Description
The Blue Diamond guppy is a dark, glittering fish built on the contrast between a bright silver face and a near black body. Behind the head sits a large, solid black shoulder patch, and from there the body turns deep navy black with fine scaling that catches the light, before opening into a round black tail lit through with electric blue rays.
Those blue rays are the whole point of this strain. They start as a glittering teal patch at the base of the tail and fan outward in sharp, bright streaks across a velvety black caudal, so the tail looks almost like cut stone catching the light, which is where the diamond in the name comes from. Against the dark body the blue reads brighter and cleaner than it would on a pale fish.
Body shape stays close to a standard guppy, neither shortened nor exaggerated, with a clean silver face and a slightly pinkish ring around the eye. The caudal is a full, round fan rather than a delta, softly edged and carried open, and the dorsal is a short, dark, fan shaped fin that sits upright over the back and matches the smoky tone of the body.
Males carry the full look, the silver face, the black shoulder, the navy black body and the blue rayed round tail. Females are a striking contrast to them, with a bright silver white body that throws back rainbow iridescence along the flank, the same pale eye ring, and a round, velvety black tail and dark dorsal, so a pair together shows the strain from both sides.
This is a straightforward strain to keep and needs standard guppy care rather than anything unusual. Dark fish show the effect of poor water quickly, with the black turning dull and the blue rays losing their brightness when conditions slip, so clean, stable water and a steady routine are what keep the colour sharp.
Good tankmates include other peaceful livebearers, small tetras, corydoras and similar calm community fish, with fin nippers best avoided as with any guppy strain. A planted tank with a lighter background suits this strain well, since the dark body can disappear against a black backdrop while a lighter setting lets the silver face and blue rays stand out.
As livebearers, a settled pair will produce broods of fully formed, free swimming fry roughly every four weeks, with no egg laying stage involved. The black tail colour usually shows early in the fry, while the blue rays and the full depth of the dark body develop more gradually, so young fish are best judged at around two to three months old.
Sold as a breeding pair.
The Blue Diamond guppy varies between individuals in how bright the blue rays show and how far the black spreads across the body, with some fish carrying bold, electric streaks and others a softer, deeper blue, both being normal for this strain. Stable, well maintained water supports the deepest black and the brightest blue, and a routine of weekly partial water changes combined with steady filtration keeps the round tail edge intact rather than ragged. A varied diet with occasional live or frozen food added to the usual flake and pellets also supports steady growth and helps the tail reach its full size and colour as the fish matures.
The blue on a Blue Diamond guppy is a glittering sheen rather than a flat colour, so it shows best under a bright white light and can look close to black in a dim tank.
