Snake Fish: A Dangerous Invasive Species in UK Waters

Snake fish, also known as snakehead fish or channa, are a type of freshwater fish that have been causing a stir in recent years.

These predatory fish are native to parts of Africa and Asia, but have been introduced to other parts of the world, including the UK, where they are considered an invasive species.

One of the most distinctive features of snake fish is their long dorsal fins, which run the length of their bodies.

They also have large mouths and shiny teeth, making them formidable predators in their native habitats. What sets them apart from other fish is their ability to breathe air with gills, which allows them to migrate short distances over land. This has earned them the nickname "walking fish".

Snake fish have become a popular topic of discussion due to their potential impact on local ecosystems. As an invasive species, they can outcompete native fish for resources and disrupt food chains.

In this article, we will explore the biology and identification of snake fish, as well as their ecology and impact. We will also answer some frequently asked questions about these fascinating creatures.

Key Takeaways

• Snake fish are a type of freshwater fish with long dorsal fins and the ability to breathe air with gills.
• They are native to parts of Africa and Asia, but have been introduced to other parts of the world, where they are considered an invasive species.
• Snake fish can outcompete native fish for resources and disrupt food chains, which can have a negative impact on local ecosystems.

Biology and Identification

Physical Characteristics

Snakeheads are a type of freshwater fish that are known for their elongated bodies and snake-like heads.

These fish have large mouths and sharp teeth, which they use to catch their prey. They also have scales covering their bodies and a long dorsal fin that runs along their backs. The anal fin is located near the tail and helps the fish to maintain balance in the water.

The size of snakeheads can vary greatly depending on the species and location.

For example, the Northern Snakehead (Channa argus) can grow up to 33 inches in length, while the Striped Snakehead (Channa striata) typically reaches a maximum length of 24 inches.

Species and Distribution

Snakeheads belong to the family Channidae and are native to parts of Africa and Asia, including China, India, and Southeast Asia. They have also been introduced to other parts of the world, including North America, where they are considered an invasive species.

In North America, snakeheads have been found in Florida, Maryland, California, and other states.

They were first discovered in the Potomac River in Virginia in 2002 and have since spread to other waterways in the region.

Respiration and Breeding

One of the most unique characteristics of snakeheads is their ability to breathe air with their gills.

They also have a suprabranchial organ that allows them to extract oxygen from the air. This adaptation enables snakeheads to survive in low-oxygen environments and even migrate short distances over land.

Snakeheads reproduce through spawning. Sexual maturity is reached at around 2-3 years of age, and females can lay up to 15,000 eggs at a time.

The eggs hatch after a few days, and the juveniles are left to fend for themselves. Snakeheads can be aggressive towards other fish and may even eat their own young.

Ecology and Impact

Diet and Predation

The Northern Snakehead is a carnivorous fish that feeds on a variety of prey including insects, frogs, goldfish, plankton, carp, crayfish, and worms.

They have a unique ability to breathe air, which allows them to survive in low-oxygen environments. The Northern Snakehead can also tolerate a wide range of temperatures, making them adaptable to different habitats.

Invasive Species Concerns

Northern Snakeheads are an invasive species that can have a significant impact on native species and their habitats. According to the U.S. Geological Survey, they have been sighted in ponds, lakes, and rivers in several states.

Their ability to reproduce quickly and their aggressive feeding behaviour can lead to a decline in native species populations. They also have the potential to outcompete native species for food and habitat, which can lead to their displacement.

Human Interactions

Northern Snakeheads were introduced to the United States as a food fish and for the aquarium trade. However, they have since become a problem due to their invasive nature.

In some areas, they are considered a sport fish and have even been caught in world record sizes. Despite their potential as a food source, they are not recommended for consumption due to their high levels of mercury.

Frequently Asked Questions

What's the proper name for a snakehead fish?

The proper name for a snakehead fish is Channa. There are several species of snakehead fish, including the Northern snakehead and the Giant snakehead.

How much does a snakehead fish typically cost?

The price of a snakehead fish can vary depending on the size and species. On average, a small snakehead fish can cost around £20, while a larger one can cost up to £200.

Can snakehead fish really walk on land?

Yes, snakehead fish are known to be able to "walk" on land using their fins to move short distances. However, they cannot survive out of water for long periods of time.

What size do snakehead fish generally reach?

Snakehead fish can grow to be quite large, with some species reaching up to 1.5 meters in length. However, the average size of a snakehead fish is around 50-60 centimeters.

What kind of problems are caused by snakehead fish in the wild?

Snakehead fish are an invasive species and can cause a number of problems in the wild. They can outcompete native fish for food and habitat, and can also spread diseases to other fish populations.

Are snakehead fish known to be aggressive towards other fish or humans?

Snakehead fish are known to be aggressive towards other fish, but they generally avoid contact with humans.

However, it is important to handle them with care as they have sharp teeth and can bite if they feel threatened.