Dave,
I don't have any scientific papers on this species to hand, I'm afraid. But it's always worth doing a Family search at Fishbase, in this case for the Toxotidae, you get this:
http/www.fishbase.org/Summary/FamilySummary.cfm?ID=337
Follow that up by clicking on the 'show species' link, thus:
http/www.fishbase.org/identification/spe...e=337&areacode=
What's interesting, for example, is of the 7 described species, 4 are exclusively freshwater. So while we think of archers as "brackish water fish", that's really not strictly accurate. Mind you, the commonest species,
Toxotes jaculatrix and
Toxotes chataereus certainly are brackish water fish. My understanding is that only
Toxotes jaculatrix is commonly found in marine waters, and hence is the only one able to migrate to oceanic islands. All the others more-or-less hug the coastlines.
Another general comment seems to be that archers prefer salinities somewhat lower than scats and monos. Half-strength seawater, as would suit green chromides and mudskippers, for example, is about right. These aren't really fish that go into the open sea, they tend to skirt around the edges of mangroves looking for prey. As insects aren't that common in the open sea, there's no reason for them to go there. Really, everything about them is designed (evolved, rather) for a life close to the roots of trees, either mangroves or regular rain forest ones.
Definitely try and get hold of the Aqualog book on brackish water fishes. Until my book comes out next year, it's pretty well the only decent brackish water book out there. For one thing, it has a nice guide to identifying which archerfish you have. For example, if it has 4 dorsal fin spines, it's
Toxotes jaculatrix. If it has 5 dorsal fin spines, it could be
Toxotes chatareus,
Toxotes microlepis, or
Toxotes oligolepis. It's important to key these three out: they look alike, but only
Toxotes chatareus normally occurs in brackish water.
Toxotes chatareus has additional small spots between the series of bands.
Here's the interesting thing: according to Schaefer,
Toxotes microlepis is actually much more commonly sold as the "common archer" than
Toxotes jaculatrix.
Toxotes microlepis tolerates brackish up to about SG 1.008, but prefers fresh water. To tell them apart you can use the fin spine counts mentioned above. If your fish aren't looking happy, check whether you really have
Toxotes microlepis and not
Toxotes jaculatrix.
Toxotes microlepis, by the way, only reaches 15 cm in length, and it's very probable that a lot of the "small" archers people have kept are actually this species. Others have noted that archers seem to 'stunt' in captivity, and if Schaefer is right, then maybe that's because we're all keeping a totally different fish!
Toxotes jaculatrix supposedly reaches 30 cm or so.
If you do have
Toxotes microlepis, then a neutral pH and moderate hardness is probably the way to go. All archers seem to like fairly high temperatures, so I'd certainly consider 26 C upwards, though you may need to boost the aeration to compensate for the reduced oxygen concentration in the water.
By the way, your foods sound fine. I'd try to train them onto a decent quality pellet food (a cichlid diet of some type). Prepared foods like these are by far the most reliable when it comes to making sure a fish gets all the vitamins and minerals it needs.
Cheers,
Neale
Toxotes microlepis, at Fishbase. Note the four dorsal fin spines. Ignore the colours; they vary with mood and individual. It does have a very yellow tail, though, like your fish, perhaps?