Habitat selection by dabbling ducks in the Baie Noire marsh, southwestern Quebec

1979 ◽  
Vol 57 (11) ◽  
pp. 2230-2238 ◽  
Author(s):  
Réal Courcelles ◽  
Jean Bédard
Keyword(s):  
Analytical Techniques ◽  
Plant Distribution ◽  
Dabbling Ducks ◽  
Important Species ◽  
Ottawa River ◽  
Black Duck ◽  
Waterfowl Habitat ◽  
Management Plans ◽  
Correspondence Factor Analysis ◽  
Myriophyllum Exalbescens

We monitored the waterfowl distribution in a recently flooded 260-ha marsh along the Ottawa River during 1974 and 1975. The birds (the three most important species were the black duck. Anas rubripes; the mallard, A. platyrhynchos; and the blue-winged teal, A. discors) did not distribute randomly among the five major habitats recognized, but clearly preferred a habitat dominated physiognomically by broken cattail (Typha angustifolia) cover but best characterized ecologically by ivy-leaved duckweed (Lemna trisulca), whitish water-milfoil (Myriophyllum exalbescens), and common bladderwort (Utricularia vulgaris). On average, broods (0.3/ha) and adult birds (6.6/ha) were four times more abundant per hectare there than in the next best habitat. This pattern of use was stable throughout the summer and throughout the daylight period as well. Multivariate analysis (correspondence factor analysis) enabled us to extract those ecological variables that played a determinant role in controlling plant distribution throughout the marsh. The observational and analytical techniques developed in this work could be applied to the development of marsh management plans designed to promote the expansion of the preferred waterfowl habitat.

Hybridization between the Mallard and native dabbling ducks: causes, consequences and management.

2014 ◽  
Vol 20 (1) ◽  
pp. 41 ◽  
Author(s):  
P-J Guay ◽  
A Taysom ◽  
R Robinson ◽  
J P Tracey
Keyword(s):  
Introduced Species ◽  
Anas Platyrhynchos ◽  
Management Strategies ◽  
Dabbling Ducks ◽  
Monitoring Techniques ◽  
Duck Species ◽  
Black Duck ◽  
Dabbling Duck ◽  
The Pacific ◽  
The World

Waterbirds are currently facing various threats throughout the world. One threat that is often overlooked is hybridization with introduced species. This threatening process is especially significant for dabbling ducks (Genus Anas). The Mallard (Anas platyrhynchos) has been introduced to various parts of the world and now hybridizes and threatens numerous Anas species. In this paper, we review hybridization between Mallards and dabbling ducks with a specific emphasis on threats to the Pacific Black Duck (A. superciliosa). We then present an overview of the potential mechanisms of hybridization and discuss monitoring techniques. We conclude by proposing management strategies and speculating on the future of native dabbling duck species.

Effects of freshwater flow on the fish assemblage of the Mondego estuary (Portugal): comparison between drought and non-drought years

2010 ◽  
Vol 61 (4) ◽  
pp. 490 ◽  
Author(s):  
Joana Baptista ◽  
Filipe Martinho ◽  
Marina Dolbeth ◽  
Ivan Viegas ◽  
Henrique Cabral ◽  
...  
Keyword(s):  
Extreme Events ◽  
Fish Assemblage ◽  
Fish Community ◽  
River Flow ◽  
Fish Assemblages ◽  
Freshwater Species ◽  
Freshwater Flow ◽  
Important Species ◽  
Mondego Estuary ◽  
Management Plans

Warming of the planet is indisputable and will lead to more frequent extreme events, such as droughts. From June 2003 to March 2008, the effects of variations in river flow, associated with drought conditions, were studied in the fish assemblage of the Mondego estuary, Portugal. Over this time, two distinct hydrological periods were identified: non-drought years and drought years, with consistent changes in the fish assemblages. In the drought years, salinity increased inside the estuary, displacing the estuarine brackish habitats to more upstream areas. During this period, new marine adventitious species were found mainly in the most downstream areas, while the freshwater species disappeared from the Mondego estuary catchment area. For the marine estuarine-dependent species that use estuaries as nursery areas, a decrease in abundance was observed during the drought years, owing to the decrease in freshwater flow and reduced river plume to the coastal area. In non-drought years, there were higher densities of most species and the more important species of the fish community. Our work shows that extreme events such as droughts, related to climatic changes, influenced the structure and composition of the Mondego estuary fish assemblages, and should be further considered when undertaking management plans for transitional waters.

scholarly journals New leaf-mining Nepticulidae (Lepidoptera): potential pests of aromatic Lamiaceae plants from equatorial Andes

Zootaxa ◽  
2021 ◽  
Vol 4926 (3) ◽  
pp. 363-383
Author(s):  
JONAS R. STONIS ◽  
ARŪNAS DIŠKUS ◽  
JOSÉ L. FERNÁNDEZ-ALONSO ◽  
ANDRIUS REMEIKIS ◽  
M. ALMA SOLIS
Keyword(s):  
New Species ◽  
Host Plant ◽  
Potential Distribution ◽  
Ornamental Plants ◽  
Plant Distribution ◽  
South American ◽  
Leaf Miners ◽  
Important Species ◽  
Leaf Mining ◽  
Distribution Ranges

Members of the Lamiaceae, or mint family, are used worldwide for medicinal, culinary and/or magical-religious purposes, as well as in pesticides and as ornamental plants. Very little is known about nepticulids, or pygmy moths, as leaf miners of Lamiaceae, but they may be an important component of South American diversity and potential pests of economically-important species of the mint family. In this paper, four new species of leaf-mining Nepticulidae are described from the equatorial Andes of Ecuador: S. mentholica Diškus & Stonis, sp. nov., Stigmella aromatica Diškus & Stonis, sp. nov., S. odora Diškus & Stonis, sp. nov., feeding on Minthostachys mollis (Benth.) Griseb., and S. tomentosella Diškus & Stonis, sp. nov., feeding on Clinopodium tomentosum (Kunth) Govaerts. It is hypothesized that host-plant distribution ranges can provide clues to potential distribution ranges of these newly discovered, trophically specialized leaf miners. The leaf mines, adults, and the genitalia of the new species are illustrated with photographs. 

Numerical Definition of Groundfish Assemblages Caught Off the Coasts of Oregon and Washington Using Commercial Fishing Strategies

1992 ◽  
Vol 49 (12) ◽  
pp. 2648-2656 ◽  
Author(s):  
Jean Beyer Rogers ◽  
Ellen K. Pikitch
Keyword(s):  
Single Species ◽  
The Other ◽  
Commercial Fishing ◽  
Mixed Species ◽  
Important Species ◽  
Trawl Fishery ◽  
Fishing Strategies ◽  
Management Plans ◽  
Recorded Data ◽  
Definition Of

Numerical definition of species caught together by the groundfish trawl fishery operating off the Oregon and Washington coasts during 1985–87 indicated six major assemblages of species. Observers on commercial vessels recorded data allowing estimation of the weights of commercially important species caught in each tow. Assemblages were selected based on consistencies in three types of analysis of the species weights: detrended correspondence ordination, two-way indicator species clustering, and Bray–Curtis group average clustering. Two of the assemblages were dominated by a single species, one consisting largely of smooth pink shrimp (Pandalus jordani) and the other primarily of widow rockfish (Sebastes entomelas). The other assemblages identified were a deepwater rockfish assemblage, a deepwater Dover sole assemblage, a nearshore mixed-species assemblage, and a bottom rockfish assemblage. These assemblages of commercially cooccurring species may be treated as units in developing mixed-species management plans. The deepwater rockfish assemblage we identify has not been previously described.

scholarly journals Identification, partial characterization, and use of grey mullet (Mugil cephalus) vitellogenins for the development of ELISA and biosensor immunoassays

2019 ◽  
Vol 11 (4) ◽  
pp. 389-399
Author(s):  
Paolo Cocci ◽  
Francesco Alessandro Palermo ◽  
Stefania Pucciarelli ◽  
Antonino Miano ◽  
Massimiliano Cuccioloni ◽  
...  
Keyword(s):  
Indirect Elisa ◽  
Dynamic Range ◽  
Polyclonal Antibodies ◽  
Sediment Quality ◽  
Analytical Techniques ◽  
Mugil Cephalus ◽  
Partial Characterization ◽  
Grey Mullet ◽  
Important Species ◽  
Optical Immunosensor

Abstract Vitellogenin (Vtg) has proven to be a sensitive and simple biomarker in determining sex, sexual maturity, and xenoestrogenic effects in fish. Thus, our investigation has been focused on identification, partial characterization, and quantification of grey mullet (Mugil cephalus) Vtg through the use of a variety of biochemical and immunological analytical techniques. Mullet is considered both a promising aquaculture candidate and an important species for improving sediment quality in polyculture systems. In the first part of this work, grey mullet Vtg was purified from plasma of 17β-estradiol (E2)-induced male fish by a one-step chromatographic protocol, and partially characterized. Specific polyclonal antibodies were then raised against the mullet Vtg, and both an indirect ELISA and an optical immunosensor were set up and validated to quantify plasma Vtg. The indirect ELISA and the optical immunosensor assay developed showed linear measuring in the range 56.8–1047.1 ng mL−1 and 70–739 ng mL−1 Vtg concentrations in standard solutions, respectively. The results obtained suggest that the indirect ELISA allows Vtg detection over a wide dynamic range, thus resulting more suitable for rapid and sensitive sample screening. Therefore, we suggest that the direct immunosensor is a promising tool which needs more investigation to improve the sensitivity.

scholarly journals Catch composition of deep-sea resources of commercial importance in the Colombian Caribbean

2019 ◽  
Vol 54 (2) ◽  
pp. 194 ◽  
Author(s):  
Marcela Grijalba-Bendeck ◽  
Jorge Paramo ◽  
Matthias Wolff
Keyword(s):  
Deep Sea ◽  
Unit Area ◽  
Base Line ◽  
Total Biomass ◽  
Sustainable Utilization ◽  
Depth Stratum ◽  
Important Species ◽  
Management Plans ◽  
Catch Composition ◽  
Management And Conservation

Recent studies in the Colombian Caribbean Sea describe the potential for a new deep-sea crustacean fishery between 200 a 550-m depth. In order to support appropriate management plans for their sustainable utilization, the goal of the present study was to identify the catch composition and to detect general trends in the bathymetric distribution of the main four biological categories (crustaceans, teleostean, chondrichthyes and molluscs), in relation to depth strata. A total catch per unit area of 8,759 ind. km-2 and 226 kg km-2 was reported and the major contribution was supported by teleostean fish (89 species; 62% abundance and 73% of total biomass), dominating the depth stratum 200-300 m, followed by crustaceans (36% and 22%, respectively) for deeper waters (> 500 m). Most important species were the fish Coelorinchus caelorhincus (20.2 ind. km-2; 16.7 kg km-2) and the crustaceans Penaeopsis serrata (579 ind. km-2, 7% of the total abundance) and Pleoticus robustus (12.6 kg km-2, 6% of the total biomass). The information obtained is part of a base line required to describing the potential effects of deep-sea fisheries on the ecosystem and supporting future decisions about use, management and conservation of deep resources for this region.

Morphologie bucco-linguale d'une guilde de canards barboteurs

1986 ◽  
Vol 64 (10) ◽  
pp. 2176-2180 ◽  
Author(s):  
Serge Tremblay ◽  
Richard Couture
Keyword(s):  
Resource Partitioning ◽  
Anas Platyrhynchos ◽  
Morphological Characters ◽  
Food Resources ◽  
Average Weight ◽  
Dabbling Ducks ◽  
Interspecific Differences ◽  
Interspecific Variations ◽  
Duck Species ◽  
Black Duck

Interspecific variations of bucco-lingual characteristics were measured in a guild of dabbling ducks and the influence of these characteristics on the use of food resources was studied. Morphological characters of the bill and tongue were measured in eight species of dabbling ducks of the genus Anas. Our results show that there are interspecific differences in the bucco-lingual characteristics of all species studied except for the Black Duck (Anas rubripes) and the Mallard (Anas platyrhynchos). There was a significant correlation between the density of bill lamellae and the weight of the species (r = −0.935, P < 0.01). In six species, the density of the lamellae was correlated with the volumetric index of the bill (r = −0.960, P < 0.01). These results indicate that in species with large bills the density of the lamellae is low, whereas in species with small bills, the number of lamellae is high. The volumetric index of the bill was significantly related to the average weight of each duck species (r = −0.905, P < 0.01). Dabbling ducks that filter benthic material can thus be classified on a scale based on lamellar density and bill volume. The differences in bucco-lingual morphlogical characters seem to reflect a mode of resource partitioning that diminishes competition.[Journal translation]

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

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