Did you know fantastic help is an anagram of Planet Catfish? This forum is for those of you with pictures of your catfish who are looking for help identifying them. There are many here to help and a firm ID is the first step towards keeping your catfish in the best conditions.
This is another post in what is possibly the longest Cory id debate ever and I think a few pointers are needed from time to time so that people can at least make a reasonable calculated guess as to the identity of their fish.
First of all the name 'julii' is constantly used by exporters for any fish showing this colour pattern, basically the name 'julii' carries a better sales rate than 'trilineatus' so is the one they uses. C.trilineatus is very rarely seen on exporters lists. C. trilineatus, C. acrensis, C. julii and W060 show very similar colour patterns and in many cases even overlap. So to try and give a couple of clues as to the possible right id, or at least to point you in the right direction.
C. trilineatus probably the most common of all and is a species from Peru/western brazil/southern Colombia. Also described from this area was C. acrensis.
C. julii is from the Rio Parnaíba in north eastern Brazil, some 4000km from Peru. The forth more recently discovered species CW060 was discovered from the Rio Anapu a direct affluent of the Rio Amazonus near to the Rio Xingu.
So before anyone can decide what fish they are looking at it is best to find out where they were collected or at at least where they were exported from. If the fish were shipped from Peru then it is almost certain they are C. trilineatus of possibly C. acrensis, the latter was described from a single specimen, which would also make it hard to positive of id.
Fish shipped from Belem, Brazil would almost certainly be C. julii.
In answer to the original post I would say that the fish is just a variant of the rest of the group and without knowing where they were exported from I would not attempt to put a name on them.
there is not much to add to Ians post.
C. trilineatus is quite variable, the variation that we see here is not unusual for this species.
In one batch off offspring the variation can easily be more than this.