The Basic Transfer Record for a Small School Fish
Fork-tail rainbowfish are almost always bought as a group, so the first record to bring home is a receipt or transfer note that reflects that: the seller or breeder's name, the number of fish in your school, and their condition when they were bagged. If a fellow keeper bred them, a short note covering the parent tank and how the youngsters were raised is worth more than a bare receipt. These fish live fast, colourful but comparatively short lives, which means ownership may change, tanks may be restocked, and questions about where a particular blue-eyed school began arise sooner than owners expect. Paper taken at the start answers them.
Sex Balance and Group Makeup to Note Down
Write down the balance of males to females in the school you bought, and how the seller judged it. Male fork-tails carry the longer, forked fins and stronger yellow colouring, while females are plainer and rounder, and a group skewed too far toward males turns display into constant harassment. Recording the starting ratio lets you correct the group deliberately at the next purchase instead of drifting further. Note size and approximate age as well: a school of near-adult fish and a school of juveniles may look similar under shop lighting yet be at very different points in their lives, with different breeding and replacement timelines ahead of them.
Water History From the Breeding or Selling Tank
Fork-tails come from soft, warm forest streams, and captive groups settle best when the move between waters is understood rather than abrupt. Ask for the temperature, acidity, and hardness of the seller's water in writing, plus how long the fish had been in that system. Add the foods offered, which for fish with such small mouths usually means fine crushed flake, powdered fry foods at first, and small live foods as treats or conditioning fare. If the seller kept them with particular tank mates, note that too. Together these details explain early behaviour in your tank: a school that hides may be adjusting to brighter light or different flow, not necessarily falling ill.
Breeding Notes That Extend the Record Beyond One School
Because fork-tail rainbowfish are short-lived, breeding information is a genuine part of their paperwork rather than a bonus. Ask whether the group has produced eggs, what spawning medium the seller used, and whether fry were raised from these parents or close relatives. If you breed them yourself, keep your own notes on which mop or plant thicket collected eggs, how fry were fed, and how many youngsters you raised or passed on. That continuity matters to the next keeper, who inherits not just fish but a family line with known feeding habits and vigour. It also helps you avoid unknowingly narrowing the line by repeatedly breeding from one pair.
Starting Your Own Arrival and School Log
From the first evening, record how the school feeds, whether every fish joins the group or one hangs back, and how males colour and display once settled. Note losses, additions, and tank moves as they happen; in a fast-living species, a school can turn over completely while its paperwork still describes the original fish. Photographing the group against the same background every so often gives a visual thread through those changes. Keeping the transfer note, water history, and breeding notes together in the Pet Passport in KinsLe means your fork-tail rainbowfish school carries a continuous record even as individual fish come and go.