There is no vaccine card to build for a corydoras catfish, because pet fish are not routinely vaccinated. What this bottom-dwelling shoal needs instead is a group health record: a running log that treats the shoal as one household, tracking water, food, numbers, and the small physical signs, especially around the barbels, that show whether life on the bottom suits them.
Start With the Shoal, Not the Individual
One corydoras looks much like another, and chasing individual identities in a record quickly becomes guesswork. Open the log with the basics that do stay true: the species or variety, how many fish make up the shoal, where they came from, and the tank they live in. Then log the group. Note the count whenever you feed, because a quiet drop in numbers is exactly the kind of change a written record catches and memory misses.
Arrivals and losses both belong in the log in the order they happen. A short line on each new fish, including how long it was quarantined before joining the shoal, explains later entries if illness follows an introduction. A loss recorded with the water readings from that week often tells its own story when you reread it.
The Entries That Matter for a Bottom Feeder
Water test results anchor every entry, as they do for any fish, but a corydoras log should add three things other fish records skip. First, the substrate: note what the floor is made of and any change to it, because these fish push their snouts into the ground all day. Second, barbels: record whether the whiskers around the mouth look full and even or short and worn, since barbel condition is a visible summary of how the bottom is treating them. Third, food reaching the floor: log which sinking foods were offered and whether the shoal ate eagerly, because fish that live low in a community tank are easily outcompeted.
Behaviour notes complete the picture. Corydoras that rest together, forage in short bursts, and occasionally dart to the surface are showing their normal pattern. A fish sitting apart, breathing fast, or refusing the floor is worth its own line in the log that day.
Photos and Water History
Photograph the shoal from above or at floor level while they feed, under the same light each time. In a group photo, worn barbels, a thin fish, or one individual hanging back are easier to compare across entries than in a written description. Keep the water test history beside the photos so appearance and conditions can be read together.
Keep the log in entry order and resist tidying it into summaries. The raw sequence, tests, appetite, barbels, behaviour, is what an aquatic veterinarian will actually use, and a rewritten summary loses the small step where things began to change.
Sharing the Record With Sitters and Vets
For a sitter, pull a short summary from the front of the log: shoal count, sinking food and amount, water change routine, and the signs that should trigger a call, especially a fish separated from the group or gasping at the surface. For a vet visit, bring the recent entries, the substrate note, and the group photos; barbel wear together with the water history points the conversation in the right direction quickly.
Review the log whenever you add fish or change the floor. Those two events explain most turns in a corydoras shoal's health, and the record should make both easy to find months later. KinsLe Pet Passport holds this shoal log, its photos, and its feeding summary alongside the tank's other records, so the whole bottom-feeding picture travels with whoever needs it.