Have you ever wondered why carp roll?.....
it's a question that has always interested me, after doing some research this is what i have found in the hope of answering this question
now we have all been impressed by the spectacular splashes that a leaping carp can make, especially when a fish over 30lb comes clean out of the water
it is an impressive spectacle and one that gets every carp angler’s heart racing, you know they are there and you’re in with a chance to catch one
but what makes the fish behave in this fashion?
there are several answers to this question but the principle reason is physiological, as most fish have a swim bladder the swim bladder is linked to their oesophagus and is used to control their depth in the water
by increasing or decreasing the volume of gas in the swim bladder the fish can either move up or sink down in the water, by leaping or swilling on the surface a carp can force air into its swim bladder through its oesophagus, thus allowing the fish to adjust its level in the water
it is often the case that carp can be seen jumping more often in deeper lakes and less in shallow waters, this would appear logical in as much as the fish has less need to vary its depth in a shallow lake as it does in a deep one, generally the carp are able to eliminate the gas in their swim bladder by their natural bodily processes, but there are also times when they need to eliminate this build up and a leap facilitates the task
a carp jumping out of the water and landing with a splash can force the air out of its swim bladder, this is often the situation when the fish have spent a fair amount of time in deeper parts of the lake, say depths over 15 feet
as the fish moves to the upper layers of the water so the pressure in it's swim bladder increases, in the same way as a diver risks the bends if he comes up to the surface too fast
in order to rapidly expel this excess of gas in it's system, what better way than a nice big ‘Ploof’! the shock caused by the fish landing serves to force the gas out of its body
from a fishing point of view this can give us an indication that the carp are feeding in the deeper water this physiological necessity is just one of the reasons why carp jump, there are also social and feeding linked reasons
carp often feed on aquatic creatures such as mussels, crayfish etc, a fish feeding on these creature with rigid shells can find itself with sharp particles of shell in its gills, if the natural sucking and blowing that characterizes a carp’s feeding habits don’t suffice to remove these annoying particles, a good old jump does the job
in silty lakes a carp feeding in the soft matter on the lake bed may push its head several inches into the silt in order to find the food it is looking for
to clear its gills of any organic matter that has entered them can also be done quickly with a leap or two out of the water, finally carp are shoal fish and often move together in groups of several individuals, jumping acts as a way for individual fish to follow the shoal, this has often been seen on large French lakes such as the Orient, the Lac du Der etc, where fish moving in open water regularly “porpoise” out of the water as they make their way across the lake
so one can see that there are numerous reasons why carp leap out of the water, but also the nature of this leaping, (straight up and down , a sideways flop, of a dolphin like jump) also gives precious clues as to the behavior of the fish in the water and as such how to best lay our traps to catch them