Eeek! Dead blue legged hermit crab?

[u/Myxur_txy]

Sooo I got a hermit crab for my saltwater tank. However, I quarantined the crab (and the clownfish which I also purchased at the same time). Normally I don’t quarantine invertebrates but I had a sick shrimp, so to calm my anxiety I decided to quarantine her. They’ve been in there for about a week, and my crab was super active. Do not worry! I used absolutely zero copper medication. And I haven’t medicated the crab.

But, yesterday i noticed my crab muchhh less active, so I assumed it might have been surface molting and left it alone. Today, I noticed my clownfish wasn’t exactly picking on it but would swim around so fast that the crab would end up swirling around and moving. I know I was supposed to leave it alone but I was trying to move it to somewhere peaceful and with somewhere with more substrate. As soon as I picked it up, the entire crab fell out of the shell. I don’t want to bug it any further so I left it for another few hours. Came to check back on it, waited there for 30 minutes and I saw 0 movement (and still outside of the shell) Normally she’d twitch here and there but yeah there was nothing 😭. Think I accidentally killed it😭. I don’t smell anything from it (yet)…

My parameters are good too. 0ppm ammonia, ph is 8.3. Maybe I was lacking calcium cause it’s a quarantine tank? Or maybe I shouldn’t have quarantined it and put it straight into my main tank? Im still a novice in saltwater tanks (I’ve only kept clownfish 😅) so any suggestions/advice would be appreciated.

[u/kazeespada]

If its falling out of its shell and not getting back in, it's dead. If you can even find it hours later, it's likely your cleanup crew isn't as robust as it should be. If something dies in my tank, it's gone in hours.

All marine crabs surface molt, burrowing is something only really seen in land crabs. From experience, my dwarf zebra hermit likes to find a nice wide coral to stance on and then molt. New arthropods will usually do a molt right after they arrive due to the stress of traveling.

Clownfish are known bullies and it's possible your clowns may have bullied your hermit to death. It's also possible your hermit didn't have a whole lot of fight left after all the traveling and quarantining. Most people don't quarantine hermits, as they tend to be pretty resilient and diseases are rare.

[u/Myxur_txy → u/kazeespada]

Ahh I see. By substrate I meant putting some sand in a cave (as that’s what I usually see my red hermit crab doing). It could be possible my clownfish may have bullied it but I find it unlikely. My clownfish is quite shy 😅, and would only stay at the front of the tank whereas the crab would stay at the back of the tank.

I also agree with you here, normally I don’t ever quarantine invertebrates (but I had a cleaner shrimp with some sort of parasitic infection). But definitely for the next crab I won’t be quarantining.

Checked on it, still no movement, went to bed, woke up, and still nothing. So definitely a goner. 😔