A preliminary study on the age and growth of some commercial fishes was done by the junior author while he was a fourth year student in the Department of Biology at Tsing Hua University. The data on body weight and body length thus gathered, with some scales of these fishes, were placed at the bands of the senior author for reexamination, generalization, and report. It was a pity that the materials originally used for this study were lost shortly after the 1937 accident.
The object of the present work was to secure certain information on the growth rate and longevity of some common fishes which inhabit in the fresh waters of this region. All of them are valued by the local populace as in important source of food. 0
During the past decade, a considerable amount of work -,ims done on the systematic study of Chinese fishes by native Ichthyologists. However, very little has been undertaken concerning the life history, ago, and rate of growth of local species, except a short article by the senior author (SHAW, 1930). Therefore, the present paper, incomplete as it is, supplies certain information for fishery work, and forms a basis of subsequent biological investigation.
The materials used for this study were collected from different sources, More than one half of the specimens were obtained from Sin-an or the so-called Paoting lake region in the central part of Hopei province, few specimens of Cyprinus carpio (LINN.) were secured from the Yellow River, and the rest of them were either collected from the ponds or streams in the vicinity of Tsing Hua University or purchased from the fish market within the walled city of Peking. A total of some 180 specimens, belonging to six species, had been examined by the junior author from 1935 to 1936. In order to confirm these data previously secured, additional materials have also been examined by the senior, author in the zoological collection of the Fan Memorial Institute of Biology.
So far as known, there are five different methods used for the calculation or determination of the age of individual fish. Only the scale reading method has been employed by the authors; the size, otoliths, marking, and direct observation methods being not used.
Scales taken from several. parts of the body were stored in scale envelopes. Data recorded on each envelope included date, locality, body length (in mm.), body weight (in grams), and sex. In general, four scales were separately picked with forceps from individual fish. The skin covering at the posterior end of the scale was removed by hot wa ter with the help of the thumb and index figure. It was washed in water, dehydrated and mounted in balsam. These dry slides were examined under a low power microscope. Some of the scales were stained, serving better for the study of winter ring.
The growth of an individual fish is largely influenced by the environmental conditions. Fish with abundant food grows faster than those with scarce food. So the growth rate in various individual is more or less different, while the width of the rings or annuli of scales is not similar.
A total of six species of fresh-water fishes are reported under the following pages. The first five species belong to the Carp Family or Cyprinidae, -and the last one belongs to the Snake-head Fish Family or Ophicephalidae.
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The Snake-head fish or Hei-yü occurs in great numbers in the ponds or streams in this area. It is carnivorous in its food habits.
|C. argus. Schematic drawing|
The average length of 23 specimens collected at different localities of Hopei province is 197 mm. Largest specimen examined has a length of 480 mm. and a weight of 1,430 grams. According to the natives of Sin-an, giant specimen may reaches a weight of some 3 or 4 kilograms, but those commonly met with in the market rarely weighed more than 1,500 grams.
The body of this fish is somewhat elliptical or fusiform in outline (Fig. 6). The depth of its body is about 5.6 in total length, and its width nearly 7.1 in the same The gasterion is placed in front of the apex.
Most specimens secured were on their first three year groups. Second year fish is well mature. It can be mated and produce eggs. Seventh year group seems to be the oldest fish usually met with in the field. The growth rate of this species is not very rapid. Its growth coefficient (k - 3.09) does not differ very much from Squaliobarbus curriculus Richardson.
Uchida and Fujimoto (1933) recorded a 850 mm. specimen from Korea. The age of that fish was supposed to be over 20 years old.
The age and growth of six fresh-water fishes have been studied by the scale reading method.
There is a definit relationship between the body weight (y) and body length (x) of a given species (Fig. 7). The relative growth of those fishes seem to be rather uniform.
The correlation between body weight and body length can be best expressed by Huxley's (1932) equation:
y = bx k
Where the value of k is not exactly 5, for the growth coefficient may be somewhat less or slightly greater than that sum, The following table gives the value of k used in the six species of fishes.
|Name of species||No. of specimens||Values of k|
The specific gravity of fresh-water fishes seems to be rather constant in various species, as well as in different -age groups of the same fish. The form of a given species is correlated with the growth coefficient or the value of k. The depth or the vertical diameter of the fish (Gregory, 1928) is in important factor. The width of the body, on the other hand, is of equal importance.
There is in indication of heterogenic growth (Needham, 1935). The growth coefficient in the fish (first period) is relatively greater than in the larger specimens (second period or later years). However, this character is not graphically shown in Fig. 7.
The age, of these fishes, as observed from the specimens onhand, varies from five to eight years.
The weight and length of a given year group in the same species differs in various individuals according to the nature of food or other environmental conditions.
The growth rate in the body weight of the female, except its breeding season, does dot differ very much from that of the male.
Gregory, W. K. 1928 Studies on the Body Formes of Fishes. Zoologica (N. Y.), vol. VIII. pp. 325-421.
Hecht, S. 1916 Form and Growth in Fishes. Jour. Morph., vol. 27, pp. 379-400.
Huxley J. S. 1931 Notes on Differential Growth. Amer. Nat., vol. 65, pp. 289-315 (Metamorphosing Herring, pp. 305-310).
Huxley J. S.1932 Problems of Relative Growth. London: Methuen & Co. Ltd.
Jobes F. W. 1932 Preliminary Report on the Age and Growth of the Yellow Perch (Perca flavascens Mitchal) from Lake Erie, as Determined from a Study of its Scales. Pap. Mich. Acad. Sci. & Latteres, vol. 17. pp. 643-652,
Flower, M. S. S. 1935 Further Notes on the Duration of Life in Animals.- I. Fishes: as Determined by Otolith and Scale-readings and Direct Observations on Living Individuals. Proc. Zool. Soc., London, 1938. pp. 265,304.
Marchall, S. M., Nichols A. G., & Orr. A. P. 1939 On the Growth and Feeding, of the Young Herring in the Clyde. jour. Mar. Biol. Assoc. U. K., vol. 23, pp. 427-455.
Needham, A. E. 1935 On Relative Growth in the jaws of Certain Fishes. Proc. Zool. Soc., London, pp. 773-784.
Shaw, T. H. 1930 Observations on the Life History of the Chinese Bitering, Paracheilognathus imberbis Günther. Bull. Fan Mem. Inst. Biol., vol. 2, pp.245-256.
Uchida, K. & Fujimoto, M. 1933 Life History and Method of Culture of the Corean Snake-head Fish, Ophicephalus argus. Bull. Fish. Exper. Sta. Chosen, no. 3 (Chapter 3. Growth Rate, Age, and Longevity, pp. 33-34).
This text was originally published in: Bulletin of the Fan Memorial Institute of Biology, (Zoological Series), vol. 9, no.3; pp. 251-261; 1939.
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