Looks like a C. arcuatus (or C20?) with aberrant coloration to me. The broken stripe and the markings on the lateral line are typical of juveniles of these species at least.
I guessed it is a c.arcuatus but it sure does not look like one cos I've got 6 juvenile arcuatus with me. The dorsal fin is also black if you noticed. Do juvenile arcuatus have a lateral line on the body???
Here's a juvenile C20 from Ian's website. The juvenile coloration of C. arcuatus is very similar.
Note the broken stripe and the dark marks on the lateral line.
C20 and C. arcuatus are one and the same fish. Some juvenile C. arcuatus will show the broken band for quite a long time, they do eventually develope the full band.