Salvelinus agassizi

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Salvelinus agassizi
Salvelinus agassizi.jpg

Salvelinus agassizi

Systematics
Overcohort : Clupeocephala
Cohort : Euteleosteomorpha
Order : Salmonid fish (Salmoniformes)
Family : Salmon fish (Salmonidae)
Genre : Char ( salvelinus )
Type : Salvelinus agassizi
Scientific name
Salvelinus agassizi
( Garman , 1885)

Salvelinus agassizi (English common names : Silver trout or Dublin Pond trout ) is an extinct freshwater fish species from the genus of char . The occurrence was limited to two bodies of water in the US state of New Hampshire . The type epithet honors the zoologist Louis Agassiz .

features

Salvelinus agassizi usually weighed between 1.4 and 2.3 kilograms. However, individuals who weighed 3.2 kilograms have also been caught. In the male, the upper side was dark gray-green, the color of the lateral line organ was lighter and yellowish. The underside was yellow to pale pearly gray with a light satur red tinge. The throat and abdomen were pure white. Dull orange-yellow dots and five pale purple eggspots with purple centers were scattered across the midsection. The head was light olive green with numerous metallic-shimmering pink, pearl, yellow, purple or reddish tones. The lower jaw was whitish with dark speckles and a slightly flesh-colored or dull orange-tinged tip. The iris was straw yellow. The dorsal fin was dull yellow with irregular dark horizontal lines. The fin rays were dull purple and slightly lighter on the upper edge with a narrow dark line. The pectoral fins, the pelvic fins and the anal fins were light purple-pink.

die out

Salvelinus agassizi began to decline in the late 19th century when the stocks were overfished in spring and autumn . However, the dramatic collapse of the population came when alien fish species such as Atlantic salmon , rainbow trout , American arctic char , king salmon , catfish , arctic smelt , yellow perch and American striped bass were released in Dublin Pond and Christine Lake. They chased the char and decimated the brood and eggs. In addition, both Dublin Pond and Christine Lake were used for breeding brown trout and brook trout , which led to hybridization between Salvelinus agassizi and Salvelinus fontanalis . The last record in Christine Lake was 1926. The last six specimens were caught in Dublin Pond in 1930. In 1939 the species was declared extinct.

Systematics

Salvelinus agassizi was discovered in 1849, but was not scientifically described as Salmo agassizii until 1885 by Samuel Garman . In 1885 it was classified by David Starr Jordan and in 1914 by William Converse Kendall as a subspecies of brook trout ( Salvelinus fontinalis ). In a comparison between Salvelinus agassizi and Salvelinus fontinalis , which the American ichtyologist Robert John Behnke of the Museum of Comparative Zoology at Harvard University had carried out in 1972, however, he recognized differences in morphology and coloration between the two taxa , which led to a reclassification from Salvelinus agassizi as a species.

literature

  • Frank M. Johnson: Forest, Lake and River; the fishes of New England and eastern Canada. sn, Boston MA 1902.
  • William Converse Kendall: The Fishes of New England. The Salmon Family. Part 1: The trout or charrs (= Memoirs of the Boston Society of Natural History. Vol. 8, 1, ISSN  0271-5708 ). Boston Society of Natural History, Boston MA 1914.
  • Levi W. Leonard, Josiah L. Seward: The History of Dublin, NH Published by the Town of Dublin, Dublin NH 1920.
  • Herbert E. Warfel et al .: Notes on Lakes of the Connecticut watershed. In: Biological survey of the Connecticut watershed. New Hampshire Fish and game department, Concord NH 1939, pp. 88-121.
  • David S. Lee et al .: Atlas of North American Freshwater Fishes. North Carolina State Museum of Natural History, Raleigh NC 1980, ISBN 0-917134-03-6 .
  • Robert R. Miller, James D. Williams, Jack E. Williams: Extinctions of North American Fishes During the Past Century. In: Fisheries. Vol. 14, No. 6, 1989, ISSN  0363-2415 , pp. 22-38, doi : 10.1577 / 1548-8446 (1989) 014 <0022: EONAFD> 2.0.CO; 2 .

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