Larval identification of the ruffe, Gymnocephalus cernuus (Linnaeus) (Percidae: Percini), in the St. Louis River Estuary, Lake Superior drainage basin, Minnesota

1991 ◽  
Vol 69 (2) ◽  
pp. 436-442 ◽  
Author(s):  
Thomas P. Simon ◽  
Joe T. Vondruska
Keyword(s):  
North America ◽  
Yellow Perch ◽  
Drainage Basin ◽  
Lake Superior ◽  
River Estuary ◽  
Swim Bladder ◽  
Species Occurrence ◽  
Caudal Peduncle ◽  
Gymnocephalus Cernuus ◽  
Native North American

A reproducing population of the Eurasian percid Gymnocephalus cernuus was discovered in the St. Louis River, Lake Superior basin, near Duluth, Minnesota. This study is the first documented evidence of the species occurrence and reproduction in North America. Larvae resemble typical percids and are described with emphasis on meristic, morphometric, and pigmentary characters. Ruffe are distinguished from all native North American percids by the presence of a slightly concave head becoming attenuated at larger length intervals, a pointed snout with teeth on the maxillary and premaxillary by the time a length of 11 mm is reached, a large dorsally pigmented swim bladder, a serrated preopercle, and few postanal myomeres (usually 18–22). In particular, ruffe superficially resemble johnny darters as yolk-sac larvae, and walleye, yellow perch, and logperch at lengths greater than 10 mm, but can be distinguished by the previously mentioned characteristics and a deep shoulder depth and a narrow caudal peduncle.

Ruffe, Gymnocephalus cernuus: Newly Introduced in North America

1992 ◽  
Vol 49 (8) ◽  
pp. 1616-1618 ◽  
Author(s):  
Dennis M. Pratt ◽  
William H. Blust ◽  
James H. Selgeby
Keyword(s):  
North America ◽  
Ballast Water ◽  
Lake Superior ◽  
Late Summer ◽  
Gymnocephalus Cernuus ◽  
Eurasian Ruffe

The Eurasian ruffe, Gymnocephalus cernuus, was collected from the lower St. Louis River, Lake Superior's westernmost tributary, in late summer 1987. This is the first known occurrence of the ruffe in North America. The likely vector for this species was ballast water of a transoceanic vessel dumped into the international port of Duluth-Superior located on the lower end of the St. Louis River. The ruffe is increasing in abundance and expanding its range into other tributaries and nearshore areas of Lake Superior.

Enumeration and Identification of Asbestos Fibres in Water

1974 ◽  
Vol 32 ◽  
pp. 526-527 ◽  
Author(s):  
O. Mudroch ◽  
J. R. Kramer
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Drainage Basin ◽  
Lake Superior ◽  
Research Work ◽  
List Type ◽  
The West ◽  
Asbestos Fibre ◽  
Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

Coccomyces papillatus. [Descriptions of Fungi and Bacteria].

2001 ◽  
Author(s):  
D. W. Minter
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
North American ◽  
European Countries ◽  
Native North American ◽  
Pinus Wallichiana

Abstract A description is provided for Coccomyces papillatus. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: The ecology of this fungus is completely unknown. SHERWOOD (1980) noted strong similarities with Coccomyces strobi (IMI Descriptions No. 1292), which is known to occur on brittle dead attached twigs of native North American five-needled pines in North America and some European countries to which they have been introduced. This habitat is often associated with endobionts involved in self-pruning ecosystems which later fruit on dead twigs, best exemplified by Colpoma quercinum on Quercus and C. crispum on Picea (IMI Descriptions Nos 942. 1333), and Therrya fuckelii and T. pini on Pinus (IMI Descriptions Nos 1297, 1298) and it is tempting to speculate that C. papillatus too will prove to occupy this sort of niche. HOSTS: Pinus wallichiana (twig). GEOGRAPHICAL DISTRIBUTION: ASIA: Pakistan. TRANSMISSION: Not known. Presumably by air-borne ascospores released in humid conditions.

The biology of Canadian weeds. 130. Solidago nemoralis Ait.

2004 ◽  
Vol 84 (4) ◽  
pp. 1221-1233 ◽  
Author(s):  
Jerry G. Chmielewski ◽  
John C. Semple
Keyword(s):  
United States ◽  
North America ◽  
Deciduous Forest ◽  
Sandy Soils ◽  
The United States ◽  
Eastern Deciduous Forest ◽  
Rock Outcrops ◽  
Native North American ◽  
Forest Region ◽  
Riparian Habitats

Solidago nemoralis, the gray goldenrod, is a polycarpic hemicryptophyte that reproduces vegetatively from branched caudices. This native North American species is morphologically variable throughout its range, and includes an eastern (ssp. nemoralis) and western (ssp. decemflora) race. The eastern subspecies occurs throughout the eastern deciduous forest region of North America and is commonly diploid, though tetraploids do occur throughout. The western race typically occurs on the prairies and is strictly tetraploid. The species occupies riparian habitats, rock outcrops and open fields and roadsides and grows best in well-drained sandy soils in full sunlight. Although the species is weedy in both Canada and the United States it is not noxious. Key words: Solidago nemoralis, gray goldenrod, verge d'or des bois, Asteraceae, Compositae

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