Last updated on August 20th, 2022 at 12:28 am
With so many interesting freshwater fish species to choose from, it’s easy to overlook the fascinating brackish water fish species. Brackish water originates in saltwater but has less salinity than that of seawater and more salinity than freshwater, so the fish within this environment have to adapt accordingly. Luckily, there are quite a few awesome brackish water fish species out there.
Freshwater fish have long been the focus of freshwater aquariums, but brackish water aquariums are starting to rise in popularity as well. Because brackish water aquariums can accommodate fish species that are not able to live in freshwater, they often make great choices for both beginners and seasoned aquarists alike.
Many people are surprised to learn that there are actually different species of fish living in brackish water environments, as they assume that all species of fish can live in any type of water. While most types of fish can live in both saltwater and freshwater, there are several exceptions, including those found in brackish water environments.
Find out which 25 amazing brackish water fish species you’ll want to try the next time you hit the pet store!
Brackish water fish species
Marble Lyretail Molly (Poecilia sphenops)
The Marble Lyretail Molly is a popular brackish water fish species in ponds and tanks. The Marble Lyretail Molly has distinctive black markings on its body and fins, which gives it its name. They are peaceful fish that will not bother other tank mates. These fish can grow up to 4 inches in length, but they are usually smaller than that. Due to their long lifespan of around 5 years, they make great additions to any aquarium.
When breeding these fish, you should have at least one male per 2 females. You should also make sure there are plenty of hiding places for them to spawn in.
Dalmatian Lyretail Molly (Poecilia latipinna)
Dalmatian lyretail mollies are a species of livebearer fish native to South America. They inhabit freshwater bodies of water, including lakes and rivers, but do very well in slightly brackish water with high salt content. This gives them an advantage over other livebearers that are only able to survive in freshwater environments.
The dalmatian lyretail molly is generally kept in aquariums as an addition to other species or as part of a community tank. It’s a relatively peaceful fish that gets along well with others of its own kind and many other species. It’s also known for being easy to breed, which makes it popular among hobbyists.
A beautiful species of tropical fish that ranges in color from silver and blue to black. The Dalmatian Lyretail Molly gets its name from its long anal fin, which is often tipped with white spots. They live in waters between 1.5 and 30 degrees Celsius and can grow up to 8 inches in length.
This brackish water fish species thrive in groups and will eat a variety of live foods including worms, crustaceans, insects, and small fish. It’s important to note that these fish should not be kept with other members of their own species as they are mildly aggressive. They are also susceptible to disease and should only be purchased from reputable dealers who have tested them for parasites.
Fan Dance Goby/Knight Goby (Stigmatogobius sadanundio)
Also known as Knight Goby, the Fan Dance Goby is a stunning little goby that lives in tropical brackish waters and has an almost alien-like appearance. It’s all thanks to their black, silver, and orange stripes along with large eyes that give them a unique appeal among fish. Even though they are small, these little guys are fierce predators and even eat other fish eggs!
On top of all of that, there are some interesting behaviors you can witness if you’re lucky enough to encounter one of these brackish water fish species. They dart back and forth while waving their fins rapidly, which creates a mesmerizing effect for any onlookers.
The Knight Goby lives in brackish waters on tropical reefs across parts of Asia and Oceania. Like other members of its species, it can live out of water for up to three days as long as it remains moist.
Unfortunately, many aquarists have reported difficulty keeping them alive in captivity. They are carnivores and feed primarily on invertebrates such as shrimp. They will also eat small fish if given the opportunity. They grow to be about 6 inches (15 cm) long and are a dark brown color with black dots running down their sides.
Prehistoric Dragon Goby/Violet Goby (Gobioides broussonnetii)
Also known as the Violet goby, dragon goby fish, dragonfish goby, or dragon fish goby, the Prehistoric dragon is an exotic species of Gobioides broussonnetii, also known as Philippine Dragon Goby. These brackish water fish species are found in freshwaters of Philippines. These fishes usually live under submerged logs, among weeds and rocky areas. This species is one of our favorite sports fishes because they get quite large when they reach 5 inches (13 cm) in length and are also fun to catch because they can hide among rocks or weeds.
They feed on small invertebrates such as worms, insect larvae, and crustaceans. They will eat smaller fish if given chance. They are not considered good aquarium fishes due to their territorial nature but can be kept with other brackish water gobies such as Redfinned goby, Sailfin goby, and Bluebanded goby. In captivity, it requires lots of hiding places such as rock work, PVC pipes filled with sand etc for them to feel secure and comfortable.
The dragon goby is one of the numerous types of gobies that are known for hiding under rocks in fast-moving streams and rivers. This brackish water fish species is often brown in color with darker spots, but can also be grey. It primarily lives in marine environments but will move into brackish water if it has to.
Like most fish species, it eats smaller organisms like crustaceans, worms, and small invertebrates. However, unlike many other fish species, it does not eat algae. Instead, it uses its mouth to scrape off sediment from rocks so that it can feed on insects living underneath. It is a popular aquarium fish due to its unique appearance and behavior.
Bumblebee Goby (Brachygobius doriae)
Also known as bumble bee fish, the bee goby, or bumblebee fish, the bumblebee goby fish (Brachygobius doriae) is one of around 100 species in the family Gobiidae and one of just three types native to fresh and brackish waters in Australia.
These brackish water fish species can be found from central Queensland down to southern New South Wales along rocky shorelines, where they bury themselves in sandy bottoms during low tide.
They typically inhabit depths between 0–20 meters (0–65 feet) but have been found up to 37 meters (120 feet). They live for about five years on average, with some living up to eight years. Their favorite foods include polychaete worms and crustaceans like crabs and mantis shrimp, though they will eat anything that fits into their mouths!
Columbian Shark (Arius jordani)
Also known as Columbian shark catfish, or just Colombian catfish, the Columbian shark is found in rivers and estuaries of Ecuador and Colombia, where it feeds on aquatic invertebrates like fish, mollusks, crustaceans, and frogs. Most sharks are fully marine, but a few species are adapted to life in freshwater or even brackish water.
This species grows up to 14 inches long and has a lifespan of around 15 years. It’s listed as Near Threatened by IUCN Red List due to habitat loss from human development.
Figure 8 Puffer Fish (Tetraodon biocellatus/Dichotomyctere ocellatus)
The figure 8 puffer fish is beautiful but somewhat dangerous, the dorsal fin is what sets it apart from other puffers. This small, freshwater fish has a circular band of pectoral and tail fins that resemble a figure eight, hence its name.
Unfortunately, humans are one of these amazing brackish water fish species natural predators—figure 8 puffer fish have a poisonous gland in their gills, which they release in response to danger or injury. It’s incredibly painful and can be fatal if not treated immediately.
While most encounters with humans will result in nothing more than a bad experience for both parties, some divers who handle them without gloves suffer long-term nerve damage as a result. Figure 8 puffers tend to be found around South Africa and Australia.
Green Spotted Puffer (Tetraodon nigroviridis/Dichotomyctere nigroviridis)
One of two species in its genus, the green spotted puffer fish is one of just a handful of fish species that can live their entire lives in both fresh and salt water. Some brackish water fish species of puffer are able to survive in water with extremely high salinity levels—about 35% higher than average ocean salinity. They’re also known for their ability to walk on land.
This walking behavior is thought to be an adaptation to low oxygen conditions in stagnant waters where they spend much of their time hunting for food at night. Green spotted puffer fish get their name from a bright green spot located on each side of their head between their eyes.
The green spotted puffer fish (Tetraodon nigroviridis) is also known as giant pufferfish, black-spotted pufferfish, and green boxfish. They are not true freshwater fish and prefer brackish water.
They are very large compared to other species of puffer fish. They grow up to 6.7 inches (17 cm) in length and weigh around 6 pounds. Their skin is smooth but can be rough on their backs where they have small spines that stick out making them appear rough in texture but they are still considered one of the more attractive species of puffer fish.
They have a big mouth with teeth that protrude outward making it easy for them to consume their prey whole.
Black Lyretail Molly (Poecilia latipinna)
The black lyretail molly (Poecilia latipinna) is a hybrid fish originating from two of its parent species, being a cross between an African molly and a Sailfin molly. This fish was created as part of an experiment to study inheritance patterns in relation to temperature. It has been bred many times since then and can be purchased online or through local pet stores. It will grow up to 6 inches long and can live for up to 5 years with proper care.
These brackish water fish species thrive best when kept in an aquarium that has plenty of hiding places for them, such as live plants, rocks, or wood pieces. It can be fed flake food and freeze-dried bloodworms.
It is generally peaceful with other fish and can be kept with mollies, guppies, platys, and swordtails among others. They should not be kept with other black lyretail mollies, however, because they will breed together to form hybrid offspring which will eventually lead to genetic defects if left unchecked.
Mono Argentus (Monodactylus argenteus)
Also known as silver mono fish, silver moonfish, silver moony fish, or Silver Sailfin Sand Perch, the mono argentus is a small marine fish native to Australia and surrounding islands. Its eyes are situated high on its head, and it sports a set of venomous spines on its dorsal fin and tail. The Mono Argentus feeds primarily on crustaceans and worms.
Very little is known about its mating habits. In terms of conservation status, the Mono Argentus is considered near threatened by both IUCN and CITES. Habitat destruction due to overfishing has caused a marked decline in population numbers over recent years.
Gold Dust Molly (Poecilia sphenops)
This unique brackish water fish species is native to Costa Rica. Gold Dust Mollies are best kept in an aquarium with at least 20 gallons of water, with a temperature between 75 and 79 degrees Fahrenheit. The ideal pH level is 7, while the general hardness should be 4-12 dH.
This species reaches a maximum size of 4 inches long and should be fed a diet rich in algae, greens, and live foods. Because they’re schooling fish, they need plenty of companionships.
This species was originally described by Walter Koelz in 1935. The gold dust molly is sometimes referred to as Poecilia sphenops variegata but many experts believe that it should not be considered a separate subspecies from P. sphenops.
Gold Dust Mollies are also sometimes confused with Sunshine Peacock Mollies, which are also known as Gold Dust or Sunshine Mollies, and more correctly known as Poecilia latipinna. However, unlike true Gold Dust Mollies, Sunshine Peacock Mollies can only survive in freshwater conditions and cannot tolerate brackish water at all.
Dwarf Indian Mudskipper (Periophthalmus novemradiatus)
Also known as Pearse’s mudskipper, the dwarf Indian mudskipper, Periophthalmus novemradiatus, is one of many brackish water fish species living in coastal waters and estuaries. You may think you’re looking at a salamander or lizard because it has four legs and a lizard-like tail! However, it’s not a reptile; instead, it’s an amphibious fish species that like to live on muddy bottoms.
It can be found in brackish water areas like mangroves and tidal flats. This little guy (it only grows up to 5 cm long) can survive out of water for up to three days by breathing air through its skin, which is unusual for a fish species.
Oyster Toadfish (Opsanus tau)
Found in estuaries and brackish waters across South America, some areas of Central America, and parts of Africa. Just like its marine toadfish cousins, it has a powerful poisonous spine that can leave a painful wound behind—but only if it comes into contact with skin. It is equipped with barbels (sense organs used for sensing food) that are longer than those on other toadfish species.
The Oyster Toadfish eats small fish, crabs, shrimp, worms, mollusks, and crustaceans. It’s also known as Toadfish or Sea Cricket. Its scientific name means looks like an oyster.
These brackish water fish species can reach up to 12 inches long and live at depths between 0.5–10 meters below sea level, making them one of many fascinating saltwater aquarium species found in brackish water habitats. They usually swim near oysters during low tide; hence their name!
Wrestling Halfbeak (Dermogenys pusilla)
If you have a wrestling halfbeak and you live in a brackish water environment, life can be tough. Bigger, more powerful fish have no problems hunting down your weaker species for dinner. But when those bigger fish try to swim in your brackish water habitat, they run into a few problems—namely, their bodies adjust to living in freshwater or saltwater, but never both. That means that if a big fish from either side of your habitat wants to eat your fish, it will die before it even gets close enough to grab a bite. It’s hard out there for a tiny fish!
This is especially true of Dermogenys pusilla, also known as wrestling halfbeaks because of their tendency to fight with each other over territory and food sources. Halfbeaks are small tropical fishes that live in brackish waters along coasts throughout South America.
Golden Wonder Killifish (Aplocheilus lineatus)
Found in Africa, golden wonder killifish are known for their vibrant golden scales. They can reach up to 5 inches in length and may live for up to 8 years! Native to Tanzania, Malawi, Zambia, and Zimbabwe. Found in Africa, these brackish water fish species are known for their vibrant golden scales.
They can reach up to 5 inches in length and may live for up to 8 years! Native to Tanzania, Malawi, Zambia and Zimbabwe.
African Lungfish (Protopterus dolloi)
This odd-looking fish is native to Africa. It is a close relative of Australian lungfish and American mud puppies (which aren’t actually pups). These unusual creatures breathe air through a set of branching, wormlike gills on top of their heads. This odd-looking fish is native to Africa.
African Monodactylus Sebae (African moony)
Also known as the mono angelfish, or African moony, monodactylus sebae is an amazing saltwater fish that has adapted to survive in brackish water. They can survive in both fresh and saltwater but prefer brackish waters, which is why they have evolved to live there.
They live in a wide range of areas including Lake Malawi, Tanganyika, and Victoria. The Mono Sebae is also called a freshwater boxfish or African sebae, although it’s not actually related to true boxfish.
It’s sometimes called a living fossil because its ancestors lived over 200 million years ago. It has been popular with aquarists for many years because of its interesting appearance and behavior. It grows up to about 10 inches long and lives for up to 20 years if cared for properly.
Top Hat Blenny (Omobranchus fasciolatoceps)
The Top Hat Blenny (Omobranchus fasciolatoceps) may look like a simple little fish with a fancy hat on its head, but it’s actually one of the largest and most amazing brackish water fish species in existence. Native to shallow reefs near Fiji, New Caledonia, Vanuatu, and Australia, these fish feed primarily on small invertebrates that live within coral colonies.
They can grow up to 7 inches long and weigh over 1 pound! They are also some of the most colorful brackish water fish species you will ever see. They have bright yellow spots all over their bodies, as well as purple lips and tails. Their most recognizable feature is their large, red top hats. The male has a tall red crown while the female does not have any crown at all.
This brackish water fish species is very territorial and aggressive towards other males during the breeding season. In fact, they often fight each other until one of them dies or leaves for good! These fish reproduce by laying eggs which hatch into planktonic larvae that drift around for about 3 weeks before settling down on an algae-covered rock or coral reef where they mature into adults.
Reedfish (Erpetoichthys calabaricus)
Reedfish are common in south Asia and Africa, where they burrow into mud to hide from predators. They’re colorful and easy to breed, making them popular with hobbyists. But don’t be fooled by their pacifist demeanor—reedfish have a neurotoxin in their skin that can paralyze an aggressor within minutes.
While not deadly, it’s certainly effective at defending against would-be attackers. The toxin is so powerful that even handling these fish can cause numbness or respiratory distress in humans. Don’t worry, though, all you need to do is avoid touching your face after handling one of these fish!
Pacific Blue Eye Rainbowfish (Pseudomugil signifer)
Also known as signifer rainbow fish, the pacific blue eye fish are native to Australia, where they inhabit freshwater streams and lagoons. Their dazzling colors will add a splash of color to any aquarium tank. However, it’s recommended that you keep them in saltwater, as they will only live for about a year if kept in freshwater. Like many other rainbowfish species, Pacific Blue Eye Rainbowfish are ideal community fish.
They get along well with others of their own kind, as well as with most other types of brackish water fish. In fact, they can even be kept with tropical marine fish such as clownfish! As long as you provide plenty of hiding places for your Pacific Blue Eye Rainbowfish, you shouldn’t have any problems keeping them happy and healthy.
Hogchoker (Trinectes maculatus)
The hogchoker is a fascinating brackish water fish species, especially because it displays both characteristics of saltwater and freshwater fish. The hogchoker can survive in varying degrees of salinity, from fully marine conditions to freshwater. The easiest way to identify a hogchoker is by its armor plating and distinct physical traits.
The hogchoker’s size ranges from 5–20 inches long, with its average length at about 10 inches. Its body shape resembles that of a sunfish or carp. Its dorsal fin starts just behind its head and extends nearly all the way down to its tail, making it easy for you to distinguish between other types of fish when you are out on your fishing trip.
As an omnivore, the hogchoker will eat anything that comes across its path including small crabs, shrimp, clams, and even other small fish. It has large teeth which help crush shells as well as fleshy foods.
Fat Sleeper Goby (Dormitator Maculatus)
The fat sleeper goby comes from Cambodia and Vietnam and is one of over 250 brackish water fish species. Fat Sleeper Gobies are named for their ability to store large amounts of fat during times of plenty, which they use during times of famine. These fish can survive extreme temperatures ranging from -5 degrees Celsius to 30 degrees Celsius, allowing them to inhabit some areas that are inhospitable for other fish species.
They’re omnivorous and feed on algae, crustaceans, insects, plankton, and detritus. Their lifespan in captivity is about five years. The female Fat Sleeper Goby lays its eggs in a nest constructed by both parents; these nests can be found on hard surfaces such as rocks or wood where there’s an abundance of algae growing nearby.
Banded Banjo Catfish (Platystacus cotylephorus)
Native to Malaysia, Borneo, and Sumatra, Platystacus cotylephorus are critically endangered due to habitat destruction. These brackish water fish species have large protruding lips that look a bit like their namesake, which they use to suck in food and direct it towards their mouth.
The Banjo Catfish is considered a living fossil due to its similarity to species that lived over 200 million years ago! While not as colorful as some of its relatives, it makes up for that with personality, some individuals have been observed rubbing against rocks or other objects for unknown reasons. It’s also one of the very few catfish that can be kept in brackish water without special equipment.
Indonesian Tiger Fish (Datnioides microlepis)
Commonly referred to as a tiger fish, Datnioides microlepis is native to Southeast Asia and Australia. They can be found in both fresh and brackish water environments, with adults reaching up to 23 inches long. Tiger fish are popular aquarium fish, but they are not considered safe for beginner aquarists due to their aggressive natures and fast growth rates.
However, if you’re looking for an exciting challenge and don’t mind being bitten or scratched by your new pet, then consider adding one of these beautiful creatures to your tank! Although it may look like a piranha, it is actually more closely related to sunfish and bass. The Indonesian tiger fish gets its name from its striped coloration, which makes it appear similar to a tiger.
When kept in captivity, these brackish water fish species will eat just about anything that fits into their mouths—including other smaller fish! Despite their fierce reputation and large size, they are generally peaceful towards other species when housed together. It is important to provide them with plenty of hiding places during feeding time so that weaker individuals do not become lunch for larger ones.
Guppy Fish (Poecilia reticulata)
One of more than three hundred species of guppy fish, Poecilia reticulata is a common aquarium fish. Found mainly in freshwater areas, these colorful brackish water fish species are found in two different forms: their wild form, which can grow up to four inches long and features beautiful multicolored scales; and their short-form form (also known as splendens) that usually stays under an inch in length.
Guppies are very social creatures that thrive when kept in groups of at least six individuals. They eat algae, insects, worms, plant matter, and small crustaceans. In captivity, they live for about five years but can live twice as long if well cared for. Guppies have been introduced into many countries outside of their native range, including Australia, Japan, and New Zealand.
These non-native populations may be either natural or manmade introductions. A number of color variations have been bred by both professional breeders and hobbyists.
Banded Archerfish (Toxotes jaculatrix)
Native to a variety of Southeast Asian waters, banded Archerfish make their homes in rivers and coastal areas. They swim in small schools and are noted for their ability to shoot water droplets at insects on overhanging branches, smashing them into a pulp with deadly accuracy. There are two species of Archerfish: The Giant (Toxotes jaculator) and The Pygmy (Toxotes microlepis). They can grow up to 17 inches long.
Both species have an orange belly and a grey back. Juveniles have bright blue spots on their bodies that fade as they mature. When they shoot water at prey, they use an air bubble in their mouth as a pressure chamber to generate enough force to break through insect exoskeletons. After shooting out of their mouths, these bubbles collapse, allowing the fish to breathe again. Both males and females look identical except for one major difference, Males have thicker lips than females!
Indian glass fish (Parambassis ranga)
The Indian glass fish is a stunningly beautiful breed of freshwater aquarium fish. With its vibrant colors and intriguing pattern, it’s among our top picks for any brackish water fish species collection. Glass fish are native to South Asia, primarily India, but are now found in parts of Southeast Asia as well. They get their name from a translucent quality in their scales that makes them look like they’re made out of crystal.
This species can be kept in community tanks with other peaceful species. However, because they tend to be skittish around larger tank mates, you may want to keep them by themselves if possible.
The Indian glass fish has an average lifespan of about five years, though some have been known to live up to 10 years with proper care. These little guys grow up to 2 inches long.
Siamese tiger fish (Datnioides pulcher)
The Siamese tiger fish is native to Southeast Asia. Although it has been introduced to Florida and Texas, it remains primarily a brackish water fish species. Although there are several types of Datnioides in existence, the Datnioides pulcher is a popular aquarium specimen. It’s moderately hardy and feeds well on meaty foods like worms, shrimp, and bloodworms.
This brackish water fish species grows to about six inches long and is an active swimmer. They tend to be territorial towards one another, so if you plan on keeping more than one in your tank, you should consider getting a larger tank for them.
In addition to being beautiful fish with vibrant colors, they also make interesting additions to your aquarium due to their behavior patterns.
Kribensis fish (Pelvicachromis pulcher)
Probably one of the most popular types of cichlids in the hobby today, Kribensis fish (often called “Krib” by many hobbyists) are primarily captive bred. They are more adaptable than wild fish to water chemistry. In addition, these brackish water fish species tend to have fewer aggressive traits when breeding. Aquarium sport albino forms are available and are fairly popular.
As a beginner to Cichlids or fish breeding, this fish is a perfect choice because it has good size, entertaining to watch, good-looking and easily breedable. It has been a favorite ever since it was introduced to the hobby in the 1950s, and its popularity is assured for a long time.