1984 Vol. 8 No. 4
Open Access
1984, 8(4): 371-388.
Abstract：
Coreius heterodon and C. guichenoti, the two of the total three species belonging to the genus Corcius, are most famous fishes of the upper and middle reaches of the Changjiang Valley. The most conspicuous external features comparing with those of other cyprinids of the Changjiang River are smaller eyes and rather longer maxillary barbels.The successive developmental stages of the early development of these two fishes were examined under natural water tempertures, ranging from 18.2 to 32.8℃. The newly cast eggs were collected during the summer seasons of the years 1961—1966, 1973, 1976—1978 and 1981 in the very spawning area of the main streams of the Changjiang River and one of its main tributaries, the Hanjiang. Although the rivers were obstructed at Danjiangkou and Gezhouba by the construction of dams, yet most of the spawning grounds are still functional and even extended both to the main reaches below the dams and to the upper part of the Danjiangkou reservoir.The morphological features of 49 stages of the embryonic and postembryonic development of these fishes are rather similar with each other. However, there are also some obvious differences in a few stages. The formation of proembryo of C. guichenoti during embryonic development occurs in middle gastrula, while it arises in late gastrula for C. heterodon. The first appearance of the muscle segments is prior to the formation of eye vesicle in C. guichenoti, but they come out in reverse order in the other species. Furthermore, the emergence of the barbel bud is earlier, the pectoral fin is shorter and the eye is a little larger in C. heterodon than that of C. guichenoti throughout the period of post-embryonic development.
Coreius heterodon and C. guichenoti, the two of the total three species belonging to the genus Corcius, are most famous fishes of the upper and middle reaches of the Changjiang Valley. The most conspicuous external features comparing with those of other cyprinids of the Changjiang River are smaller eyes and rather longer maxillary barbels.The successive developmental stages of the early development of these two fishes were examined under natural water tempertures, ranging from 18.2 to 32.8℃. The newly cast eggs were collected during the summer seasons of the years 1961—1966, 1973, 1976—1978 and 1981 in the very spawning area of the main streams of the Changjiang River and one of its main tributaries, the Hanjiang. Although the rivers were obstructed at Danjiangkou and Gezhouba by the construction of dams, yet most of the spawning grounds are still functional and even extended both to the main reaches below the dams and to the upper part of the Danjiangkou reservoir.The morphological features of 49 stages of the embryonic and postembryonic development of these fishes are rather similar with each other. However, there are also some obvious differences in a few stages. The formation of proembryo of C. guichenoti during embryonic development occurs in middle gastrula, while it arises in late gastrula for C. heterodon. The first appearance of the muscle segments is prior to the formation of eye vesicle in C. guichenoti, but they come out in reverse order in the other species. Furthermore, the emergence of the barbel bud is earlier, the pectoral fin is shorter and the eye is a little larger in C. heterodon than that of C. guichenoti throughout the period of post-embryonic development.
Open Access
Abstract：
The reproductive habit of Elopichthys bambusa is rather similar to the famous Chinese "domestio fishes"——grass carp, black carp, silver carp and big-head. Its spawning sites are widely distributed in the mainstream of the Changjiang River and one of its large tributaries——Hanjiang River. Those sections with mingled whirlpool current and turbulent flow are characteristic regions fit for spawning. In the breeding season, the rise of the water level of 0.12—5.5m., accompanying with the increase of the current velocity of 0.01—0.29m./sec., is the main factor that stimulates the ripe fishes of both sexes to discharge their eggs and sperm simultaneously. As a rule, spawning takes place at the time following the increase of the water level at any magnitude within 1—3 days and it was occasionally observed that the spawning activity was either exactly corresponding to the beginning of the increase of water level or prolonged, though intermittently and in a less extent, during the fall of the water level.The water temperatures in the spawning time were in the range of 16.9—30.2℃, whereas 20.0—27.0℃ were the most favorable. The turbidity of the water showed no connection with spawning behaviour.The embryonic development is subdivided into 46 stages, where the pre-embryonic period covers 30 stages and the post-embryonic 16 respectively. Comparing with those of the "domestic fishes", which are also charactericed by laying drifting eggs, this fish is distinguished from them in the course of early development as follows:1. In the stages before the 16-celled, the contour of the dividing germinal cells of Elopichthys bambusa is more or less squarish instead of arched.2. The bulk of the cell mass from morula to early gastrulation stages is almost identical to that of the yolk.3. The differentiation of the eye is delayed to such extent that the optic bulge begins to come out when 13 body segments have already been formed.4. The embryo appears to be particularly slender after the otolith-formation stage.5. The body segments, counted 52 constantly for the fry, are obviously more numerous than those of others species.
The reproductive habit of Elopichthys bambusa is rather similar to the famous Chinese "domestio fishes"——grass carp, black carp, silver carp and big-head. Its spawning sites are widely distributed in the mainstream of the Changjiang River and one of its large tributaries——Hanjiang River. Those sections with mingled whirlpool current and turbulent flow are characteristic regions fit for spawning. In the breeding season, the rise of the water level of 0.12—5.5m., accompanying with the increase of the current velocity of 0.01—0.29m./sec., is the main factor that stimulates the ripe fishes of both sexes to discharge their eggs and sperm simultaneously. As a rule, spawning takes place at the time following the increase of the water level at any magnitude within 1—3 days and it was occasionally observed that the spawning activity was either exactly corresponding to the beginning of the increase of water level or prolonged, though intermittently and in a less extent, during the fall of the water level.The water temperatures in the spawning time were in the range of 16.9—30.2℃, whereas 20.0—27.0℃ were the most favorable. The turbidity of the water showed no connection with spawning behaviour.The embryonic development is subdivided into 46 stages, where the pre-embryonic period covers 30 stages and the post-embryonic 16 respectively. Comparing with those of the "domestic fishes", which are also charactericed by laying drifting eggs, this fish is distinguished from them in the course of early development as follows:1. In the stages before the 16-celled, the contour of the dividing germinal cells of Elopichthys bambusa is more or less squarish instead of arched.2. The bulk of the cell mass from morula to early gastrulation stages is almost identical to that of the yolk.3. The differentiation of the eye is delayed to such extent that the optic bulge begins to come out when 13 body segments have already been formed.4. The embryo appears to be particularly slender after the otolith-formation stage.5. The body segments, counted 52 constantly for the fry, are obviously more numerous than those of others species.
Open Access
Abstract：
This paper reports the results of estimations of population dynamics and production of Daphnia hyalina and D. carinata ssp. in lake Donghu in Wuhan carried out during 1980—1982. The ecological factors affecting the population dynamics and production of these two species are analyzed. Daphnia hyalina and D. carinata ssp. are considered to be the most dominant Cladoeerans in the lake. The two species prevailed alternately. In general, the population density of Daphnia hyalina expressed as number of individuals/1 shows a maximum in spring or winter, But, the occurrence of summer or autumn maximum was recorded for D. carinatta ssp. On the basis of data in 1980—1982 at station Ⅱ, the average annual abundance was 28.43(17.59—38.50) ind./1 for D. hyalina and 4.64(3.79—5.31) ind./l for D. carinata ssp.The instantaneous birth rate (b) was nearly always in greater than the instantaneous growth rate (r); the instantaneous death rate (d) in general paralleled changes in birth (b).Similarily, the mean annual biomass of Daphnia hyalina was 0.218 (0.175—0.315)mg dry weight/1; 0.046(0.039—0.060)mg dry weight/1 for D. carinata ssp.The average annual production of Daphnia hyalina was 9.181(4.877—13.428)mg dry weight/1./year, 3.417(2.752—3.829)mg dry weight/1./year for D. carinata ssp. The average annual P/B ratio was 42.38 (27.76—56.7) for D. hyalina and 77.04(61.24—99.74) for D. carinata ssp..
This paper reports the results of estimations of population dynamics and production of Daphnia hyalina and D. carinata ssp. in lake Donghu in Wuhan carried out during 1980—1982. The ecological factors affecting the population dynamics and production of these two species are analyzed. Daphnia hyalina and D. carinata ssp. are considered to be the most dominant Cladoeerans in the lake. The two species prevailed alternately. In general, the population density of Daphnia hyalina expressed as number of individuals/1 shows a maximum in spring or winter, But, the occurrence of summer or autumn maximum was recorded for D. carinatta ssp. On the basis of data in 1980—1982 at station Ⅱ, the average annual abundance was 28.43(17.59—38.50) ind./1 for D. hyalina and 4.64(3.79—5.31) ind./l for D. carinata ssp.The instantaneous birth rate (b) was nearly always in greater than the instantaneous growth rate (r); the instantaneous death rate (d) in general paralleled changes in birth (b).Similarily, the mean annual biomass of Daphnia hyalina was 0.218 (0.175—0.315)mg dry weight/1; 0.046(0.039—0.060)mg dry weight/1 for D. carinata ssp.The average annual production of Daphnia hyalina was 9.181(4.877—13.428)mg dry weight/1./year, 3.417(2.752—3.829)mg dry weight/1./year for D. carinata ssp. The average annual P/B ratio was 42.38 (27.76—56.7) for D. hyalina and 77.04(61.24—99.74) for D. carinata ssp..
Open Access
Abstract：
Cyclops vicinus vicinus Uljanin is the dominant copepoda in the Lake Donghu, Wuban. The development times of the eggs, nauplii and copepodites of C. vicinus vicinus were obtained by experiments at constant temperatures ranging from 6.5 to 25℃.The duration of egg development was obviously inversely related to temperature through the whole range of experimental temperatures. Development times of nauplii and copepodites were decreased with increasing temperatures and retarded at temperature above 20℃. The relationships were expressed by various regression equations.The female body was generally longer than that of the male, and smaller adults were generally produced at higher temperatures. The longevity of the adult stage was inversely related to temperatures.The duration from the hatching of one brood to the extrusion into eggsacs of the next brood and the average time from the adult to the production ot the first eggsacs were also decreased as temperature increased. The present results also showed the inverse relationships between clutch size, clutches per female and temperatures. The effect of diet on development of C. vicinus vicinus was also discussed in this paper.
Cyclops vicinus vicinus Uljanin is the dominant copepoda in the Lake Donghu, Wuban. The development times of the eggs, nauplii and copepodites of C. vicinus vicinus were obtained by experiments at constant temperatures ranging from 6.5 to 25℃.The duration of egg development was obviously inversely related to temperature through the whole range of experimental temperatures. Development times of nauplii and copepodites were decreased with increasing temperatures and retarded at temperature above 20℃. The relationships were expressed by various regression equations.The female body was generally longer than that of the male, and smaller adults were generally produced at higher temperatures. The longevity of the adult stage was inversely related to temperatures.The duration from the hatching of one brood to the extrusion into eggsacs of the next brood and the average time from the adult to the production ot the first eggsacs were also decreased as temperature increased. The present results also showed the inverse relationships between clutch size, clutches per female and temperatures. The effect of diet on development of C. vicinus vicinus was also discussed in this paper.
Open Access
Abstract：
Phycobilisomes were isolated from Anabacna variabilis. The cells were disrupted by sonication, treated with 2% Triton X-100 and ultracentrifuged on a sucrose step gradients. Isolation was carried out in 0.9 M Na-K-Phosphate buffer(pH 7.0) at 20℃. Phycobilisomes were recovered in the dark blue band.There are three liquid nitrogen temperature fluorescence emission bands in phyco bilisomes of A. variabilis. In intact phycobilisomes, the relative fluorescence of 686nm was very high, those of 655nm and 666nm were low, the ratios of relative fluorescence of 686nm to 655nm was more than 20, and that of 686nm to 666nm was more than 10. In non-intact phyeobilisomes, the relative fluorescence of 686 nm deereased, those of 655nm and 666mn increased. The room temperature fluorescence emission maximum of intact phycobilisomes was Iocated around 678nm, that of non-intact phycobilisomes was less than 673nm.We suggest that the main criteria to be used in assessing intact phycobilisomes of A. variabilis should be the fluorescence emission around 678nm at room temperature and the ratios of relative fluorescence of 686nm to 655nm and 666nm at liquid nitrogen temperature.Liquid nitrogen temperature fluorescence excitation spectra of F655, F666 and F68 were studied.
Phycobilisomes were isolated from Anabacna variabilis. The cells were disrupted by sonication, treated with 2% Triton X-100 and ultracentrifuged on a sucrose step gradients. Isolation was carried out in 0.9 M Na-K-Phosphate buffer(pH 7.0) at 20℃. Phycobilisomes were recovered in the dark blue band.There are three liquid nitrogen temperature fluorescence emission bands in phyco bilisomes of A. variabilis. In intact phycobilisomes, the relative fluorescence of 686nm was very high, those of 655nm and 666nm were low, the ratios of relative fluorescence of 686nm to 655nm was more than 20, and that of 686nm to 666nm was more than 10. In non-intact phyeobilisomes, the relative fluorescence of 686 nm deereased, those of 655nm and 666mn increased. The room temperature fluorescence emission maximum of intact phycobilisomes was Iocated around 678nm, that of non-intact phycobilisomes was less than 673nm.We suggest that the main criteria to be used in assessing intact phycobilisomes of A. variabilis should be the fluorescence emission around 678nm at room temperature and the ratios of relative fluorescence of 686nm to 655nm and 666nm at liquid nitrogen temperature.Liquid nitrogen temperature fluorescence excitation spectra of F655, F666 and F68 were studied.
Open Access
Abstract：
The fry of mosquitofish (Gambusia affinis) were exposed to low concentrations of copper, mercury, cadmium, BHC and parathion in soft water. Tests were started with 2-day-old fry and lasted for 40 days. Total length and weight of mosquitofish were determined after 20 days and at the end of the tests. Under the test conditions described, the maximum allowable toxicant concentrations (MATC's) bare been obtained according to the effect on the growth of mosquitofish. MATC's estimated for copper, cadmium, and parathion were: 0.015—0.030, 0.005—0.010 and 0.0015—0.0030 mg/1 respectively. Their application factors were: 0.05—0.1, 0.0005—0.0009, and 0.01—0.05 respectively.
The fry of mosquitofish (Gambusia affinis) were exposed to low concentrations of copper, mercury, cadmium, BHC and parathion in soft water. Tests were started with 2-day-old fry and lasted for 40 days. Total length and weight of mosquitofish were determined after 20 days and at the end of the tests. Under the test conditions described, the maximum allowable toxicant concentrations (MATC's) bare been obtained according to the effect on the growth of mosquitofish. MATC's estimated for copper, cadmium, and parathion were: 0.015—0.030, 0.005—0.010 and 0.0015—0.0030 mg/1 respectively. Their application factors were: 0.05—0.1, 0.0005—0.0009, and 0.01—0.05 respectively.
Open Access
1984, 8(4): 443-448.
Abstract：
A method for obtaining axenic culture of blue-green algae was developed. A pure culture of Anabaena azollae was obtained with this method. A. azollae could grow heterotrophically in the dark. Fructose, glucose and sucrose supported the hcterotrophic growth of A. azollae. The culture adapted to photoautotrophic growth grew better in the dark when NaNO3 was used as nitrogen source, but the culture adapted to heterotrophic growth grew better when N2 in air was used as nitrogen source. Stirring stimulated heterotrophic growth of A. azollae. The concentration of chlorophyll a of the culture grown in the dark for half year decreased to 1/3—1/4 of that in the light. When A. azollae grew at 5500 lux, exogenous fructose and glucose still stimulated growth and increased nitrogen fixation.
A method for obtaining axenic culture of blue-green algae was developed. A pure culture of Anabaena azollae was obtained with this method. A. azollae could grow heterotrophically in the dark. Fructose, glucose and sucrose supported the hcterotrophic growth of A. azollae. The culture adapted to photoautotrophic growth grew better in the dark when NaNO3 was used as nitrogen source, but the culture adapted to heterotrophic growth grew better when N2 in air was used as nitrogen source. Stirring stimulated heterotrophic growth of A. azollae. The concentration of chlorophyll a of the culture grown in the dark for half year decreased to 1/3—1/4 of that in the light. When A. azollae grew at 5500 lux, exogenous fructose and glucose still stimulated growth and increased nitrogen fixation.
Open Access
Abstract：
The toxicity of mercuric chloride (as Hg++) to Daphnia magna was studied under renewed static conditions. Under 25±℃ and 9—10 hour dialy lighting (3,000—3,300 lux), Daphnia magna, derived from a pure strain and aged 6±6 hours, were exposed to 1—28μg Hg/L. Experiment of each concentration was carried out by means of ten beakers, each containing 50ml of filtered water and a single Daphnia. Scenedesmus obliquus was provided for the animals throughout the experiments.The LC50 of mercuric chloride to D. magna was estimated to be 13.5±2.1μg/L for 48 hours. The chronic test showed that Daphnia died totally in 3.40±0.84 days when the mercuric concentration increased μp to 28μg/L, but there were no significant differences in the survival rates and growth rates in the media with concentrations ranging from 1 to 21μg Hg/L except for the totalnumber of offspring. In addition, the net reproductive rate (R0) of the animals was found to decline gradually with increasing mercuric concentration.
The toxicity of mercuric chloride (as Hg++) to Daphnia magna was studied under renewed static conditions. Under 25±℃ and 9—10 hour dialy lighting (3,000—3,300 lux), Daphnia magna, derived from a pure strain and aged 6±6 hours, were exposed to 1—28μg Hg/L. Experiment of each concentration was carried out by means of ten beakers, each containing 50ml of filtered water and a single Daphnia. Scenedesmus obliquus was provided for the animals throughout the experiments.The LC50 of mercuric chloride to D. magna was estimated to be 13.5±2.1μg/L for 48 hours. The chronic test showed that Daphnia died totally in 3.40±0.84 days when the mercuric concentration increased μp to 28μg/L, but there were no significant differences in the survival rates and growth rates in the media with concentrations ranging from 1 to 21μg Hg/L except for the totalnumber of offspring. In addition, the net reproductive rate (R0) of the animals was found to decline gradually with increasing mercuric concentration.
Open Access
Abstract：
1. The pond smelt in the Shui Feng Reservoir has more scales along the lateral line, more gill rakers and more vertebrae than those in other parts of the world (North America, Soviet Russia, Japan, and Korea), but less branched rays in the dorsal, anal and pectoral fins than those in Korea.2. The scale has been used for age-determination; annulus on the scale is characterized by a "check". The fish is about 74 mm in fork length (body length measured from tip of snout to the fork of caudal) and 3g in body weight when one year old; 99 mm and 6.5 g at 2 years of age. The regression equation of body weight (W) and fork length (L) may be expressed as log W=2.5306 log L—1.7590.3. The pond smelt is an omnivorous fish which feeds mainly on zooplanktion (Cladocerans and Copepods, etc.); the components of its food vary with habitats.4. First maturity of this fish is reached at 1 year old. The overall sex ratio in 1000 specimens examined was 446 females to 554 males, or 1♀: 1.2♂, but specific ration varied markedly with habitats. The individual absolute fecundity varied from 905 to 19051, with 4330 eggs on average. Its relation to the fork length may be expressed as Y=58.4860 L—402.7606 (Y—absolute fecundity in unit of 100 eggs, L—fork length in cm). The population fecundity index is 1871; the generative rate of population is 1494 females per "primary female". Spawning takes place in littoral areas of the reservoir in April or May. The eggs are adhesive, and hatch in about 12 days when water temperature ranges from 10° to 15℃.5. The structure of population of pond smelt is simple: there are three year classes in all population, the average age of 1321 specimens being 1.15 years. Body-length (fork length) groups ranging from 65.1 to 80 mm were dominant in that batch of sample (65.6%).
1. The pond smelt in the Shui Feng Reservoir has more scales along the lateral line, more gill rakers and more vertebrae than those in other parts of the world (North America, Soviet Russia, Japan, and Korea), but less branched rays in the dorsal, anal and pectoral fins than those in Korea.2. The scale has been used for age-determination; annulus on the scale is characterized by a "check". The fish is about 74 mm in fork length (body length measured from tip of snout to the fork of caudal) and 3g in body weight when one year old; 99 mm and 6.5 g at 2 years of age. The regression equation of body weight (W) and fork length (L) may be expressed as log W=2.5306 log L—1.7590.3. The pond smelt is an omnivorous fish which feeds mainly on zooplanktion (Cladocerans and Copepods, etc.); the components of its food vary with habitats.4. First maturity of this fish is reached at 1 year old. The overall sex ratio in 1000 specimens examined was 446 females to 554 males, or 1♀: 1.2♂, but specific ration varied markedly with habitats. The individual absolute fecundity varied from 905 to 19051, with 4330 eggs on average. Its relation to the fork length may be expressed as Y=58.4860 L—402.7606 (Y—absolute fecundity in unit of 100 eggs, L—fork length in cm). The population fecundity index is 1871; the generative rate of population is 1494 females per "primary female". Spawning takes place in littoral areas of the reservoir in April or May. The eggs are adhesive, and hatch in about 12 days when water temperature ranges from 10° to 15℃.5. The structure of population of pond smelt is simple: there are three year classes in all population, the average age of 1321 specimens being 1.15 years. Body-length (fork length) groups ranging from 65.1 to 80 mm were dominant in that batch of sample (65.6%).
