Why in the wild shoal size matters.

[gwand]

Better together: Study finds bigger fish shoals make faster, more accurate predator-escape decisions

When predators strike, fish need to decide fast: dive or stay? It's a life-or-death choice, and getting it wrong, whether by overreacting to harmless disturbances or missing a real threat, can be costly.

phys.org

 

[GaryE]

That's really interesting. As aquarists, we don't have to worry about birds sweeping across the water surface, but we can't forget the instinct needing that cooperation is likely present in our fish.

 

[gwand]

Absolutely. That gene-driven instinct is likely millions of years old. Evolution knows what she, them, they is doing.

 

[Innesfan]

Especially interesting that a molly species was the subject. They are not front of mind--my mind, anyway--when speaking of shoaling species. Fascinating article.

 

[gwand]

I was thinking the same thing. But I know next to nothing about wild Mollys.

 

[GaryE]

I kept sulphur mollies for a while. Not a large species, and one I never thought of as a shoaler.

The red finned mollies I watched in the Yucatan lived in enormous social groups - thousands of them, but I saw them feeding on submerged cliff walls and not moving in mid water.