Growth rates and prey selection of two congeneric predatory caddisflies (Trichoptera: Rhyacophilidae)

1983 ◽  
Vol 61 (4) ◽  
pp. 895-900 ◽  
Author(s):  
Ian D. Martin ◽  
Rosemary J. Mackay
Keyword(s):  
Growth Rates ◽  
Laboratory Experiments ◽  
Prey Selection ◽  
Southern Ontario ◽  
Weight Gains ◽  
Prey Organism ◽  
Selection Of

Rhyacophila fuscula (Walker) and R. melita Ross inhabit cool southern Ontario streams, often together. In laboratory experiments, R. fuscula and R. melita showed significant weight gains in 2 weeks on four common prey taxa occurring in the field (Diptera: Chironomidae and Simuliidae; Ephemeroptera: Baetidae; and Trichoptera: Hydropsychidae). Rhyacophila melita grew significantly less than R. fuscula on three prey, but significantly better on Chironomidae. The prey eliciting highest growth rates from R. fuscula (Prosimulium, Baetis) and R. melita (Chironomidae) are most abundant in the habitats occupied by each of these predators. Prosimulium and Baetis are common on the surface of rocks in headwater regions where R. fuscula are at high densities, and chironomids are the most abundant prey organism in the marl (travertine) microhabitat of R. melita farther downstream. Where the two predators co-occur, they may compete for foraging areas in the spring, when prey and microhabitat resources are reduced by flood scour.

Seasonal abundance and prey selection of the nymphs of three sympatric species of Sympetrum (Odonata: Libellulidae) in an intermittent pond

2005 ◽  
Vol 137 (6) ◽  
pp. 723-727 ◽  
Author(s):  
Catherine M. Febria ◽  
A. Katarina Magnusson ◽  
D. Dudley Williams
Keyword(s):  
Life Cycle ◽  
Prey Selection ◽  
Sympatric Species ◽  
Early Spring ◽  
Seasonal Abundance ◽  
Gut Contents ◽  
Southern Ontario ◽  
Size Data ◽  
Selection Of

Odonates are obligate predators (Pritchard 1964), and the composition of their diet is reflective of their microhabitat and effectiveness in detecting and capturing prey (Griffiths 1973; Thompson 1978). In an intermittent woodland pond in southern Ontario, Canada, three species of Sympetrum (Odonata: Libellulidae) were found to coexist: S. internum Montgomery, S. costiferum (Hagen), and S. obtrusum (Hagen). Sympetrum species spend most of their life cycle in the aquatic stage and consume prey at all nymphal stadia (Pritchard 1964; Corbet 1999). They overwinter in the egg stage, hatch in early spring, and typically emerge in late June to late July (Walker and Corbet 1975). To better understand the role of coexisting Sympetrum nymphs in this intermittent pond environment, and to evaluate potential mechanisms behind their coexistence, we collected seasonal abundance and body size data for 2 years and analyzed gut contents of each species. In addition, we experimentally tested the prey selection and predatory rate of two different size classes of Sympetrum nymphs and two of their potential competitors, Lestes sp. (Odonata: Lestidae) and Acilius sp. (Coleoptera: Dytiscidae), in laboratory microcosms.

Diet composition and prey selection of vendace Coregonus albula in the mesotrophic, temperate Lake Ostrowite (Northern Poland)

2008 ◽  
Vol 37 (1) ◽  
Author(s):  
Tomasz Kakareko ◽  
Paweł Napiórkowski ◽  
Jacek Kozłowski
Keyword(s):  
Diet Composition ◽  
Prey Selection ◽  
Temperate Lake ◽  
Coregonus Albula ◽  
Northern Poland ◽  
Mesotrophic Lake ◽  
Selection Of

Diet composition and prey selection of vendaceLake Ostrowite is a mesotrophic lake in Northern Poland 280.7 ha in area and 43 m deep at its deepest point. To study vendace (

scholarly journals Changes in genetic constitution and sterol composition during growth of nystatin-resistant heterokaryons ofNeurospora crassa

1983 ◽  
Vol 42 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Jill E. Ogden ◽  
Morris Grindle
Keyword(s):  
Growth Rates ◽  
Minimal Medium ◽  
Resistant Mutant ◽  
Sterol Composition ◽  
Sensitive Strain ◽  
Genetic Constitution ◽  
Polyene Antibiotic ◽  
Ofneurospora Crassa ◽  
Synthetic Media ◽  
Selection Of

SUMMARYHeterokaryons ofN. crassawere synthesized from homokaryotic strains differing in sterol composition and sensitivity to the polyene antibiotic nystatin. Mycelia of the nystatin-sensitive strainerg-1+contained ergosterol and episterol, and the nystatin-resistant mutanterg-1 contained fecosterol and lichesterol. Mycelia of heterokaryons with different proportions oferg-1+:erg-1 nuclei contained various proportions of the four sterols. Ergosterol was the principal sterol in heterokaryons with more than 5%erg-1+nuclei.Heterokaryons with various proportions oferg-1+:erg-1 nuclei were grown for several weeks along tubes of synthetic media. Growth rates were stable on minimal medium and nutritionally supplemented media but nuclear proportions often fluctuated. Growth rates fell sharply on nystatin-supplemented media and there were adaptive increases in proportions of mutanterg-1 nuclei which resulted in selection of nystatin-resistant homokaryotic mycelia.

WEIGHT GAINS IN THE FIRST FOUR WEEKS OF INFANCY: A COMPARISON OF THREE DIETS

PEDIATRICS ◽  
1956 ◽  
Vol 18 (3) ◽  
pp. 362-368
Author(s):  
Ruth T. Gross ◽  
Lincoln E. Moses
Keyword(s):  
Human Milk ◽  
Statistical Methods ◽  
Full Term ◽  
Clinical Judgement ◽  
Careful Selection ◽  
Term Infants ◽  
Weight Gains ◽  
The Many ◽  
Selection Of

Four hundred seven healthy, full-term infants were divided into three groups and fed, respectively, a formula of evaporated milk and water with 5% carbohydrate; human milk; and a special modified evaporated milk designed to simulate human milk. No other foods were added to the diet. A comparison of the three groups was made, based on weight gains from birth to the end of the first 4 weeks. The conclusions refer only to weight gains; no attempt was made to determine the superiority of any particular diet. The data show no significant differences in the 4-week weight gains among the three groups of infants, although sensitive statistical methods could be validly applied to the problem. These methods are explained. The authors wish to emphasize the many variables which must be taken into account in a study of this sort; the necessity for careful selection of valid statistical methods; the importance of critical clinical judgement in the evaluation of the results.

scholarly journals Coriolis effects on the elliptical instability in cylindrical and spherical rotating containers

2007 ◽  
Vol 585 ◽  
pp. 323-342 ◽  
Author(s):  
M. LE BARS ◽  
S. LE DIZÈS ◽  
P. LE GAL
Keyword(s):  
Growth Rates ◽  
Close Agreement ◽  
Unstable Mode ◽  
Quantitative Agreement ◽  
Fixed Rate ◽  
Elliptical Instability ◽  
Normal Mode Theory ◽  
Set Up ◽  
First Time ◽  
Selection Of

The effects of the Coriolis force on the elliptical instability are studied experimentally in cylindrical and spherical rotating containers placed on a table rotating at a fixed rate $\tilde{\Omega}^G$. For a given set-up, changing the ratio ΩG of global rotation $\tilde{\Omega}^G$ to flow rotation $\tilde{\Omega}^F$ leads to the selection of various unstable modes due to the presence of resonance bands, in close agreement with the normal-mode theory. No instability occurs when ΩG varies between −3/2 and −1/2 typically. On decreasing ΩG toward −1/2, resonance bands are first discretized for ΩG<0 and progressively overlap for −1/2 ≪ ΩG < 0. Simultaneously, the growth rates and wavenumbers of the prevalent stationary unstable mode significantly increase, in quantitative agreement with the viscous short-wavelength analysis. New complex resonances have been observed for the first time for the sphere, in addition to the standard spin-over. We argue that these results have significant implications in geo- and astrophysical contexts.

scholarly journals Prey species and prey selection of dholes at three different sites in Thailand

2020 ◽  
Vol 21 (11) ◽  
Author(s):  
KHWANRUTAI CHARASPET ◽  
Ronglarp - Sukmasuang ◽  
NORASET KHOEWSREE ◽  
MANANYA PLA-ARD ◽  
YUWALUK CHANACHAI
Keyword(s):  
National Park ◽  
Prey Species ◽  
Dietary Diversity ◽  
Prey Selection ◽  
Selection Index ◽  
Camera Traps ◽  
Total Biomass ◽  
Wildlife Sanctuary ◽  
Khao Yai National Park ◽  
Selection Of

Abstract. Charaspet K, Sukmasuang R, Khoewsree N, Pla-ard M, Chanachai Y. 2020. Prey species and prey selection of dholes at three different sites in Thailand. Biodiversitas 21: 5248-5262. The study of prey species and prey selection of Dholes at 3 different sites was conducted at Khao Yai National Park, Salak Pra, and Huai Kha Khaeng Wildlife Sanctuaries from 2013 to 2020. Information on Dhole prey at the sites was collected from the residues of dhole scats, from which the selection index, the relative biomass of the prey, and the relative amounts of the consumed prey were calculated. The data were collected simultaneously with the use of camera traps at each site. The study revealed that there were 13 species of Dhole prey with body weight over 5 kg. The result indicated that there were 7 species of even-toed ungulates. The relative biomass of even-toed ungulates ranged between 76.78 - 90.50% of the total biomass of all the Dholes’ consumed prey for all study sites. The dietary diversity index unveiled a similar index in all areas, which proved the adequacy of the analyzed scats. However, the Niche breadth index, which indicates the relevance of prey selection and prey species to the appearances of the prey at each site, was found to be high at Huai Kha Khaeng Wildlife Sanctuary, Khao Yai National Park, while the index was found to be low at Salak Pra Wildlife Sanctuary. The results revealed that Dholes consumed viverrid species and Malayan porcupine more often at the site where there were large carnivores. The recommendation from this study was the conservation and restoration of the ungulate populations, the main prey, as it greatly affects the conservation of the Dhole populations in Thailand.  Grassland and salt lick sites, water sources improvements are also important to promote prey population. The conservation of wildlife prey by releasing them to nature, as currently conducted, has an effect on the increase of Dholes’ prey species.

scholarly journals Intrinsic Prey Preference and Selection of the Giant Gartersnake: A Threatened Predator in a Nonnative Prey-Dominated Community

2020 ◽  
Vol 11 (1) ◽  
pp. 164-173
Author(s):  
Julia S.M. Ersan ◽  
Brian J. Halstead ◽  
Erica L. Wildy ◽  
Michael L. Casazza ◽  
Glenn D. Wylie
Keyword(s):  
Exotic Species ◽  
Native Species ◽  
Prey Selection ◽  
Central Valley ◽  
Prey Preference ◽  
Live Prey ◽  
Species Of Conservation Concern ◽  
Conservation Concern ◽  
Behavioral Trials ◽  
Selection Of

Abstract The introduction of exotic species into an environment can introduce great change in the trophic dynamics of native species. This is of even greater concern if the native species is of conservation concern. The giant gartersnake, Thamnophis gigas, an endemic predator of the Central Valley of California and a species of conservation concern at the state and federal levels, has declined as a result of conversion of its once vast wetland habitat to agriculture. Another anthropogenic factor contributing to this snake's changing ecology is the introduction of nonnative prey into the species' habitats. These introductions have resulted in a prey community that is almost completely composed of exotic species and have potential for considerable effects. In order to assess prey preference and selection we performed three sets of behavioral trials on naïve neonates. We examined 1) neonate prey preference in response to olfactory cues of prepared prey extracts, 2) neonate consumption of different live prey items presented simultaneously; and 3) terrestrial feeding behavior and/or latency to successful attack. Results from the olfactory study suggest that native Sierran treefrogs, Pseudacris sierra, are preferred by neonates. Results from consumption trials suggest that neonates are more likely to select frog species than fish species. This is the first study that we are aware of that examines prey selection of this threatened species and serves to inform its conservation and management.

scholarly journals Prey selection of the least weasel Mustela nivalis in the laboratory

1997 ◽  
Vol 42 ◽  
pp. 179-188 ◽  
Author(s):  
Pirjo Pekkarinen ◽  
Jari Heikkilä
Keyword(s):  
Prey Selection ◽  
Least Weasel ◽  
Mustela Nivalis ◽  
Selection Of

scholarly journals Growth and Flowering of ‘Alice du Pont’ Mandevilla in Response to Sumagic

1992 ◽  
Vol 10 (1) ◽  
pp. 36-39
Author(s):  
C. Frederick Deneke ◽  
Gary J. Keever ◽  
John A. McGuire
Keyword(s):  
Growth Rates ◽  
Vegetative Growth ◽  
Foliar Application ◽  
Application Rate ◽  
Single Application ◽  
Flower Diameter ◽  
Selection Of

Abstract Vegetative growth of ‘Alice du Pont’ mandevilla can be controlled by selection of an appropriate foliar application rate of Sumagic (uniconazole) and application interval. A single application of 5 to 20 ppm ai Sumagic (uniconazole) controlled vegetative growth for only 3 to 4 weeks; after this time, growth rates were similar to control plants. Multiple applications of 5 to 20 ppm ai Sumagic (uniconazole) effectively restricted vegetative growth; as the concentration of Sumagic (uniconazole) increased, the interval between applications increased from about 4 (5 ppm) to 6 (20 ppm) weeks. A single application of higher rates (30 to 120 ppm) of Sumagic (uniconazole) was phytotoxic. Generally, time to flowering increased and flower diameter decreased when application rate increased.

scholarly journals Habitat utilization and prey selection of the kestrelFalco tinnunculusin relation to small mammal abundance

2008 ◽  
Vol 75 (4) ◽  
pp. 401-409 ◽  
Author(s):  
S. Casagrande ◽  
L. Nieder ◽  
E. Di Minin ◽  
I. La Fata ◽  
D. Csermely
Keyword(s):  
Small Mammal ◽  
Prey Selection ◽  
Habitat Utilization ◽  
Selection Of
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