A koi has no collar to carry, and pond fish look alike to anyone who does not know them well. Pattern does the work instead. Each koi carries a mix of colour blocks, spots, head markings, and scale shading that stays recognisable over long periods, even as the fish grows and the pattern softens at the edges. A careful photo record turns that pattern into identification that another person can use. The record needs a clear method, taken the same way each time, so a photo from this year can be compared with a fish found later.
The six-field record for every fish
Give every koi one record with exactly six fields. The six fields are: a working name or label for the fish, a left-side photo, a right-side photo, a head-and-pattern close-up photo, the date the photos were taken, and the measured length of the fish. Keep the six fields together for each fish, and do not split the photos from the date and the length. The date matters because patterns shift slowly as a fish grows. The length matters because it narrows a match when two fish share a similar pattern. Update the record once a year, and update it again after any major change in the pond, such as a move to a new pond or a long illness that changed body condition.
How to take photos that another person can match
Use a shallow viewing bowl with pond water, set in open shade so the colours read true without harsh glare. Lift one fish at a time with a soft net, place it gently in the bowl, and work calmly so the fish settles. Photograph the full left side first, then turn the bowl or move to the other side for the full right side. Finish with a close view of the head and a clear pattern detail, such as a distinctive spot, a colour break, or an unusual scale patch. Include a ruler or a measuring board beside the fish in one side photo so the length reads from the image as well as from the written field. Return the fish to the pond promptly, and repeat the sequence for the next fish only after the first fish is back in the water.
Keeping the record safe and ready to share
Store one copy of the record away from the pond, such as a printed set in the house and a digital copy held off the pond site. A record kept only beside the pond helps no one when a fish goes missing from that pond. Share the record with a koi club or society where that fits, and ask what records the club keeps for lost or recovered fish. When a fish goes missing, share the working name, the date of the photos, and the length, together with the side photos and the close-up. Away from the pond, KinsLe stores all six fields for each fish under its Pet Passport entry, making a match check quick if a fish turns up elsewhere.