| Oyagoi
Join Date: Sep 2004 Location: Hakipu'u Posts: 1,383
| I'm not an expert and provide this only because I'm hoping someone will correct me...
You will know if they are black babies or white babies in the first week. If there are any black ones you can throw them away immediately. Some kohaku lines are pretty good about not throwing black babies.
At about four weeks (depends on temperature - could be 3-5 weeks) you can tell if they are going to be solid red. There will probably be a lot of these and they can be discarded. If it has a red belly, toss it. About this time you will start to see a few with red showing under the white skin. It will look sort of pinkish. Keep all of these for now. Some that look solid white now will start to develop the pinkish pattern under the skin later so don't toss the solid white ones yet.
At eight weeks, they are looking like koi. It's probably safe to toss the solid white ones now. Since some kohaku have some sanke in the bloodline (e.g. Momotaro, I'm told), you may see hints of sumi developing. Keep them if you want a shot at making some sanke or bekko. Otherwise, toss them. You should also toss ones with red in the pectoral fins, red wrapping way below the eye or red down on the belly. You will want some odome so you can toss the ones with red bleeding into the tail. If the hi pattern looks to large, but does not wrap way below the lateral line, you should probably keep them for now. The hi pattern will shrink as the fish grows so one that looks like a perfect kohaku now may have a pattern that is too weak when its grown.
Of course, toss anything that looks deformed. Pay particular attention to the gill operculum. If you can see gill tissue from a side view (operculum too short), toss it. It the rear edge of the operculum seems to curl outward, toss it. With my fish, many of the fingerlings with the best patterns have flared gills (curled operculum). Trust me, they do not grow out of it - toss them.
Unfortunately, before you can cull them, you have to catch them. This is the hard part. Everyone's situation is different and you will have to learn as you go with respect to catching fish for culling.
For the one-week-old fry, about all you can do is dip-net the larger concentrations of fish from around the edges of the pond. You cannot catch them all. If you do not see a lot of black babies (sorry, I'm told these are called kuroko) then its probably not worth fooling with them until they are at least four weeks and about 1 inch long.
Catching one-inch fish in a mud pond is possible, but tricky. On occasion, I have been able to trap them with funnel tarps (minnow traps) of one-eighth inch mesh. Usually, this does not work at all and I do not understand why it's so hit-or-miss with the traps. A seine net is much better, but can be dangerous. If there is any string algae or the lead line digs into the mud, you can have the fish rolled up in mud and/or algae when the net is pulled ashore. At this size, it will kill them if they do not come up clean. They are large enough to get out of the way so you will not be stepping on them. However, the footprints you leave in the pond will make it difficult to catch fish on the next pull because they will duck into the footprints and the net will pull over them. Try it with a cheap, lightweight ten-foot minnow seine. The brown ones are lighter, do not scoop up as much mud, but do not last long. The nylon ones from are more expensive, last much longer, but are more prone to scooping up mud. If you are killing fish, then stop and try again a few weeks later.
By six weeks there will be some tobi. These are fast growing fish which are much larger than the others. Part of the reason they grow so fast is that they are cannibals and have been eating smaller siblings. You would like to separate these if you can. Try the fine mesh ten-foot seine again and see if you can catch many of them - but you cannot catch all of them. It seems that very few of the tobi will be "keepers". In kohaku spawns, most seem to be solid red, some solid white and a few kohaku. Despite their bad habits, these fish have had a great start in life and have the potential to turn into some of your best.
By eight weeks, they may be able to out-run the ten-foot seine; especially the tobi. You may have to move up to a twenty or thirty-foot seine with 1/4 inch mesh and a little more weight. The seine will not catch all of them - ever. You will be tempted to buy a 60-foot seine which will reach all the way across your pond. It won't work. Because of the bow in the seine as it is pulled, you would really need a 80-footer to reach across your pond and still hug the bottom. Small-mesh seines that long are really difficult to pull, especially if the bottom is soft. You also risk stirring up too much of the bottom at one time and depleting the oxygen. Finally, when you get to the other side you may have so much mud, algae and fish rolled up in the net that you cannot pick through and get the fish out before they die. Best to stay with the 20-30 foot net and do not try to drag more than about 10% of the pond area in one pull. Make a pull, collect the fish from the net, cull them, put the keepers in an aerated container, then make another pull. You will find you need a beach umbrella, lots of buckets and tubs, some way to aerate water, and an assortment of dip nets. The cooler and radio are optional.
From 8-weeks on, you will be able to catch a few fish with a cast net. Unless they are being gilled in the netting, a cast net can be gentler on the fish. To increase your odds, throw out a hand full of sinking food, wait a few minutes, then cast on that spot.
At some point, you will need to drain the pond to collect everything and prepare to start over. A sloped bottom makes the process much easier. You will also need a high volume gas or electric pump so you do not spend a week trying to drain the pond.
You need to decide what you will do with the tategoi (keep fish) from eight-weeks on. Will you just throw them back in the pond? If there was another small pond or very large tank to put them in you would not have to keep catching the same fish over and over, and you could spread them out at a lower density so that they grow faster.
-steve hopkins |
03-08-2005
Linear Mode
Similar Threads 
