Several barbs are brackish water-tolerant, including:
- Puntius vittatus
- Puntius ticto
- Puntius sophore
- Puntius amphibius
- Puntius sarana
- Puntius cataractae
- Puntius anoplus
- Esomus lineatus
- Esomus lineatus
- Chela laubuca
- Probarbus jullieni
Of these, only Puntius ticto and Puntius vittatus are traded regularly, though you sometimes see Chela and Esomus species in the shops.
As for the tetras, among the ones found in brackish water are:
- Hyphessobrycon axelrodi
- Brycinus longipinnis
- Brycinus macrolepidotus
- Astyanax aeneus
- Roeboides bouchellei
- Pristella maxillaris
Hyphessobrycon axelrodi, Brycinus longipinnis and Pristella maxillaris are widely traded; the others less so.
Admittedly, most of these fish are only tolerating brackish water rather than being characteristic of it, and their tolerances are fairly low compared with, say, livebearers. In other words, these are for tanks with low salinities, around SG 1.002-1.003, rather than mid salinity systems alongside scats and monos.
Brycinus longipinnis and Puntius sarana may be exceptions, being associated with brackish water to a rather greater degree than the others, and so may even go up to SG 1.005. Are any of these good for livebearer tanks? I'd guess quite a few, if the amount of salt being added was at a "therapeutic" level rather than an attempt to create a bona fide brackish water aquarium.
It should be mentioned that many cyprinids in the UK are decidedly salt-tolerant, including bream and roach. So simply because a fish is a "primary freshwater fish" and a member of the cyprinid or tetra families doesn't automatically mean it is salt-intolerant. Some of these barbs and tetras will tolerate salt rather better than, say, soft water cichlids, despite cichlids belonging to a group often talked about as being salt-tolerant "secondary freshwater fish". As with everything in biology, it's complex!
Dave Sands has mentioned in at least one catfish book of mine that Corydoras will tolerate low levels of salt without harm, making them adequate companions for mollies and guppies. Personally, I'd probably go with Hoplosternum littorale if I was after a low-salinity catfish; it's essentially a souped-up Corydoras but tolerates up to 40% seawater and is incredibly hardy. But with care, I'm sure the tougher Corydoras from coastal regions in the Guyanas and the like would do well in a low salinity system.
Cheers, Neale
Neale, you mentioned barbs and a tetra? Which ones are you talking about? Are there ANY barbs that would be brackish AND safe with guppies?
