generally who is the lone wolf, on schooling fish???

[Magnum Man]

schooling / shoaling fish, are not something I really witness in my aquariums... loose and intermixed groups happen, but maybe I lack enough danger in my tanks to keep tight groups???

and while often I get loose grouping, there is almost always one or two that are not in the group... often these are fish that are difficult to sex, or even tell apart, for that matter... and there doesn't seem to be actions of driving them out of the group... wondering if these lone wolves are males, or females, that would go looking to start another group if in the wild, or dare devils, that would be lost to predators in the wild, maybe too immature to understand the group dynamic, yet???

the fish that made me notice this more, is the new silver dollars that came the other day... I have one mature ( likely female ) and added a few medium sized new fish... in this case, the smallest one interacts with the others, but is often on the other side of the tank, from the group... being a social fish, I've not witnessed anything antisocial directed towards the solo fish...

I've noticed this same thing with various tetras... maybe these mostly farm raised fish lack the instincts or experience of predatory fish??? seems like I try to keep them in recommended numbers, but there is always one or two that didn't get the memo on group sizes???

 

[GaryE]

Another huge question I doubt everyone truly understands.

I always figure shoalers, with their fluid movement but hierarchies don't need violence to communicate messages. A lot of it is chemical, and if for example you're a small young male and the shoal has a hierarchy you would be at the end, receiving point of, why stay for the abuse? You can smell/sense it's in the cards from the messages broadcast. In nature, you can hide in a group of many. In a tank, you're lucky if your fishkeeper has 12 in the shoal.

It seems better (to me), to risk branching out and maybe finding a new, decent sized shoal where you could fit quietly as you grew. In a fishtank, there's no other shoal coming, and very little room, but fish aren't evolved for fishtanks.

I'm speculating, and even if I'm right for one species, I could be wrong for others.

Shoals are defensive structures adopted by social groups. When there's no danger, they can spread out and forage. It appears they need to see or sense the possibility of a defensive group at all times. They may not have to use it, but I have seen shoalers kept alone become very weird as a result.

Some of the worst bullying we tried to counter when I taught High School was via social media, via phones. No one got hit or beaten, but the phones let us behave like hierarchical fish. That's progress. Kids were targeted, and some of their twisted peers tried to drive them to self-harm. High School always reminded me of a too small fishtank - crowded and nasty.

 

[gimme30]

I've witnessed the same and think you answered it yourself in your first sentence. Like @GaryE mentioned in the wild it's a survival mechanism. They seem to figure out pretty quickly our little glass boxes are relatively safe spaces. A shame really. Tightly schooled fish are a real pleasure to observe.

 

[Back in the fold]

Not all who wander are lost .

 

[plebian]

There's more to it than that. Just to expand on what GaryE said, shoaling/schooling is a defensive adaptation. While it increases the likelihood of survival with respect to any single individual in the presence of predators, it also increases competition for food. It is important to note that adaptation is dependent upon individual variation. In short, personality plays a role.

One can imagine a reduced probability of predation for any number of reasons. Shoaling behavior then becomes a liability and those individuals spreading out from the group increase their chance of survival by having greater access to food. Given enough time, a shoaling species could theoretically evolve to become a non-shoaling species. In other words, variation in behavior (personality) is an important component of evolutionary adaptation.

I think most people underestimate intra-species variation. It's one reason why some people have very different experiences with the same species. More importantly, as GaryE noted, they also fail to take into account the effect restricted spaces have on behavior.

 

[GaryE]

There's a myth I hear less now than I used to. It says that hard wired, instinctive behaviour immediately changes in aquarium fish, in one or two generations. Even if one individual fish has such a mutation, very few of the people who argue this actually breed fish. It's a beginner's fantasy.

More likely, individual fish have different degrees of fear, or fight or flight, and of sensitivity to the environment. A species where everyone is the same has much less of a chance of surviving catastrophes and rapid changes. The brain's a body part like the kidneys - no more, no less. If a species has evolved shoaling as a behaviour, not all individuals are going to be good at it, and not all will work at doing it well. Those ones tend to get eaten in nature.

Take away the danger, and they live to breed, and that can cause a slow, gradual divergence in group behaviour, as they become more and more incompetent. It isn't just finnage and colour that are modified by captive breeding. And it has no direction - I don't keep the group anymore, but there were longtime reports of firemouth cichlids becoming psycho aggressive in tank bred lines compared to how they'd been at first import. Evolution has no direction - it changes things and if they survive, changes spread. But radical change is an exception in aquarium populations. Technically, we should also see really tighter schooling evolve as well as see social breakdown.

If we want to have shoaling fish in aquariums, we can have very large dangerous tanks (not very ethical) or we can be content with the knowledge that every now and then when something in the wider room disturbs them, our fish will call upon ancient mental resources and go into defence mode.

As a tourist, I've watched buffalo (bison) on the Great Plains. The herds are small and there are old reject males wandering alone along the edges, grouchy and from my limited experience, dangerous. I'm sure that's wired into their social structure, and as I turn into a grumpy old hermit fish guy, I wonder about our own species. But I also wonder what they were like when the buffalo herds were in the millions, and if the grumpy oldies formed larger groups on their own. We only get to see survivor groups in tanks. We try to reduce their size so we can see more species (3, 6, 10 fish - formulas for species that probably prefer hundreds, thousands, millions).

Fish behaviour and fish watching matter to me. I don't want to have every species, but I want to look at the ones I keep so I can ask why. Realistically, that's often impossible as we do change their lives radically in fishtanks.

 

[gimme30]

Bit of a tangent, but I wonder if communication behaviors modify for wild caught fish placed into captivity. Lateral line perception is surely different in our much less dynamic environments, auditory or acoustic cues possibly more so with visuals being the only constant. The former's genetic; is the latter learned behavior? Just curious, I know I've rambled off the path here.

Btw buffalo are absolutely dangerous practically from birth. They're not necessarily grumpy, they just have really short fuses. I did some volunteer work for Denver parks & rec up in Genesee and I still can't believe I survived the summer. Looking at them wrong can set them off.

 

[GaryE]

I looked at a buffalo wrong. It was adreniline producing.

I think the lateral line has to be affected by the buzz and rattle of filter motors. Then again, they can tune out waterfalls and rapids. I wonder if it's like my great-grandparents, who lived with their yard onto a very busy railway with 8 or 10 tracks, but never heard the trains.

 

[gimme30]

I suppose that's probably the case, like us they seem to be able to get used to anything with time. It'd be interesting to be able to peek a century or two ahead to see how that particular trait has evolved for tank bred fish--it plays a role in finding mates so I wouldn't think it'd disappear completely. Maybe future aquarists will see less of the "best kept in groups of X+" advice in books (should those exist) or online.

I looked at a buffalo wrong. It was adreniline producing.

Same happened to me with the (ex) mother-in-law. I made sure never to wear a red shirt around her.

 

[GaryE]

I suppose that's probably the case, like us they seem to be able to get used to anything with time. It'd be interesting to be able to peek a century or two ahead to see how that particular trait has evolved for tank bred fish--it plays a role in finding mates so I wouldn't think it'd disappear completely. Maybe future aquarists will see less of the "best kept in groups of X+" advice in books (should those exist) or online.

I'm a pessimist. I think the farms will have engineered fish to the point of them being hard to recognize for us. We already buy mutant fish in great numbers, and that'll accelerate until natural forms are gone, both in nature and in the hobby. Once we get to celestial balloon longfinned glofish, they won't be able to swim in shoals anyway.

 

[gimme30]

Once we get to celestial balloon longfinned glofish, they won't be able to swim in shoals anyway.

That had me cracking up until I realized you're right. Imagine Osteoglussum bicirrhosum or some other big predator getting that kind of treatment?
Ugh. Hopefully I'll be dead long before it happens.

 

[Magnum Man]

side tracking my own thread... but to what do you think we can attribute ( weak ) non robust fish to??? not always illness or parasites... I've received many, of several varieties... that don't seem robust before they get here , but shippers are shipping them ( several different sellers as well ) I got a few nice sailfin molly's, out of 4 different orders... the paradise fish I just got, look droopy, and don't hold their fins up... surviving for a week now, but they just don't look robust.. guessing most of these non robust fish, were bred at fish farms... I've tried worming my live bearer tanks... I'm so far, not seeing an improvement, I've not wormed the paradise fish... I personally think that not the best parents are used... and the genetics on some fish has tanked... thoughts???

 

[gimme30]

Greed. A shipped fish is money in the bank. The fact some survive upon receipt must offset the cost of live arrival guarantees.

 

[GaryE]

It's a very unpopular position, but I will go out of my way to avoid farm raised fish. I have decided not to buy fish many times because I found out they were from Singapore or Malaysia, when the species was African or South American. The exception for me is fish from limited ranges being bred, but there we're best to get them and breed them. Bought stock will be weak.

Why? The large chains have enormous economic clout, and they use it to reduce what they pay to producers. The producers cut corners and lower quality to meet the pricing demands. It's simple economics. We're close to monopoly situations in this little trade, and a lot of the reputable start ups over the past few years have begun to buy farmed fish too. They make a reputation with wild caughts, but the markups are so tempting.

I'm sometimes asked why I don't keep Asian fish, in spite of how interesting they are. I actually like them, but all of the ones available where I am are farmed.

 

[Magnum Man]

While my wild type swords , came in small ( young ), but they look robust... and while both paradise fish, are still alive they don't seem as active, as my other gourami, for example... short of picking your own fish from a local aquarium store ) not really possible... and I can buy fish from the most expensive of on line sources, and that is no guarantee, that the fish will be "dynamic" they will arrive live, but may or may not look healthy, and active... my last long fin Rosy barb male is dynamic, even though that fish has likely been line bred to near death...