My Common & Comet Goldfish Spawning & Fry
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I have been wondering how to tell the difference between male and female goldfish. One way that I read about is that the female swims for her life while the males chase her - kinda sounds like high school. Another way is that mature males are supposed to grow bumps on their gill plates, think these are supposed to help them squeeze the eggs out of the female.

So it is February, my heater was holding the water temp barely at 66 degrees, then we had a warm spell for about a week. The water temp went up to 75, and one morning I went out to see (for the first time) this spawning frenzy. I had read about it, and seen some casual chasing, but wow! Never seen it this enthusiastically before!

Many web pages talk about making spawning mops for the fish to drop their eggs on, and I was thinking about doing something like that, but figured by the time I got around to doing it, the eggs would be deposited (and eaten). The fish had been doing figure 8's around my pvc plant holders, so out of curiosity, I lifted one out of the water. It was covered in eggs that sort of resembled the clear beads in tapioca pudding. So I put the whole PVC stand in a bucket half full of water, then used part of a cut up butter tub to scrape the eggs off into the bucket. Since I made the scraper from a butter tub, it was half moon shape and the contour fit well around the PVC. I then took this water and dumped it, into an aquarium inside. Didn't realize at the time how much algae I was taking along for the ride too - the fry will probably munch on that, so it is a good thing. I also treated the water with malachite green to kill fugus that heard comes with the eggs.

Quick search about fish eggs and fry, and couple of pages said the eggs are super delicate, and should not be touched. Great, I probably killed them all by scraping them! Didn't have anything to loose so I let the aquarium run for a few days. Some pages also said that the female can die during the process of spawning, and that if you disturb them, they will stop. So I netted her plus the males, put them right back in the pond, and then backflushed my biofilter - which makes a bunch of noise and makes everyone hide for a couple hours. Did the trick, they stopped chasing her around.

5 days later, and look what I found. About 20 of these little fry are around the aquarium. I heard them described as an eye lash with 2 dots, and they were right!



This picture is a couple days after the above one.

At 6 days since I harvested the eggs from the pond, they are now free swimming & eating the brine shrimp. Big fat little tummies on them too!

I bought a package of brine shrimp from the pet store. The instructions said all sorts of stuff, so just to see what happens, I put about 1/8 tsp of brine eggs in a pint jar with water, and 1 tsp of solar salt (from home depot, for swimming pools, but I use it for the pond - no iodine). I sat that jar next to the window and a day later, I had hatched some brine shrimp. About half the eggs were in the bottom of the jar unhatched, there were a bunch of shrimp in the middle, and floating on top was a layer of the left over egg shells. Strained them thru a coffee filter, fed to my fry.

Figured since only half of them hatched, I should try to read the instructions and research a little on the internet. Everyone seems to have a bubbler in a jar or bottle of sorts, so I made something similar. Had it running and WHEW! What a difference! Almost all of the eggs seem to have hatched.

Here is the formula that I am working with:
- 1 pint jar filled with tap water
- add salt, 1/2 to 1 tsp per pint
- if a lot of eggs still in bottom, try increasing the salt
- add eggs, up to 1/2 tsp of eggs (but more like 1/8 tsp for the small amount of fry I have)
- keep temp between 80-82 F, adjust temp by moving light closer or further away
- have the bubbler running whole time, enough to really stir the water
- eggs hatch in 12-24 hours
- turn off air, let settle for 10 minutes, shells float to top, shrimp swim to bottom
- use turkey baster to suck out shrimp from bottom of jar
- dump the shrimp in the aquarium
- watch the fry eat


Read that need to feed brine shrimp to the fry within 24 hours of hatching, because the shrimp eat their yolk sack and loose nutritional value. And that bubbler really stirs the water violently, but think that is the point and seems to help it work better.



At 18 days since the eggs were laid, they are looking like real little fish now.

I counted them as best I could, and I have just under 30 fry that made it -- despite me harvesting them by scraping.

Since the comets laid their eggs on my PVC pipe plant holders, I had an idea about converting them into spawning mats / mop. I put the plants in another tray, drilled a bunch of holes up and down the pipe, and only have enough rocks in the bottom of the pipe to keep it standing upright for when they bump into them.

To check for fry, I go out at night and use a light to shine down in from the top to spot any fry, also I move the (waterproof) light up and down the sides. The crosswise lighting really does a good job illuminating all the stuff inside.

I checked a bunch the first couple days I had them setup like that, and NOTHING. Forgot about it for 2 weeks and went out, looked in one tube, nothing. Looked in the other tube... and there were 2 of the eyelash-with-dots fry ! I sucked them up with a turkey baster and am trying to grow them out in a gallon pickle jar.