Gymnothorax nudivomer has a yellow mouth, this animal doesn't have that. This summer I saw this particular moray myself; it is a challenging animal to identify. Conclusion: Muraena lentiginosa from the Eastern Pacific. I didn't think of it because rarely anything gets imported from this region for years now, but I simply can't think of any other possible match. That species matches the moray perfectly. He's certainly of age because the yellowish spots have become pale and white. Only the back and lower jaw still have some yellow.