Nic;1769924; said:are the marks on there faces normal???
No this is not normal and not really all that good...Could you add some details on what you feed, what your water parameters are and frequency of water changes?
What you have going on with your fish is kind of the gar equivalent of "Lateral line (sensory pore) erosion".. This is usually easier to prevent than cure but it can be reduced some. This is a common problem in Public aquarium gars that is oddly not so common in the home aquarium. Often feeding is directly related it is not however the only cause.