7 Saltwater Fish For Experts Only (#5 Will Surprise You)

There is so much to learn in the aquarium hobby and over time you will go from being a beginner to being an experienced hobbyist.

As you gain experience and knowledge, you will want to try new and challenging things. Keeping different types of fish with challenging needs is something that most people want to attempt.

There are certain saltwater fish that are considered easy to keep and are best for beginners.

Then there are more challenging types of fish that are only recommended for more experienced fishkeepers.

Some will say that keeping all saltwater fish is difficult. That is not true in my opinion. I agree that not all fish are the same with respect to their needs and requirements but not all are considered to be difficult to keep.

As you go from being a beginner to becoming an advanced hobbyist, there are some really great saltwater fish that you can start to keep.

Some of them are not as available as others and can be rare to keep. They might also cost more than the more common saltwater fish that you are used to seeing.

Here are 7 saltwater fish for expert fishkeepers.

Before you attempt to keep these fish, do your research so you can provide them with the proper home they need and can meet all of their requirements.


  1. Mandarin Goby
  2. Lyretail Anthias
  3. Clown Tang
  4. Lionfish
  5. Copperband Butterfly
  6. Regal Angelfish
  7. Achilles Tang


Mandarin Dragonette Goby



This peaceful and colorful fish is at the top of the list as it requires a fully established and mature aquarium to survive. If your tank is new this is one fish you don’t want to consider.

The Mandarin Goby will only grow to about 3″ and can live in tank sizes of 30 gallons or more. They are very peaceful and won’t bother other tankmates.

In order to prevent them from starving, they require a healthy supply of copepods that live in the live rock in your tank.

So a good amount of live rock is needed.

Copepods can be purchased and added to the tank where they can reproduce. Some Mandarin Gobies will eat certain foods but it is rare. They are a carnivore and may eat Mysis shrimp and black worms.

I have seen too many beginners try to keep these fish and it rarely works out. Most times they end up starving to death. But if you can provide them with an ongoing supply of copepods in a mature tank, they are an amazing fish to keep.


Lyretail Anthias



There are many different types of Anthias fish available for home aquariums. They are one of the most unique and stunning fish you can keep. These fish are generally peaceful and are reef safe.

Many people would love to keep a school of Anthias in their tank. Unfortunately, they are not recommended for beginners. They have specific needs that must be met for them to survive.

Anthias need to be in a school of 5-8 fish. They can live alone as well but do better in groups. These fish are hermaphrodites and should be kept in groups of 1 male and the rest female.

They also require a large tank of a minimum of 125 gallons.

The biggest concern with these fish is their dietary requirement. They need to be fed several times each day due to their constant activity and high metabolisms. 

I recommend that they are fed 3 times per day. You may need a reliable auto-feeder if you can not feed the tank manually. This can also be a problem for other fish in the tank that doesn’t need several feedings per day. Overfeeding your tank can lead to poor water quality and other issues. It’s crucial that you stick to this feeding commitment in order to keep Anthias healthy.


Clown Tang



The Clown Tang is a member of the Acanthuridae family and is fairly common to see in large reef tanks. This fish is very colorful and needs a large tank as they will grow to about 15″ or more. A 250-gallon aquarium is required when they are fully grown.

When these fish are young, they are generally peaceful but as they mature they can become quite territorial and bully other tankmates.

It really depends on the other types of fish in the tank with them.

The Clown Tang is a very fast-moving fish and it swims constantly. They require a lot of open swimming space combined with plenty of rock formations to swim around.

I have talked to many people who have had success with these fish and others who said they were a nightmare to keep. So it can be hit or miss with them.

If you are an experienced fishkeeper and have a large tank with suitable tankmates, you will really enjoy this fish. But I don’t recommend them for beginners.





One of the most unique saltwater fish is the Lionfish. These are predator fish which can give you a nasty sting that is very painful. Although they won’t directly attack you, they can if they feel threatened.

There are a few different varieties available and come in 2 groups. Common and dwarf.

The common Lionfish will grow to about 12″ and the dwarf will grow to around 6″.

The Lionfish is actually a peaceful fish and won’t bother other tankmates providing they don’t fit in their mouth.

They can’t be kept with invertebrates as they will be eaten.

Lionfish are actually reef safe and shouldn’t bother your corals. They do require a large tank size of 125-gallon for the common Lionfish and the dwarf can be housed in a 30-40 gallon tank.

Lionfish are huge waste producers so this can present a problem for saltwater tanks with corals. Water quality can be a concern if routine maintenance is not done.

These fish mainly eat live and frozen meaty foods. Lionfish are definitely interesting and a conversation piece if you can keep one.


Copperband Butterfly



The Copperband is one fish that so many people have problems with. Such a nice fish with unique characteristics that everyone wishes they could keep.

The issue with the Copperband Butterfly is that they usually die from starvation.

They are very difficult to keep fed and if they are newly added into your tank, they may not eat for a long time. If at all.

This fish is not for beginners and your tank will need to be mature with lots of live rock for them to pick at. This is one fish that you should see eating at the store before purchasing. If they are not eating there, the chances of it eating in your tank are slim.

If you are able to keep your Copperband well fed, they are an awesome fish. They are very peaceful and fun to watch.

Another concern with keeping them is they don’t like much water movement. If you have a tank with high water flow, this fish is not for you. They will do much better in a saltwater tank with low flow.


Regal Angelfish



If you are looking to add a ton of color into your tank, check out the Regal Angelfish. These fish are considered to be semi-aggressive and challenging to care for.

They should be placed in the tank first before other tankmates. This will allow them to establish a territory before others.

The Regal Angelfish are somewhat reef safe. Although it’s possible to keep them with certain corals, they will usually end up nipping at LPS, soft corals, and clams. If kept well-fed and healthy, you have a better chance of them not touching corals.

This fish can grow to around 10″ in size so a large tank of at least 125 gallons is required. They need plenty of live rock to graze on with many hiding places.

Tankmates should be chosen carefully as these fish tend to bully others of the same type. Regal Angelfish are very picky eaters and can be difficult to start feeding. Once they are established and comfortable, they will accept food easier.


Achilles Tang



The Achilles Tang is one of the more expensive members of the Acanthuridae family. There are many different Tangs that are highly desired and this is one of them. They are a stunning fish.

The Achilles will grow to about 8″ in size and requires a minimum of 125-gallon tank. They are considered to be reef safe and should not bother your corals.

This fish is very difficult to find tankmates for. Well, any other Tangs I should say.

Many types of fish can be a great tankmate for the Achilles providing it is not another Tang.  

Most people that keep Tangs will have a variety of them mixed in the same tank. Many Tangs will get along with each other without issues but the Achilles is not one of them.

In order for them to live with other Tangs, you will need a very large tank around 500 gallons or more. And even then it’s a risk.



There are many different types of saltwater fish that are generally kept by experts only. The ones mentioned here are just a few.

If you are a beginner or can’t provide the care necessary for these fish, there are many other fish choices that are suitable for you.

Once you gain experience and your tank is matures over time, you will have a much better chance of successfully keeping any of the above-mentioned fish.