Thanks for the mention! My first recommendation would be the
Columbian shark catfish (
Arius jordani). Usually, it is sold for the freshwater/brackish hobby, but it does well in saltwater.
Lookdowns (
Selene sp.) go absolutely crazy when feeding live foods (from what I’ve seen).
Squirrel and Soldierfish (
Holocentridae sp.) are nocturnal and hide under ledges during the day.
Toadfish (such as
Opsanus tau) look fascinating, though I do not know much about them. I also do not know much about
Monos (
Monodactylidae sp.), besides the fact that they school and can survive in fresh, brackish, and saltwater.
Remoras (
Echeneidae sp.) are great at removing external parasites from elasmobranchs, though the former might irritate the latter with its “sucker.” Large
Northern clingfish (
Gobiesox maeandricus) are likely almost indestructible and highly tame, though they, like your Round stingray, have a preference for somewhat cool water (down to the Gulf of California). I already mentioned the
Yellow stingray (Urobatis jamaicensis) whose care specifications are basically identical to that of the Round stingray. If you can get your hands on it, the
Striped stingaree (
Trygonoptera ovalis) would provide great contrast against the sand. Finally, a
Sea biscuit (
Clypeaster subdepressus) would make for another odd sand sifter if you don’t care too much about sand biodiversity and are willing to feed sinking tablets/live Brine shrimp.
Lookdown feeding:
Some sites you could check/contact to see if they have/could obtain some of the rarer livestock on the list:
Gulf Specimen Marine Laboratory
Shark Supply LLC
Matsu Collections
MarineFishEZ
Well that was a long post.
