Murdering Lawnmower Blenny

[ReefSCTim]

My lawnmower blenny is a murderer. This week I paid $87 for a cleanup crew of 12 nassarius snails and one blood red fire shrimp. They arrived in great condition from a reputable fish vendor and I added to my tank. A few hours after adding the snails, I noticed the lawnmower blenny kept coming out to the front of the tank where I added the snails. On closer inspection, he would pick up each snail, chomp down on it and proceed to eat it or take it back to his cave, never to be seen again. He ended up eating all of them that night. Then this morning I see his tail wiggling up from the bottom of the tank and walk over only to realize that he was chomping down on the last bit of the blood red fire shrimp. I previously had a goby fish that disappeared but I never assumed he was eaten by the blenny.
He is well fed and fat! I’m worried because I have a few smaller clown fish that could be an appetizer too. I have a few extra large snails that I guess he can’t get in his mouth. What other fish do lawnmower blennies have issues with?

 

[PDR]

That’s odd to say the least...I can’t say I’ve ever heard of them eating snails and shrimp.

 

[justjes45]

Holy crap that is crazy! I have a lawn mower Blenny that will not eat a single bit of algae… But I have not noticed him snacking on my snails. Unfortunately I just ordered a cleanup crew I guess I will see how it goes – I am following along! And in your picture he looks so fat! LOL

 

[eatbreakfast]

That's very unusual, especially taking down a blood shrimp. I've seen the move snails away from their territory, but not eat them" especially snails that close themselves in.

 

[Supurderek]

I have owned over four of them in my lifetime and have not seen such behavior; other than the occasional moving of snails shells with algae on them! But there could always be that oddball!

 

[davocean]

Yep, new one for me as well, and I've had a number of LMB's, very odd.

 

[ReefSCTim]

Ok. The LMB didn’t eat the red blood shrimp. I guess he was just messing with the skeleton shell the shrimp shed. I thought it was the shrimp dead. Imagine my surprise this afternoon when he suddenly appeared.
Several of you have suggested the LMB was perhaps moving the snails, not eating them. He may have accidentally bit and broke one in half? I want a peaceful tank. Fingers crossed ! He gets another chance! He is interesting!
Thanks for all of the feedback!! I’m new to this world!

 

[Angie Eaton]

I bought a fire shrimp a couple of days ago and I believe my lawnmower Benny ate him. He is fine with my clown fish but he ate my chocolate chip star fish and my fire shrimp.

 

[eatbreakfast]

I bought a fire shrimp a couple of days ago and I believe my lawnmower Benny ate him. He is fine with my clown fish but he ate my chocolate chip star fish and my fire shrimp.

What makes you think he ate your chocolate chip star and fire shrimp? It would be very unlikely that a lawnmower blenny ate the shrimp and pretty much impossible for it to eat the star.

 

[ReeferPat]

Just watched my lawnmower blenny attack my latest addition of nassarius snails. I have to add them at night and in the opposite side of the tank. Even so, I have to add more every few months because he will eventually eat them all. He is fat and well fed but an absolute killer. Can’t catch him either...

 

[Big G]

Fish trap and a new home.

 

[fluked]

Old post but related info - Mine is a coral eater, its smashed an acan, its attacking a trachy and a deshy. Cant say im happy about him after going for a lawnmower because they are meant to be reef safe

 

[jaganshi066]

My lawnmower blenny is a murderer. This week I paid $87 for a cleanup crew of 12 nassarius snails and one blood red fire shrimp. They arrived in great condition from a reputable fish vendor and I added to my tank. A few hours after adding the snails, I noticed the lawnmower blenny kept coming out to the front of the tank where I added the snails. On closer inspection, he would pick up each snail, chomp down on it and proceed to eat it or take it back to his cave, never to be seen again. He ended up eating all of them that night. Then this morning I see his tail wiggling up from the bottom of the tank and walk over only to realize that he was chomping down on the last bit of the blood red fire shrimp. I previously had a goby fish that disappeared but I never assumed he was eaten by the blenny.
He is well fed and fat! I’m worried because I have a few smaller clown fish that could be an appetizer too. I have a few extra large snails that I guess he can’t get in his mouth. What other fish do lawnmower blennies have issues with?

I don’t know why this is surprising, lawnmower blennies (and some other blennies) are really aggressive from what I’ve seen. I’ve seen at the fish store a lawnmower chase a fish like he was a shark getting ready to eat. Another time a saw a different blenny at a store chasing every fish in the tank the same way. I know dwarf angels are territorial but in my opinion blennies are way worse. I have two dwarfs in a tank and one chases another once in awhile but nothing like this, plus they don’t eat the clean up crew.