PDA

View Full Version : Are koi fry photopositive?



bonsainut
05-22-2008, 11:59 AM
Are koi fry attracted to light? Can you place a light at the edge of the pond at night to get them to gather? (like some marine fish larvae)

Dirk
05-22-2008, 11:18 PM
I dont know, but when my breeding tank is in the sunlight, they tend to seek the shadow....

Lori Jo
05-22-2008, 11:38 PM
I have shined a flashlight in my pond at night and the koi hate it. The tosai especially. I would bet they hide.

Shorty
05-23-2008, 11:21 AM
When I go hunting for fry at night with a flashlight, they always swim away from the light. Not sure if it is because the light is moving -- a stationary light might work differently.

Guessing you are looking to collect some fry - you can setup a trap for them. Concept is to provide an area they can swim into that bigger fish can't get to, which is easy to look in and see if there are any there.

Take a white bucket, and cut the top half off, so you end up with a 6" deep bucket. Attach floatation around the rim so it floats. Drill holes around the top perimeter so the fry can swim in. You don't need to put anything in it, just float it near your plants and fry will swim into the trap along with really tiny bugs. Check every day, and when a fry is in there, simple as lifting it up and moving the fry to another container.

Algae and lots of other debris also collects in there, and it can be really hard to see the fry, especially when they are only a couple days old.

Noahsnana
05-23-2008, 11:47 AM
Bait trap supposedly work to catch fry :rolleyes2: It was a long tedious project for me. I want no more babies :no:

kgt1223
05-25-2008, 11:00 PM
The answer is 100 percent yes! We actually had a little fun last night moving the dome lite we had over the hatching tanks and watching the whole ball off fry moving back and forth trying to catch up with it.

ed adams
05-26-2008, 06:03 PM
The answer is 100 percent yes! We actually had a little fun last night moving the dome lite we had over the hatching tanks and watching the whole ball off fry moving back and forth trying to catch up with it.

Hi Kiefer,

Any chance you could post a photo or video of the fry tank? sounds very interesting. Is the light for additional heat, source of light, or to help food be found?

kgt1223
05-26-2008, 08:56 PM
Hey Ed

At this stage of their lives these little guys are strictly sight feeders so the light certainly helps for that. It also helps me draw them into one area so no one misses any meals. Will snap a pic this evening before feeding.

ed adams
05-28-2008, 11:20 AM
Sounds excitingly interesting! Hope you are able to get a picture.

bonsainut
05-30-2008, 11:44 AM
I have hundreds if not thousands of fry in a 10' pool. My original plan was to move the eggs into a small fry hatchery but the koi spawned everywhere - walls, bottom, plants. Now that they are hatching I am trying to centralize them so that I can move them into a fry grow-out while I get the 10' pool ready for the next spawn. With marine clownfish larvae, on the night they hatch they are strongly photopositive (they swim towards the moon / stars) so it is easy to place a small LED in a corner and the larvae will aggregate beneath it.

Shorty
06-01-2008, 08:37 PM
I've got an idea for you -- you could trap them in a 55 gallon barrel next to your pool. Setup a siphon or some kind of pipe from the pool into the barrel, then have a small pump in the barrel with a big mesh covered screen around it that pumps the water back to the pool.

Won't get them all, but could get a lot of them and is very simple to setup. And would make for some great photos to post. :)

bonsainut
06-01-2008, 11:43 PM
I've got an idea for you -- you could trap them in a 55 gallon barrel next to your pool. Setup a siphon or some kind of pipe from the pool into the barrel, then have a small pump in the barrel with a big mesh covered screen around it that pumps the water back to the pool.

Excellent suggestion :) I am way ahead of you. I have a 25 gallon tub that I have cut square holes into the sides and covered with 100 micron plankton netting - water flows through but the fry (and even newly hatched brine shrimp) cannot pass. The tub is going to sit in the larger pool, and water will be pumped from the pond and sprinkled into the tub via a spray bar. Water will constantly be flowing from the tub into the pool, so i will not have to worry about water quality (though I will still have to deal with solid waste removal).

Shorty
06-02-2008, 02:01 AM
Excellent suggestion :) I am way ahead of you. I have a 25 gallon tub that I have cut square holes into the sides and covered with 100 micron plankton netting - water flows through but the fry (and even newly hatched brine shrimp) cannot pass. The tub is going to sit in the larger pool, and water will be pumped from the pond and sprinkled into the tub via a spray bar. Water will constantly be flowing from the tub into the pool, so i will not have to worry about water quality (though I will still have to deal with solid waste removal).

Sounds neat !! Got any pictures?

I am currently raising a batch of fry too - started out with probably a thousand hatched fry, but down to 200 or so, I didn't seperate the tobies quick enough. They gobbled up most of my fry, and new tobies appear (or grow) almost weekly it seems. Looks like a reliable method for sorting your fry weekly is important to have.

bonsainut
06-02-2008, 11:27 AM
Sounds neat !! Got any pictures?

I am currently raising a batch of fry too - started out with probably a thousand hatched fry, but down to 200 or so, I didn't seperate the tobies quick enough. They gobbled up most of my fry, and new tobies appear (or grow) almost weekly it seems. Looks like a reliable method for sorting your fry weekly is important to have.

Do you have green water? Are there a lot of hiding places in your grow out? Or are the tobies just really good at making themselves scarce? It is the one thing I am most concerned about at this point...

Shorty
06-03-2008, 02:54 AM
Do you have green water? Are there a lot of hiding places in your grow out? Or are the tobies just really good at making themselves scarce? It is the one thing I am most concerned about at this point...

Here is a thread with my fry, I just updated it with a couple of pictures from today.
http://www.koiphen.com/forums/showthread.php?t=76578

Did a big cull today, I have been removing tobies along the way, but found the biggest one yet that has been living down in the bottom of the tank. Yes, green water, but no plants or anything to hide, and the tank is really small, about 5' diameter. Even if had plants, think the tobies would still eat most of them. I watched a tobie near the surface one day and it hunts the small fry just like a bluegill going after a bug.

I've got a feeling that if you want to raise a lot of fry, the tank will have to be completely drained on a regular basis to remove the tobies. Heard the nice koi are very inbred and don't grow so fast, so they get eaten first.