Redear sunfish Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: December 17, 2022

The redear sunfish (Lepomis microlophus) is a freshwater fish native to the southeastern United States. It is a member of the sunfish family (Centrarchidae) and is closely related to the bluegill (Lepomis macrochirus). The redear sunfish is also known as the shellcracker, due to its propensity for feeding on snails.

The redear sunfish is a popular game fish and is often considered a nuisance by anglers targeting other species. It is also a popular aquarium fish.

The redear sunfish is a deep-bodied fish with a laterally compressed body. It has a small mouth located under the snout. The body is olive-green to brown in color, with a yellowish or orange-red breast and belly. There are dark vertical bars on the sides of the body. The fins are dark and the tail is forked.

The redear sunfish grows to a maximum length of 30 cm (12 in) and a maximum weight of 1.3 kg (2.9 lb).

The redear sunfish is found in freshwater lakes, ponds, and streams in the southeastern United States. It is most common in the Mississippi River basin.

The redear sunfish is a omnivorous fish. Its diet consists of aquatic insects, crustaceans, mollusks, and small fish.

The redear sunfish is a popular game fish. It is often considered a nuisance by anglers targeting other species. It is also a popular aquarium fish.

The redear sunfish is a hardy fish that can be easily kept in an aquarium. It does best in a tank with plenty of hiding places and a sandy bottom. The aquarium should be at least 30 gallons in size. The redear sunfish is a peaceful fish that gets along with other peaceful fish. It is not aggressive towards other fish and can even be kept with smaller fish. The redear sunfish is a good algae eater and will help to keep the aquarium clean.

The redear sunfish is easy to breed in an aquarium. The female lays her eggs in a nest that the male has built. The male guards the eggs until they hatch. The fry are free-swimming after about a week.

Species overview

The redear sunfish (Lepomis microlophus) is a freshwater fish that’s native to the southeastern United States. It’s most commonly found in the Mississippi river basin but can also be found in parts of Louisiana, Arkansas, and Texas.

This fish gets its name from the red or orange hue around its gills. The body itself is usually greenish-brown in color with darker spots dotting its sides.

Redear sunfish are most commonly found in ponds and lakes with a sandy or muddy bottom. They prefer waters that are fairly clear and free of vegetation.

Although they are not the most popular fish in the aquarium scene, redear sunfish make for interesting and hardy additions to most freshwater tanks.


Redear sunfish

The first thing you’ll notice about this species is their name sake, the red “ear” on their gills. This is a small, fleshy piece of tissue that’s used to help attract mates. The coloration on this piece will be a bright red or orange.

The second thing you’ll notice is their beautiful coloration. The body of the Redear sunfish is olive green on the top half and transitions to a yellowish color on the bottom. There are large, dark spots all over their body (usually 2-3 per side).

The fins are where this fish really shines though. The dorsal fin is tall and pointed with a black edge that really makes it stand out. Their caudal fin is forked and also has a black edge.

The anal fin is rather small in comparison to the other fins. It has a white margin and a black stripe that runs down the center. The pectoral fins are also quite small.


The average lifespan of redear sunfish is about 4 years. However, these fish can live much longer in captivity.

One study showed that redear sunfish in captivity had a median lifespan of 9.4 years. This is nearly double the lifespan of wild redear sunfish!

It’s important to note that the study only looked at a small sample size (30 fish). But it’s still a pretty good indicator that captive redear sunfish can have a much longer lifespan than their wild counterparts.


The average Redear sunfish size is about 4-7 inches. However, they can grow to be up to 12 inches in length! These fish typically don’t weigh more than a pound.


Tank Size

The recommended tank size for redear sunfish is 30 gallons. If you’re looking for a freshwater fish that can fit in an average-sized tank, this is not the fish for you.

If you want to keep two flowerhorn fish in the same tank you’ll want to add at least another 70 gallons to that minimum number if you want them to thrive.

Another reason why you need to provide enough space is for the sake of enrichment and comfort. These fish like to roam and will often run gentle but steady laps around your tank. Giving them a little bit of extra space can go a long way in making sure they can comfortably turn around in the tank.

Water Parameters

The Redear sunfish is a freshwater fish that is a part of the Centrarchidae family. This family also includes the bluegill and pumpkinseed. The Redear sunfish is also sometimes referred to as the shellcracker due to its love of snails.

The Redear sunfish is a popular choice for many aquarists because they are relatively easy to care for and they are not too demanding when it comes to water parameters.

However, there are still some water parameters that you need to keep in mind in order to keep your Redear sunfish healthy and happy.

Here are a few things to keep in mind:

  • Water temperature: 70 to 75 degrees Fahrenheit
  • pH levels: 6.5 to 7.5
  • Water hardness: 4 to 10 dGH
  • Alkalinity Levels: 4-8 dKH

What To Put In Their Tank

Redear sunfish are a little bit different from most other fish when it comes to their habitat.

They prefer to have a lot of open space to swim around in and aren’t too fond of being cramped. This means that you’ll want to avoid putting too many decorations in their tank.

A few rocks or pieces of driftwood are fine, but don’t go overboard. These fish also like to dig so you might want to avoid having a gravel substrate.

Something like sand or a soft clay would be a better choice. You can also get away with no substrate at all if you’d like!

Plants are a bit of a touchy subject with Redear sunfish. They will eat just about any plant you put in their tank, so we recommend avoiding them altogether.

If you really want to include plants then we suggest going with something that’s too big for them to eat (like Java Fern).

Common Diseases

Redear sunfish are a hardy species that doesn’t often get sick. However, like all fish, they can fall ill if they’re not kept in the right conditions or if they’re exposed to disease.

The most common disease that affects redear sunfish is ich. This is a parasite that will attach itself to your fish and cause white spots to form on their body. If left untreated, it can be fatal.

Other common diseases include bacterial infections, fungal infections, and parasites. These are all relatively easy to treat if you catch them early, but they can quickly become serious if left unchecked.

As always, the best way to prevent your fish from getting sick is to maintain a clean and stable environment. Redear sunfish are relatively hardy, but they still need clean water to stay healthy.

Behavior & Temperament

The Redear sunfish is a peaceful fish that gets along with most other fish species. They are not an aggressive fish, but they can be territorial if they feel like their space is being invaded.

These fish are mostly bottom-dwellers, but they will occasionally swim to the surface of the water to feed. When they are feeding, they use their long, slender mouth to vacuum up small insects and larvae.

Redear sunfish are relatively calm fish. They don’t tend to swim around a lot, but they are always on the lookout for food. If you have other fish in your tank, they may chase them away from their food source.

Tank Mates

When it comes to finding tank mates for redear sunfish, there are a few things you need to take into consideration.

First, these fish are quite large. They can grow to be up to 12 inches long! As a result, you need to make sure any potential tank mates are sufficiently sized.

Secondly, redear sunfish are known to be a bit on the aggressive side. They’re not the most territorial fish, but they can hold their own in a fight.

You’ll need to be careful when choosing tank mates that are similar in size. If they’re not, the redear sunfish might see them as potential prey.

Here are a few compatible tank mates that tend to work well:

  • Largemouth Bass
  • Bluegill
  • Black Crappie
  • Channel Catfish
  • Green Sunfish
  • Pumpkinseed Sunfish
  • Yellow Perch


The Redear sunfish is a beautiful freshwater fish that’s native to the southeastern United States. It’s a popular choice for aquariums because of its vibrant colors and easy-going personality.

Redear sunfish are also relatively easy to breed in captivity. If you’re interested in breeding these fish, there are a few things you need to know.

To start, you’ll need a breeding tank. It should be at least 20 gallons in size. Then, set the temperature to 80 degrees Fahrenheit. The water should be on the alkaline side with a pH of 7.5.

As for decor, use live plants and some driftwood for hiding places. Redear sunfish like to lay their eggs in plants, so the more the better.

When everything is set up, it’s time to add the fish. You’ll need one male for every three females. The males are the larger of the two sexes and have brighter colors.

Once the fish are in the tank, feed them a diet of live foods. This will help to bring them into breeding condition.

When the fish are ready to spawn, you’ll see the female lay her eggs in the plants. The male will then fertilize them. After that, he’ll stay close by to protect the eggs.

It takes about a week for the eggs to hatch. When they do, the fry will feed on microscopic organisms in the water. You can supplement their diet with live foods like baby brine shrimp.

As the fry grow, you can slowly transition them to a diet of pellets or flakes. Once they’re big enough, you can move them to your main tank.


The Redear sunfish is a great fish for any beginner aquarist. They’re easy to care for and are very peaceful, making them a great addition to any community tank.

Although they’re not the most exciting fish to look at, they more than make up for it with their personality. These fish are very active and love to explore their surroundings.

We hope this guide has helped you learn a little bit more about the Redear sunfish and has given you the confidence to add them to your tank.