Something attacked my starfish :s

[gqlmao]

A lot of people keep their reef tanks at 1.025 ~ 1.026 salinity with no ill affects on starfish. Any higher would be dangerous to lots of things not just starfish. There could be many possibilities on what happened. In my opinion that injury doesn't look like its been attacked by something. I'd keep an eye out and see how it is doing, maybe check on it a few hours after the lights turn off.