Abberant Koi Behavior

[ellen]

All of our koi are "normal" except our new baby tancho showa. I bought him in October 2006, so he has been in our pond for several months. Ever since we brought him home, he loves to suck/nip at the other fish. He doesn't do it all the time, but the behavior seems to escalate at feeding time when the fish are congregating and getting excited.

I took a video of this abberant behavior and posted it on youtube:
YouTube - Abberant Koi Behavior!

My husband is worried that if this doesn't stop, when he gets bigger he could suck out someone's eye (half joking).

Has anyone ever seen anything like this before? Can you imagine what's going on in his head? Is there Koi Prozac to tone down this compulsive behavior?

I really don't think parasites have anything to do with it--he is the only fish (out of 14) that does this, and he does it indiscriminately to all the other fish, usually whoever is closest.

The video shows him in our Q-tank, where we've put all our young fish in order to get them into warmer water and thus bigger meals and more growth early in the season.

[MikeM]

Small koi often act peculiarly among larger ones. I think it will out-grow the behavior.

Over the years I've had a couple of tosai that would gravitate to one larger fish, swimming under the abdomen of the larger one like a calf staying with its mother cow. It irritated the larger fish to have the little one hanging around like that, but it was kinda fun to watch as the little one raced like crazy to keep up with a big gal who was exerting almost no effort to sail through the water. Perhaps it was seeking protection or just feeling safer? Others isolate themselves away from the larger fish for days, weeks or months. Currently I have 5 tosai being grown to nisai. The 3 smallest stayed in a school for a couple of weeks, apart from the others. They still re-form as a pack if there is a sudden disturbance. The other 2 mixed in with the adults almost immediately. Of the 5, 4 come to the surface to eat without hesitation. One waits for sinking food rather than mix in with the big gals. Koi do have different personalities. In our confined ponds, I think we have little opportunity to observe how diverse their behaviors really are.

[JasPR]

I don't think so mike? What you are describing is normal schooling behavior and in some cases, the scent of hormones leaving the vent area that attracts males.
Ellen is right, this is abnormal behavior. It is similar to frantic feeding in fry and just morphed larval stage fish. But even they tend to learn to co-ordinate their attack on the pellets, often seen climbing over the backs of slower fish. After-all this is very awkward behavior to begin with - that is, bottom/mid-water feeding fish species being asked to find food at the surface in pelleted form! So they can look clumsy at times.
But this is different.
Koi find their food through sense of smell and touch and also by eye sight.
This fish is having difficultly locating the good and seems to go for movement ( bodies and moving gills in one case). It could very well be neurological? or it could be a sight problem. The fish could be blind or have sensory brain damage of some type?
I’d love to hear a history on this fish. Has it always done this? Has it ever been treated with meds for parasites ? Has it been injected with antibiotics? Have you ever tried sinking pellets and if so, does the fish do the same thing?
Very , very interesting. Thanks so much for sharing. JR
Some normal babies eating---

[JasPR]

One further thought and maybe a clue- when a fish 'chews' the pellets or any meal it still breaths. And the chewing action and breathing can send crumbs and 'food odor' out of the gills along with ammonia. I see how interested this little guy is in the gill area of that one fish? What happens when of if this little guy is fed alone? It looks well fleshed, is it a normal eater when other fish are not present? JR

[Sangreaal]

I'd like to see a good clear pic of this koi's head. I've noticed with every koi I've ever had that they just can't see what's in front of their noses once they get up close to what they want to taste. It's hard to tell from the video, but the little guy's eyes look a little sunken, which would make this problem worse, I would think....

Another thing I've observed my smaller koi doing is gleaning bits of feed that the bigger koi will sometimes expel while chewing. Maybe this little guy is trying to glean crumbs by hassling the bigger ones to give them up.

...or it's having a neurological moment like JR suggests.

Just an early morning before coffee thought...

Marie

[Sangreaal]

Quote: Originally Posted by JasPR One further thought and maybe a clue- when a fish 'chews' the pellets or any meal it still breaths. And the chewing action and breathing can send crumbs and 'food odor' out of the gills along with ammonia. I see how interesting this little guy is in the gill area of that one fish? What happens when of if this little guy is fed alone? It looks well fleshed, is it a normal eater when other fish are not present? JR

*nodnodnodnod* Ayup, that's what I'm talking about.

[Eugeneg]

Another thing I've observed my smaller koi doing is gleaning bits of feed that the bigger koi will sometimes expel while chewing. Maybe this little guy is trying to glean crumbs by hassling the bigger ones to give them up.

In a natural enviroment the smaller koi would not be with the bigger fish . Raising small and large fish together is not a good practice and not done by breeders in Japan . The reason being that the food requirements are completely diffrent .
Regards
Eugene

[JasPR]

Agreed Eugene. Baby fish are pure predators getting their 'veggies' mostly from single celled algae and that is often in the form of stomach content of animal plankton. Baby koi are definitely stimulated by movement in the water.
And baby fish live in pretty shallow water looking for animal life and their live in water water than adult fish due to solar effects on shallow water. The breeders are simply going with the nature on this. Good point.
And baby fish also have shorter guts and higher metabolisms so naturally they will fed differently. Honestly sometimes I think baby fish could eat food every 20 minutes!

But still, this behavior doesn't look like competition to me? This little guy is a 'weirdo' in that regard. ( sorry Ellen, it is said with 'love'! LOls)

JR

[MikeM]

Well, let's see if it is still acting this way in a month.

[ellen]

The behavior I'm describing happens pre-feeding. When I put the pellets in, he goes for the pellets, no problem. He takes 5-6 and then swims down low to "chew". He's prone to this behavior all the time, it escalates in fervor pre-feeding, but when the pellets are in the water he actually stops and eats.

Pictures attached. It's hard to get pictures of the little ones, they're quick. He is 6". Like I said, I got him in October and he's been doing this since October.