on Mesozoic and Cenozoic coastline positions and the availability ...

Observations on a nesting aggregation of Perdita (Perdita) difficilis in south eastern Arizona indicate that this species is solitary, provisions two cells per day during two foraging periods (0700-1000 and 1700-1930 hr) and requires only three trips (two with pollen and one with nectar, in that order) to provision a cell. Nests are occupied for less than 5 days and bees most likely occupy seve...

Zug, George R. The Distribution and Patterns of the Major Arteries of the Iguanids and Comments on the Intergeneric Relationships of Iguanids (Reptilia: Lacertilia). Smithsonian Contributions to Zoology, 83: 1-23. 1971.—The spatial arrangement of the major arteries, i.e., systemic arches, carotid arches and major branches, subclavians, coeliac, and mesenteries, are described for 42 genera of ig...

Zug, George R. The Distribution and Patterns of the Major Arteries of the Iguanids and Comments on the Intergeneric Relationships of Iguanids (Reptilia: Lacertilia). Smithsonian Contributions to Zoology, 83: 1-23. 1971.—The spatial arrangement of the major arteries, i.e., systemic arches, carotid arches and major branches, subclavians, coeliac, and mesenteries, are described for 42 genera of ig...

Waterfowl, including ducks, geese, rails and others, are host to a great diversity of ectosymbiotic arthropods. In this study, we collected ectosymbionts from waterfowl and analyzed taxon richness and total abundance to determine whether there were differences in the mite and louse assemblages of waterfowl of different species, genera, sexes, and feeding behaviors. Data were collected from 53 i...