Koi Food - Some Thoughts part 2

[bekko]

A guy once told me that the white fish meal they were buying was basically everything that was left over after the minced fish flesh for McDonalds Filet-O-Fish and Mrs. Paul's Fish Sticks was removed from a cod. The guy worked in Idaho.

-stevehopk ins

[johnsmith]

Feeding and school behavior.

It is pretty easy to NOT notice that koi in 'their group' take on behavior unique to that school member's age, sex and pecking order. But koi are keenly aware of what other members of its extended group are seeing, doing and yes--- feeling! Nuts?? Not at all- scientific, actually.
Koi communicate with one another in a variety of ways. One of the most subtle but powerful forms of communication involves 'reading' one another's chemical responses to anything that enters the environment. Phermones, hormones and alarm substances released from skin and kidneys can warn, seduce or 'tell' the others what leaders in the school are 'thinking'.

In an experiment with another fish species, the members were actually able to detect that a new species of predator introduced into their environment was a 'carp eating' species by the scent that the stranger released.

As an experiement, it would be interesting to feed your daughter's fish a few days of watermellon and then introduce those fish into the pond of your non-watermellon eating koi. I would theorize that the new members would both 'teach' watermellon eating as a behavioral thing, AND also communicate hormonally/waste enzyme, that watermellon is not a danger but a meal.

JR

[PapaBear]

"As an experiement, it would be interesting to feed your daughter's fish a few days of watermellon and then introduce those fish into the pond of your non-watermellon eating koi. I would theorize that the new members would both 'teach' watermellon eating as a behavioral thing, AND also communicate hormonally/waste enzyme, that watermellon is not a danger but a meal.

JR"
...All of my daughters Koi came FROM my pond where they had previously not cared for it either Their taste for watermelon was acquired after they moved to her water... go figure.
I've got to agree with you about Koi communication though. One of them starts feeding and they all come running in short order. One of them gets spooked by something and in less than 1/2 second the entire pond reacts. The behavioral modification of a Chagoi introduced to a pond of seemingly "untameable" fish is another great example. The acceptance of handfeeding by observation of the Chagoi's natural tameness seems to be pretty universal.
The pecking order is another interesting study in behavior.
Last year when we introduced our fry into the main pond they all schooled together and the adults kept to themselves. One by one as they grew to 4"-5" they went from being "leader of the pack" amongst the fry school to "junior members of the pack" amongst the adults.
The other thing I thought really interesting was how the adults responded to the fry. At feeding time before the fry were introduced the adults would all come and get it as soon as the food hit the water. Once the fry became part of the picture, the adults would all hang back and wait for the babies to finish eating before coming over to have their meal. My theory is that they are hard wired for survival of the species by making sure the next generation thrives. Has anyone else observed similar behaviors?

[l113892]

Larry-

I would be surprised if the adult koi waited for the small koi to eat to ensure their survival. My adult koi don't wait. But I too agree with your other observations and Jim's about koi behavior. There is so much to learn about your water quality and changes to the water parameters from the behavior of your koi.

Mike

[Chris Neaves]

Hi,

White fish meal = a by-product of meal made from fish processing waste and because of its high bone content usually has ash values in excess of 16%.
Ogino & Yang reported carp displaying signs of zink deficency when fed on white fish meal. These deficiencies are alleviated by the addition of supplemental zink in the diet.
Satoh demonstrated that there was a nonavailability of magnesium in carp fed on diets containing high-ash fishmeals.
Regards,
Chris

[MikeM]

Koi behavior is always giving a surprise... and something to speculate on. About 16 months ago I got a Maruyama tosai Kohaku in a grow-out project For 14 months she was among the first to go for floating pellets. About 2 months ago she simply stopped coming to the surface. It began following some noisy equipment being in the yard for a day. I worried over her, but nothing seems to be wrong...physically. She eats well when sinking pellets are fed and grazes on algae regularly. A week or so after she stopped coming to the surface, two others joined her on the bottom. These are a Showa and another Kohaku. The three hang together pretty much all the time. They all eat well as long as they don't have to surface. ...None of the other koi in the pond avoid the surface like these three. The two that joined the Maruyama Kohaku are also Maruyama-bred. They were nisai when added to the pond last February. That is, they were born in the spawning season at the same koi farm and may have been raised in the same mud pond as fry.

It becomes easy to have an anthropocentric interpretation. Since I've not been able to figure out a non-psychological explanation, projecting human emotion on these fish is a real risk.

[luke frisbee]

MikeM,
i HAD a large showa that used to have no fear of me at all. The koi was an Aggravation this Winter when i was feeding them starvation rations during my enforced Winter fast. She wouldn't go away and was getting about half the shrimp. I decided to gently interupt her from feeding. When she would rise to take a shrimp i would slowly pass my arm over the water.... She started ignoring that, so i would make a darting motion when she'd go for more than her share....She quit coming to any shrimp and has since become a peripheral feeder.
I blame the "peripheral feeder" behavior a choice. not a choice based on one dimension. With "her" i believe i scared ot annoyed her, and she has become so large she doesn't maneuver as well as the many smaller koi.
So I think her decision (which isn't anthropomorphic as animals can decide..well if man can) was based on me instilling fear into her to back off and stay in the crowd, and then she wasn't getting food like she did before I made her back off. So she chose another strategy to feed.
It really didn't take much "scaring" to get her to dramatically change.
But other fish had already gone through the "change" without me scaring them. They are all about the same size and about 26-30 months old when they started being peripheral feeders.
And every so often they come into the swarm that is feeding.