Deep water whitefish
| Deep water whitefish | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
.jpeg)
Deep water whale ( Coregonus johannae ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Coregonus johannae | ||||||||||||
| ( Wagner , 1910) |
The deep water whale ( Coregonus johannae ) is an extinct North American freshwater fish from the salmon fish family (Salmonidae).
description
The deep water whitefish was one of the largest whitefish in the Great Lakes . Their average length was 29 cm, their weight about 680 grams. It differed from other vendace by its relatively long pectoral fins and its unpigmented jaws. Furthermore, it had 27 to 32 short gill spines on the first gill arch . The color of the scales was silvery with a delicate pink or purple tinge. The back was greenish or bluish. The belly was white.
Occurrence
The deep water whitefish occurred at depths of 50 to 160 m in Lake Huron and Lake Michigan .
Way of life and food
The spawning season was in late summer from mid-August to the end of September. The main diet consisted of small crustaceans and mussels such as mysis , pisidium and pontoporeia .
die out
The overfishing of the deep water whitefish began as early as the mid-19th century and by the early 1920s the stocks were so seriously depleted that this species was extinct in large parts of its former range. In 1951 the deep-water whitefish was last detected in Lake Michigan and in 1952 last in Lake Huron. Other reasons for their extinction were the hybridization with Coregonus hoyi (English: Bloater) and the parasitism by the invasive sea lamprey .
literature
- David Stephen Lee et al .: Atlas of North American Freshwater Fishes . North Carolina State Museum of Natural History, Raleigh 1980, ISBN 0-917134-03-6 .
- David Day: The Doomsday Book of Animals . Ebury Press, London 1981, ISBN 0-670-27987-0 .
Web links
- Deep water whitefish on Fishbase.org (English)
- Canadian Species at risk ( Memento of March 10, 2005 in the Internet Archive )
- Fish of the Great Lakes - Coregonus johannae ( DjVu viewer required)
- Coregonus johannae in the Red List of Threatened Species of the IUCN 2008. Posted by: World Conservation Monitoring Center, 1996. Retrieved on March 2 of 2009.