Gobies eating fish???

[jaihutcherson]

Hey All!

question; I have 3 engineer gobies, had them since about an inch long, that I believe are eating my fish one by one. They are about 11-12 inches long, fat as my thumb, and definitely work in pack mentality. I didn’t have any issue first 2 years of their lives. Love them!!!

about 6 months ago I introduced a goatfish to the tank approx 2 1/2”. He was healthy, swimmer, picker, doing his goat thing for about 6 weeks. Very healthy. Then one day gone. Never found him or remnants of him. Just kinda went on with daily reef life.

About 2 months later introduced a 2” foxface. Went in great. Healthy social swimmer, ate my rocks and more, etc. healthy. Then one day nmaybe 2 weeks later gone. Again, never recovered his body. Figured died and maybe crabs took care of him. But started thinking maybe Gobies…..

next was a platinum clown 1 1/2” gone. No sign
Next, and this one still makes me wonder… a starry blenny that was about 5” long and very healthy, very strong, very active, very much a big personality in the tank.

and now, last night, a medium size clown. Another very active swimmer.

tank parameters are spot on:
78
9.5 alk
420 cal
1324 mag
0 nitrite
0 ammonia
10 nitrate
.03 phospates
8.13-8.22 ph
35.5 salt

very stable system with apex triton, active dosing, good sump with about 40 mangroves. Running radions on ab+ schedule with 90 par on floor and about 275 at top of tank.
All other fish (15) are smallish 2-3 1/2” and been with the gobies as long as they have been in the tank.

so all that being said to ask…. Do engineer gobies start eating fish as they become huge like mine? If so, can I pull them out and put in my FOWLR predator tank with lions, eels, and puffers?

 

[maleks.reef]

No experience with them but found this

Do engineer gobies eat small fish?

Has this happened to anyone?

www.reef2reef.com

 

[jaihutcherson]

No experience with them but found this

Do engineer gobies eat small fish?

Has this happened to anyone?

www.reef2reef.com

Hey!
Thanks for taking the time to find it. Yea, I found that too and was what finally drove me to think they did in fact eat the fish. I mean seriously, if not eaten I would think I’d find something. I do have a great clean up crew but just surprised. Again, thanks for your time.
Jai

 

[i cant think]

The only reason I can think of why they’d eat small fish is if they arent fed enough. They can be terrors with sand but not always fish.

 

[monkeyCmonkeyDo]

Are they omnivore?
You can test it by adding a bigger tank mate... lol.
I've seen them that big and yes I would not put it past them. Lol.
D

 

[Mr. Mojo Rising]

can you post some pics? I love gobies, but have never seen one that size, I've never seen one bigger than 6 inches.

as far as I know, a fish will eat any other fish that can fit in its mouth. But gobies are so timid, I cant picture it lol

 

[i cant think]

I will add since I forgot to say this earlier:
Engineering gobies aren’t a true goby or eel and are instead in their own family (Pholidichthyidae). they get the name of goby due to how similar they can be to the family gobiidae.

 

[Karen00]

I will add since I forgot to say this earlier:
Engineering gobies aren’t a true goby or eel and are instead in their own family (Pholidichthyidae). they get the name of goby due to how similar they can be to the family gobiidae.

Based on the size of the OP's it sounds like they should be part of the eel family. LOL

 

[jaihutcherson]

Lol yes, they are almost as big as my snowflake. They get plenty, maybe too much to eat…. My nitrates tell me so. Not funny. Ok, pretty funny unless you are the one pulling the hair sale out. Ouch. Anyway, they are definitely carnivore. I’ve never so much as seen them eat the herb. Rods, algae, or the nori I put in the tank for the others. I’ve got several big fish in there with them and then a lot of lil ones. I’m getting about 11 more fish to finally fill the tank up (300g system) this coming week. It’s a mix of large and small. All pretty peaceful. I’m worried about my new leaped wrasse and baby foxface the most. I think the tangs can hold their own lol.

I want to move them to my predator tank. However, I’m finding that 3 eels and 3 gobies really won’t be to comfy cozy. The rest in the tank… puffers and wrasse with a sailfin wouldn’t be an issue. Plenty of room though (400g system). Any thoughts?

 

[DeniseAndy]

I had one for years that was easily 10". Never noticed it eat any fish, but it was one of the later additions and most my fish were larger (over 3"). Bummer about the fish though.

 

[jaihutcherson]

I had one for years that was easily 10". Never noticed it eat any fish, but it was one of the later additions and most my fish were larger (over 3"). Bummer about the fish though.

Thanks!
all the fish have been super small… 1-1 1/2” at most. I’m in the middlenn be of moving quite a lot around in my tank and as I’m moving looking for any sign. I do not expect to find anything, my clean up crew have been around a long time and they devour anything that isn’t nailed down on the floor. I’ve looked each time a fish has disappeared and I mean no more than 10 min. On this last one and have never found so much as a spec. They really are great gobies. We love them. They were the first in this tank 2 1/2 years ago. Lots of personality and they do a great job of moving my sand around completely. Lol
Jai

 

[DeniseAndy]

I loved mine. Just lost in tank move. Miss the constant sand rearrangement.

 

[BostonReefer300]

I had two engineer gobies that grew to be well over a foot long. One died last year from unknown causes, but the other is healthy and still growing. I added two small engineers several months ago so my big one would have friends, since he and the other one were always hanging out together. Those babies disappeared within a couple days and I did see the big one eyeing them suspiciously beforehand. I also lost a couple of blue-green chromis babies from my big school not long after. Of course, chromis are notorious for killing their own, so I didn't instantly blame my engineer. I got two new baby engineers a few months ago and have been keeping them in my anemone tank until they get significantly bigger. Once they reach 6 inches, I was going to put them in the big tank. I'm hoping they survive if they're that big. Engineers are really cool fish if you don't mind constant sand rearrangement---and, I guess, missing fish occasionally!

 

[jaihutcherson]

I had two engineer gobies that grew to be well over a foot long. One died last year from unknown causes, but the other is healthy and still growing. I added two small engineers several months ago so my big one would have friends, since he and the other one were always hanging out together. Those babies disappeared within a couple days and I did see the big one eyeing them suspiciously beforehand. I also lost a couple of blue-green chromis babies from my big school not long after. Of course, chromis are notorious for killing their own, so I didn't instantly blame my engineer. I got two new baby engineers a few months ago and have been keeping them in my anemone tank until they get significantly bigger. Once they reach 6 inches, I was going to put them in the big tank. I'm hoping they survive if they're that big. Engineers are really cool fish if you don't mind constant sand rearrangement---and, I guess, missing fish occasionally!

Thanks for replying!

I love my goby’s! We thought we lost one about six months ago and did the same by introducing a new one to the tank. We searched and found one about 6” long and he liked it thankfully. I remember reading online that the adult males eat the young if left in the tank so I didn’t want to risk putting a small one in. Come to find out when we upgraded tanks 3 months later, the original goby was indeed still alive and in fact, huge. We now have 3 engineer gobies that stick together like triplets. They are a blast to watch, give me something to do in the tank daily as they cover this or that up….. we really do like them. It’s why it’s so difficult that they are eating the small ones in the tank. The original pair of gobies are the first two fish we got getting into this hobby.