How important is school size?

[Chick-In-Of-TheSea]

Over time I have had losses due to old age or illness in schools of tetras. I'm now left with 5 pristella tetra and 4 black neons.  I noticed that they have been nippy and chase each other. The pristellas only nip the neons, they don't nip each other.  The neons also nip other neons, but not the pristella.  The neons are getting the raw deal here.  Is this because of school size or something else (territory, etc)?  They are in a 29 gal with one ram and 3 snails.

Edited August 15, 2022 by Chick-In-Of-TheSea

[JettsPapa]

It could be that the fish don't feel secure due to too few of their own kind.  I know six is often given as the minimum number for shoaling fish, but I'm pretty sure fish can't count, so it's difficult to say where the threshold is.  I prefer eight as a minimum, but there isn't a magic number.

If you don't already have hiding places and sight breaks (tall and/or dense live plants are good options), adding some might help.

[Chick-In-Of-TheSea]

On 8/12/2022 at 12:31 PM, JettsPapa said:

It could be that the fish don't feel secure due to too few of their own kind.  I know six is often given as the minimum number for shoaling fish, but I'm pretty sure fish can't count, so it's difficult to say where the threshold is.  I prefer eight as a minimum, but there isn't a magic number.

If you don't already have hiding places and sight breaks (tall and/or dense live plants are good options), adding some might help.

Thanks. I picked up some tall plants today to try to break up the middle area where disputes happen. Oddly enough everyone is very peaceful now, in the afternoon. So, I’m thinking feeding time is the main problem. I plan to get more tetras but they are going to have to go through quarantine. 

Edited August 12, 2022 by Chick-In-Of-TheSea

[anewbie]

School size helps but to make them truely comfortable you might need several hundred 😉 I try to keep the school size decent for those fishes i want to keep but those i don't intend to keep i let the school size dwindle to 0. I think that is how you should make your decision - if you like your black neon or pristella I'd think about getting a few more - you can start with some young ones if you order from aquahuna so they will have time to grow up.

[Brandon p]

I like school sizes to be at least 6 but closer to 12 if the tank is large enough 

[nabokovfan87]

On 8/12/2022 at 8:37 AM, Chick-In-Of-TheSea said:

The pristellas only nip the neons, they don't nip each other.  The neons also nip other neons, but not the pristella.  The neons are getting the raw deal here.  Is this because of school size or something else (territory, etc)? 

Attacking the other fish I would think is "protect the herd" mentality and one fish having a bit more of a temper than the other.  Think of it like a dominant male protecting the pack.  Something like line of sight breaks would lessen this.  My first question is just going to be, what does the tank look like and how much of the vertical space do the fish have for the sake of getting away from others.  Is there a "bush" where the neons can go hide in away from the others.  If this is the case, then the interaction I would expect to see is one of the fish swimming in open water, the other hiding in the plants kind of like finding nemo and hiding in the anemone from predators/nuisances.

In pretty much everything I've kept.... the mindset I have for my tanks i that trying to maximize the amount of fish of one type to "have enough" of them is pretty critical.  When I had my barbs they are often semi-aggressive, but none of them would touch the solo white cloud I had in the tank.  He was on his own, wouldn't leave the top of the water surface,  and everything in the tank was 2-3x his size.  The store didn't have more, so it wasn't a situation where I could get more. 

Odessa barbs, when they went from ~10 down to 4-6 the aggression and issues increased.   Tiger barbs, same thing.  Rasboras, same thing.  Skirt tetras and the "wider body" tetras I have seen do this as well.  I think something in the 8-10 range usually does a bit better than something in the 4-6 range.  Scape has a ton to do with how the fish interact though.  Minimizing how often they come into conflict with one another is what I would start with to try to alleviate the issues in your tank.

Sidenote story somewhat related....

When I was working on my big display tank I had to get GTB (green tiger barbs) in several batches at a time.  I would have to wait a few weeks for the stores to get more in, then go and search for more.  I told them several times I needed a lot of them and every time I'd go into the big box store they would have 3-5 in stock.  I am sure they had heavy losses, that just the quality of the store around me.  Things have improved and more options are available, but the key point here is that I had a need for 20+ of one fish and I would go from 6 fish, to 10 fish, to 12 fish, etc.  One of the behaviors I noticed and enjoyed most was feeding and watching the fish after they would feed.  I would drop some food in and the bossiest fist would get their taste.  I would always see the others who weren't as dominant, who were picked on, or just suffering with some ailment and I would feed those to make sure they would get some food as well.  It was our little secret, but the big barb would take his bites of food, go run and hide, eat, then come back for more.  Having that little hide or places for the fish to escape to meant that they could get away from the barrage and darting.  From feeding to about 30 minutes or so after feeding those fish would just torment one another until I had enough in the tank to distract them.  That being plants growing in or just other fish.

Edited August 15, 2022 by nabokovfan87

[Guppysnail]

When my original group of CPD lowered from old age attrition the in fighting got much worse and the injuries increased. Having fewer there were not enough of them to keep themselves busy and distracted.  If you intend on keeping them beyond natural attrition I would add more. To lessen the bullying of the neons you may want to move one or the other to a different tank during attrition however this may cause the pristella to nip at one another.  I decided to keep mine so added more and the aggression abated. 

[Chick-In-Of-TheSea]

On 8/15/2022 at 1:52 AM, nabokovfan87 said:

Is there a "bush" where the neons can go hide in away from the others.

I just added some anacharis and it seems to help.  Seems the aggression is only at feeding time and then everything is cool again.  If I add sinking food and floating food at the same time, this seems to help because while some are at the top, others can mid-feed.  Also the one that seemed to be getting picked the worst on was the sick one.  I don't know if he just got sick again or if the picking on him made him sick again due to stress.  Either way, he's back out in quarantine.  Since he's been moved out, one fish will nip, but then the fish that got nipped will go nip a different fish, and they take turns.  But again, only at mealtimes.  Seems they were pretty merciless all ganging up on the sick guy though.  I think they were trying to "get rid of the liability".  ☹️  Once he recovers he might go into the snail tank.  I don't know.  At least until I can get more of a school going.

On 8/15/2022 at 1:52 AM, nabokovfan87 said:

every time I'd go into the big box store they would have 3-5 in stock.

After an ick situation, I had one black neon left.  Seemed fine, it was schooling around with the pristellas, but I felt bad he didn't have any of his own kind.  I had SUCH a hard time getting any.  I went to 5 stores.  None.  And these are common fish.  My friend found some while she was in a store and called me.  I told her to get 4 because I didn't want her to front a bunch of money on my behalf.  I might just order some via mail - never did that before, not looking forward to it but I need to a) wait for it to get cooler (it's often 100 degrees), and b) free up the QT tank.

On 8/15/2022 at 6:20 AM, Guppysnail said:

When my original group of CPD lowered from old age attrition the in fighting got much worse and the injuries increased. Having fewer there were not enough of them to keep themselves busy and distracted.  If you intend on keeping them beyond natural attrition I would add more. To lessen the bullying of the neons you may want to move one or the other to a different tank during attrition however this may cause the pristella to nip at one another.  I decided to keep mine so added more and the aggression abated. 

You know, I started out with swordtails!  Then pristellas got added to my tank when my friend's landlord said he wasn't allowed to have an aquarium in his unit.  Then pristellas ever since.  I think I added the black neons on my own at some point.  I don't remember.  I guess I'm rolling with it, and will go ahead and increase the schools.  If I were to do over from scratch, I'd start up a cichlid tank again, but these guys are "home" now, so I will make them comfortable, the best I can.

Edited August 15, 2022 by Chick-In-Of-TheSea

[nabokovfan87]

On 8/15/2022 at 5:44 AM, Chick-In-Of-TheSea said:

I might just order some via mail - never did that before, not looking forward to it but I need to a) wait for it to get cooler (it's often 100 degrees), and b) free up the QT tank.

I definitely recommend aquahuna.  It's my local store now. With the ACO coupon it's about the same price as going to the shop for me. 🙂

Considering the issue is the black neons getting picked on, I would double their numbers first. Then see how things go. Protect the little guy in QT and then it will shift the dynamic.

[BeeD]

I've always wondered about this stuff. I had a Serpae tetra colony of 10-12 for years in the same 55 gallon. In the beginning they had German Blue Rams, Otos, and a female Betta. Every morning the Serpaes would school around low in the tank while the rams frolicked and the Betta showed off for me. For the next couple of hours after that I would get distracted from work because the top two or three Serpaes would spar in the middle of the tank, not a lot of nipping most days just posturing and slapping. I don't know if that was over favorable hiding spots, breeding, or if they just need to sort out hierarchy when they feel pressured to school up every day.

I was leaning toward the latter, because eventually it was just them, a school of White Skirts (+1 Glo Tetra), and a couple SAE. They never schooled and rarely sparred. In the end there were three of them left with the Glo Tetra in a retirement home. None of the tetras really interacted at that point. They just kind of hunted through the Anubis jungle on their own, nobody really took over a specific territory. 

Edited August 15, 2022 by BrettD
clarity

[Patrick_G]

On 8/12/2022 at 9:31 AM, JettsPapa said:

I know six is often given as the minimum number for shoaling fish, but I'm pretty sure fish can't count,

😂  

How did the fish keeping hobby as a whole end up on the number six anyway? 

[BeeD]

On 8/15/2022 at 1:18 PM, Patrick_G said:

😂  

How did the fish keeping hobby as a whole end up on the number six anyway? 

I don't know how reliable these memories are, but I'm pretty sure I was hearing the pet shop telling my dad that in the 80s, so that's pre-internet.  So it must have been the wholesalers or one of the magazines. 

I know what you're saying, though. How did they decide on that?

[Patrick_G]

On 8/15/2022 at 5:24 PM, BrettD said:

I don't know how reliable these memories are, but I'm pretty sure I was hearing the pet shop telling my dad that in the 80s, so that's pre-internet.  So it must have been the wholesalers or one of the magazines. 

I know what you're saying, though. How did they decide on that?

I know! I just find it funny that we didn’t settle on five or seven. 

I keep thinking about the Monty Python skit about the holy hand grenade. 😁

[laritheloud]

Echoing most of the folks above -- for schoolers it's better to put them in as large a school as you're comfortable getting for your tank size. I have 9 black ruby barbs but if I could get more of a similar size, I'd add more in a heartbeat. I started with 6 diamond tetras and luckily they bred themselves up to 12, and they got increasingly more peaceful the more they grew their school. My personal minimum is 8 to 10 schoolers.

[Odd Duck]

On 8/15/2022 at 12:18 PM, Patrick_G said:

😂  

How did the fish keeping hobby as a whole end up on the number six anyway? 

It seems to be about how high fish most can count.  😆  If the group is too small, somebody gets singled out and picked on.  Bigger groups, nobody gets too much harassment.  It has kind of become the general rule of thumb.  But there are species where it doesn’t work at all, so always take it with a grain of salt.  More easy going species probably don’t need higher numbers for aggression dispersion but some still seem to be happier and more confident with higher group numbers, like cories, or Kuhli loaches.

[Ken Burke]

On 8/16/2022 at 12:24 AM, Odd Duck said:

It seems to be about how high fish most can count.  😆  If the group is too small, somebody gets singled out and picked on.  Bigger groups, nobody gets too much harassment.  It has kind of become the general rule of thumb.  But there are species where it doesn’t work at all, so always take it with a grain of salt.  More easy going species probably don’t need higher numbers for aggression dispersion but some still seem to be happier and more confident with higher group numbers, like cories, or Kuhli loaches.

I’ll add: having a school not only reduces stress for the fish (more eyes alert to danger) but it ensures receive the very best education.  Further, as you increase the size of the school, you’ll see behaviors change.  The fish become less shy, more playful etc.  my guess it 6 come from an observation that these changes happen around 6

[Tanked]

How important is school size? How many people are required for a party?  

Paraphrasing a line from Alice's Restaurant: '1 is weird, 2 is a pair, 3 is an organization, 50 is a movement!'  I buy in minimum groups of three because the newcomers need to be around some of their own kind, age, and size until they assimilate.  If I want more, the next number is six.  My local LFS also happens to discount multiples of three.🙄  

As the others have said there is safety and comfort in larger numbers.  Due to attrition I have several groups of five. The Embers for some reason have chosen not to school as one.  The three youngest have chosen to remain separate from their older, larger cousins.  I believe six to be an arbitrary number.  A school has to be big enough to look larger than a mouthful.

[JettsPapa]

On 8/17/2022 at 8:20 AM, Tanked said:

How important is school size? How many people are required for a party?  

Paraphrasing a line from Alice's Restaurant: '1 is weird, 2 is a pair, 3 is an organization, 50 is a movement!'  I buy in minimum groups of three because the newcomers need to be around some of their own kind, age, and size until they assimilate.  If I want more, the next number is six.  My local LFS also happens to discount multiples of three.🙄  

As the others have said there is safety and comfort in larger numbers.  Due to attrition I have several groups of five. The Embers for some reason have chosen not to school as one.  The three youngest have chosen to remain separate from their older, larger cousins.  I believe six to be an arbitrary number.  A school has to be big enough to look larger than a mouthful.

 

. . . and be sure to take pictures, with circles and arrows, and a paragraph on the back.

[anewbie]

In my 120 i have 16 serpae; in my 550 i will have ~40 serape. Teh more the happier. I will say with the 16 they don't clump up very often - they frequently scatter around in smaller groups of 1 to 4 looking for things to nibble on. I'd get cardinals (which i prefer) but they are kind of expensive for fish food.