Uncommon or Specific:
* Umbrella Mouth Goby (Cryptocentrus cinctus): Found in the Indo-Pacific.
* Unicornfish (Naso spp.): A large family with many species, but not all are commonly kept in aquariums.
* Ulua (Caranx ignobilis): A large predatory fish found in the Pacific.
Less Common:
* Uca (Mudskippers): While not strictly "saltwater," some species tolerate brackish water environments.
It's important to note that the "U" sound in these names might be spelled differently, making it hard to find them when searching.
If you're looking for specific saltwater fish names, consider searching by family, region, or common traits instead!