Form and Function

The evolution from the salmonid-herring order reflected a strong change towards the predatory habit. The jaws in particular have developed to allow them to take much larger items of food than the salmonids can.

The Pikes large canine teeth on the lower jaw are not, as is commonly supposed, designed for stabbing and killing, but are used for catching and gripping the prey in preparation for turning it and swallowing it alive.

This is done by utilising the other small, backward pointing teeth, which cover much of the inside of the mouth, including the tongue. Almost all these teeth point backwards to prevent the prey from escaping once grabbed and even the pikes gill arches have backwards-pointing spikes to prevent smaller prey fish from escaping out through the gill flaps. The mouth of the pike has a very obvious function and over the years it has caused many grossly inaccurate stories about the food intake of Esox to be invented. “Ten times their own body weight a week” or “Everything in sight” are two of the most common quotes relative to a pike’s eating capacity, but they couldn’t be further from the truth. It is perhaps worth mentioning at this point, that when Esox tiemani existed 62 million years ago (or even earlier), the ancestors of ALL the present day species were also in existence (fossil remains have been found) and both predator and prey are still here! Pike are NOT a menace to fish stocks. They never were and they never will be.

Nature’s evolutionary strategies are devised with a great deal more common sense than the ideas of man. It was only in 1966 that research work was carried out into the food intake of pike. This research showed that a pike could survive on only l.4X its own body weight PER YEAR but needed between 2.5X and 3X per year to show a growth increment. This figure is only for stillwater pike, with running water pike (i.e. river fish) being found to need a maximum of 5X per year for growth. (This increase is necessary because a river pike has to expend additional energy in overcoming the flow). Both these figures compare very favorably with the brown trout, which requires just over 7X its own body weight. The pike has a very efficient digestive system which allows it to feed in short bursts every few weeks, then ‘hole up’ for the remainder of the time slowly digesting its meal and conserving energy. They have been on the planet for over 80 million years and haven’t changed a great deal, so they would appear to have got this part of their biological make-up just about right!

A pike’s head is covered with little holes (pores), containing sensors, which act in conjunction with the lateral line to pick up vibrations and pressure changes. Although pike find their prey mainly by sight, they can also use the lateral line and head sensors to home in on the vibrations sent out by potential prey fish. This is best illustrated by citing numerous cases of totally blind pike which have continued to survive and indeed thrive despite their handicap’. They also have a tremendous sense of smell and tests have shown that they will travel considerable distances to follow a scent trail. So pike, while primarily hunting by sight, can also use vibration detecting and smell to find their prey, making them truly efficient and adaptable predators. Getting away from the sharp end for now, the tail area of the pike is quite unlike most other fish in that the dorsal fin, caudal fin and anal fin are all grouped together at the rear of the spear-like (hence its name) body. This cluster of fins gives massive thrust and allows tremendous straight-line acceleration, over a relatively short distance from a standing start. This speed allows it to strike at prey from a considerable distance away, doing away with the need to stalk. The speed of a pike strike has yet to be measured scientifically but observations have been made of large pike striking at up to 30 yards per second, or approximately 60 mph!

There is a famous piece of BBC film footage showing a pike striking at normal speed and in slow motion, in BOTH sequences the pike is moving so fast that the image is just a blur.

It should be noted however that this speed cannot be sustained for very long (similar to the cheetah) and that it is only attainable in a straight line. If it becomes necessary, the pike will hunt in a fast, active way but it prefers to lay in ambush, using its markings, a disruptive pattern of spots and bars to render it invisible to its prey. In this way it can make the best and most energy efficient use of this ‘tool’ that nature has provided.