Meet the $6,000 Fish People Are Putting in Their Aquariums

Neptune Grouper
© John E. Randall / Creative Commons

Written by Jennifer Haase

Published: June 27, 2022

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The Neptune Grouper (Cephalopholis igarashiensis) is a rare ray-finned fish that can cost more than $6,000! It is native to coral reefs in the Indo-Pacific and is a sought-after aquarium fish all over the world. So, are you ready to meet the $6,000 fish people are putting in their aquariums? You’ll need two important things to have a Neptune Grouper of your own: a big budget and a big tank.

Also called a Japanese Cod, Garish Hind, and Goldbar Grouper, the expensive Neptune Grouper grows from 10-18 inches long! But it’s a stunning aquarium fish with pink and yellow scales on adults. The juvenile fish have orange and yellow scales.

Why is the Neptune Grouper so popular and costly? Read on to learn more about why this fish is so valuable, plus how to care for one as a pet.

The $6,000 Fish: Why is the Neptune Grouper So Expensive?

Most Expensive Fish: Neptune Grouper

The Neptune Grouper is expensive because it rarely survives removal from the ocean.

©John E. Randall / CC BY-SA 3.0, via Wikimedia Commons – Original / License

A living Neptune Grouper comes with a high price tag because it’s difficult to catch and hard to keep alive once you’ve caught it. In addition, it’s so fragile because this deep-water fish must first be decompressed before removing it from the ocean. The Neptune Grouper lives at depths between 250-800 feet below the sea’s surface.

Because not many Neptune Groupers survive the decompression process, they don’t end up in many aquarium tanks. So, healthy Neptune Groupers raised in captivity are very expensive because they are rare fish.

What Does it Mean to Decompress a Fish?

When a fish is caught from the deep sea, the sudden change in pressure can cause its internal organs to rupture. Therefore, the fish must be decompressed by slowly bringing it to the surface in stages. This process is called decompression, and it’s very important for keeping a Neptune Grouper alive.

Decompression involves putting the fish into a special chamber where it’s slowly brought to the surface over several hours. This process is expensive and time-consuming, which is why Neptune Groupers are so costly.

Neptune groupers have caught the attention of many groups.

What Do Neptune Groupers Look Like?

In addition to its pink and yellow scales, the Neptune Grouper also has yellow-colored bar shapes across its body.

Neptune Groupers can grow to be 18 inches long, but most only reach about 12 inches. Also, they have a large mouth and teeth used to eat small fish and crustaceans.

The Neptune Grouper’s fins are long and thin. Its dorsal fin has fourteen soft rays and nine spines, and the anal fin has nine soft rays and three spines. A Neptune Grouper’s caudal fin has a rounded shape.

An Atlantic salmon leaps upstream to reach its spawning grounds

Like the Neptune Grouper, a salmon is a ray-finned fish.

©Kevin Wells Photography/

What is a Ray-Finned Fish?

The Neptune Grouper is a ray-finned fish, which means they have thin, horny spines called rays that support their fins. This type of fish makes up more than half of all known fish species!

While the Neptune Grouper has ray fins, there are fish with lobe-fins or no fins. Lobe-finned fish have fleshy fins attached to their bodies by just one bone. Most lobe-finned fish are now extinct, though the Dipnoi (Queensland Lungfish) is an example of a lobe-finned fish still around today.

Ray-finned fish and lobe-finned fish are both classified as bony fishes.

The Neptune Grouper has great company in the ray-finned class of fish called Actinopterygii. Some other examples of ray-finned fish include:

The Neptune Grouper and other ray-finned fish have a few additional features that set them apart from different types of fish:

  • They have a swim bladder, an internal gas-filled organ that helps the fish stay buoyant. If a ray-finned fish wants to change its level of buoyancy in the water, it changes the gas level in its swim bladder.
  • Most ray-finned fish have scales all over their bodies.
  • They have a skeleton made of bone rather than a skeleton made of cartilage, as is found in cartilaginous fish. (By the way, cartilaginous fish don’t have gas-filled swim bladders as ray-finned fish do!)

Neptune Groupers love to hide in the coral reefs of their natural habitat.

©Brocken Inaglory / CC BY-SA 4.0 – Original / License

What is the Natural Habitat of a Neptune Grouper?

The Neptune Grouper lives in coral reefs in the Indo-Pacific. It lives between 250 and 800 feet below the sea’s surface.

Neptune Groupers are solitary fish that only come together to mate. They hide in caves and crevices during the day and come out to hunt for food at night.

Are Neptune Groupers Endangered?

Currently, the Neptune Grouper isn’t an endangered animal or under threat. However, overfishing is a significant problem in the Indo-Pacific region, where the Neptune Grouper lives. In addition, this fish is a common bycatch, which means anglers accidentally catch it when targeting other fish species. As a result, the population of Neptune Groupers could decline if not monitored and protected.

Where Do You Buy a Neptune Grouper for an Aquarium?

If you are interested in buying a Neptune Grouper, there are a few things you need to keep in mind. First, you can expect to pay $6,000 – $8,000 for this rare aquarium fish. Secondly, Neptune Groupers are only available from certain specialty retailers. So, you will likely have to order your fish online.

When buying a Neptune Grouper, it is crucial to buy from a reputable source. Because they are rare and overly expensive, scams are common. So, make sure you research and only purchase from a trusted retailer.

How To Take Care of a Neptune Grouper

Caring for a Neptune Grouper as a pet fish is not tricky, but it requires special attention. Because of its large size, the Neptune Grouper produces a lot of waste. Therefore, you need weekly water changes and clean the filter more often than you would for a smaller fish.

Because the Neptune Grouper is native to coral reefs in the Indo-Pacific, it prefers a warm and saltwater environment. Therefore, it is essential to replicate this environment as closely as possible in your home fish tank. Keep the water between 75 and 82 degrees Fahrenheit and use marine salt to recreate the ocean’s salinity levels.

What Size Fish Tank Does a Neptune Grouper Need?

Because of its large size, the Neptune Grouper needs a huge tank. The minimum recommendation is 100 gallons, but the bigger, the better. The Neptune Grouper is also a very active swimmer, so it needs plenty of space to move around.

In its natural habitat, Neptune Groupers like to lounge during the day in hiding places like caves. If possible, provide your grouper with a fish tank big enough to have at least a couple of crevices for hiding during the day.

What Do Neptune Groupers Eat?

Neptune Groupers eat frozen shrimp, squid, and fish. The Neptune Grouper is a carnivore and prefers a diet of meaty foods. Therefore, it is important to offer a variety of foods to ensure that your fish gets all the nutrients it needs.

How Does Neptune Grouper Taste?

Neptune Grouper is a tasty fish with a mild flavor and a hint of sweetness. The flesh is firm and flaky and is easy to cook. When cooked properly, the Neptune Grouper flesh tastes like lobster and other mild shellfish like a crab. This light fish is also prepared raw for Japanese sashimi.

Regal Angelfish, Pygoplites diacanthus, a saltwater angelfish from the Indo-Pacific and Red Sea.

A Regal Angelfish is a beautiful (though much smaller) aquarium fish alternative for a Neptune Grouper.


What Aquarium Fish is Similar to the Neptune Grouper?

Another luxury aquarium fish similar to the Neptune Grouper is the Coral Grouper (AKA Coral Trout). The Coral Grouper is a large and brightly-colored predatory fish from coral reefs in the Indo-Pacific region. Like the Neptune Grouper, the Coral Grouper is popular among aquarium enthusiasts. However, this fish is also quite expensive in some countries.

Which aquarium fish is as colorful as the Neptune Grouper but much more affordable? Of course, they won’t grow quite as big, but you can’t go wrong with some giant goldfish. A goldfish raised in a large tank grows as big as 13-14 inches! They have similar colors as the Neptune Grouper (orange, yellow, white), are easy to care for, inexpensive, and very easy to find for purchase.

Is your aquarium too posh for goldfish? Then get a stunning orange and blue Angelfish instead. You might still spend about $2,000, but Angelfish are cheaper than Neptune Groupers!

Want a Neptune Grouper? Prepare to Wait

The Neptune Grouper is valuable as an aquarium fish because it’s rare to keep one alive. So, this $6,000 fish people are putting in their aquariums is simply hard to come by as a living catch.

A dead fish is easier to buy if you only want a Neptune Grouper to eat for dinner. However, save your pennies and be patient if a living Neptune Grouper is the fish you desire the most. Every Neptune Grouper that manages to survive leaving the sea is coveted by collectors worldwide.

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About the Author

Jennifer Haase is a writer at A-Z Animals where her primary focus is on plants, pets, and places of interest. Jennifer has been writing professionally about plants and animals for over 14 years. A resident of Nebraska, Jennifer enjoys gardening, floral design, nutrition studies, and being a cat mama.

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