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Growth Of Stygobitic (Orconectes Australis Packardi) And Epigean (Orconectes Cristavarius) Crayfishes Maintained In Laboratory Conditions, Ann-Simone Cooper, Robin L. Cooper Oct 2004

Growth Of Stygobitic (Orconectes Australis Packardi) And Epigean (Orconectes Cristavarius) Crayfishes Maintained In Laboratory Conditions, Ann-Simone Cooper, Robin L. Cooper

Biology Faculty Publications

This study reports on maintenance and growth of the cave crayfish, Orconectes australis packardi, and the epigean crayfish, Orconectes cristavarius, with laboratory conditions for 1 and 2 years. The O. a. packardi survived well compared to the O. cristavarius in captivity. The poor survival of the epigean species was probably due to unsuitable conditions. The epigean as well as the cave crayfish molted and grew in captivity, but without any significant difference in molt frequency between species. In the first year, total body length was obtained to assay growth, whereas in the second year the more accurate measure …


Incidence, Size And Spatial Structure Of Clones In Second-Growth Stands Of Coast Redwood, Sequoia Sempervirens (Cupressaceae), Vladimir Douhovnikoff, Adelaide M. Cheng, Richard S. Dodd Jul 2004

Incidence, Size And Spatial Structure Of Clones In Second-Growth Stands Of Coast Redwood, Sequoia Sempervirens (Cupressaceae), Vladimir Douhovnikoff, Adelaide M. Cheng, Richard S. Dodd

Biology Faculty Publications

The ecology and evolutionary potential of coast redwood (Sequoia sempervirens) is significantly influenced by the important role clonal spread plays in its reproduction and site persistence. In nine second-growth stands, amplified fragment length polymorphisms (AFLPs) were used to identify redwood clonal architecture. Clones (multistem genets) dominated sites by representing an average of 70% of stems measured, ranging in size from two to 20 stems. As a result, a relatively small number of genets can monopolize a disproportionate amount of site resources, are more likely to persist over time, and have greater on-site genetic representation. Clones were not limited to fairy-ring …


Seed Mass And Morphology In Outcrossing And Selfing Species Of Clarkia (Onagraceae): An Sem Study, Jennifer L. Knies, Veronique A. Delesalle, A. R. Cavaliere Jan 2004

Seed Mass And Morphology In Outcrossing And Selfing Species Of Clarkia (Onagraceae): An Sem Study, Jennifer L. Knies, Veronique A. Delesalle, A. R. Cavaliere

Biology Faculty Publications

Seeds from three pairs of outcrossing-selfing sister taxa from the genus Clarkia (farewell-to-spring, Onagraceae)—Clarkia unguiculata, Clarkia exilis, Clarkia xantiana ssp. xantiana and ssp. parviflora, and Clarkia concinna ssp. concinna and ssp. automixa—were studied to assess the effects of contrasting mating systems on seed mass and seed morphology. For each outcrossing-selfing comparison, the seed mass of the selfing taxon was less than that of the outcrossing taxon. Seed mass typically differed significantly among populations within a taxon. Scanning electron microscopy showed that the seeds from all these taxa share several characteristics: a bullet to shield shape, a reticulate exotesta pattern, presence …


Seasonal Acclimatization Of Antioxidants And Photosynthesis In Chondrus Crispus And Mastocarpus Stellatus, Two Co-Occurring Red Algae With Differing Stress Tolerances, Nissa L. Lohrmann, Barry A. Logan, Amy S. Johnson Jan 2004

Seasonal Acclimatization Of Antioxidants And Photosynthesis In Chondrus Crispus And Mastocarpus Stellatus, Two Co-Occurring Red Algae With Differing Stress Tolerances, Nissa L. Lohrmann, Barry A. Logan, Amy S. Johnson

Biology Faculty Publications

Mastocarpus stellatus and Chondrus crispus are red macroalgae that co-dominate the lower rocky intertidal zones of the northern Atlantic coast. M. stellatus is more tolerant than C. crispus of environmental stresses, particularly those experienced during winter. This difference in tolerance has been attributed, in part, to greater contents or activities of certain antioxidants in M. stellatus. We compared the photosynthetic capacities and activities of three antioxidant enzymes - superoxide dismutase (SOD), ascorbate peroxidase (APX), and glutathione reductase (GR) - as well as the contents of ascorbate from fronds of M. stellatus and C. crispus collected over a year. Photosynthetic capacity …