Fish...

[naiad]

Yesterday I was feeding the fish at college. For two weeks I am in charge of the piranhas, so I had to feed them. (And put my hand in the tank to collect plants...) I defrosted some frozen baby trout and they ate one or two, with none of the ferocity that I expected. There were some trout left over, and I didn't know what to do with them. The next tank had about 100 fish, mostly tiger barbs of different colours and some rosy barbs. These are small tropical fish, often kept in tropical community tanks. All were about 4cm long. I dropped a 5cm trout in the tank to see what would happen.

The fish went into a feeding frenzy. They all attacked the trout, bits flying everywhere, and in about 30 seconds all that was left of it was a skeleton. Even that eventually disappeared. There was not a trace of it left.

Just goes to show that fish don't always live up to their reputation!

I also fed the red-tailed catfish, it waits with its whiskers waving out of the water, and then snaps like a crocodile. Not something to feed from my hand, better to drop the food in from a safe distance!

Lucia

 

[foxfish]

That is interesting about the carnivore behavior off the barbs, hope the filter system is up to processing all that protein? We used to look after a really big red tail called TC. He was about 35lb in weight. I would get in his tank to feed him underwater twice a week. He soon got used to me & feeding time was very popular with the visitors at the the koi farm. Unfortunately the oil boiler that supplied the heat for his 2000 gal tank broke down in the winter time & the poor creature died. I would have to say in my opinion the best place for a red tail is in the jungle from where he came.

 

[naiad]

The filters are very good, big external Eheim ones. The water was clear afterwards, I think they ate every particle.

Maybe fish behave differently depending on the size of the group. There were about 8 piranhas and about 100 barbs. Large shoals may be more likely to get into a feeding frenzy because their numbers allow them to overcome larger prey, and because they need to eat faster to compete with each other.

Many catfish are real characters. The big ones are too big to keep anywhere, but the little ones are good pets. Fortunately many species remain small. Even some of the suckermouth ones can grow huge, the largest I have seen was in a nature documentary, a Panaque sp. of about 2 metres. These feed on wood from fallen trees. Strange to see a familiar fish grown to such a size!

 

[BatRay]

That's really neat, Lucia. A local pet shop used to have a red-tailed catfish named Jimmy. He had blue eyes and was a shameless beggar.

 

[Oldsarge]

I've read that piranha feeding frenzies are related to water salinity. How that could be clear up the Rio Negro I can't imagine but the story was quite emphatic. Under normal water conditions, piranha are supposed to be rather normal predators but when the conditions change, look out cattle, cowboy, etc.!

 

[naiad]

Maybe it is something to do with the water chemistry. I don't think they ever live in salt water, but maybe it is something else, such as rainfall or evaporation, that changes the chemistry of the water and makes them more aggressive.

 

[Medic of One]

Which type of Piranha were you feeding?

 

[naiad]

I don't know, I will try and find out.

 

[foxfish]

I would guess at Red belly?

 

[Fondueset]

When I used to keep fish I had a large tank with an Arawana, a blue Koi and an Oscar. When I came in from work the Koi would push it's nose against the front of the tank and splash water all over the wall. All three subsisted quite well on Koi pellets. The Arawana attacked them viciously - once leaping out of the tank and hanging from my 4-year-old daughter's fingers by it's teeth. (she was unphased - but called it the 'bite-fish' from then on)
I once tried putting a very small local smallmouth bass in with some african ciclids known for vicious territoriality and gang tactics. Very soon there was only one fish.

 

[trux]

Bloody stories about Piranhas are largely exaggerated. In Amazonia you will commonly find kids bathing in the river just couple of meters far from a group of large Piranhas.

Chemistry can influence their behavior, but what puts them quite calm is cold water. My very good friend is the biggest (or one of the biggest) European exporter of bred aquarium fish (Petra-Aqua) and they bread and export Piranhas too. Before they started to use natural narcotics for the transport, they've used to strongly under-cool Piranhas before packing. That puts them pretty calm, but unlike other tropical fish, they survive it without bigger problems.

 

[naiad]

More fish adventures....

Yesterday I went on a college trip to a public aquarium in Bristol. They had a walk-through reef tank with hundreds of fish. It is a perspex tunnel which visitors can walk through and see all the fish. The students were allowed behind the scenes in small groups to see the filter system and the top of the tank. I went, had a look at the top of the tank, and climbed back down.

Then I had an idea. I just had to do it, it was a unique opportunity and I would always regret it if I didn't. I said I wanted to see the fish again, and climbed to the top of the tank and put my face in the water.

I couldn't help it. rofl rofl rofl

I guess everyone wasn't expecting to see my face appearing among the fish.

 

[octopus]

Bloody stories about Piranhas are largely exaggerated. In Amazonia you will commonly find kids bathing in the river just couple of meters far from a group of large Piranhas.

That is correct. I swam with piranhas during the dry season - few times a day. I was wearing my swimming trunks at the time...just in case.

 

[Oldsarge]

More fish adventures....

Yesterday I went on a college trip to a public aquarium in Bristol. They had a walk-through reef tank with hundreds of fish. It is a perspex tunnel which visitors can walk through and see all the fish. The students were allowed behind the scenes in small groups to see the filter system and the top of the tank. I went, had a look at the top of the tank, and climbed back down.

Then I had an idea. I just had to do it, it was a unique opportunity and I would always regret it if I didn't. I said I wanted to see the fish again, and climbed to the top of the tank and put my face in the water.

I couldn't help it. rofl rofl rofl

I guess everyone wasn't expecting to see my face appearing among the fish.

DB strikes again! We're everywhere, we're everywhere!

:rofl

 

[naiad]

Bringing freediving to everyone! rofl

So many fish and not enough diving.

 

[naiad]

Even some of the suckermouth ones can grow huge, the largest I have seen was in a nature documentary, a Panaque sp. of about 2 metres. These feed on wood from fallen trees. Strange to see a familiar fish grown to such a size!

Here are some pics...
[ame="http://www.plecofanatics.com/forum/showthread.php?t=11891"]Huge panaque in amazon - PlecoFanatics.com[/ame]

Notice the size compared to the diver in the first picture.

Something interesting to dive with!

 

[naiad]

Some koi carp. The big one in the middle has its head out of the water to try and get food. The noise they make is like someone eating soup with a straw.

A mirror carp. Notice the look on his face as he suddenly notices that the scale fairy has given him the leftovers.

Some big mirror carp asking for food.