early development

[bekko]

Mervyn, I am starting to appreciate why you need a camera adapter. By the time I get the shot in focus, fumble around holding the camera to the eyepiece, and put on my reading glasses so I can see the camera viewfinder, the fish has moved. Then, it all starts over again.

This guy is about 93 to 100 hours. There is a pupil forming in the eye, but you cannot see it in the photo. The intestine and stomach is much more advanced and you can see the beginnings of a swim bladder (the transparent egg-shaped thing in the center). There are functional pectoral fins and some differentiation of the tail fin. They have a bit of a yellowish cast on the dorsal surface today although it is obscured by the yellow cast from the scope lighting. Some mouth parts are forming but I am anxious to see them "chomping" the mouth open and closed. That is my signal to boost up the plankton levels. The yolk sac is smaller today, but it appears it will last another 24-36 hours.

-steve

[MikeM]

Excellent pic. Really enjoying this.

[Tamus]

I think it would be a great read if one of you something like a daily/weekly/month journal of a spawn just to see what all goes into it. Of course as they get older there wont be much to report as often, but I think one of the most fascinating things I have learned about koi recently is that they change color and pattern as they age. I am going to do one on my water garden this year mostly so I can look back and reffer to it if need.

[bekko]

Swim-up fry. That's the fish hatchery jargon for fry with developed mouth, intestine, an inflated swim bladder, and ready to eat real food. It was obvious that's what they were this morning because they were all dating around instead of hanging out on the substrate. I was off by 12 hours in guessing they would be ready to eat tonight.

This guy is 117 to 124 hours old at 24 C. It has already eaten and has a full gut. The greenish tint on the dorsal side appears yellowish on an otherwise clear fish in real life. It appears the spawn is 100% white babies. The male's line has not thrown even a hint of sumi in three generations but I wasn't sure about the female.



The zooplankton was already OK, but I boosted it a little from other ponds to get a solid 10/ml of rotifers and ciliates of appropriate size. If I had ranskye's large ponds, they could be stocked with about 50 to 100 liters per fry. At that density, you can walk away from them and come back in 6 weeks to a bunch of hardened fish ready to cull. That is real koi farming.

I am cramped for space. If the fry were spread out among the available small ponds, they would only have about 8 liters per fry. At that density, they would graze the zooplankton down to a level where it cannot regenerate itself fast enough (an "eat-out") and the fry would then starve. So, I have them in a single small pond with about 1 liter/fry and 5-6 other small green water ponds which are just for making zooplankton - zooplankton reactors. I cannot walk away and will have to fuss with them every day, doing zooplankton counts and moving plankton to the fry pond.

An advantage of this approach is that it's possible to make space available for another spawn if needed. We have some lionhead goldfish which have ovulated and will probably spawn this week so a pond will be given over to them if and when.

-steve

[ranskye]

good stuff steve, whats with the pink eye??lol.

yep its almost that easy for me, i do consider myslef lucky, its not quiet that easy but pretty darn close comparitively speaking, i know how much goes into intensive rearing, i made a note not to get too far into it years ago when i saw the costs and labour and nutritional drawbacks and disapointments. full time god.
ive been so so lucky with where my carrer has taken me in that ive got plenty of space. sometimes i play in small volumes but its plenty more work or plenty less fish. sometimes both.
i guess after filling and liming and fertiliser and spawning and maybe stocking theres not much for me to do but to throw a bit of extra feed in, watch a bloom. harvest grade and then sell. thats enough without all the rest thrown on top.
im considering going to another place where its still spacey but easier to get around and manage, smaller but i can increase production all the same with a bit more management. still about 8 meg.
this place has too many ponds!!
if i showed you a pic you wouldnt believe it. im just scratching the surface.

[ranskye]

nah really what is that close up eye picture logo thing..is that a horse with pink eye?
funny thing.. just today i checked a pond that wasnt netted, it was about 8 weeks old at most, i saw some fish there 2 weeks ago,
now there are no fish there after i drained it down even. the other arvo i saw about 8 birds flying that way and figured i knew where they were headed. looks like theyve got the lot. need more netting..

[bekko]

I have six plastic goldfish spawning tanks up under the eve of the fish house. The tops are about 3 feet off the ground. The water surface is covered in water hyacinth. Every day, I was checking the hyacinth for eggs and doing a water exchange. Nothing was happening, so I pulled them down to check the fish again last week. Three-fourths were missing! Could only have been the night heron. I'm in the process of putting up netting, but would not have thought to net those tanks. Vietnamese pot-belly bore.

[ranskye]

haha, i see the creature now. ta.

damm those night herons. youd think they wouldnt take much.
they sure do.
in what i had a count on, because id orderd 80 odd fish to grow up for breeders, i was left with 25 after about 1 month of the thing hangin round. they were about 8cm fish, i lost 4 xlge black moores and numerous feeder kois.
hed turn up early in the morning and id hate to know how many days i never saw him.. had no idea till i took a head count on what was left.
i was thinking good, its time to breed those fans now.. then hangon theres no big boys left.

for just 30 bucks i got some hail netting and the bird doesnt come around anymore and it wasnt because i hit it with a rock cause all my shots were no good.

saw a wildlife doc on similar bird a few days ago, they curl the neck back like a snake ready to strike and whack. 130km/h.

also i get these willy wagtails, a rather small bird..once i had a 5m walking raft/ float half submerged and the hatched fry were all over it and the birds were standing there feasting on the fry against the white background. peck, peck, peck, one dollar. kingfishers are one of the best, they rarely miss and theyll eat 10 fingerlings in 15 minutes, they take some back to the young..

cormorants, they are strong, said to pull out fish up to 1 kilo, will eat until gorged, waddle around on the pond bank and spew them up then go fishing, hangon, catching again. thats what took out that latest pond.

[koifishgirl]

Hi Guys what would fishing line do if I strung it across my ponds. Would that keep all the birds out. A friend of mine woke up to National Geographic in her back yard with two herons bumping chest and after that they packed a lunch of some very large koi. Rather expensive meal at that. She thinks this bumping chest this was some kind of mateing thing going on, and she did not want to shoot them so she put the fishing line across her pond and told me she had no more trouble with the birds. I have heard that the birds get caught up in the string and die and if this is the case no wonder she did not want to shoot them.

[bekko]

They do not get caught and die. They are just tripped-up a little. The smart and persistent ones learn to get in around it eventually. There is no substitute for bird netting.

-steve