The family of “Carps” is the one most numerously represented in the fresh waters of the Old World and of North America. Also numerous fossil remains are found in tertiary freshwater-formations, as in the limestones of Oeningen and Steinheim, in the lignites of Bonn, Stöchen, Bilin, and Ménat, in the marl slates and carbonaceous shales of Licata in Sicily, and of Padang in Sumatra, in corresponding deposits of Idaho in North America. The majority can be referred to existing genera: Barbus, Thynnichthys, Gobio, Leuciscus, Tinca, Amblypharyngodon, Rhodeus, Cobitis, Acanthopsis, only a few showing characters different from those of living genera: Cyclurus, Hexapsephus, Mylocyprinus (tertiary of North America).
Most Carps feed on vegetable and animal substances; a few only are exclusive vegetable feeders. There is much less diversity of form and habits in this family than in the Siluroids; however, the genera are sufficiently numerous to demand a further subdivision of the family into groups.
I. Catostomina.—Pharyngeal teeth in a single series, exceedingly numerous and closely set. Dorsal fin elongate, opposite to the ventrals; anal short, or of moderate length. Barbels none.
These fishes are abundant in the lakes and rivers of North America, more than thirty species having been described, and many more named, by American ichthyologists. Two species are known from North-Eastern Asia. They are generally called “Suckers,” but their vernacular nomenclature is very arbitrary and confused. Some of the species which inhabit the large rivers and lakes grow to a length of three feet and a weight of fifteen pounds. The following genera may be distinguished:—Catostomus, “Suckers,” “Red-horses,” “Stone-rollers,” “White Mullets;” Moxostoma; Sclerognathus, “Buffaloes,” “Black Horses;” and Carpiodes, “Spear-fish,” “Sail-fish.”
II. Cyprinina.—Anal fin very short, with not more than five or six, exceptionally seven, branched rays. Dorsal fin opposite ventrals. Abdomen not compressed. Lateral line running along the median line of the tail. Mouth frequently with barbels, never more than four in number. Pharyngeal teeth generally in a triple series in the Old World genera; in a double or single series in the North American forms, which are small and feebly developed. Air-bladder present, without osseous covering.
Cyprinus.—Scales large. Dorsal fin long, with a more or less strong serrated osseous ray; anal short. Snout rounded, obtuse, mouth anterior, rather narrow. Pharyngeal teeth, 3. 1. 1.-1. 1. 3, molar-like. Barbels four.
Fig. 272.—The Carp, Cyprinus carpio.
The “Carp” (C. carpio, “Karpfen,” “La carpe,”) is originally a native of the East, and abounds in a wild state in China, where it has been domesticated for many centuries; thence it was transported to Germany and Sweden, and the year 1614 is assigned as the date of its first introduction into England. It delights in tranquil waters, preferring such as have a muddy bottom, and the surface partially shaded with plants. Its food consists of the larvæ of aquatic insects, minute testacea, worms, and the tender blades and shoots of plants. The leaves of lettuce, and other succulent plants of a similar kind, are said to be particularly agreeable to them, and to fatten them sooner than any other food. Although the Carp eats with great voracity when its supply of aliment is abundant, it can subsist for an astonishing length of time without nourishment. In the winter, when the Carps assemble in great numbers, and bury themselves among the mud and the roots of plants, they often remain for many months without eating. They can also be preserved alive for a considerable length of time out of the water, especially if care be taken to moisten them occasionally as they become dry. Advantage is often taken of this circumstance to transport them alive, by packing them among damp herbage or damp linen; and the operation is said to be unattended with any risk to the animal, especially if the precaution be taken to put a piece of bread in its mouth steeped in brandy!
The fecundity of these fishes is very great, and their numbers consequently would soon become excessive but for the many enemies by which their spawn is destroyed. No fewer than 700,000 eggs have been found in the ovaries of a single Carp, and that, too, by no means an individual of the largest size. Their growth is very rapid, more so perhaps than that of any other Freshwater fish, and the size which they sometimes attain is very considerable. In certain lakes in Germany individuals are occasionally taken weighing thirty or forty pounds; and Pallas relates that they occur in the Volga five feet in length, and even of greater weight than the examples just alluded to. The largest of which we have any account is that mentioned by Bloch, taken near Frankfort-on-the-Oder, which weighed seventy pounds, and measured nearly nine feet in length,—a statement the accuracy of which is very much open to doubt.