Blackline blenny playing dead

[ThunderGoose]

I ordered a blackline blenny from Coral Reef TN. She arrived yesterday and I was dismayed to see her floating upside down in the shipping bag. I documented her as DOA and went on to deal with the rest of the shipment.

Fortunately I looked at her again a bit later. Now she was right side up and moving.

[side note: CoralreefTN responded immediately to my DOA email, and then to my "well, no, not DOA" email - I've been very happy with all my fish orders from them!]

Time to float her in the QT!

Once I released her in the QT she quickly started floating, upside down, again. Oh, no! Maybe she WAS dying.

I left her in the QT just in case.

This morning she's out and about and even ATE! She looks great.

So my question: is this a behavioral issue? Was she "playing dead" to look less appetizing to predators? Has anyone else seen this sort of thing with blennies? Do they sometimes swim upside down?

I'm really glad I use a QT - she'll be in there for almost 2 months so I'll have plenty of time to watch her and make sure she's not really sick.

 

[Reefing Madness]

 

[Highgrade]

I've never seen this behavior. Maybe a swim bladder issue. Any other erratic swimming behaviors?

 

[ThunderGoose]

Yesterday she was acting fine and ate very well, this morning I didn't have time to watch her but she did eat "breakfast." I'm really puzzled.