The Short List for a Very Small Fish
A celestial pearl danio purchase rarely involves formal certificates, and it does not need them. What should come home is a clear written record: a receipt or invoice naming the fish as celestial pearl danio, ideally with the scientific name alongside it, the exact number you bought, and the price line for that group. Because these fish are sold in groups rather than singly, the count on the paperwork should match the count in the bag. If the seller sexed any of them, or sold you a stated mix of the spotted, brighter males and plainer females, get that written down too, since a group heavy in males behaves differently once territories form among the plants.
Source Matters More Than a Stamp
Ask whether your fish were captive-bred or wild-caught, and have the answer recorded. Celestial pearl danios come from shallow, heavily vegetated water in Myanmar, and wild fish can arrive leaner, shyer, and less accustomed to prepared foods than tank-bred youngsters raised on commercial diets. The source also tells you what to watch during the first weeks: wild-caught fish deserve a closer eye for thin bellies and clamped fins, while captive-bred fish usually settle faster but still hide at first. A good seller will also note how long the group has been in the shop and whether they have been held separately from new arrivals, which gives you a sense of how settled they really are.
The Seller's Water, Written Down
Request the holding tank's temperature, pH, and hardness before you leave. These danios do best in cool to moderate, fairly soft to medium water, and a group moved abruptly from soft shop water into much harder home water may go off food for days. With the seller's numbers in hand you can compare them against your own test results, acclimate slowly, and aim your tank toward overlap rather than guessing. Note the numbers on the receipt itself if no separate care sheet is offered. A shop that cannot tell you its own water values is telling you something useful about how closely those fish were monitored.
Feeding History for Fish That Hide at Mealtimes
Get the recent diet in writing: which crushed flake, micro pellet, or frozen and live foods the group has actually been eating, and how often. Celestial pearl danios have small mouths and a retiring habit, hanging back in cover while bolder tankmates feed, so knowing a food they already recognise helps you confirm each fish is eating during the nervous first days. Record also any foods they refused, if the seller knows. That small detail prevents you repeating a failed offering while a shy fish loses condition unseen among the stems.
What to Add Once They Are Home
Your own records start at the tank glass: note the group size, the tank they entered, your first water readings, and when you first saw each fish feed confidently. Photograph the males once their spots and orange fin edges colour up, because those photos help you track individuals in a way a written description cannot. If a fish fades, stops joining the group, or stays thin while others round out, those dated observations turn a vague worry into a clear account for an aquatic veterinarian or an experienced shop. Storing the receipt, source note, seller water values, and your settling-in log together in KinsLe's Pet Passport keeps the whole danio file in one portable packet, ready for a vet visit, a house move, or a handoff to a trusted keeper.