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joey'd is da man
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Discussion Starter · #1 ·
how fast can they go?
how long can they keep that speed up?
how long does it take them to hit full speed?
how far can they swim - in any given time period?
what is the fastest/slowest piranha?
and how high can they jump out of the water?

 

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i like that sign

some good questions cause i would say fast and it can vary accordingly... but i bet you already knew that...


how fast can they go? = fast
how long can they keep that speed up? = until they get tired or bored
how long does it take them to hit full speed? = not too long
how far can they swim - in any given time period? = good distances
what is the fastest/slowest piranha? = the slow ones and the fast ones
and how high can they jump out of the water? = depends on how much they practice

...thats about all i can do for these questions, never really did any measements, I wonder if there have been any tests on this?
 

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I dont know any specific measurements but my p is super fast. Me and my girlfriend were watchig it much on some feeders from a distance. He would turn slightly, slowly move into position, then dart across the tank and grab it. All in all, the whole exchange lasted maybe a second. These fish have explosive powers!
 

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there's no way anyone could obtain this information without tagging and studying them in the wild. you can't exactly measure how long they can sustain top speed in a 125gallon tank. i doubt that anyone can give credible answers to these questions, but they are good ones and i hope that frank may have done a study and can give some feedback.

Joe
 

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joey'd is da man
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Discussion Starter · #7 ·
SnowCichlid said:
i like that sign

some good questions cause i would say fast and it can vary accordingly... but i bet you already knew that...


how fast can they go? = fast
how long can they keep that speed up? = until they get tired or bored
how long does it take them to hit full speed? = not too long
how far can they swim - in any given time period? = good distances
what is the fastest/slowest piranha? = the slow ones and the fast ones
and how high can they jump out of the water? = depends on how much they practice

...thats about all i can do for these questions, never really did any measements, I wonder if there have been any tests on this?
Well that I knew already


and also mine are really fast when they want to be with quick darts across the tank, but I was meaning top speeds and stuff like that - some actual figures!!!!

but 2.5ft is a pretty impressive jump for a 3" fish
- also how far can they jump in distance?
 

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according to physics, less massive creatures can jump higher or further, than more massive animals when you scale everything, thats why crickets can jump several times their length, and why ants can carry I think its about 300 times their own weight or something, so small fish will jump higher/per body length than a full grown fish, its all due to area/ volume ratios, as area increases volume increases faster and strength goes down, I am pretty sure thats worded right, but I know for sure about the small something is the stronger it is physically on scale
 

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Sir Nathan XXI said:
according to physics, less massive creatures can jump higher or further, than more massive animals when you scale everything, thats why crickets can jump several times their length, and why ants can carry I think its about 300 times their own weight or something, so small fish will jump higher/per body length than a full grown fish, its all due to area/ volume ratios, as area increases volume increases faster and strength goes down, I am pretty sure thats worded right, but I know for sure about the small something is the stronger it is physically on scale
I don't understand,

Area/Volume, 2d/3d? equal 1d?

Are you are taking about relativity? That the ratio of strength vs. body mass is higher for the smaller creature given the equivalent amount of body mass to a creature of larger size?

I personally think that it is because of the gravitational force. Fg = ma = -32.2*m. Since they weight so darn little, they don't have that much against them. Or also in the terms of water/air and etc resistance.

I am still happy I can squish an ant that lifts 30 times is own weight, when I can lift at least 3000 times its weight.
 

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Frank-
I have a related question. I work in lab with embryonic zebra fish. We are currently looking at the C-startle response and how highly conserved it is in fish. Are you familiar with this C-start? If so, does it apply to piranha (I'm assuming it does) and also would it be employed during feeding when they take a bite and get away real quick?

I've tried to watch them during feeding, but its almost impossible to see. In the zebra fish, it only takes about 30-50 milliseconds...

Thanks,

Ryan
 

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hastatus said:
Here, this should get you past all the BS.

Speed Table
Nice. But isn't this a cal. based on design and swimming mode? I think this document just trys to link the different designs of a fish and "This makes it possible to compare the swimming performance of fishes with forked, rounded or other shapes of caudal fin."

From my understanding, most data was done on tuna, sharks, trouts, and etc. I did not look further into this than the main site itself and some of the sources in the document that was easily found. But I don't believe Ps were part of the sample.

From my knowledge, muscle type, density, efficiency, along with design and style makes for a truer fish speed algorithm. These references can be found in the numerous studies on Salmons, trout, sharks, and tunas.

To generalize gives a good ballpark indicator, but this document does not even calculate in the overall fish design.

Not to bring anymore BS into this thread, but a Shark and an Angel fish with the same Aspect ratio (A) of the caudal fin and ratio'd size difference would most likely produce different speeds. Even with similarity in swimming mode, I think the overall design of the creature and its intended function counts. Designed for speed hunting or speed scavenging.

Just my 2 cents.
 

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Even with similarity in swimming mode, I think the overall design of the creature and its intended function counts. Designed for speed hunting or speed scavenging.
Quite true. S. elongatus is a good example of a torpedo shaped body built for speed in open rivers. The more compressed forms are built to live among roots of trees. The robust Pygocentrus is not built for speed but scavenging.

Not withstanding, the only species actually studied was S. rhombeus and it had nothing to do with its speed but its range. As for the balance of the work mentioned above, shark, salmon, and trout are about the closest to the shape of piranas. In the meantime, I'll see from my sources if any study has actually been done on piranas in regards to the your question.
 

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Sir Nathan XXI said:
my elongatus is pretty damn fast, but I get the impression they are like cheetas, they can only sustain short bursts of speed, but I dunno
Most animals have this quality, it is just nature people call them winds when they run they can go really fast for a short time then they get tired then they rest a bit and pick up.
 

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RedShoal said:
Sir Nathan XXI said:
according to physics, less massive creatures can jump higher or further, than more massive animals when you scale everything, thats why crickets can jump several times their length, and why ants can carry I think its about 300 times their own weight or something, so small fish will jump higher/per body length than a full grown fish, its all due to area/ volume ratios, as area increases volume increases faster and strength goes down, I am pretty sure thats worded right, but I know for sure about the small something is the stronger it is physically on scale
I don't understand,

Area/Volume, 2d/3d? equal 1d?

Are you are taking about relativity? That the ratio of strength vs. body mass is higher for the smaller creature given the equivalent amount of body mass to a creature of larger size?

I personally think that it is because of the gravitational force. Fg = ma = -32.2*m. Since they weight so darn little, they don't have that much against them. Or also in the terms of water/air and etc resistance.

I am still happy I can squish an ant that lifts 30 times is own weight, when I can lift at least 3000 times its weight.
red shoal no I am speaking of strength, smaller objects will have a greater surface area per unit of volume compared to large objects that have a larger volume then surface area, these large objects will be less strong when compared to those of small objects once scaled appropriately, thats why smaller animals are able to perform such "amazing" things like, birds that fly, insects that jump, ants carry very heavy weights, and so on, its no BS either, its proven and scientifically valid,

so what this means is small fish like Elongatus will be able to swim extradonarily fast for their size
 

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Sir Nathan XXI said:
RedShoal said:
Sir Nathan XXI said:
according to physics, less massive creatures can jump higher or further, than more massive animals when you scale everything, thats why crickets can jump several times their length, and why ants can carry I think its about 300 times their own weight or something, so small fish will jump higher/per body length than a full grown fish, its all due to area/ volume ratios, as area increases volume increases faster and strength goes down, I am pretty sure thats worded right, but I know for sure about the small something is the stronger it is physically on scale
I don't understand,

Area/Volume, 2d/3d? equal 1d?

Are you are taking about relativity? That the ratio of strength vs. body mass is higher for the smaller creature given the equivalent amount of body mass to a creature of larger size?

I personally think that it is because of the gravitational force. Fg = ma = -32.2*m. Since they weight so darn little, they don't have that much against them. Or also in the terms of water/air and etc resistance.

I am still happy I can squish an ant that lifts 30 times is own weight, when I can lift at least 3000 times its weight.
red shoal no I am speaking of strength, smaller objects will have a greater surface area per unit of volume compared to large objects that have a larger volume then surface area, these large objects will be less strong when compared to those of small objects once scaled appropriately, thats why smaller animals are able to perform such "amazing" things like, birds that fly, insects that jump, ants carry very heavy weights, and so on, its no BS either, its proven and scientifically valid,

so what this means is small fish like Elongatus will be able to swim extradonarily fast for their size
What? How does the mathematics of surface area to volume equate to strength??
That is like saying, if 1 + 1 = 2, then a piranha is a goldfish.

Birds fly also because of their bone density. Condor flies and they are not small.


I agree with this, "smaller objects will have a greater surface area per unit of volume compared to large objects that have a larger volume then surface area" as being scientifically valid.

But this, "these large objects will be less strong when compared to those of small objects once scaled appropriately" is BS, and especially confusing when following the previous scientifically valid statement.

I am just confused by how these two statements connect to each other.

BUT, if you are saying that if I was shrunken to the size of an ant, it would be stronger than me, I agree. But this does not follow your "scientifically valid" statement because my surface area per unit of volume would now equate to that of the ant and yet, I cannot do the same feats as it. I believe this is more of an evolution and genetics thing. Not all bugs can lift 30 times its own weight, if they all did this, then no one would point out that an ant could do this.


If you were taking about the ratio of lifting weight vs. body weight, then see my previous post.
 
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