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Re: flying fish



[Somebody bring this back towards dinosaurs or this is the last we'll
 see of this thread...  -- MR ]

Why should I settle for dignity when flaunting my ignorance can elicit
such good information?  I love Paul Sparks' reply to my remarks!  

I hadn't imagined they could glide up to 200 meters.  Wow!  His finding
them at least 20 feet off the water is important because it means their
launch speed was at least 11 meters per second, relative to the air.

In the North Atlantic, porpoises liked to jump through our bow wave with
lots of variations including synchronized swimming.  I used to miss
meals watching them.  They may have played an hour at a time, keeping up
with the ship while repeatedly circling for another turn in the bow
wave.  

Their speed and stamina inspired me to say some predators could probably
keep pace with a flying fish, who couldn't glide faster than he had left
the water.  A predator who continued on the course the prey had been on
at launch might be pretty close when the prey splashed down.

I said the advantage of jumping would seem marginal if the flight path
was predictable.  That certainly doesn't imply extinction.  The New York
Yankees are the world champions because of marginal advantages in most
games this year.

The Yankees wouldn't have done so well if they hadn't kept working on
skills and tactics to improve their odds.  That's why I thought that if
flying fish could truly fly, they would turn.  

The long glide, which I hadn't imagined, would be very advantageous,
whether or not a predator could keep up.  If the predator is off by 10
percent in speed and 10 degrees in direction, it will matter a lot more
in 200 meters than in 20 meters.  Besides, on long glides, breezes will
affect the splashdown position.

Wayne Anderson said something that showed me the folly of my reasoning
about turning.  He said any pilot knows you can trade altitude for a
turn.  Eureka!

Back before I got so responsible, I used to fly, thanks to friends who
owned planes and were enthusiastic enough to share.  Turning required
lateral acceleration.  I'd get that acceleration by tipping the wings so
that part of the lift would be lateral.  I loved steep turns.  

The lift required for a steep turn caused a lot of drag for engine
thrust to overcome.  At low altitude, I was banking on the dual-magneto
engines not to falter.  I guess that's why we called it banking.

At low altitude, a glider pilot will keep his turns very easy because he
can't afford much drag.  That's what I overlooked about the flying
fish.  If he produces any thrust, it's bound to be so slight that he
can't afford the drag of a hard turn.  If he turns at all, it will be
slight.

Paul Sparks says he has seen flying fish flap, while Ray McAllister says
he has never seen it and doesn't think the fish has the muscles for it. 
Maybe this disagreement is in the perception of what constitutes
flapping.  Unlike a bird, a flying fish hits the air at cruising speed. 
He wants only enough thrust to extend his glide until he has to plunge
in to resume breathing.  The required flapping may be much subtler than
a bird's.

Paul Sparks and Ray McAllister agree that a flying fish gains enough
momentum to extend his glide about 15 feet by sculling with his caudal
the first time he touches down.  

Why wouldn't he extend his glide 75 feet by touching down this way five
times?  Perhaps this is not a way to gain momentum but a way to splash
without losing momentum.  Getting nearby predators to dart toward a
decoy splash could greatly increase the life expectancy of a fish about
to plunge in. 

I don't know if flying fish can produce thrust in the air, but it's a
fun question to ponder.  Maybe some scientist found the answer long ago.

- Stephen Throop

"If I didn't have questionable knowledge, I wouldn't have much knowledge
at all!"