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Articles 1 - 9 of 9

Full-Text Articles in Life Sciences

Time, Temperature And Species Interactions In A Duckweed-Herbivore Mesocosm, Ian Waterman Nov 2010

Time, Temperature And Species Interactions In A Duckweed-Herbivore Mesocosm, Ian Waterman

School of Biological Sciences: Dissertations, Theses, and Student Research

Species interactions within a community are impacted by a variety of abiotic factors. Temperature is known to alter population dynamics such that direct and indirect interactions between populations within a community are affected. Here I investigate the effect of temperature change on species interactions within a duckweed-herbivore mesocosm. Multiple communities were constructed, from a single population of duckweed, to two populations of duckweed consumed by aphids. In the one-predator two-prey web we predicted mutually positive indirect effects between duckweed populations during the first generation of growth. As aphid populations respond numerically to more abundant prey, mutually negative and asymmetric indirect …


Osteology, Natural History Notes, And Phylogenetic Relationships Of The Poorly Known Caribbean Frog Leptodactylus Nesiotus (Anura, Leptodactylidae), María Laura Ponssa, Michael J. Jowers, Rafael O. De Sá Oct 2010

Osteology, Natural History Notes, And Phylogenetic Relationships Of The Poorly Known Caribbean Frog Leptodactylus Nesiotus (Anura, Leptodactylidae), María Laura Ponssa, Michael J. Jowers, Rafael O. De Sá

Biology Faculty Publications

The Leptodactylus melanonotus group consists of 15 species, but references to skeletal characters are available for only three species: L. leptodactyloides, L. melanonotus, and L. diedrus. Leptodactylus nesiotus is a member of the melanonotus group known only from the type locality, Bonasse swamp, on the Southwestern peninsula of Trinidad, Trinidad and Tobago. This species has been categorized as vulnerable given its restricted distribution. Herein, we report the adult osteology of L. nesiotus, the skeletal characters are compared with the available data from other Leptodactylus species. A phylogenetic analysis recovers a paraphyletic L. melanonotus group relative to the L. …


Seasonal Variation In Terrestrial Insect Subsidies To Tropical Streams And Implications For The Diet Of Rivulus Hartii, David C. Owens May 2010

Seasonal Variation In Terrestrial Insect Subsidies To Tropical Streams And Implications For The Diet Of Rivulus Hartii, David C. Owens

School of Natural Resources: Dissertations, Theses, and Student Research

Terrestrial invertebrates subsidize fish diets in lotic ecosystems. Seasonality strongly influences terrestrial invertebrate abundance in temperate regions and alters their delivery to streams. Seasonal changes in the tropics are characterized by distinct wet and dry periods, with marked variation in invertebrate abundance. However, little is known about how these seasonal changes affect invertebrate subsidies and their ecological consequences for tropical streams. We measured the effect of rainfall and canopy density on terrestrial invertebrate falling input, as well as seasonal variation in falling input, benthic and drifting invertebrate, and Rivulus hartii (Hart’s Rivulus) diet composition during both the wet and dry …


Ecology And Relationships Of Rhabdias Spp. (Nematoda: Rhabdiasidae) From North American Amphibians And Reptiles, Gabriel J. Langford May 2010

Ecology And Relationships Of Rhabdias Spp. (Nematoda: Rhabdiasidae) From North American Amphibians And Reptiles, Gabriel J. Langford

School of Biological Sciences: Dissertations, Theses, and Student Research

Lungworms of the cosmopolitan genus Rhabdias (Nematoda: Rhabdiasidae) are among the most common parasites of amphibians and squamate reptiles. The life cycles, life histories, host specificities, and evolutionary relationships of Rhabdias spp. were studied through examination of their free-living and parasitic stages in amphibians and reptiles. This study found free-living development of anuran lungworms was primarily limited to heterogonic reproduction, whereas snake lungworms primarily reproduced homogonically. Infective anuran lungworms penetrated the skin of frogs and toads; in contrast, snake lungworms penetrated snake esophageal tissue during per os infections. Our molecular phylogeny strongly supported separate clades for anuran and snake lungworms, …


Impacts Of Shoreline Development On The Littoral Zone Of Great Pond, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College Jan 2010

Impacts Of Shoreline Development On The Littoral Zone Of Great Pond, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College

Colby College Watershed Study: Great Pond (2012, 2010, 1998)

The Colby Environmental Assessment Team (CEAT) investigated the littoral zone of Great Pond in the Belgrade Lakes region of central Maine. Data collection occurred in September and October and analysis followed in October and November of 2010. Physical, biological, and chemical parameters were assessed to examine the impacts of shoreline development on the health of the littoral community. The littoral zone and adjacent riparian areas were sampled to allow comparison of aquatic and terrestrial parameters among different levels of shoreline development.


Environmental And Endogenous Factors Influencing Emigration In Juvenile Anadromous Alewives, Benjamin I. Gahagan, Eric T. Schultz, Katie E. Gherard Jan 2010

Environmental And Endogenous Factors Influencing Emigration In Juvenile Anadromous Alewives, Benjamin I. Gahagan, Eric T. Schultz, Katie E. Gherard

EEB Articles

We analyzed juvenile anadromous alewife migration at Bride Lake, a coastal lake in Connecticut, during summer 2006 and found that migration on 24-hour and seasonal timescales was influenced by conditions of the environment and characteristics of the individual. To identify environmental cues of juvenile migration, we continuously video recorded fish at the lake outflow and employed information-theoretic model selection to identify the best predictors of daily migration rate. More than 80% of the approximately 320,000 juveniles that migrated from mid-June to mid-August departed in three pulses lasting one or two days. Pulses of migration were associated with precipitation events, transient …


Beitrag Zur Säugetierfauna Des Staatlichen Naturschutzgebietes Azas In Tyva/Südsibirien = Contributions To Fauna And Ecology Of Small Mammals Of State Nature Reserve “Azas” In The Republic Of Tyva /South Siberia, Annegret Stubbe, Michael Stubbe, V. V. Unžakov, A. P. Saveljev, N. I. Putincev, W. Stubbe Jan 2010

Beitrag Zur Säugetierfauna Des Staatlichen Naturschutzgebietes Azas In Tyva/Südsibirien = Contributions To Fauna And Ecology Of Small Mammals Of State Nature Reserve “Azas” In The Republic Of Tyva /South Siberia, Annegret Stubbe, Michael Stubbe, V. V. Unžakov, A. P. Saveljev, N. I. Putincev, W. Stubbe

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

During 1988-2004 Russian and German biologists carried out a research of biodiversity of the mountain taiga within the territory of State Nature Reserve “Azas” (Republic of Tyva/Russia). Along with executing the main task – studying and development of an aboriginal population of Tuvinian beavers Castor fiber tuvinicus – materials on the fauna of small mammals of the Todzha kettle were collected. On the basis of samples (about 550 collected micromammals) information on the occurrence, reproduction and morphometric characteristics of four species of Insectivora, six species of Chiroptera and eleven species of small Rodentia inhabiting the territory of the reserve “Azas” …


Trophic Implications Of Light Reductions For Amphibolis Griffithii Seagrass Fauna, Adam Gartner Jan 2010

Trophic Implications Of Light Reductions For Amphibolis Griffithii Seagrass Fauna, Adam Gartner

Theses: Doctorates and Masters

The ongoing threat of seagrass loss from reduced light availability, coupled with our lack of knowledge of associated trophic responses has motivated this characterization of the flow-on effects of light reductions to Amphibolis griffithii seagrass fauna. Recently, field manipulations of varying light reductions, induced disturbances in a A. griffithii seagrass meadow that have been shown to effect potential food resources and the structural complexity of seagrass habitats for macroinvertebrates. This offered the opportunity to assess the flow-on effects to seagrass for fauna, a topic that has seldom been examined. This study investigated the effects of different light reduction intensity (high: …


Current State Of Ixodidae Research In Mongolia, Daniel Kiefer, K. Pfister, D. Tserennorov, G. Bolormaa, D. Otgonbaatar, Ravčigijn Samjaa, E. G. Burmeister, Mathias S. Kiefer Jan 2010

Current State Of Ixodidae Research In Mongolia, Daniel Kiefer, K. Pfister, D. Tserennorov, G. Bolormaa, D. Otgonbaatar, Ravčigijn Samjaa, E. G. Burmeister, Mathias S. Kiefer

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Our research presents the Ixodidae-fauna in Mongolia. The current taxonomic state in Mongolia shows 19 Ixodidae taxa extracted in 308 locations from 115 bird and mammal species. In 1980, the species Ixodes persulcatus SCHULZE, 1930 and Ixodes berlesei Birula, 1895 were detected in Inget Tolgoi and Ixodes laguri OLENEV, 1929 on Meriones unguiculatus 10 km southeast of Ulaanbaatar for the first time. In 2000 the species Haemaphysalis concinna Koch, 1844 was detected in the Selenge-river area and Argas (Argas) vulgaris FILIPPOVA, 1961 was detected in the Gobi area. From the collection of M. and A. STUBBE 1 N …