Fish
Deepwater Cisco
Coregonus johannaeAlso known as Deepwater Chub
Deepwater ciscoes once roamed the cold, lightless abyssal depths of Lakes Michigan and Huron, serving as a critical energy link in the historic Great Lakes benthic food web. They gathered over deep clay and gravel beds to spawn during late summer, weeks earlier than other related chubs. Heavy commercial gillnetting in the late nineteenth and early twentieth centuries, compounded by invasive sea lamprey predation, drove the species to global extinction.
DeepwaterGreat Lakes
—observations
—countries
—peak records
ExtinctConservation statusIUCN Red List categoriesLCNTVUENCREWEXExtinctRed List categories, explained →
Diet & preyOpossum Shrimp, Fingernail Clams, Chironomid Larvae
Predators
- Lake Trout
- Burbot
- Sea Lamprey
ThreatsHistoric commercial overfishing, sea lamprey predation, ecosystem disruption
HabitatsDeep coldwater benthic zones of large oligotrophic lakes
Life span8–12 years
Classification
- OrderSalmoniformes
- FamilySalmonidae
- GenusCoregonus
- SpeciesCoregonus johannae
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Safe to observe at a normal distance.
Responsible observation
- Museum Collections: Examine preserved specimens in historical ichthyology archives to view its gill raker anatomy.
- Historical Records: Consult commercial Great Lakes fishery catch logs to trace its population decline.
Predator (c) Lythronax246, some rights reserved (CC BY), uploaded by Lythronax246 · cc-by
Parasite (c) Fernando Losada Rodríguez, some rights reserved (CC BY-SA) · cc-by-sa
Image unavailableClose Relative Close Relative 
Close Relative (c) BrianGwiz, some rights reserved (CC BY) · cc-by
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