Deepwater cisco facts for kids
Quick facts for kids Deepwater cisco |
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|---|---|
| Conservation status | |
| Scientific classification | |
| Genus: |
Coregonus
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| Species: |
johannae
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The deepwater cisco (Coregonus johannae) was a type of fish that lived in the Great Lakes. It was one of the biggest ciscoes, growing to about 30 cm (12 inches) long and weighing around 1.0 kilogram (2.2 pounds). This fish was only found in Lake Huron and Lake Michigan. It lived in deep waters, usually between 50 and 150 metres down.
It was sometimes hard to tell the deepwater cisco apart from other cisco fish. One way to identify it was by its fewer than 33 gill rakers (parts used for breathing), long pectoral fins, and jaws that had no color. The deepwater cisco was a shiny silver color, sometimes with a pink or purple glow. Its back was green or blue. These fish laid their eggs in August and September, which was earlier than most other ciscoes. We don't know much about their daily habits. They ate small creatures like Mysis relicta, tiny fingernail clams, and different water insects. Because of its large size, people caught a lot of deepwater ciscoes for selling.
The deepwater cisco became extinct because of a few main reasons. These included new fish like the alewife competing for food, predators like the sea lamprey eating them, and too much commercial fishing in the Great Lakes.
Why Did the Deepwater Cisco Disappear?
Fishing and Its Impact
Before the 1900s, the deepwater cisco was very common. The bigger ciscoes didn't have many natural enemies in Lake Michigan. But this changed when people started fishing for them a lot.
In the 1930s, people began to catch the deepwater cisco for money. Fishermen often called them "chubs." They liked these fish because they were bigger than other ciscoes. As more and more were caught, the number of deepwater ciscoes dropped very quickly.
The Last Sightings
The last deepwater ciscoes were seen in Lake Michigan in 1951. In Lake Huron, the last ones were recorded in 1952. Soon after, scientists said the fish was extinct. In the 1960s, researchers looked for the deepwater cisco again in states near Lake Michigan. They couldn't find any. This confirmed that the deepwater cisco was gone forever. Its extinction was caused by too much fishing and new predators like the sea lamprey.
