If the angler fish doing the eating is big enough, yes, it can eat other angler fish. There are more than one kind of angler fish.

You will like to read more about "angles fish" on our website, here.

This is species dependent, but it appears that some angler fish do (page 62, paragraph titled Cannibalism) prey on their own species. This is perhaps unsurprising since angler fish are opportunistic feeders and more or less take what they can get and what they can handle. As described here and on ScienceLine, a special feature of angler fish allows them to take advantage of as much as possible: they have distending jaws and expandable stomachs, meaning they can eat other fish which are larger than themselves.