Mollies dead within hours

[Jake_the_reefer]

so i decided to acclimaye mollies to my tank to let them graze on algae and it didn't go well. Within 5 hours 2 of them are dead and covered in white spots before they died. Could disease kick in and kill these fish that quickly or did they just not adjust too well?

 

[Fishurama]

Sounds and looks like velvet. Sorry for you loss, start dosing copper if you can and dont have invertebrates to save the other fish.

velvet info

Fish with velvet.

 

[Jake_the_reefer]

Sounds and looks like velvet. Sorry for you loss, start dosing copper if you can and dont have invertebrates to save the other fish.

velvet info

Can velvet kill within hours of introduction? This tank is a reef tank. Im going to have to pull the remaining molly and watchman goby and fallow the tank

 

[Fishurama]

Can velvet kill within hours of introduction? This tank is a reef tank. Im going to have to pull the remaining molly and watchman goby and fallow the tank

Yes, it's hours for you, but you don't know how long the fish were sick prior if you just caught it.

" Initiate treatment immediately because the disease has such a high mortality level if not treated quickly. "

I also wouldn't start treating until another member can confirm it's velvet. Don't want to stress out your other fish,the whitesh dots are alarming and how fast they died, it just sounds like velvet.

 

[Bpp124987]

How did you acclimate the Molly’s?

 

[Jake_the_reefer]

How did you acclimate the Molly’s?

They were drip acclimated for 6 hours

 

[javisaman]

If they were freshwater mollies, they had zero immunity to saltwater parasites. It could have very much been velvet. Though it's surprising the other molly is alive.

 

[Jake_the_reefer]

If they were freshwater mollies, they had zero immunity to saltwater parasites. It could have very much been velvet. Though it's surprising the other molly is alive.

First one was snatched up by my torch coral within 3 hours. 5 hours later the 2nd one is pinned to the overflow. Dead.
Other one is not showing any signs of stress.

 

[Hugh Mann]

It's hard to tell by your picture, the spots you mentioned. I would recommend looking up pictures of fish with ich, velvet and flukes.

As mentioned, freshwater mollies have zero tolerance for marine parasites, so they are usually the first to show signs. Velvet can kill in the time frame you mentioned, but it is strange the other one is still alive.

It could potentially be ich, which may not show on healthy fish, but overwhelmed the mollies. Or they showed the spots and then died due to acclimation issues?

Attached is a picture of the mollies that came out of my tank after velvet struck.

 

[Jake_the_reefer]

It's hard to tell by your picture, the spots you mentioned. I would recommend looking up pictures of fish with ich, velvet and flukes.

As mentioned, freshwater mollies have zero tolerance for marine parasites, so they are usually the first to show signs. Velvet can kill in the time frame you mentioned, but it is strange the other one is still alive.

It could potentially be ich, which may not show on healthy fish, but overwhelmed the mollies. Or they showed the spots and then died due to acclimation issues?

Attached is a picture of the mollies that came out of my tank after velvet struck.

They were schooling and happy during and after acclimation. Spots showed a little after introduction.

 

[Fishurama]

They were schooling and happy during and after acclimation. Spots showed a little after introduction.

Read the link When you transferred your fish one or more may have already been carrying it and the change triggered it.
" Adding a new fish to an aquarium is obviously very stressful for the new fish and can be stressful for the existing tank inhabitants as well. Fish that are properly quarantined and fed are not as stressed and are much less likely to become infected with the disease and to create an outbreak when transferred to the existing display tank. "

velvet info

It's hard to tell by your picture, the spots you mentioned. I would recommend looking up pictures of fish with ich, velvet and flukes.

As mentioned, freshwater mollies have zero tolerance for marine parasites, so they are usually the first to show signs. Velvet can kill in the time frame you mentioned, but it is strange the other one is still alive.

It could potentially be ich, which may not show on healthy fish, but overwhelmed the mollies. Or they showed the spots and then died due to acclimation issues?

Attached is a picture of the mollies that came out of my tank after velvet struck.

Good idea on the flukes. One of them looks raised. If OP still has the bodies a FW dip would confirm it.

 

[phatduckk]

there’s no way the mollies brought in a parasite as they’re from fresh water.

Black mollies are used quite a bit as a canary in quarantine situations as they’d be quick to show signs of any issues/parasites in the tank as they’ll have zero immunity to any saltwater parasites/diseases.

now, could they get Velvet and die in a few hours? I dunno but the velvet dinospores do often hit the gills first which could be what happened here.

Personally I’ve never seen pics of fish with velvet out of water so I’d hesitate to comment whether that’s what’s visible in the pics or not.

more info on velvet at https://humble.fish/marine-velvet/

 

[Jake_the_reefer]

Update. The final molly is still alive and showing no signs of sickness

 

[Jake_the_reefer]

Final update. I moved my clownfish into this tank and they killed the final one.

Since then I decided to switch 12 mollies for my frag tank. A month later I have 9 alive. The 3 that died where very young so they didn't handle acclimation well

 

[tim132]

Evening Jake. I'm still new to the hobby so take this with a pinch of salt but I was reading just the other day re the acclimation time of mollies into saltwater and the general consensus seemed to be a longer acclimation time caused more problems and fatalities.

A couple of people reported a quick temperature acclimation followed by adding the mollies directly to SW was the most successful method!! I wish I could link you to the forum but I can't remember where I read it - really surprised me though!

 

[vlangel]

Hi Jake, I recently acclimated 4 mollies to SW to help with nuisance algae in my refugium. 2 made it and 2 did not. I have conversed with several reefers who have macro algae tanks and it's pretty common to lose some.

I wondered if the higher the salinity the higher the risk of loss. That would make sense. I keep my tank at .023 which is close to NSW. A lot of reef tanks are higher than that however.

 

[Jay Hemdal]

Just chiming in here: the early molly issues were not velvet, that kills fast, but that THAT fast. It is definitely an acclimation issue. Going from FW to reef tank salinity has to be done over days,. not hours. I don't mean hold them in a tub for days, what you do is set them up in a tank and gradually raise the salt over five days... 7 ppt per day. .or .005 SG units per day.

Jay

 

[K7BMG]

Just chiming in here: the early molly issues were not velvet, that kills fast, but that THAT fast. It is definitely an acclimation issue. Going from FW to reef tank salinity has to be done over days,. not hours. I don't mean hold them in a tub for days, what you do is set them up in a tank and gradually raise the salt over five days... 7 ppt per day. .or .005 SG units per day.

Jay

Yes this is what I thought as well.
Its over days not hours, but you got here first.
This is true with saltwater fish as well.
Ones that come from LFS that have been in very low salinity like 1.019 for example.
Should be brought up to proper salinity over a few days.

 

[Jake_the_reefer]

Yes this is what I thought as well.
Its over days not hours, but you got here first.
This is true with saltwater fish as well.
Ones that come from LFS that have been in very low salinity like 1.019 for example.
Should be brought up to proper salinity over a few days.

Whats weird is my big batch of mollies i put into my frag tank were acclimated over a couple hours and have been thriving for a month. They have even had babies and I am raising the babies in a different tank. I lost 3 of the big batch and they were all very small mollies.

 

[K7BMG]

Whats weird is my big batch of mollies i put into my frag tank were acclimated over a couple hours and have been thriving for a month. They have even had babies and I am raising the babies in a different tank. I lost 3 of the big batch and they were all very small mollies.

I don't know if its weird or luck of the draw.
But if the mollies were compromised or stressed from the start they could die quickly.
Jay is one of the R2R doctors I would listen to him over me.