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What to Know About the Killifish Life Cycle

What to Know About the Killifish Life Cycle

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

There are many different types of killifish out there. The term killifish refers to many types of egg-laying fish.

It’s said that there are 1,270 species of killifish. Many people love buying these types of fish for their aquariums.

You’ll also find killifish being sold as pupfish. If you’ve been thinking of getting some for your fish tank, you might want to learn more about them.

For example, you might be interested to learn about the life cycles of these fish. Below, you’ll get all of the information that you need to know about the killifish life cycle.

There Are Different Categories of Killifish Based on Reproductive Strategies

Killifish are put into many different categories. One way that killifish are put into different categories involves reproductive strategies.

Above, you heard that killifish are all egg-laying fish. There are three distinct reproductive strategies that you should know about.

These fish are either going to be categorized as annuals, semi-annuals, or non-annuals. Right now, these words probably don’t mean anything to you, but you need to understand what the categories represent.

Annual Killifish

Killifish that are considered to be annuals live in environments that dry up during half of the year. This has forced these fish to evolve so they can put up with such an environment.

Annual killies can go through their entire life cycle in just a few months. They need to do this because they live in non-permanent bodies of water.

An annual killifish will only live for a few months in the wild. When caring for these fish in a fish tank, they can live for several months longer.

These fish are interesting because they have short lifespans but they mature rapidly. There are some annual killifish that reach maturity just three weeks after hatching.

Because of the environments that these fish live in, their eggs must go through long dry periods to be able to hatch.

Semi-Annual Killifish

Semi-annual killifish are the next category to consider. These fish can live for quite a bit longer than the annual killifish mentioned above.

These types of fish live in streams and rivers that only occasionally run dry. They don’t have to deal with their bodies of water drying out every single year.

So they haven’t evolved to have very fast lifespans. A semi-annual killifish can live for several years.

It’s said that semi-annual killifish have average lifespans that fall between two and five years. That’s much different than the annual killifish.

Semi-annual killifish have eggs that can survive a dry period. Unlike the annual fish, these eggs don’t require a dry period to be able to hatch.

Non-Annual Killifish

Non-annual killifish live in bodies of water that don’t dry out. These fish don’t have to deal with the same issues that annual and semi-annual killifish do.

These types of fish are far more common to find being sold in stores. Since they have longer lifespans, it’s more practical to sell them to fish tank enthusiasts.

Most non-annual killifish are expected to live for around three years in a fish tank. Many of the most well-known and popular killies fall under this category.

Since these fish don’t have to worry about the bodies of water that they live in drying out, they grow a lot slower. It takes non-annual killifish longer to reach maturity.

There are many popular types of non-annual killifish that are perfect for home fish tanks. One great example is the striped panchax.

The striped panchax is rather large for a killifish. It can reach up to four inches in length.

There’s also a color variation of this fish that’s known as the golden wonder killifish. These fish are some of the most affordable and popular killifish that you can own.

Are Killifish Easy to Care for in Aquariums?

Yes, most killifish are considered to be easy to care for. These fish will be good options for people who are beginners to the hobby of keeping home aquariums.

To keep killifish in good health, you simply need to focus on the water parameters. Ensure that the temperature, pH balance, and water softness are in the right range.

Generally, killifish do well with pH balance settings between 6.0 and 7.0. They seem to like temperatures that range from 68 degrees Fahrenheit and 75 degrees Fahrenheit.

You want to keep killifish in water that is soft and slightly acidic. Of course, the exact preferred water parameters will differ slightly based on the specific species that you’re looking at.

Regardless, you can easily take care of these fish. They like to be kept in clean fish tanks, though.

This means that you should use a filter to help keep the tank clean. Also, you need to clean the tank regularly and do water changes often enough.

Killifish Can Be Hard to Find

Finding killifish in pet stores won’t always be easy. Many types of killifish are somewhat rare.

The rarity of the fish makes it hard for them to be kept in stock at stores. Sometimes you might see killifish being sold at fish stores in your area, but they might not stay around for long.

It’s a bit easier to find popular killifish types online. You can look for specific fish if you have a type that you’re interested in.

The rarer fish are going to be more expensive. Luckily, you can get really pretty killifish such as the golden wonder killifish without breaking the bank.

Final Thoughts

Looking into killifish life cycles is very interesting. The life cycles of these fish vary quite a bit based on what reproductive strategy they use.

Some killifish are annuals that have very fast life cycles. These fish go through their entire life cycles in just a few months.

They have to do so because they live in bodies of water that dry up for half of the year. Semi-annuals live in bodies of water that dry up every so often, but they live much longer lives.

Most semi-annual killies will live for at least three years, but some might live for longer than that. Non-annual killifish don’t have to worry about the bodies of water that they live in going dry.

The non-annual killifish will live for three years in a fish tank setting. They don’t grow or mature as fast as annual or non-annual killifish.

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