Although it is quite common to see Corydoras trilineatus incorrectly labeled as Corydoras julii, the Julii Cory will sometimes be seen for sale in fish shops. However, the region the Julii comes from is not heavily fished commercially, and most shops do not carry true Julii Corys.
Many owners who think they have taken home the Julii Cory, Corydoras julii, have accidentally purchased Corydoras trilineatus. Julii Corys are smaller and more stout in build, with a shorter head and rounded snout. They also have smaller spots, while Corydoras trilineatus has spots that tend to connect into a reticulated pattern. This is particularly noticeable on the head. This species reaches an adult size of a bit over 2 inches.