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A re-occuring pattern in nature

Started by Guest_centrarchid_* , Mar 25 2014 02:49 PM

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11 replies to this topic

#1 Guest_centrarchid_*

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Posted 25 March 2014 - 02:49 PM

Check this out. We see it a lot and to my eye it is not a demonstration of randomness.

What does this look like? Imagine you are looking at something inanimate rather than a bunch of pro-larvae. Something is going on here and may have a relationship to schooling behavior to occur later.

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#2 Guest_Skipjack_*

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Posted 25 March 2014 - 03:16 PM

When I raised several hundred juvenile bowfin in a 700 gallon round stock tank, they swam continually in a counter clockwise motion around the tank. Never clockwise. I bet it would have been the opposite if I lived in the southern hemisphere.

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#3 Guest_Erica Lyons_*

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Posted 25 March 2014 - 03:26 PM

Did you see this article about cow herds all facing the same direction when grazing?
"With Google Earth’s images at their disposal, Begali’s team spied on a massive sample of cattle across six continents, from South Africa to India to the UK. They recorded the positions of over 8,500 individuals at more than 300 sites, including a range of different breeds, altitudes and times. Their global cattle census showed that the animals oriented themselves along a north-south axis so consistently that the odds of them doing so by chance was less than one in a hundred thousand."
http://scienceblogs....gn-like-compas/

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#4 Guest_Skipjack_*

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Posted 25 March 2014 - 03:42 PM

I actually have 60 head of cattle, and can attest to this. Though not 100% on the north south thing.

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#5 Guest_centrarchid_*

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Posted 25 March 2014 - 03:45 PM

Dogs alleged to do similar when deficating as they align with magnetic field. My dogs consistent with such.

Picture shows only small portion of brood. From more distant perspective, not all aligning in same direction but pattern with nearest neighbor conserved. To me looks like iron filings around magnet. Somehow they communicate with each other and sire.

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#6 Guest_Gavinswildlife_*

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Posted 25 March 2014 - 05:09 PM

I wonder what would happen if you held magnets up to these fish?

if they really act like compasses, they would follow it.

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#7 Guest_centrarchid_*

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Posted 25 March 2014 - 05:46 PM

The magnet idea has been considered. We a brood due to hatch tonight. Once they start lining out like in photograph I will play around with a stir-bar magnet placed under nest.

I am thinking the larvae are producing the magnetic field and it not only helps young fish stay together, it is as important to the father.

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#8 Guest_gerald_*

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Posted 25 March 2014 - 07:12 PM

Are they not just responding to the water current? (created by pumps or father fanning)?

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#9 littlen

NANFA Member

Washington, D.C.

Posted 25 March 2014 - 07:32 PM

Just out of curiosity, what species of fish is pictured?

Nick L.

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#10 Guest_guyswartwout_*

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Posted 25 March 2014 - 08:33 PM

I wonder what would happen if you held magnets up to these fish? if they really act like compasses, they would follow it.

I think that only works with needlefish.

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#11 Guest_centrarchid_*

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Posted 26 March 2014 - 06:46 AM

Fish shown are bluegill although other sunfishes do it as well. This occurs immediately prior to exodus / swim-up. Brood in photograph was incubated without male in a 200-gallon larval rearing tank. Such tanks do have a flow. There may be a critical mass issue where smaller broods do not do it.