Your account is interestingly sad, especially the resulting water pollution even though nothing had yet died. A small tank records small decay in a big way (and why we are so adamant about larger tanks -- in addition to size needed for freedom of movement) but it is hard to try to guess if the ammonia and nitrites rose before or after the attack. As much as I am a high proponent of keeping brittle/serpent stars with octos anecdotal evidence is getting stronger for putting any starfish on the black list.
If (and at this point I am guessing when ) you are given another, be sure you test the water before putting it in and then as often as possible (with water change water at hand) for the next two days.
I'll be glad (but your wallet won't be) when you guys jump further into committing to saltwater and we can reduce the environment aspects of the viability of sushi as a pet. At the moment, I have an adult blue crab (Fred) raised from dime size, 4 other intended for octo food crabs, three bicatch fish (also part of a plankton tow for octo food), At least one abalone from the Korean market and a small lobster (acquired for the tank on purpose -- several year old adult but looks like a juvenile of the type caught for food in FL). The family and a few friends often suggest a seafood banquet at my house .
If (and at this point I am guessing when ) you are given another, be sure you test the water before putting it in and then as often as possible (with water change water at hand) for the next two days.
I'll be glad (but your wallet won't be) when you guys jump further into committing to saltwater and we can reduce the environment aspects of the viability of sushi as a pet. At the moment, I have an adult blue crab (Fred) raised from dime size, 4 other intended for octo food crabs, three bicatch fish (also part of a plankton tow for octo food), At least one abalone from the Korean market and a small lobster (acquired for the tank on purpose -- several year old adult but looks like a juvenile of the type caught for food in FL). The family and a few friends often suggest a seafood banquet at my house .