Cisco (fish) facts for kids

Quick facts for kids Ciscoes
Coregonus artedi
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Salmoniformes
Family:	Salmonidae
Subfamily:	Coregoninae
Genus:	Coregonus (in part)

Ciscoes are a type of fish that belong to the salmon family. They are part of a group of fish called Coregonus. What makes ciscoes special is that their upper and lower jaws are about the same length. They also have many gill rakers, which are like tiny combs that help them filter food from the water.

Scientists have been studying ciscoes a lot. They want to understand how different types of ciscoes are related to each other. The word cisco is also used for a specific North American fish called Coregonus artedi, which is also known as the lake herring.

In the past, ciscoes were thought to be a separate subgroup within Coregonus. But new studies, using information from their DNA, show that ciscoes actually come from two different family lines within the freshwater whitefish group. This means they are not all as closely related as once thought.

Ciscoes of North America's Great Lakes

In the Great Lakes region of North America, scientists have found eight different kinds of ciscoes. These fish live in the Great Lakes and other lakes that were once covered by glaciers.

Here are some of the cisco types found there:

• †Longjaw cisco – Coregonus alpenae (This one is extinct)
• Cisco (also called lake cisco or lake herring) – Coregonus artedi
• †Deepwater cisco – Coregonus johannae (This one is extinct)
• Bloater – Coregonus hoyi
• Kiyi – Coregonus kiyi
• †Blackfin cisco – Coregonus nigripinnis (This one is extinct)
• Shortnose cisco – Coregonus reighardi (This one might be extinct)
• Shortjaw cisco – Coregonus zenithicus

Often, several types of ciscoes live in the same lake. They live in different parts of the lake and eat different foods. They also have different ways of breeding. For example, their gill rakers can be different depending on what they eat. In the Great Lakes, at least five types of ciscoes live together.

Scientists have found that these different cisco types are not always separate species. Instead, similar cisco forms have developed on their own in each lake. This means that many of them might just be different forms of one species, Coregonus artedi. However, for protecting these fish, it's important to treat each group as special.

Ciscoes were once very important for fishing, especially in the Great Lakes. People used to catch many deepwater ciscoes. But over time, the number of ciscoes went down. This happened because of overfishing and because new fish, like sea lamprey, rainbow smelt, and alewife, came into the lakes. Alewives, for example, eat cisco eggs and young fish. They also compete with ciscoes for food. Because cisco numbers dropped so much, the fishing industry for them has mostly stopped.

Ciscoes of Northwestern North America

There are three types of ciscoes that live in the waters of northwestern North America. Studies of their DNA show that these are truly different species.

• Arctic cisco – Coregonus autumnalis
• Bering cisco – Coregonus laurettae
• Least cisco – Coregonus sardinella

Ciscoes of Europe and Asia

The cisco species found in northwestern North America also live across Beringia (the land bridge that once connected Asia and North America) to the coasts of Asia. The Arctic cisco and least cisco are found all over northern Siberia. In northern Europe, the European cisco (also called vendace, Coregonus albula) takes the place of the Siberian sardine cisco.

Some cisco groups are very similar genetically, like the European and sardine ciscoes. Within some species, groups living in different places have been called different types, even if they are very closely related. For example, the pollan in the British Isles is very similar to the Arctic cisco.

The European cisco has also developed into different groups within the same lakes. These groups have different habits, like spawning in autumn or spring, or being normal-sized or dwarf-sized. This makes it tricky to classify them, much like the Coregonus artedi group in North America.

Here are some of the ciscoes found in Europe and Asia:

• Bering cisco – Coregonus laurettae
• Arctic cisco – Coregonus autumnalis
  • Irish pollan - "Coregonus pollan": a group of populations in Ireland
• Sardine cisco (= least cisco) – Coregonus sardinella
• Peled – Coregonus peled: part of the C. sardinella group
• European cisco (=vendace) – Coregonus albula
  • "Coregonus vandesius": a group of British populations
  • Stechlin cisco – Coregonus fontanae: a local, smaller species that spawns in spring
  • Coregonus trybomi: a local species that spawns in spring
  • Coregonus lucinensis: a local, smaller species

Cisco Family Tree

Based on DNA studies, ciscoes actually belong to two different, unrelated groups:

• One group includes the Coregonus artedi types, along with C. laurettae and C. autumnalis.
• The other group is the Coregonus sardinella types, which includes C. peled and C. albula. This second group is actually more closely related to "true whitefishes" like the common whitefish (C. lavaretus) and lake whitefish (C. clupeaformis) than to the first group of ciscoes.

• "Coregonus". FishBase. Ed. Ranier Froese and Daniel Pauly. October 2004 version. N.p.: FishBase, 2004.

Images for kids

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  Bering cisco