Our fish had a baby

Mundane Pointless Stuff I Must Share (MPSIMS)
#1

We don’t know whether it’s a koi or a goldfish. We have three koi and seven gold fish. We think that two of the koi are male and one female. (We’re just guessing based on size.) We have no idea what the goldfish are. But yesterday late afternoon, Edlyn (my wife) was cleaning out the filter net when she found the young one in there.

Any tips for helping to ensure its survival among all those big fish? He’s about two inches long by her description, and the largest koi is probably 14 inches or so. I don’t think any of them can eat him, but they do go at rocks for the algae, so I’m wondering if they could sort of chew on his fins or something and effectively cripple (and therefore doom) him.

#2

Oh, yes, they can. And they will.

He’s only two inches long? Then he’s the exact size of the appropriately named “feeder goldfish” at the pet store. And, never mind the koi roommate who’s 14 inches long–he’s surrounded by seven other, larger, goldfish. They’re the ones you have to worry about, because in my experience they’re quite aggressive when it comes to potential meals–which an injured fish becomes–and all it takes is for one of them to peck at him enough to damage him, and slow him down, and make him swim funny, and then in their minds he doesn’t count as “One Of Us” anymore. They will peck him to death, and then feast on the drifting corpse.

I’d definitely put him in a totally separate tank. The only reason he’s survived this long is because he got sucked into the filter.

Failing that, assuming that they’re all in some sort of koi pond, I’d add lots and lots and LOTS of water plants for hiding places–he’s gonna need them.

And I found this, FWIW:

#3

Agreed. Segregate that fry before he becomes Friday’s Catholic dinner.

But I did once have a single fry in my tank that grew to adulthood.

I had an interesting experience a few weeks ago. I was on vacation and at the beach. The water was clean, clear, and wonderful. But it was infested with tiny insects. Really tiny. And they were all skimming the surface of the water. On closer examination, though, they weren’t on the surface. They were under it. And they weren’t insects, they were fish. Really tiny fish. Millions of them.

#4

Thanks, y’all. And yes, there are lots of lily pads and water hyacynths as well as lots of rock crevices coated with algae. It’s a smallish pond, about 12’ by 6’ with a stream and a couple of waterfalls. But we really don’t have the resources for a separate tank. If it matters, the other goldfish aren’t that big themselves, the biggest being maybe 6 or 7 inches. The whole pond is only a bit more than a year old.

#5

It is an unwanted fish, so if it lives it lives, if it dies it dies. It’s lived a while, because they don’t hatch that big.

#6

Crazy question: why’s there only one? Do we assume there were more and all the others got eaten? Do goldfish bear live young?

I never really think about fish having babies, you see.

#7

Goldfish lay eggs. However, even with my 12 pregnant livebearers, which drop babies close to monthly, I’ve only had one fry to survive.

Anyway, do what you can for the little fish, If you want to. However, you should be more pleased with the fact that your fish have spawned. It’s usually a sign of extremely good water, nutritional, and environmental factors.

So congratulations!

#8

Yeah. Goldfish females can release anywhere from 500 to 1000 eggs at a time, so it’s safe to assume that at least 499 other goldfish fry didn’t make it to the safety of the filter.

Natural selection at its finest.

#9

Thanks! :slight_smile: We do test it regularly and have it maintained by the guy who built it. This is the first little one we’ve seen so far. I won’t swear there weren’t others becuase there really are lots of places to hide.

#10

The filter may have done the others to death. Little fry go in and stay plastered in place until they die and disappear cell by cell into the water.