Molly Miller Blenny went rogue

[Oregon Grown Reef]

It is with a heavy heart that I must work on removing my Molly Miller blenny. I love this fish due to its personality, but I witnessed it commit a sin most foul. To back up a bit, I've never been able to get acros to survive for long in this tank. I've never had problems with growing them in another tank, but this one seems to hate them. Despite stability in parameters, they would die after a couple of months. That brings me to today. I was watching the tank because I got a new shipment of corals from SBB Corals and I saw the blenny eat a polyp off! Surely my eyes deceived me, so I watched it intently. It then ate another right off of it! I then inspected the tips of other acros and found some had no polyp or had flesh removed from them! Goodbye, Mr. Blenny.

 

[Gumbies R Us]

It is with a heavy heart that I must work on removing my Molly Miller blenny. I love this fish due to its personality, but I witnessed it commit a sin most foul. To back up a bit, I've never been able to get acros to survive for long in this tank. I've never had problems with growing them in another tank, but this one seems to hate them. Despite stability in parameters, they would die after a couple of months. That brings me to today. I was watching the tank because I got a new shipment of corals from SBB Corals and I saw the blenny eat a polyp off! Surely my eyes deceived me, so I watched it intently. It then ate another right off of it! I then inspected the tips of other acros and found some had no polyp or had flesh removed from them! Goodbye, Mr. Blenny.

Sometimes you have to do what's best for the tank, especially if your acros keep being eaten haha, sorry you are having to get rid him though!!

 

[Oregon Grown Reef]

Sometimes you have to do what's best for the tank, especially if your acros keep being eaten haha, sorry you are having to get rid him though!!

Either I keep buying very expensive snacks for a $50 fish, or I get rid of the fish. It's an easy choice.

 

[Oregon Grown Reef]

Update. The fish is now living happily in my 90 fowlr. When I made the hardscape, I initially had it as one solid piece that I'd be able to remove. I dropped it before putting it in the tank and it broke directly in half. I left it like that because I could still fit the pieces together and have it be structurally sound. One of the benefits of this is I can easily remove all of the hardscape within 5 minutes and catch any fish with ease.

 

[Mr. Mojo Rising]

its extremely michevious and not reef friendly at all, I pulled mine out after about 3 weeks after catching it eating my $100+ RFA's

 

[Cthulukelele]

They will eat literally anything. Never interacted with a fish that ate literally anything

 

[Oregon Grown Reef]

its extremely michevious and not reef friendly at all, I pulled mine out after about 3 weeks after catching it eating my $100+ RFA's

They will eat literally anything. Never interacted with a fish that ate literally anything

I wish this information was more readily available! I had never heard of this and I've kept them before! If my acros start taking off now, I'm going to cry.

 

[jakeb]

I have a molly miller blenny and after having him for 6 months he ate both of my RFA's. Around 6 months after this I have seen him picking at the edges of my freak hair pavona.

I knew he would be a risk with the RFA's but didnt realise he would be an issue with other corals. He's a great fish, but I think it is time for him to be rehomed...

 

[Jposch]

I have 28 Scartella Cristata and NEVER once saw them touch coral or anything. Let's see photos of these culprits. There are several similar species wild caught sold as "molly millers" that truly are a different species.
I keep them with RFAs, acros, lobophyllia, leather corals, micomussa, zoas, euphyllia, mushrooms, etc. Never issues besides a few tipped over frags when they squabble. I started with 30, and lost 1 in each frag tank. Likely because I wasn't feeding them everyday. They eat alage, aptasia, etc. EVEN VALONIA. this is an act I cannot seem to catch on video, but I see them tearing it up often. And the amount of bubble alage is reduced. One system has 2 tanks. One with blennies, one without. The blenny tank has ZERO bubble alage. The other I ended up tearing out because of the bubble alage getting 1" thick on all sides of a 100gal. Stock tank.
Male and female

Male in pipe, thw other might be female, but more likely a subordinate male.

Photos from a book on Atlantic coast fish. Most benthic fish change colors and patterns when stressed, and thus improper ID is very much common.
Those on the fence, I suggest going through biota. They have the correct species.

 

[Amber.]

I have 28 Scartella Cristata and NEVER once saw them touch coral or anything. Let's see photos of these culprits. There are several similar species wild caught sold as "molly millers" that truly are a different species.
I keep them with RFAs, acros, lobophyllia, leather corals, micomussa, zoas, euphyllia, mushrooms, etc. Never issues besides a few tipped over frags when they squabble. I started with 30, and lost 1 in each frag tank. Likely because I wasn't feeding them everyday. They eat alage, aptasia, etc. EVEN VALONIA. this is an act I cannot seem to catch on video, but I see them tearing it up often. And the amount of bubble alage is reduced. One system has 2 tanks. One with blennies, one without. The blenny tank has ZERO bubble alage. The other I ended up tearing out because of the bubble alage getting 1" thick on all sides of a 100gal. Stock tank.
Male and female

Male in pipe, thw other might be female, but more likely a subordinate male.

Photos from a book on Atlantic coast fish. Most benthic fish change colors and patterns when stressed, and thus improper ID is very much common.
Those on the fence, I suggest going through biota. They have the correct species.

If you don’t mind me asking, the book in the bottom, which one is it? I would love a reference book to have on hand.

 

[Jposch]

If you don’t mind me asking, the book in the bottom, which one is it? I would love a reference book to have on hand.

Looks like 1986.

 

[jakeb]

I have 28 Scartella Cristata and NEVER once saw them touch coral or anything. Let's see photos of these culprits. There are several similar species wild caught sold as "molly millers" that truly are a different species.
I keep them with RFAs, acros, lobophyllia, leather corals, micomussa, zoas, euphyllia, mushrooms, etc. Never issues besides a few tipped over frags when they squabble. I started with 30, and lost 1 in each frag tank. Likely because I wasn't feeding them everyday. They eat alage, aptasia, etc. EVEN VALONIA. this is an act I cannot seem to catch on video, but I see them tearing it up often. And the amount of bubble alage is reduced. One system has 2 tanks. One with blennies, one without. The blenny tank has ZERO bubble alage. The other I ended up tearing out because of the bubble alage getting 1" thick on all sides of a 100gal. Stock tank.
Male and female

Male in pipe, thw other might be female, but more likely a subordinate male.

Photos from a book on Atlantic coast fish. Most benthic fish change colors and patterns when stressed, and thus improper ID is very much common.
Those on the fence, I suggest going through biota. They have the correct species.

Here's my one. Sold as a captive bred Molly miller blenny.

 

[jakeb]

And mine unfortunately died when I was on holiday, which is a real shame as it was a great fish with real personality (even if it did eat some corals).

No noticeable signs of injury/illness, no other fish with health issues, nothing wrong on an ICP, etc. And had someone feeding pre-measured food twice a day whilst I was away.

I have noticed a couple of small valonia since he died a month ago, which may mean he was eating them.

 

[Jposch]

And mine unfortunately died when I was on holiday, which is a real shame as it was a great fish with real personality (even if it did eat some corals).

No noticeable signs of injury/illness, no other fish with health issues, nothing wrong on an ICP, etc. And had someone feeding pre-measured food twice a day whilst I was away.

I have noticed a couple of small valonia since he died a month ago, which may mean he was eating them.

That's unfortunate. I'm unsure where it would have been captive bred at. Sustainable aquatics who was the main, and likely only producer, stopped them after the knowledgeable staff had left, and they couldn't produce them in a volume large enough worth continuing.
That does appear to be a molly miller. A female perhaps.
They certainly do handle valonia. Somewhere between rabbitfish and emerald crab. Emerald crabs always failed to make a noticeable impact for me, but the blennies will get the valonia knocked out with enough time. Its not a delicately to them, but when there hungry, which is always, they'll start eating it. Manual removal for the bulk of it, and blennies for longterm management. Its really a great option for those with smaller tanks. I thought about it, and I suppose I always had rock flowers in baskets where they could not reach. I'll get some of the cheap brown ones and let them go free range and see if I can spot a blenny munching on them. I've otherwise knly had the issue of blenny battles causing knocked over coral, so I solved that with large, heavy concrete tiles on the bigger frags/colonies. I mostly keep these blennies in frag tanks. 48"×48" 122cm×122cm)and 70"x30" (178×76cm)
Not to call anyone a liar, but the blennies won't eat aptasia that gets over like 1/2" (1.25cm) diameter, so taking down a rock flower seems unlikely IME. I'm willing to look into it first hand. No fish is perfect, but research guys come close. Ha.
As full grown adults, there has been some territorial disputes, but I have mostly males. No cases of murder though.

 

[jakeb]

That's unfortunate. I'm unsure where it would have been captive bred at. Sustainable aquatics who was the main, and likely only producer, stopped them after the knowledgeable staff had left, and they couldn't produce them in a volume large enough worth continuing.
That does appear to be a molly miller. A female perhaps.
They certainly do handle valonia. Somewhere between rabbitfish and emerald crab. Emerald crabs always failed to make a noticeable impact for me, but the blennies will get the valonia knocked out with enough time. Its not a delicately to them, but when there hungry, which is always, they'll start eating it. Manual removal for the bulk of it, and blennies for longterm management. Its really a great option for those with smaller tanks. I thought about it, and I suppose I always had rock flowers in baskets where they could not reach. I'll get some of the cheap brown ones and let them go free range and see if I can spot a blenny munching on them. I've otherwise knly had the issue of blenny battles causing knocked over coral, so I solved that with large, heavy concrete tiles on the bigger frags/colonies. I mostly keep these blennies in frag tanks. 48"×48" 122cm×122cm)and 70"x30" (178×76cm)
Not to call anyone a liar, but the blennies won't eat aptasia that gets over like 1/2" (1.25cm) diameter, so taking down a rock flower seems unlikely IME. I'm willing to look into it first hand. No fish is perfect, but research guys come close. Ha.
As full grown adults, there has been some territorial disputes, but I have mostly males. No cases of murder though.

I think I got the blenny in January 2022 - maybe this was before Sustainable Aquatics stopped breeding them?

I work from home and my desk is right next to my tank, so I got to watch him a lot. The video I posted was my attempt to capture it pecking at the pavona, but it always stopped whenever I got my camera out.

He would really go for the RFA, biting and pulling at the tentacles around the edge, but it might have been very rare behaviour that I was unlucky to experience. I wish I was able to video it.

If you decide to do it, I'd be interested to see if you experiment how well yours behave with RFA's. I had the RFA before I had the blenny, and it's main territory/resting spot was right next to the RFA (and he left it alone for several months). Maybe he only ate them because they where right next to him?

 

[Jposch]

I think I got the blenny in January 2022 - maybe this was before Sustainable Aquatics stopped breeding them?

I work from home and my desk is right next to my tank, so I got to watch him a lot. The video I posted was my attempt to capture it pecking at the pavona, but it always stopped whenever I got my camera out.

He would really go for the RFA, biting and pulling at the tentacles around the edge, but it might have been very rare behaviour that I was unlucky to experience. I wish I was able to video it.

If you decide to do it, I'd be interested to see if you experiment how well yours behave with RFA's. I had the RFA before I had the blenny, and it's main territory/resting spot was right next to the RFA (and he left it alone for several months). Maybe he only ate them because they where right next to him?

Perhaps. There is a good chance mine are too busy squabbling to start sampling anything. Lol
They stopped breeding them years ago. So, either someone over the pond is breeding them, like dejong marine life, or someone was sold a wild fish as tank raised. The wild ones are caught small, so could pass as a juvenile tank raised fish. Not sure why yours died. They do need to eat ALOT. They don't get to be primary herbivores until they reach adult size.

 

[jakeb]

Perhaps. There is a good chance mine are too busy squabbling to start sampling anything. Lol
They stopped breeding them years ago. So, either someone over the pond is breeding them, like dejong marine life, or someone was sold a wild fish as tank raised. The wild ones are caught small, so could pass as a juvenile tank raised fish. Not sure why yours died. They do need to eat ALOT. They don't get to be primary herbivores until they reach adult size.

I got mine from one of the better stores in the UK. They wouldn't say where they got them from at the time, but I trust they checked their supply chains.

Mine was definitely feeding well, he'd push past anything in the tank to get to food and looked well fed. I have a theory that he ate something stupid - I'd seen him with bits of rubble sticking out of his mouth in the past...

 

[Jposch]

its possible. they like those spicy bristle worms too. lol

 

[Northern Flicker]

I am starting to think Blennies just aren't as reef safe as people seem to think they are. My bicolour blenny nips my LPS all the time!