A corydoras spends its life nosing along the substrate, so the records that matter for a new vet are ground-level ones. This is also a schooling fish that is rarely kept alone, and its condition is tangled up with its group, its tankmates, and the floor it feeds from. A handover that only says 'catfish, unwell' leaves the vet guessing about almost everything that shapes this species.
Describe the Group and the Tank Floor
State how many corydoras live together, which kind they are if you know, and how long this individual has been with you and with its group. Record the substrate in plain terms — soft sand, smooth gravel, or sharp-edged gravel — because corys push their faces into the floor to feed and rough material wears the sensitive barbels around the mouth. Note tank size, filtration, and whether the bottom gets vacuumed at water changes or left undisturbed. If you recently swapped substrate, added new fish to the group, or lost other corys, write that down with rough timing, since changes at floor level are often where a cory's trouble starts.
Bring Water Readings and a Feeding Record
Corydoras are closely tied to water conditions at the bottom, where waste settles. Bring recent readings for ammonia, nitrite, nitrate, pH, and temperature, plus your water-change rhythm and how much you replace. Then list what actually reaches them: sinking pellets or wafers, frozen foods, and how much is left for bottom feeders after faster tankmates feed above. Record whether this fish still joins the group at feeding time or hangs back, and whether it roots through the substrate as usual or sits still on it. A cory that stops foraging is telling a different story from one that eats but looks thin, and your notes let the vet separate the two.
Note Barbels, Breathing, and Surface Trips
Write down what you have seen around the mouth: barbels that look shortened, pale, or uneven compared with the other corys, and any redness or marks along the belly where it rests on the floor. Corys occasionally dart to the surface for a gulp of air, so record how often this fish does it now versus before — a few trips look very different from constant rushing up and down. Bring video filmed at substrate level if you can, showing how it swims, rests, and interacts with the group. Note tankmates above it too, especially any that nip, chase, or outcompete it for food.
Add Recent Changes and What You Have Tried
Close the packet with recent events: a filter clean, a medication added for another fish, a new ornament, a period when the tank ran warm, or a missed week of water changes. List anything you have already added to the water or changed in response to the problem, and what you observed afterwards. Corydoras react to some treatments differently from scaly fish, so a complete list protects this fish from a repeat application of something unsuitable. Add your contact details and any previous vet's name. Assembling group, substrate, and water notes inside KinsLe's Pet Passport gives the new vet the whole bottom-of-the-tank picture in one packet.