Disappearing fish

[cpiefer]

Not exactly a pond or aquarium beginner but not kept many "peaceful" community fish in the past --

I have a 500 gal. L-shaped pond in my atrium that was supposed to be for koi when we built it however that is horribly small for koi, and I really dislike goldfish - so last year I made it a tropical community tank with a variety of residents.  I couldn't get much advise for what would survive our outdoor winter temps so it's been trial and error.  Things that survived last winter - rosey barbs, gold barbs, danios, and some unknown single fish I felt sorry for at the petstore.  

I just noticed that almost over night I had about 5 neons, a honey gouramy, and 9 danios disappear from the pond, I thought with all the rain the missing fish had found their way out the drain, so I added a strainer to the outlet.  Yesterday I bought 3 more gold danios, 6 neons and 6 galaxy rasboras.  Within about 3 hours the danios were missing, I don't know yet about the neons and galaxy rasboras.  Funny, they don't seem to be any fry missing.  I suspect some of the larger fish have developed carnivorous habits --

Any thoughts on likely culprits:

Paradise fish (3 - 3" males, 1 sm albino female)
Spanner or T barbs (4 - 2" or so)
Gold barbs (4 2-3" or so)
goldfish (5-6 leftovers from my cat's fishing adventures)
Giant Danios (5 or so) - anyone interested in these - they don't show up in the pond
rosey barbs (several adults and various size fry)
red glass barbs (3 sm adults)
angel botia (might be missing - haven't spotted it for a few days)
filament barb (1 - but was originally 2, found 1 more yesterday - love these if anyone knows were to find more!!)
brilliant rasboras (4 added, but can only spot 2 lately)
Buenos aries barbs (5-6 adults)
Killifish relative (don't know name - 5 - 4 females, 1 very happy male - 5 fry).

My vote is probably the paradise fish.  Let me know your experience, thoughts.

thanks

chantal piefer

[MateFrio]

Re: Disappearing fish

I'm thinking bigger predator Bird, raccoon, cat etc.

[Spot86t]

Re: Disappearing fish

Snakes and bullfrogs can also be culprits, although I've got guppies in with my bullfrogs and they don't seem to be bothered.  Snakes I know will rapidly reduce fish populations.  If the killifish are a large variety, they'll snatch up smaller fish too (note the size of their mouths)

[cpiefer]

Re: Disappearing fish

I certainly thought about other predators too - however the atrium is enclosed by my house, has a screen roof and the only entrance would be through the 2 box drains, and I bet those openings would be less than 1/2 inch.  That pretty much rules out every thing except small snakes or frog/toads.  My cats are also out there alot and I think they would have noticed an intruder - but maybe not.  More investigation.

[cpiefer]

Re: Disappearing fish

I certainly thought about other predators too - however the atrium is enclosed by my house, has a screen roof and the only entrance would be through the 2 box drains, and I bet those openings would be less than 1/2 inch.  That pretty much rules out every thing except small snakes or frog/toads.  My cats are also out there alot and I think they would have noticed an intruder - but maybe not.  More investigation.

[Spot86t]

Re: Disappearing fish

Snakes can easily pass through a 1/2" hole.  

I have 4 golden wonder killifish and they will make short work of anything guppy sized.  I've seen them snatch a carnivore wafer and gobble it whole witout a speck of difficulty.  

Flagfish (I know you didn't mention them) are known to be algae eaters, but I caught them gobbling baby guppies one after the other when I was moving my outdoor 'little fish' pond.  I was horrified!  now I keep them withthe goldfish in another pond.  Just goes to show that little wiggling things are quite tempting even to non-carnivorous fish.

[sproett]

Re: Disappearing fish

I'd vote paradise fish, the killifish, or the goldfish (if they are big they'll eat smaller fish as snacks).