Count the shoal on the harlequin rasbora page
A harlequin rasbora record begins with a number, not a single fish. Write how many arrived, photograph the whole shoal against the tank glass, and note the distinctive dark wedge marking and copper body colour of the group on day one. That wedge and colour deepen or fade with water and diet, so an honest arrival photo becomes your comparison point. Record the source and any fish that arrived pale, thin, or separated from the group, and update the count immediately whenever one is lost — a shoal that quietly drops from ten to five behaves differently, and the record should say when that happened.
Soft-water numbers this species needs logged
Harlequin rasboras come from soft, gently acidic forest waters, and their records should track the numbers that reflect that home. Log pH and temperature at setup and weekly, plus hardness if your kit measures it, alongside ammonia, nitrite, and nitrate. Note your water source and whether you use tap water, a mix, or remineralised water, because a keeper change in supply can shift pH without any tank change. Record each partial water change and the readings before and after it during the first month, while you learn how stable your preparation routine really is.
Shoal behaviour worth writing down weekly
For a harlequin rasbora, behaviour is data: note whether the shoal holds together mid-water, scatters only when startled, or fragments for days. Record which fish, if any, hangs alone near the filter or surface, and whether the copper colour washes out across the group or in one individual. Add spawning signs if they appear — rasboras scatter eggs under broad leaves — including which plant was used and whether eggs were eaten. These short weekly lines turn a vague feeling that the fish seem off into a dated sequence a vet or experienced keeper can actually interpret.
Feeding notes for small mouths and mid-water feeders
Write down the food size and type offered, because harlequin rasboras have small mouths and feed mainly in the middle of the water column. Note whether the whole shoal rises for crushed flake or micro food, whether sinking food reaches them before tank mates take it, and any fish that mouths food and spits it repeatedly. Log live or frozen treats and the response, and record fasting days or missed feedings during holidays with the sitter's name. A feeding line beside a colour or behaviour line often explains both: a washed-out shoal that also stopped competing at the surface is telling one connected story.
Keeping one rasbora file for vets and future keepers
Keep the shoal count, soft-water history, and behaviour lines in a single backed-up file rather than split between a notebook and a phone gallery. Add equipment details — tank length for swimming space, filter, lighting hours, and the broad-leaf plants present — because any of them can matter in a health conversation. If the shoal is ever enlarged, record the quarantine or acclimation steps for newcomers and their source. Filing the complete rasbora history in KinsLe through a Pet Passport keeps the records together in one portable packet, ready for a vet visit, a tank move, or a careful handover.