Green Sunfish (Lepomis Cyanellus)

Green sunfish

Last updated on August 22nd, 2022 at 03:53 pm

Green sunfish, also known as Lepomis cyanellus, are popular additions to aquariums because of their attractive colors and friendly dispositions. They are easy to care for if provided with the proper environment and diet. Although some extra effort may be required on your part, green sunfish can make great pets!

There are several varieties of sunfish native to North America, but the green sunfish (Lepomis cyanellus) is probably the most familiar to people living in the United States. Green sunfish are fairly common, and they’re easy to care for as long as you provide them with the right environment.

They are hardy fish that can live in almost any home aquarium, as long as the water temperature remains between 70 and 75 degrees Fahrenheit. As omnivores, they feed on animals, plants, and algae, so you should stock your tank with an ample amount of aquatic flora to keep them satisfied and healthy. The average green sunfish grows up to six inches in length and can live anywhere from five to 10 years in captivity, depending on the conditions provided by their caretakers.

Origin and descriptions

Green sunfish

Lepomis cyanellus is native to North America. Though similar in appearance to a number of other species of sunfish, it can be distinguished by its coloration; it possesses yellow or gold sides with four dark bars, compared with red and silver coloring in most of its relatives.

The green sunfish have been introduced worldwide and can be found anywhere there are large bodies of water. They have become an invasive species in many areas because of their adaptability and ability to breed quickly. In some regions, they are actively targeted as game fish. They prefer warmer climates than most members of their family.

They usually live in rivers, streams, lakes, and ponds but may also venture into brackish waters where suitable habitat exists. Their preferred water temperature is around 25°C (77°F), though they will thrive over a much wider range.

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Species profile

The green sunfish is a member of a family of fish called Centrarchidae, or true sunfishes. This family is characterized by their forward-facing mouth, which reflects their voracious appetites and athletic abilities.

They are found in streams and lakes throughout eastern North America and range in size from three to seven inches long.  The green sunfish’s scientific name translates literally as blue perch with little yellow dots and refers to both its coloration and diet.

Adult green sunfish can be distinguished from other species by their distinct blue coloration at the base of their dorsal fin and abdomen.

Newly hatched green sunfish are red or orange with dark spots on their dorsal fins. Their spotted appearance makes them difficult to distinguish from juvenile bluegill or redear sunfish; however, green sunfish have eight anal rays versus seven anal rays in those two species, distinguishing them by that number alone.

Green sunfish scientific name

The scientific name of the green sunfish is Lepomis cyanellus

Green sunfish habitat

Green sunfish are primarily freshwater fish and can be found in lakes, ponds, creeks, and slow-moving streams. Though they can survive in brackish water (i.e. saltwater), green sunfish need access to freshwater sources during warmer months of the year as their bodies have trouble regulating water content when exposed to high concentrations of salt.

For optimal health, keep your green sunfish in an aquarium with neutral or slightly acidic water that’s kept at 68–72 degrees Fahrenheit. They prefer clear waters but are highly adaptable and will tolerate dirty conditions if no other option is available; if you notice that your green sunfish appears listless or is refusing food, it may be time to give its habitat a cleaning.

Green sunfish size

They can grow between 3 and 7 inches (8-18 cm) in length. Maximum size of around 12 inches (30 cm) in length has been recorded in some species with a weight of about 2.2 pounds (960 g).

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Green sunfish tank size

Due to their sizes, the minimum recommended tank size for a single fish is 30 gallons (114 liters). Although bigger gallons, like 55 gallon tanks, are better. While 125-150 gallons (473-568 liters) can house a group of 4 or 5 sunfish.

Tank requirements

Lepomis cyanellus are freshwater fish that can be housed in tanks of around 20 gallons, but they prefer more space than that. At least 30 gallons should be provided so they can swim around freely and not get overcrowded. Plenty of decoration and hiding places should be added as well, such as driftwood, rocks, or caves.

They enjoy living with other species of sunfish or even other small fish like tetras. Plants are also beneficial because they help keep water clean. Water flow is important as it encourages algae growth which is what green sunfish feed on. Most importantly, make sure your tank has a tightly-fitting lid because these fish have been known to jump out of their tanks if left open!

Tank mates

The green sunfish is known as peaceful fish that shouldn’t be kept with any aggressive species, due to its diminutive size. Though it can live alongside other kinds of small, docile fish without issue (like betas and danios), it isn’t wise to put it in an aquarium with larger or more boisterous varieties (such as cichlids).

When choosing tank mates for your sunfish, keep in mind that multiple members of the same variety will likely become territorial—this means you can keep only one adult male per tank; young males should be removed after they reach two inches long.

Some good tank mates are small fish, danios, livebearers, and guppies. As well as other peaceful species like mollies, platys, and swordtails.


Green sunfish

Male green sunfish typically build nests by pulling aquatic plants or grasses together and then fanning them out into a circular nest. The female lays her eggs on top of each structure and then both parents guard it carefully until their young are ready to swim away on their own.

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It usually takes about 15 days from laying of eggs until hatching occurs. At first, baby green sunfish will eat mainly plankton but they’ll eventually graduate to larger, more solid foods as they grow up.

They need large tanks with plenty of shelter in order to thrive in captivity and many hobbyists keep them in multiple fish tanks so that adults don’t hurt babies and vice versa. As long as you can provide your fish with ample food and space, you should be able to find these fish fairly easy at most pet stores.

Are they aggressive or peaceful?

Some green sunfish individuals are more aggressive than others. Males tend to be more aggressive and display territorial behaviors such as chasing away other fish from their territory, rubbing themselves against large objects like rocks and aquarium glass, or attempting to spawn with small decorations. However, these behaviors usually subside when you house one male sunfish with several females.

Green sunfish care

Green sunfish

Aquarium sunfishes are some of the most enjoyable fish to keep. However, these are larger fish and require ample room and good water quality, as well as specific tankmates. Green sunfish do best in an aquarium of at least 30 gallons (114 liters), with enough plants and decorations so they feel secure.

They also need lots of open swimming space; active fish like green sunfish will quickly become stressed in an overcrowded aquarium, making them less active and possibly leading to sickness. These fish eat live foods such as mosquito larvae, blackworms, and daphnia.

Green sunfish diet

Because they’re omnivores, they should also be fed high-quality flakes or pellets containing plant material as well. This is especially important if you don’t have live plants in your aquarium, you want to make sure your greens are getting adequate vegetable matter.

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Feed green sunfish frozen or live mosquito larvae, small earthworms, and bloodworms. You can also give them dried flakes, tubifex, and cyclops. Feed small amounts several times per day in the summer months. In winter, reduce feedings because they do not eat as much.

Remove any uneaten food after 15 minutes of not eating it. Green sunfish are omnivores so provide more vegetable-based foods like zucchini slices, lettuce leaves, or mealworms occasionally in your tank.

Green sunfish lifespan

Green sunfish

They typically live between 4 and 6 years with proper care.

Parasites and diseases

It’s not uncommon for fish kept in an unmonitored aquarium, or those that swim freely in ponds, lakes, and rivers, to be infested with parasites. These include ich (Ichthyophthirius multifiliis), gill flukes (Dactylogyrus spp.), anchor worms (Lernaea spp.), and flatworms.

Symptoms of infection may show up when water conditions change or when fish are overcrowded; sometimes though, you won’t see any outward signs at all. Treatment is by quarantine, removing infected fish immediately, and then using medication prescribed by your veterinarian to treat the remaining animals.

Be careful if using tapeworm treatments, these will also kill any helpful livebearers as well as lumpsuckers like sculpins and mullets that eat algae but don’t harm your koi and goldfish.

Do they make good pets?

Yes. These fish can make excellent pets. As long as you have the tank set up correctly and take proper care of your fish, they can live more than 6 years. Of course, there are factors that will affect their lifespans such as water quality, tank size, and temperature. All things considered, these little guys make great pets!