Effect of Algal Cover on Size-Selective Predation of Gammarus mucronatus by the Striped Killifish, Fundulus majalis

1995 ◽  
Vol 189 (2) ◽  
pp. 243-244 ◽  
Author(s):  
C. Drake ◽  
P. J. Behr ◽  
I. Valiela
Keyword(s):  
Selective Predation ◽  
Algal Cover ◽  
Gammarus Mucronatus

Selective Predation and Productivity Jointly Drive Complex Behavior in Host‐Parasite Systems

2005 ◽  
Vol 165 (1) ◽  
pp. 70-81 ◽  
Author(s):  
Spencer R. Hall ◽  
Meghan A. Duffy ◽  
Carla E. Cáceres
Keyword(s):  
Complex Behavior ◽  
Selective Predation ◽  
Host Parasite

Moray Firth marine fouling communities

1986 ◽  
Vol 91 ◽  
pp. 213-220 ◽  
Author(s):  
Gordon B. Picken
Keyword(s):  
Shallow Water ◽  
Depth Range ◽  
Soft Corals ◽  
Fouling Communities ◽  
Algal Cover ◽  
Marine Fouling ◽  
Moray Firth ◽  
Hanging Chain ◽  
Fouling Organisms

SynopsisFouling communities typical of shallow water inshore sites were found at three locations in the Moray Firth. At each, an initial background cover of solitary tubeworms and barnacles was overgrown by secondary fouling organisms. On the piles of Nigg jetty, overgrowth consisted of mussels in the depth range 0–6 m and hydroids, sponges, soft corals and anemones from 6–26 m. Buoys in the approaches to Cromarty Firth were completely covered by a mixture of algae and mussels. Sunlit areas of the float cleaned annually bore a diverse algal cover, whereas uncleaned shaded areas and the freely hanging chain had three-year-old mussels up to 7 cm long. Mussel fouling extended down the chain to within 1 m of the seabed at 26 m depth. Concrete anchor blocks on the seabed were covered with solitary tubeworms and hydroids. Steel piled platforms in the Beatrice Field were completely fouled after four years. Mussels and seaweeds were abundant from 0–5 m. In the depth range 8–35 m the background calcareous layer was overgrown by soft corals up to 10 cm long and hydroids. From 35 m to the seabed at 46 m, soft overgrowth was provided mainly by hydroids and ascidians, with only a few small corals.

scholarly journals Evolution of a predator-induced, nonlinear reaction norm

2017 ◽  
Vol 284 (1861) ◽  
pp. 20170859 ◽  
Author(s):  
Mauricio J. Carter ◽  
Martin I. Lind ◽  
Stuart R. Dennis ◽  
William Hentley ◽  
Andrew P. Beckerman
Keyword(s):  
Evolutionary Dynamics ◽  
Daphnia Pulex ◽  
Reaction Norm ◽  
Maximum Response ◽  
Selective Predation ◽  
Evolutionary Trajectory ◽  
Defensive Reaction ◽  
Selection Gradients ◽  
Hunting Strategies ◽  
Evolutionary Response

Inducible, anti-predator traits are a classic example of phenotypic plasticity. Their evolutionary dynamics depend on their genetic basis, the historical pattern of predation risk that populations have experienced and current selection gradients. When populations experience predators with contrasting hunting strategies and size preferences, theory suggests contrasting micro-evolutionary responses to selection. Daphnia pulex is an ideal species to explore the micro-evolutionary response of anti-predator traits because they face heterogeneous predation regimes, sometimes experiencing only invertebrate midge predators and other times experiencing vertebrate fish and invertebrate midge predators. We explored plausible patterns of adaptive evolution of a predator-induced morphological reaction norm. We combined estimates of selection gradients that characterize the various habitats that D. pulex experiences with detail on the quantitative genetic architecture of inducible morphological defences. Our data reveal a fine scale description of daphnid defensive reaction norms, and a strong covariance between the sensitivity to cues and the maximum response to cues. By analysing the response of the reaction norm to plausible, predator-specific selection gradients, we show how in the context of this covariance, micro-evolution may be more uniform than predicted from size-selective predation theory. Our results show how covariance between the sensitivity to cues and the maximum response to cues for morphological defence can shape the evolutionary trajectory of predator-induced defences in D. pulex .

Size-selective predation by roach (Rutilus rutilus) on zebra mussel (Dreissena polymorpha): field stuides

Oecologia ◽  
1990 ◽  
Vol 83 (3) ◽  
pp. 378-384 ◽  
Author(s):  
A. Prejs ◽  
K. Lewandowski ◽  
A. Stańczykowska-Piotrowska
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Rutilus Rutilus ◽  
Selective Predation ◽  
Roach Rutilus Rutilus

scholarly journals A seascape approach for guiding effective habitat enhancement

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Filippo Ferrario ◽  
Thew Suskiewicz ◽  
Ladd Erik Johnson
Keyword(s):  
Artificial Reefs ◽  
Spatially Explicit ◽  
Ecological Interactions ◽  
Eastern Canada ◽  
Algal Cover ◽  
Artificial Structures ◽  
The Past ◽  
Green Sea Urchin ◽  
Ecological Importance ◽  
Habitat Enhancement

Kelp habitats are threatened across the globe, and because of their ecological importance, active conservation and restoration solutions are needed. The use of man-made structures as artificial reefs is one way to enhance kelp habitat by providing suitable substrata, but in the past the ecology of artificial structures has been investigated mainly in contrast to natural coastal habitats, not as elements integrated into the seascape. Indeed, it is now emerging that structuring processes, including ecological interactions (e.g., herbivory), can depend on properties of the surrounding seascape. In Eastern Canada, grazing by the green sea urchin can jeopardize the success of artificial reefs for kelp enhancement. Urchin activity is, however, likely to be influenced by the bottom composition, and thus a seascape approach is needed to integrate urchin behavior and habitat heterogeneity. Adopting a spatially explicit framework, we investigated whether the seascape creates areas of differential grazing risk for kelp by affecting urchin habitat use. Specifically, we transplanted kelp onto modules of artificial substrata distributed on a heterogeneous area that we mapped for bottom type and algal cover. After following kelp survival and urchin distribution over time, we modeled kelp survival as function of urchin metrics and coupled it to urchin use of the habitat models to map grazing risk in the area. Kelp survival was a function of the frequency of the urchins presence. Urchins avoided sandy patches, while bottom composition and algal cover modulated the within-patch urchin use of the habitat, creating heterogeneity in grazing risk. Discrete seascape features (boulders) also increased the grazing risk locally. The heterogeneity of coastal seafloor can thus play a major role in determining the ecological outcomes on artificial structures. Incorporating this information when planning artificial reefs could minimize the detrimental grazing risk, thereby increasing the success of artificial reefs for kelp habitat enhancement.

Interlake variation in growth and size structure of bluegill (Lepomis macrochirus): inverse analysis of an individual-based model

1998 ◽  
Vol 55 (2) ◽  
pp. 387-396 ◽  
Author(s):  
Nathan P Nibbelink ◽  
Stephen R Carpenter
Keyword(s):  
Predation Risk ◽  
Food Availability ◽  
Inverse Modeling ◽  
Habitat Structure ◽  
Size Structure ◽  
Lepomis Macrochirus ◽  
Habitat Choice ◽  
Selective Predation ◽  
Free Parameters ◽  
Contrasting Habitats

Habitat structure alters food availability and predation risk, thereby directly affecting growth, mortality, and size structure of fish populations. Size structure has often been used to infer patterns of resource abundance and predation. However, food availability and predation risk in contrasting habitats have proven difficult to measure in the field. We use an inverse modeling approach to estimate food availability and habitat choice parameters from changes in length distributions of bluegill (Lepomis macrochirus). The model suggests that dynamics of bluegill length distributions primarily reflect food availability and habitat choice. Bluegill behavior minimized effects of size-selective predation on size structure. Parameters for food availability and habitat choice were correlated. It was therefore not possible to attain unique estimates of food availability and habitat selection when both were free parameters. However, when one parameter was estimated independently, the other could be identified. In five Wisconsin lakes, seining studies were used to estimate the size at which bluegill switched from littoral to pelagic habitats. Using this measure of switch size in the model, we estimated food availability for bluegill in each lake. These estimates were positively correlated with observed growth (r2 = 0.91), demonstrating the model's ability to estimate food availability.

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