New fish constantly disappearing

[eesab]

I have a 25 gallon tank, 2 clowns and a banged Cardinal. I've introduced a tamarind wrasse, he went straight into the sand and didn't see him since (that was over 4 months ago). I then tried adding a large blenny, was doing perfectly fine, didn't look stressed found a nice hiding spot in-between some rock. The next morning he was nowhere to be found. Most recently I added a 6 line wrasse. Initially he was being chased around by the 2 clowns, eventually they started to leave him alone and he started exploring. He seemed comfortable in one of the rock caves, he even ate when I fed, the next morning he is nowhere to be found. That's 3 fish now that have disappeared without a trace, there are no predators in the tank, I have a couple of snails, a sand sifting star and a blue legged hermit crab. There are also a decent amount of bristle worms, I have been removing them with a trap and the population seems to have shrunk significantly. Not sure what's happening to the new fish that I add, have looked all around the outside of the tank on the floor behind furniture, have even checked the sump. No sign of the new fish at all. I'm giving up with putting in new fish, i have a friend with the exact same size tank and similar set up who has 2 clowns, a fire fish, a blue damsel and a chromis, I assumed more fish in my tank wouldn't be an issue.

 

[Gumbies R Us]

Are they jumping out of your tank? Seems odd to me that you have three fish that size who are just outright vanishing like that.

 

[shawnycool319]

I have a 25 gallon tank, 2 clowns and a banged Cardinal. I've introduced a tamarind wrasse, he went straight into the sand and didn't see him since (that was over 4 months ago). I then tried adding a large blenny, was doing perfectly fine, didn't look stressed found a nice hiding spot in-between some rock. The next morning he was nowhere to be found. Most recently I added a 6 line wrasse. Initially he was being chased around by the 2 clowns, eventually they started to leave him alone and he started exploring. He seemed comfortable in one of the rock caves, he even ate when I fed, the next morning he is nowhere to be found. That's 3 fish now that have disappeared without a trace, there are no predators in the tank, I have a couple of snails, a sand sifting star and a blue legged hermit crab. There are also a decent amount of bristle worms, I have been removing them with a trap and the population seems to have shrunk significantly. Not sure what's happening to the new fish that I add, have looked all around the outside of the tank on the floor behind furniture, have even checked the sump. No sign of the new fish at all. I'm giving up with putting in new fish, i have a friend with the exact same size tank and similar set up who has 2 clowns, a fire fish, a blue damsel and a chromis, I assumed more fish in my tank wouldn't be an issue.

It sounds like the disappearing fish in your 25-gallon tank aren't being eaten but are instead getting themselves into trouble due to the tank size and setup. Active species like wrasses and large blennies naturally burrow, wedge into rock crevices, or even jump out if the tank isn't fully covered. In a small tank with lots of rocks and hiding spots, it's easy for these fish to hide permanently, suffocate in the sand, or get stuck in tight spaces, which explains why they vanish overnight. Your clowns are mostly harmless, and your invertebrates like snails, starfish, and hermits aren't predators, so the problem isn't aggression- it's the environment. Compared with your friend's tank, which has smaller, non-burrowing, less active fish such as damselfish and firefish, just too risky a choice for a 25-gallon tank. Avoid further losses by sticking to small, peaceful, non-burrowing fish, securing all rocks to eliminate gaps, and covering the tank to prevent jumpers. Essentially, your tank is just too small for wrasses and larger blennies, and the behavior of these species in tight spaces is what's been causing the "disappearances."

 

[salisal]

Those 3 were all very hard to keep examples that also go to sandbed or rocks. In that tank size I’d a single blue with yellow tail damsel and a neon dottyback. 6 line wrasse nickname is the devil in stripes lol