Variable demographics and consumption requirements of Bythotrephes longimanus (Crustacea, Cercopagididae) along a nearshore to offshore gradient in Lake Michigan

Hydrobiologia ◽  
2018 ◽  
Vol 830 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Steven A. Pothoven ◽  
Henry A. Vanderploeg
Keyword(s):  
Lake Michigan ◽  
Bythotrephes Longimanus

Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

2014 ◽  
Vol 71 (7) ◽  
pp. 1072-1086 ◽  
Author(s):  
Mark W. Rogers ◽  
David B. Bunnell ◽  
Charles P. Madenjian ◽  
David M. Warner
Keyword(s):  
Food Web ◽  
Functional Groups ◽  
Lake Michigan ◽  
Neogobius Melanostomus ◽  
Trophic Levels ◽  
Nutrient Concentrations ◽  
Ecosystem Structure ◽  
Bythotrephes Longimanus ◽  
Nutrient Inputs ◽  
Food Web Structure

Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

Temporal and spatial separation allow coexistence of predatory cladocerans: Leptodora kindtii, Bythotrephes longimanus and Cercopagis pengoi, in southeastern Lake Michigan

2010 ◽  
Vol 36 ◽  
pp. 65-73 ◽  
Author(s):  
Joann F. Cavaletto ◽  
Henry A. Vanderploeg ◽  
Radka Pichlová-Ptáčníková ◽  
Steven A. Pothoven ◽  
James R. Liebig ◽  
...  
Keyword(s):  
Lake Michigan ◽  
Spatial Separation ◽  
Bythotrephes Longimanus ◽  
Cercopagis Pengoi ◽  
Leptodora Kindtii ◽  
Temporal And Spatial

Light-dependent predation by the invertebrate planktivore Bythotrephes longimanus

2009 ◽  
Vol 66 (10) ◽  
pp. 1748-1757 ◽  
Author(s):  
Kevin L. Pangle ◽  
Scott D. Peacor
Keyword(s):  
Light Intensity ◽  
Lake Michigan ◽  
Ingestion Rate ◽  
Prey Type ◽  
Water Clarity ◽  
High Water ◽  
High Light Intensity ◽  
Bythotrephes Longimanus ◽  
Low Light ◽  
Effect Of Light

We evaluated predation by the invasive invertebrate planktivore Bythotrephes longimanus on a Lake Michigan prey assemblage as a function of light intensity. Daphnia mendotae was the only prey type significantly reduced and light intensity strongly affected this reduction. Specifically, Bythotrephes consumption of D. mendotae was not detected under low light intensity (<1 µmol·m–2·s–1) but increased with greater light intensity and leveled off under high light intensity (>100 µmol·m–2·s–1) at which point Bythotrephes ingestion rate was 2.3 Daphnia per hour. These results indicate that Bythotrephes predation is more sensitive to light than previously thought, a discrepancy that can be explained after considering the ability of D. mendotae to detect Bythotrephes’ hydromechanic disturbance. The observed effect of light intensity on Bythotrephes predation is more like that of planktivorous fish than that of other previously studied invertebrate planktivores. Our findings elucidate the role that Bythotrephes plays in the food web and provide a novel explanation for its tendency to invade lakes of high water clarity. The importance of light-dependent predation found here may extend to other visually oriented predatory cladocerans.

Ultrastructure of Melosira resting cell rejuvenation

1984 ◽  
Vol 42 ◽  
pp. 734-735
Author(s):  
C. E. M. Bourne ◽  
L. Sicko-Goad
Keyword(s):  
Electron Microscopy ◽  
Lake Michigan ◽  
Light And Electron Microscopy ◽  
Resting Cells ◽  
Planktonic Diatoms ◽  
Resting Cell ◽  
Vegetative Survival ◽  
Cytological Changes ◽  
Recent Attention ◽  
Freshwater Diatom

Much recent attention has been focused on vegetative survival forms of planktonic diatoms and other algae. There are several reports of extended vegetative survival of the freshwater diatom Melosira in lake sediments. In contrast to those diatoms which form a morphologically distinct resistant spore, Melosira is known to produce physiological resting cells that are indistinguishable in outward morphology from actively growing cells.We used both light and electron microscopy to document and elucidate the sequence of cytological changes during the transition from resting cells to actively growing cells in a population of Melosira granulata from Douglas Lake, Michigan sediments collected in mid-July of 1983.

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