early development

[bekko]

I'm stoked becasue I didn't know you could take a picture through a microscope just by putting the lens of a crappy little camera up to the scope's eyepiece. Thought you had to have a special camera adapter or something.

Here are koi eggs at 7 to 14 hours (22 C). You can see the perivitelline space near the outer edge and the beginnings of a blastodisc (signet ring) with thickening at one end. The egg showing no development was not fertilized or was non-viable when spawned. They are attached to water hyacinth root hairs.

-steve hopkins

[Mike T]

"I'm stoked becasue I didn't know you could take a picture through a microscope just by putting the lens of a crappy little camera up to the scope's eyepiece."

Didn't know this either, good tip if I ever have problems with the Koi... When time comes, and I hope it never does, I'll just have to contact you to find out how to post the picture...

Or better yet...Do you make house calls?

Goofy foot....

[ranskye]

hey steve try a video or camera set on time lapse, youll be able to see them hatching. looks really good.

[ranskye]

thats a pretty good pic that takes.

[ranskye]

good topic actually, viability and fertilisation.
anyone had experience with really great fertilisation rates and can come up with some reasons (most likely) for why there was such a good rate?
apart from health of parents and prime condition, ive heard somewhere or read it atleast that you can get certain koi crosses that just dont produce viable eggs or 25% or something are just never gonna develop through a fatal gene combination or something they called it.
with koi i ussually just use an overkill of breeders and let nature take its toll but id like to look into doing it another way so i can stock known quantities into ponds.
anyone hatch in mcdonald jars? flow through hatchers? anyone used salt or milk to make them non sticky and flowing around a jar?

the big one id like to know, once the egg hasnt fertilised and it becomes prone to fungus, does that fungus then attack good eggs?.
i worked with someone that reckoned that fungus attacked eggs and still some of them hatched. i thought i could see some embryos inside a fungus egg once as well which would back the theory.
this would indicate that fungus doesent only attack non viable happening eggs but can attack whatever. i know i get fungus in cold water more so and warm hatches seem better. maybe its fertilisation is lesser in cool water that allows the fungus to attack.
how about you guys that use UV that should tell us something, do you get brilliant fertilisation and hatch rates or what?

[Bancherd]

Steve, thank you for the hint. I have been trying to take pictures through my microscope for ages, not having much success.

Did you use stereo microscope, and did you take the picture through the eyepiece?

Thanks,

[dick benbow]

ranskye,

Often times among backyard breeders they will take a goodlooking (fat) male

and attempt to breed it with a female and get less than proper fertilization. Next time your in japan take a look at the pros breeders. They are alot skinnier and in much better shape for reproduction then males bulked up for the show.

[bekko]

Bancherd,
Its actually a stereo zoom dissecting scope - haven't tried it yet with the compound scope. I just put set the camera to the finest resolution in the point-and-shoot mode and held it against the eyepiece. When I could see something useable in the little LCD view-finder on the camera, I would snap the photo. If the camera lens is not sitting flat against the eyepiece, nothing shows in the view-finder. The original picture had a large black border with a round photo in the center. I cropped out the center section using Microsoft Paint, but any photo editing software would also work. Everything looks more yellowish in the photo than it does under the scope. I think it's a halogen back-light.

Ranskye,
My estimate on this batch is 95% fertilization. The eggs are really caked on the spawning substrate which usually means more fungus. I am not treating them with anything. The adults are 60 cm kohaku from different bloodlines. They spawned in a floating 2.3 square meter net pen with strips of shade cloth and water hyacinth for substrate. The net pen is in a 8 mt liner pond.

I expected this female to go on the full moon at the end of last month. She was really plump and I thought I saw another kohaku following her a few days before the moon. So, I move both the fish to a 4 mt spawning tank (24 C). For good measure, I checked two other kohaku for milt and put them in the spawning tank. Nothing happened. After about a week, I decided to move the female and one male to a net pen in a small green water pond because the temp there was already 27 C (full sun and the green water soaks up heat faster). When I went to move them I found out that the fish which I thought was following her originally was actually a female - oops. So I moved her and a known male. Nothing happened. There were several days of cloudy, rainy, cooler weather. The algae crashed. The pond cooled off to 22 C. They had been in that little net pen for more than a week. I had given up and was about to move them back to a larger pond - they spawned. Go figure.

-steve

[ranskye]

thanks dick,
appreciate your input and i spose that could be the case, a fat lazy koi.. not that my fish are well conditioned for show, it sure may be that my fish arent all that crash hot in the sperm quantity department..i know i could check sperm quantities and mobility but i always figured i do too many pairs to be a concern and that if one fish sperms no good it wont enter an egg but leave it for a good one. but thats probably whats happening, a lack of a hit.
in future i want to use better stock and so get better hatch outs of the good ones as opposed to using my lesser fish to make up quantities.
i want to try spawning in smaller volumes of water with good fish instead of just whacking a heap together in cages in a million lite pond.
i tried that the other week but very late in the season and the fert rate was poor. 50 percent..small bellies on the girls too.
as for japan, i wish... lucky youve been for us bloke and can share!!!
id go there someday if i was allowed to bring back the genetic but id only be teasing myself or get a jaol term... i often tell myself not to go too crazy over these fish. you know,thinking,thinking,thinking..i guess one day ill find some good lines over here. smugglers..lol.

yeah steve i use the cage and the mesh netting too, i use bird netting tied up and shade cloth loosely surrounding the entire cage to catch them from hitting the mud.
go figure allright with the fish, who knows what theyre thinkging sometimes.. sometimes theres more to it than we can see, i usssually try get em to spawn anytime, any weather, but ive noticed what helps.
i go for it after the ponds dry, filled and settled out the iron..just by beggining with fresh bore water and putting them together seems to work mostly but there are those times though when some of the fish paired dont go at all, they stay fat and i chuck em back into a cage for another try next pond. i remember once when no asagis would let any out at all but everything else had their go.
also once this guy had his barramundi release eggs naturally in his recirc tank and he was talking up 99 percent, he was trying to work out what caused it to naturally spawn cause ussually theyd need a hormone shot in captivity.. never heard his analysis of what the fish went through as for water changes temp fluctuations moon pull and weather and the like so i couldnt make any judgements on why.

i think when they go naturally, exactly when theyre ready, as opposed to be forced into it through the triggers (cause it maybe a month too early), the eggs are plenty and all top quality. maybe why you hit 95%. i get much less than that mostly through forcing them to suit my pond availability.
one thing i beleive is that they dont want to breed once the nutrient is there in a pond, like say when the algae was present. its an indication of nutrient.
it becomes too late for them in their brains. theyll put it off to next opportune, ive had a theory that in a closed pond, they will wait till all the nutrient is cleared out, shortly after a bloom crash in your case. water is clean with not much predacious life organism. it simulates a new rain almost.
consider through the evolution of the spawning mechanisms that any fish that spawns as it rains and floods (new water), and leaves its eggs to hatch in coincIdence with an algae bloom and subsequent zooplanktons gets to have its genetic passed on, any that spawned at the wrong time for succesful life conditions died out and arent here now. but there is slight variation to keep the species alive, the reason why not 100% of femals go off on the same night.. youd know what i mean by that. i reckon they have it in their brains to release with the new rains, or just as its about to back off more so, as the suns about to come out, for me in summer its a drop in barometer and then as its beggining to rise and bring on some sunshine, remember egg stick so it can wait for the stream to slow and bloom up in the shallows. the rains have fallen, and then slowly the nutrient is released off the surrounding high lands.
i guess youve had a few of the triggers met, cloudy period, barometric pressures, a bloom that cleared out nutrient, a crash- drop to the bottom of algae and planktons.. the partial addition of new water, sun about to come out and start a bloom up again and they say in their heads "hey lets go!!!!"
i think often the water cooling is there when the cloud comes, i still think its mainly the new water and not just cool water about to go on the rise again that makes em spawn but when everything comes right, as most natural, its a really good spawn.

[bekko]

This is after at least 25 hours. It was a beautiful day in paradise and the temp is back up to 24 C. The big glob in the center is the yolk sack. The developing fish is wrapped around the yolk sack. You can see the head forming at about the 2-3:00 position to the right of the yolk. There are two egg-shaped objects near the perimeter of the egg at the 2-3:00 position which will become the eyes. The body then wraps around the back of the yolk sack and you see the tail end coming around from left to right (below the equator) in front of the yolk sack. The end of the tail terminates back where the head is. If you can find the little 'V's or chevrons - that is the tail musculature. The developing vertebrae can be seen in the middle of the tail section.

At this point, the developing larva is starting to move inside the egg. I had to wait for it to quit wagging its tail before taking the photo.

Tomorrow, there will probably be a fungus among us. With any luck, they could start hatching tomorrow night.

-steve