This fascinating piece from Dr Mike Ladle looks at the mechanics of how carp feed. This information summarises many of the scientific experiments that have been undertaken and is invaluable in helping an angler time the strike to maximise the likelihood of a solid hook set.

“Like most anglers I have often wondered what was happening at the far end of my line – usually without any hope of finding out. Trying to deduce the behaviour of fish from the twitchings, tugs and twiddles transmitted up a nylon (or even braid) filament can be a really tricky business. Only rarely is it possible to actually watch the fish that are causing the bites so most of your response has to be based on guesswork. By trial and error experienced anglers have often developed tactics which succeed in a particular situation. They may opt to strike when the line is running out, strike as it slackens and drops back or they may even hit the first movement – but only on the odd occasion can they know for certain just what is going on down there – so luck must play a large part in the outcome. Never fear, help is at hand!

For years scientists have been studying the feeding behaviour of fish. In these studies carp have received more than their fair share of attention. High tech equipment and sophisticated modern methods are beginning to reveal lots of fishy facts which could prove to be invaluable to anglers. In Holland fish biologists have used video films, X-ray cinematography (using food pellets laced with radio-opaque barium sulphate) and even observations of the electrical activity taking place in the muscles around the mouths of feeding carp. In this way it has now been established exactly how Cyprinus carpio goes about picking up, chewing and swallowing different items. This could be vital information for the carpaholic if he is to make the most of his chances.

So just how do these fish feed? It seems that when a carp comes across a large particle of food (such as the boilie on your hook – not on mine – I never use them) the following series of events occurs –

1. Having found your boilie the carp “aims” its mouth at the bait.

2. By expanding its mouth cavity the fish sucks in the pellet at high speed (60cm per second). It takes only a fraction of a second for the bait to enter the carp’s mouth.

3. The pellet, now well inside the carp’s capacious gob, is trapped and held between the roof and floor at the back of the mouth. It is kept in this position for about half-a-second.

4. The trapped food pellet is now rinsed and tasted by the fish, which slowly and repeatedly pumps water over it through the mouth and gills. A further two seconds are spent in this part of the feeding operation.

5. With the mouth closed the carp’s jaws are pushed forwards, drawing water in through the open gill slits. This often washes the food pellet forwards into the mouth again. Tough or dirty food is given this treatment more often than soft “easy” material.

6. By now the carp is ready to chew its meal and the food pellet is slowly shifted back to the throat teeth. This process takes one more second.

7. At this stage the carp often takes a breather lasting a few seconds.

8. The food is loaded into the throat teeth and chewed, again for several more seconds. During chewing the mouth is often open but the lips are not pushed forwards.

9. At last the fish has completed its feeding cycle, with the whole business taking anything up to fifteen seconds, and at this point the food is swallowed.

Of course all this is all a bit technical and the times given are rather variable. Nevertheless, anglers who catch a lot of carp may well be able to recognise some of these actions signalled up their line and adjust their tactics accordingly. If you hook a carp deeply clearly it must have been undetected for some time. If, as is often the case, the fish rushes off with the bait producing a screaming run it is either scared or has decided to find a quieter place to eat its meal because of competition from other fish. Quite often the carp may detect something amiss in the early stages of the feeding process and simply reject the bait (unless your carefully designed hair rig actually does its job).

In many waters carp must feed largely on the free offerings of meat, dog biscuits, boilies, bread and other morsels, chucked in by anglers. However, these are not the natural foods of the species. In fact carp have catholic tastes and are quite prepared to try most things once. Despite the fact that these are fish which often grow to a large size they generally eat fairly small items of food. Both animal and vegetable material are readily consumed, notably in the form of small aquatic animals (pond slaters, worms, insect larvae) and the seeds and shoots of various plants including grasses and duckweeds. In order to sustain themselves and to grow fatter big carp must devour huge numbers of these tiny, favoured foods. If the water temperature is high enough, almost their entire existence (when they are not breeding) is concerned with finding large concentrations of suitable food and gorging themselves as though there is no tomorrow.

As already mentioned the sequence of feeding movements which a carp uses to catch, clean, crush and swallow an artificial food pellet (boilie or mixer) are quite complicated. Essentially they consist of – SUCKING IN – RINSING – REPOSITIONING – BACKWASHING – MOVING – CHEWING – SWALLOWING in that order. Think about it!”

Hopefully this summary gives you a better idea of what is happening from the time the carp first grabs your bait and allows you to time the strike to best effect.