Seasonal Occurrence of Tokophrya quadripartita (Suctoria) as Epibionts on Adult Limnocalanus macrurus (Copepoda: Calanoida) in Southeastern Lake Michigan

Tumor-like abnormalities (exophytic lesions) were found on a variety of planktonic calanoid copepods and cladocerans (Diaptomus spp., Epischura lacustris, Limnocalanus macrurus, Polyphemus pediculus, Diaphanosoma sp., and Daphnia galeata mendotae) collected from inshore (3-m depth contour) and offshore (100- to 110-m depth contours) stations of eastern Lake Michigan. The abnormalities, which were quite large relative to animal size and variable in shape, are documented in photographs. Abnormality incidences among species ranged between 0 and 72%. Predatory species of calanoids and cladocerans had higher incidences of tumors than herbivorous species. The abnormalities on some copepods were very similar to cysts described for calanoid copepods in Lago Maggiore, Italy, which like Lake Michigan is undergoing oligotrophication. The recent appearance of the lesions in Europe and North America may indicate an emerging global phenomenon that has a common cause.

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Large-Lake Responses to Declines in the Abundance of a Major Fish Planktivore—the Lake Michigan Example

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f90-198 ◽

1990 ◽

Vol 47 (9) ◽

pp. 1738-1754 ◽

Cited By ~ 25

Author(s):

Marlene S. Evans

Keyword(s):

Yellow Perch ◽

Lake Michigan ◽

Dry Weight ◽

Fish Predation ◽

Water Clarity ◽

Zooplankton Biomass ◽

Rainbow Smelt ◽

Adult Copepod ◽

Limnocalanus Macrurus ◽

Offshore Region

Alewife abundances declined dramatically in southeastern Lake Michigan over 1973–77, several years before the lakewide decline occurred. The regional effects of this decline on adult copepod abundances, zooplankton biomass, and water clarity are examined. In the offshore region, the two largest copepods, Limnocalanus macrurus and Diaptomus sicilis, increased in abundance during the mid-1970's, reflecting the decrease in alewife predation. Limnocalanus macrurus abundances declined in later years, reflecting increased prédation pressures from the increasing bloater population. The small-bodied D. minutus and the medium-bodied D. ashlandi exhibited no apparent response to the decline in alewife abundance. Large-bodied D. oregonensis and small-bodied C. bicuspidatus thomasi declined in abundance. Size-selective fish prédation pressures continued to remain high in the inshore region: increased abundances of yellow perch and rainbow smelt apparently compensated for the alewife decline. Zooplankton biomass, zooplankton mean dry weight, and water clarity apparently were not affected by the decline in alewife abundance in either the inshore or offshore region. The results of this study are evaluated in terms of the lakewide decline in alewife abundance, the summer 1983 dominance of Daphnia pulicaria in offshore waters, the 1983 marked improvement in offshore water clarity, and later changes in summer offshore D. pulicaria populations.

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Ultrastructure of Melosira resting cell rejuvenation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010011355x ◽

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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Multi-sensor Study of Lake Michigan�s Surface using GNSS-Reflectometry

Proceedings of the 31st International Technical Meeting of The Satellite Division of the Institute of Navigation (ION GNSS+ 2018) ◽

10.33012/2018.15860 ◽

2018 ◽

Cited By ~ 1

Author(s):

Roohollah Parvizi ◽

Houshine Sabbagh Zadeh ◽

Li Pan ◽

Boris Pervan ◽

Seebany Datta-Barua

Keyword(s):

Lake Michigan ◽

Gnss Reflectometry

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Seasonal occurrence and hatching of calanoid eggs in sediments of the northern Baltic Sea

Marine Ecology Progress Series ◽

10.3354/meps171133 ◽

1998 ◽

Vol 171 ◽

pp. 133-143 ◽

Cited By ~ 1

Author(s):

T Katajisto ◽

M Viitasalo ◽

M Koski

Keyword(s):

Baltic Sea ◽

Seasonal Occurrence

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Birds eaten by King James V of Scotland in 1525–1533, and the prices decreed by his daughter Mary Queen of Scots in 1551

Archives of Natural History ◽

10.3366/anh.2006.33.1.135 ◽

2006 ◽

Vol 33 (1) ◽

pp. 135-139

Author(s):

W. R. P. Bourne

Keyword(s):

Quantitative Information ◽

Seasonal Occurrence ◽

Household Accounts

The household accounts of King James V of Scotland provide the first quantitative information on the seasonal occurrence of birds there, and some first records.

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