How Many Types Of Fish – Are There? Discover The Best Species

If you have ever stood in front of a massive wall of tanks at your local fish store, you have likely felt that familiar sense of wonder. You might find yourself wondering exactly how many types of fish are available to the modern hobbyist and which ones are right for your specific setup.

It is a common question for beginners and seasoned pros alike, as the sheer diversity of the aquatic world is nothing short of breathtaking. Whether you are looking for a shimmering school of tiny tetras or a majestic, long-finned Betta splendens, the options can feel endless.

In this guide, we are going to dive deep into the different categories of fish, from freshwater favorites to saltwater spectaculars. By the end of this article, you will have a clear understanding of the species available and how to choose the perfect inhabitants for your Aquifarm-inspired sanctuary.

Understanding the Global Scale: Just how many types of fish Exist?

Before we narrow our focus to the home aquarium, it is helpful to look at the big picture. Marine biologists and taxonomists have identified over 34,000 species of fish in the wild, and new species are discovered every single year.

This massive number includes everything from the tiny, translucent gobies of the deep sea to the massive whale sharks roaming the open ocean. However, only a small fraction of these—roughly 2,500 to 3,000 species—are commonly found in the aquarium trade.

When asking how many types of fish you can realistically keep, it helps to categorize them by their water requirements and biological needs. This ensures that you aren’t just picking a “pretty fish,” but rather building a sustainable ecosystem where your pets can thrive for years.

The Three Main Water Categories

The first step in narrowing down your choices is deciding on the type of water your aquarium will hold. This choice dictates the biological equipment you will need and the maintenance routine you will follow.

• Freshwater Fish: These are the most popular for beginners due to their hardiness and the relative ease of maintaining their environment.
• Saltwater (Marine) Fish: Known for their vibrant, neon colors, these fish require more specialized equipment and a higher level of attention to water chemistry.
• Brackish Water Fish: These live in the “in-between” zones where rivers meet the sea. They are unique and fascinating but require specific salt levels to stay healthy.

how many types of fish Can You Keep in a Freshwater Aquarium?

Freshwater tanks are the heartbeat of the hobby. If you are just starting out, don’t worry—there is a massive variety within this category that caters to every taste. Let’s break down the most popular groups you will encounter.

Community Schooling Fish

These are often the “bread and butter” of a beautiful tank. When people think about how many types of fish they want, they often picture a shimmering school moving in unison. This group includes Tetras (like Neons and Cardinals), Rasboras, and Danios.

These species are generally peaceful and do best when kept in groups of six or more. Seeing twenty Rummy Nose Tetras darting through a planted tank is one of the most relaxing sights an aquarist can enjoy!

The Hardy Livebearers

If you want to see the miracle of life in your living room, livebearers are for you. Unlike most fish that lay eggs, these species give birth to fully formed, swimming fry. Guppies, Mollies, Platies, and Swordtails fall into this category.

They are incredibly colorful and very forgiving of minor beginner mistakes. Just be careful—they breed quickly! You might start with five fish and end up with fifty before you know it.

Labyrinth Fish: The Surface Breathers

This unique group includes the world-famous Betta and various species of Gouramis. They possess a specialized organ called a “labyrinth” that allows them to breathe atmospheric air directly from the surface.

This adaptation makes them very hardy, but it also means they have specific social needs. For example, male Bettas must be kept alone, while Pearl Gouramis are much more social and peaceful in a community setting.

Exploring the World of Cichlids

Cichlids represent one of the most diverse families in the entire animal kingdom. When hobbyists ask how many types of fish offer high intelligence and complex behavior, the answer is almost always Cichlids.

South American and Central American Cichlids

This group includes the elegant Angelfish and the stunning Discus. These fish often prefer softer, slightly acidic water and are known for being excellent (and sometimes aggressive) parents.

On the larger side, you have the Oscar. These are often called “water dogs” because they can recognize their owners and even “beg” for food. Just keep in mind they need very large tanks!

African Cichlids

Hailing primarily from the Great Rift Lakes (Malawi, Tanganyika, and Victoria), these fish are famous for their intense, rock-dwelling lifestyles and vibrant colors that rival saltwater species.

They require high pH levels and hard water. If you love a tank full of activity and “drama,” a colony of Mbuna cichlids might be exactly what you are looking for.

Bottom Dwellers: The Cleanup Crew

No aquarium is complete without inhabitants for the lower levels. These fish fulfill a vital role by consuming leftover food and keeping the substrate “turned over.”

Corydoras Catfish

These are perhaps the most charming fish in the hobby. Corydoras are small, armored catfish that scurry along the bottom in groups. They are incredibly peaceful and come in dozens of patterns, like the popular Panda Cory or the Bronze Cory.

Plecostomus and Algae Eaters

Commonly known as “Plecos,” these fish use their sucker-mouths to graze on algae. Pro tip: Always check the specific species! The “Common Pleco” can grow to 18 inches long, while the Bristlenose Pleco stays a manageable 5 inches.

Always research the adult size before buying, as a “cute” little fish can quickly outgrow a 20-gallon tank. I’ve seen many hobbyists have to upgrade their entire setup just to accommodate one fast-growing Pleco!

Marine Fish: The Jewels of the Ocean

If you are ready for a bit more of a challenge, saltwater tanks offer colors that are simply unmatched in the freshwater world. When considering how many types of fish fit into a reef environment, the variety is staggering.

Clownfish and Damselfish

Thanks to popular movies, the Ocellaris Clownfish is the ambassador of the saltwater hobby. They are hardy, full of personality, and have a fascinating symbiotic relationship with sea anemones.

Tangs and Surgeons

These are the vibrant yellow, blue, and purple fish that graze on algae across the reef. Species like the Yellow Tang or the Blue Hippo Tang are staples of large marine displays but require plenty of swimming room and high water flow.

Blennies and Gobies

If you have a smaller “nano” saltwater tank, these are your best friends. They have massive personalities and often “perch” on rocks, watching the room with curious eyes. The Midas Blenny is a personal favorite for its beautiful color and wavy swimming motion.

How to Choose the Right Fish for Your Tank

Knowing how many types of fish are out there is only half the battle. The real skill lies in selecting species that are compatible with each other and your water parameters. Here is a quick checklist to guide your decision:

• Water Parameters: Do your fish prefer “hard” or “soft” water? What is their ideal temperature? Never mix coldwater fish like Goldfish with tropical fish like Tetras.
• Tank Size: Always plan for the adult size of the fish. A tiny Oscar will eventually need a 75-gallon tank (or larger).
• Aggression Levels: Some fish are “community” (peaceful), some are “semi-aggressive,” and some are “predatory.” Mixing these usually leads to stress or loss of fish.
• Swimming Levels: Aim for a balance. Choose some surface dwellers, some middle-water schoolers, and some bottom-dwelling catfish. This fills out the “visual space” of your tank beautifully.

Remember, a successful aquarium is a balanced aquarium. It is better to have a few happy fish than a crowded tank full of stressed inhabitants.

The Role of Invertebrates in the Modern Aquarium

At Aquifarm, we are huge fans of shrimp and snails! While they aren’t technically fish, they are a massive part of the “types of inhabitants” you can keep. Neocaridina shrimp (like Cherry Shrimp) add a pop of color and help control algae.

Adding a few Nerite snails or Amano shrimp can transform a standard fish tank into a thriving, complex ecosystem. They occupy a different niche and make the tank feel much more “alive” and natural.

Common Challenges When Mixing Species

One of the biggest hurdles is “Compatibility.” You might find yourself asking how many types of fish can live together without fighting. This is where the concept of a Biotope Aquarium comes in handy.

A Biotope setup involves keeping fish that naturally live together in the wild (e.g., an Amazon River setup). Because these fish evolved in the same water conditions and shared the same space for millennia, they are often the most compatible choices for your home tank.

Always watch out for “fin nippers.” Some fish, like Tiger Barbs, are notorious for nipping at the long, flowing fins of slower fish like Angelfish or Bettas. Avoid this combination to keep your fish stress-free!

Frequently Asked Questions (FAQ)

How many types of fish can a beginner start with?

For a beginner, it is best to stick to one or two hardy species to start. Good choices include Guppies, Zebra Danios, or Cherry Barbs. Once your tank is stable and you understand the nitrogen cycle, you can slowly add more variety.

What are the easiest fish to keep alive?

Generally, White Cloud Mountain Minnows, Betta fish, and Mollies are considered very hardy. However, “easy” is relative; every fish requires a filtered, cycled tank and regular water changes to truly thrive.

Can I keep freshwater and saltwater fish together?

No. Freshwater fish lack the biological mechanisms to handle high salt concentrations, and saltwater fish will perish in freshwater due to osmotic shock. You must choose one environment or the other.

How many fish can I put in a 10-gallon tank?

A 10-gallon tank is relatively small. You could keep a single Betta, or a small school of 6-8 Chili Rasboras. Avoid putting large or high-waste fish like Goldfish in a tank this size.

Do fish get lonely?

It depends on the species! Schooling fish like Tetras definitely get stressed and “lonely” if kept alone. However, solitary fish like the male Betta are perfectly happy (and safer) living by themselves.

Conclusion: Finding Your Perfect Aquatic Match

As we have explored, the answer to how many types of fish exist is staggering, but for the hobbyist, the choices are wonderfully diverse. Whether you are drawn to the shimmering schools of the Amazon or the rocky kingdoms of the African lakes, there is a fish out there for everyone.

The key to success at Aquifarm is always research and patience. Take the time to learn about the specific needs of each species before bringing them home. By matching the right fish to the right environment, you create a peaceful, thriving world right in your own home.

Don’t be afraid to start small! A well-maintained 10-gallon tank with a few healthy inhabitants is much more rewarding than a massive, struggling aquarium. Happy fishkeeping, and enjoy the journey into the wonderful world of aquatic life!