Carp Fishing

The Intestine

The carp does not have a stomach but instead has a very long intestine, where its food is broken down by enzymes. The carp's diet is very varied (it is omnivorous) so the intestine needs to cope with both meat and weed products. Weed generally requires more mastication by the fish and takes longer to digest (due to the large number of cells it possesses), and this is why the intestine is so long. Within the intestine, which starts directly behind the oesophagus, powerful digestive juices assist with the passage of food. The reaction caused by digestion is usually alkaline (pH 7-7.7); recent experiments have shown that the pH level fluctuates depending on the temperature of the water. Pepsin (an essential protein-digesting enzyme) is not found naturally in the carp, but has to be gained by the fish through its food sources.

Feeding

The carp will sample most food items with its lips, which are equipped with minute receptors. If the item is found attractive, it will pass to the carp's throat teeth before ingestion. The pharyngeal teeth are located behind the mouth proper and comprise between one and three rows of teeth, depending on the type of carp. These will crush food items with the assistance of a pad in the palate of the mouth, and these do wear out with time and excessive use. Besides the lips and teeth, the carp also possesses a bronchial system which filters out minute particles from the water (comprised of branchiospines, branchial arches and bronchial apertures). Generally speaking, small young fish have a finer and better developed bronchial system than larger carp, but both are capable of feeding on suspended particles like branchiopods (such as Daphnia hyalina, Simocephalus vetalus, and so on), ostracods (such as Cyprus), and copepods (for example Cyclops, Diaptomus castor).

Growth

The genetic make-up of a carp and its available resources determine how big a fish will grow. The current accepted world record for a rod-caught king carp (Cyprinus carpio) is a reported 37kg (two fish of this weight), but it is very likely that the species will grow to above this size. There is a traditional saying amongst fish breeders that a 'quality food source results in a quality fish'. Fed the correct diet in a relaxed environment, three-year-old carp can reach a weight of well over 5lb. The carp's optimum growth rate is reached at approximately 25C, with potential size decreasing progressively from 20C, virtually ceasing at 5C. Female carp usually show the greater sudden increases in weight, but these fish are often in a stressed state due to ovulation. It is the males that have the solid but steady growth potential, and it is these fish that often live the longest.

Habitat

Carp can adapt to both relaxed and stressed river and lake environments. They are widely regarded as a territorial species, but within river networks it is not unusual for them to travel long distances to feed or spawn. The type of habitat a fish is subjected to usually dictates its physical characteristics. Very often fish in rivers become long and lean to accommodate the water currents, whereas in the lakes and stillwaters they are often fatter and deeper in body section. Habitat also has a huge influence on the growth potential of a carp, as its availability is very much associated with water quality and stocking densities, which in turn, are connected to available food.