Does schooling deter predation in aquariums

[Hybridfish7]

I know of a species of tetra I like from Costa Rica, hyphessobrycon tortuguero. However, I cannot find it in the hobby. To substitute, I have used pristella maxilaris to fit the aesthetic in some of my tanks. However I would like to use them in tanks with fish such as amatitlania septemfasciata in larger tanks. In a smaller school I could see them getting picked off in spite of the fact that they are very tight schooling.
Now say if I had a school of 30 balled up and swimming around the tank, would such deter any sort of predation for the most part once the septemfasciata hit their maximum adult size?

 

[AaronKWolfe]

I think duanes might have some insight on this.

I don't know if it really would, though. I don't know much when it comes to those specific fish, but I know oftentimes larger fish "break up" the school of fish and then attack.

 

[duanes]

Amatitlania septemfasciatum is not really a predator/piscavore.
It is an omnivore, but...if the tank is too small, any cichlid will take advantage of an easy high protein meal, if its easily corned.
The question is, what's too small. I believe any tank under 6 ft is too small if trying to limit predation.
Most smaller cichlids give up beyond a 4 ft chase, whether its a meal, or a territorial dispute, larger cichlids need more.

 

[Deadeye]

My piranha took out a school of Buenos, but that was a small school and a piranha, so not the best example.
In the confines of a tank, there is only so much schooling can do, as the predator will almost always be able to catch its meal.

 

[neutrino]

Speaking generally, in my experience the size of the group or school doesn't matter if larger fish are going to eat small tetras. The main difference with having a large school is you may not notice right away if one or two are picked off now and then, but at some at some point (if all they're doing is picking off one at a time) you realize your school of 40 or 50 has become more like 25-30. ?

 

[DrownedFishonFire]

It actually depends on the individual fish as well and another factor is keeping them fed. Too many factors IMO in play here. Some individual fish are too skittish causing the schools to react and will trigger a chase flashing here and there you got the bigger fish’s attention and you got the same species of bigger fish that would be triggered while other same species would be like meh look other way. I just witnessed an interesting video maybe a week or two ago of fish interaction on a local FB group featuring at least a foot long plus pacu just swimming by placidly chilling a feeder comet was twirling in front of it that was intended for the TSN hybrid which was for sale lol that stayed on the bottom of the video while the comet was in middle of the tank just swimming minding its own business the pacu slowly approaches it like a nonthreatening blimp in the comets line of sight and it just opened its maw and quickly inhaled it like like a tasty gumball or a grape and kept swimming on like nothing happened. My reaction ? what did I just witness?did not expect that at all! I was expecting the catfish to do something about the feeder. It didn’t chew or bite it in half whatsoever. A PACU- I still can’t get over that myself lol ?

 

[Deadeye]

It actually depends on the individual fish as well and another factor is keeping them fed. Too many factors IMO in play here. Some individual fish are too skittish causing the schools to react and will trigger a chase flashing here and there you got the bigger fish’s attention and you got the same species of bigger fish that would be triggered while other same species would be like meh look other way. I just witnessed an interesting video maybe a week or two ago of fish interaction on a local FB group featuring at least a foot long plus pacu just swimming by placidly chilling a feeder comet was twirling in front of it that was intended for the TSN hybrid which was for sale lol that stayed on the bottom of the video while the comet was in middle of the tank just swimming minding its own business the pacu slowly approaches it like a nonthreatening blimp in the comets line of sight and it just opened its maw and quickly inhaled it like like a tasty gumball or a grape and kept swimming on like nothing happened. My reaction ? what did I just witness?did not expect that at all! I was expecting the catfish to do something about the feeder. It didn’t chew or bite it in half whatsoever. A PACU- I still can’t get over that myself lol ?

Not like my pacu at all lol
Mine went full piranha when hunting.

 

[mattybecks]

I tried a school of 6 tinfoil barbs with my Arowana, he picked them off one by one until they were all gone.

 

[Stanzzzz7]

Speaking generally, in my experience the size of the group or school doesn't matter if larger fish are going to eat small tetras. The main difference with having a large school is you may not notice right away if one or two are picked off now and then, but at some at some point (if all they're doing is picking off one at a time) you realize your school of 40 or 50 has become more like 25-30. ?

I agree with this does not matter if you have 6 or 200 tetras, if a predator wants some it will get some.