Brackish water aquarium fish
10 species from the AquaLog care guide · Updated
In short: Brackish fish come from estuaries and mangroves, where rivers meet the sea. Most do poorly in pure freshwater long-term even though shops often sell them as freshwater fish. Keep them in a dedicated brackish tank, and check each species page: some move to full saltwater as adults.
Brackish water is a mix of fresh and salt water, found in estuaries, mangroves and coastal lagoons. Every species below is listed as brackish in the AquaLog care guide. Several, including the orange and green chromides, Indian glassfish and archerfish, come from India's coasts and backwaters.
Brackish tanks are set up with marine salt and measured with a hydrometer or refractometer. Salinity depends on the species and, for some, on their age.
The species
| Species | Min. tank | Temperature | pH | Temperament | Group | Care level |
|---|---|---|---|---|---|---|
| Bumblebee gobyBrachygobius doriae | 40 L (11 gal) | 24–29 °C | 7.4–8.2 | Peaceful | 6+ | Intermediate |
| Figure eight pufferDichotomyctere ocellatus | 110 L (29 gal) | 24–28 °C | 7.5–8.2 | Semi-aggressive | 1 | Intermediate |
| Indian glassfishParambassis ranga | 110 L (29 gal) | 22–28 °C | 7–8.2 | Peaceful | 6+ | Intermediate |
| Knight gobyStigmatogobius sadanundio | 110 L (29 gal) | 22–28 °C | 7.5–8.2 | Semi-aggressive | 1 | Intermediate |
| Orange chromidePseudetroplus maculatus | 110 L (29 gal) | 22–28 °C | 7–8.2 | Peaceful | 2+ | Intermediate |
| Sailfin mollyPoecilia latipinna | 110 L (29 gal) | 24–28 °C | 7.5–8.5 | Peaceful | 4+ | Beginner |
| Green spotted pufferDichotomyctere nigroviridis | 210 L (55 gal) | 24–28 °C | 7.8–8.4 | Aggressive | 1 | Advanced |
| Green chromideEtroplus suratensis | 380 L (100 gal) | 22–30 °C | 7–8.5 | Semi-aggressive | 2+ | Intermediate |
| Banded archerfishToxotes jaculatrix | 450 L (119 gal) | 25–30 °C | 7.5–8.5 | Semi-aggressive | 3+ | Advanced |
| Mono argentusMonodactylus argenteus | 570 L (151 gal) | 24–28 °C | 7.8–8.5 | Semi-aggressive | 4+ | Advanced |
Often sold as freshwater fish
Puffers, gobies and archerfish are commonly sold in freshwater shop tanks. The green spotted puffer is a classic example: small and cute in the shop, it grows large, is aggressive and needs increasingly salty water as it matures. Read the species page before buying.