Common Carp Fry Research Articles

Effect of decreased water oxygen content on common carp fry with Dactylogyrus vastator (Monogenea) infection of varying severity

Effect of decreased water oxygen content on common carp fry with Dactylogyrus vastator (Monogenea) infection of varying severity

Effects of different levels of exogenously introduced plankton on growth of common carp reared under favourable water quality

One-hundred-ninety-eight fry of common carp were placed into each of nine outdoor tanks (9580 1) and subjected to three different levels (dry weight) of exogenously introduced plankton, viz. 134 mg l −1 (normal), 264 mg l −1 (two-fold) and 412 mg 1 −1 (four-fold) every other day. Frequency distribution of different weight groups of fishes at the time of harvest after a 90-day growing period revealed significant differences between the normal live food system and the two-fold or four-fold treatments, but no marked differences between the latter two treatments. Mean weight of common carp was 20.76, 23.82 and 24.04 g in the normal, two-fold and four-fold treatments, respectively, whereas yield per tank ranged from 3.69 to 4.37 kg. Carp growth in these three systems was found to be strongly dependent on plankton density. The mortality of common carp did not differ from one system to another, with values ranging from 8 to 10% in the three treatments. Fish production in the four-fold treatment was not proportionate to the rise in Zooplankton density and, hence, the two-fold treatment was the most appropriate for carp growth.

Bioturbation induced changes of fertilizer value of phosphate rock in relation to alkaline phosphatase activity

The effect of bioturbation by common carp fry in increasing the fertilizer value of phosphate rock in relation to microbial phosphatase activity was investigated in a series of experiments using glass jars (31) containing a 3-cm layer of dry soil, phosphate rock at the rate of 3.33 g l −1 and common carp fry introduced per jar in the range of 1 to 12. The level of phosphate coupled with alkaline phosphatase activity tended to rise in a logistic manner with an increase in the number of common carp fry introduced into the system. In any given treatment, alkaline phosphatase activity of the water was directly correlated with phosphate level to a certain extent, beyond which an inverse relationship between them was indicated.

Optimum food particle size in relation to body size of common carp, Cyprinus carpio L., fry

. An investigation was conducted under laboratory conditions to determine the optimum food particle size of an inert diet for common carp fry ranging in size from 15 to 466mg body weight and 13 to 31 mm total length (TL). Speed of consumption of a standard quantity of food was used as a measurement of feeding preference/efficiency for different particle size ranges. It was observed that for carp of this size range preferred food particle size increases with fish size. On the basis of ingestion time and feeding behaviour, food particle sizes in the ranges 125-300μm. 300-500μm, 300-790μm and 500-1000μm diameter were found to be most appropriate for carp fry weighing 15-23mg(TL 13-18), 46-97 mg(TL 17-22), 105-209 mg (TL 20-25) and 210-466mg (TL 24-31) respectively. This study also demonstrated that for carp fry of these size ranges the mean preferred food particle sizes are about 02-04 that of mouth size. Based on this relationship, general recommendations are made on the optimum food particle sizes for different size classes of carp fry reared under hatchery and nursery conditions.

Herpesvirus cyprini: lethality and oncogenicity

Abstract. Cyprinid herpesvirus 1 (CHV) or Herpesvirus cyprini was virulent for carp, Cyprinus carpio L., fry following 1 h immersion in water at 20 °C. Cumulative mortality for carp fry was 86–97% in 2‐week‐old common carp, 20% in 4‐week‐old fancy carp, and 0% in both 8‐week‐old common and fancy carp. The virus did not produce mortality in fry of crucian carp, grass carp or other cyprinids. It was also oncogenic in carp, inducing papillomas to the extent of 55% among both common and fancy carp fry. The neoplasms appeared 5–6 months after carp had been exposed to the virus by immersion and recurred at an incidence of 83% in carp 7·5 months post‐desquamation of the tumour. The CHV was reisolated from all moribund fish and from all survivors. It also induced papillomas at an incidence of 13% in adult mirror carp and at 10% in adult fancy carp 5 months after intraperitoneal inoculation of 105 TCID50 ml‐1 fish. The virus was rcisolated only from the ncoplastic tissue and not from internal organs. The neoplasms were normally located on fin, skin or mandible, at the intraperitoneal inoculation site. Specific fluorescence for CHV antigen was frequently detected in the gills, liver, kidneys and intestine of 2‐week‐old fry from 3 to 21 days following challenge with CHV. It was found in greater concentrations in experimentally induced papillomata on 2‐week‐old carp fry survivors examined 24 weeks after challenge than in naturally occurring neoplasms.

Growth induction of common carp, Cyprinus carpio L., fry as a function of plankton density and improved water quality

. One hundred and ninety-eight fry of common carp, Cyprinus carpio L., were reared in outdoor tanks containing 9580 1 of water under five management schemes — separate live-food system (LF), intermediate system (I), static manured system (M), manured system with water exchange (EM) and supplementary food system (SF) — in triplicate for a growing period of 90 days. Examination of frequency distribution of different weight groups of fishes at the time of harvest showed a maximum proportion of larger and smaller fishes in the live-food and supplementary food system, respectively. Maximum growth and production of common carp in the LF treatment was the consequence of greater abundance of plankton food and improvement of water quality expressed in terms of higher values of pH and DO and lower values of COD and BOD.

Plankton intake as a function of body weight by common carp fry in different feeding conditions

Plankton intake by common carp fry was investigated in relation to composition and abundance of plankton as well as water quality in five culture systems: live-food system (LFS), manured system (MS), exchanged manured system (EMS), intermediate system ((IS), and reference control system (CS). The amount of plankton consumed by the common carp fry tended to rise gradually with increase in average body weight of carp held in all five culture systems. At a given time, the plankton intake for LFS was significantly higher than for the remaining four systems. Related to maximum intake, the maximum concentration of plankton in the live-food system was a consequence of improved water quality. Food consumption varied as a function of W b , and estimates of the power b ranged from 0.479 to 0.864 in relation to culture systems and from 0.033 to 0.908 among age groups.

Gynogenesis in common carp ( Cyprinus carpio L.) : II. The production of homozygous gynogenetic clones and F 1 hybrids

Homozygous gynogenetic fry of common carp ( Cyprinus carpio L.) were produced by heat-shocking eggs, activated with UV-irradiated sperm (1 : 3 diluted, 10 ml, at 2200 J m −2 min −1) during metaphase of the first mitosis. Consistent yields of 5–15% viable, gynogenetic fry were obtained when eggs were shocked at 40°C for 2 min, 28–30 min after fertilization. The homozygous nature of the gynogenetic fry was demonstrated by the mendelian segregation patterns of three recessive mutant pigment genes. Homozygous inbred strains were produced by heterozygous gynogenetic reproduction (second polar body retention) of homozygous gynogenetic females, while F 1 hybrids were produced by crossing these females with homozygous gynogenetic male siblings. The clonal nature of these strains was unequivocally demonstrated by the acceptance of reciprocally exchanged skin allografts.

Food preferences and selection by common carp (Cyprinus carpio) fry under different feeding regimes

Summary Food preferences of common carp fry were investigated in relation to qualitative and quantitative abundance of plankton in five culture systems (live food system, manured system, exchanged manured system, intermediate system and control system), which differ in management protocols. While phytoplankton was strongly avoided, as evident in the electivity index, cladocerans constituted an important source of natural food for common carp fry held in all five culture systems. There was a positive selection of cladocerans in the manured system as well as rotifers in the live food system, although the environment was dominated by copepods and cladocerans, respectively. While in all the culture systems there was a gradual rise in the relative abundance of copepods, cladocerans tended to decline in relative abundance in the diet of older common carp held in the manured system. Résumé Préferences et sélection de la nourriture par le frai de la carpe commune sous differents régimes alimentaires Les préferences alimentaires de la carpe commune ont été observées en rélation avec l'abondance qualitative et quantitative de plancton dans cinq systémes de culture qui differaient dans leur ménagement (systeme de nourriture vivante, application d'enrais, application d'engrais avec Cchange d'eau, systtme intermediaire et systkme contrôle). Alors que le phytoplancton était fortement rejeté, comme mis en evidence dans l'index de sélection, les cladocéres constituaient une source de nourriture naturelle importante pour le frai de la carpe commune dans les cinq systémes. Il y avait une sélection positive pour les cladocéres dans le systéme d'application d'engrais, ainsi que pour les rotiféres dans le systéme de nourriture vivante, bien que l'environnement était domine par des copépodes et des cladocéres respectivement. Dans tous les systémes de culture, il y avait une augmentation graduelle de l'abondance relative des copépodes, pendant que les cladocéres tendaient á décliner en abondance relative dans le régime des carpes plus âgées élevées dans le systéme d'application d'engrais. Zusammenfassung Nahrungspráferenzen und Selektrion bei Karpfen-(Cyprinus carpio) Jungfischen bei unterschiedlichen Fütterungsregimen Die Nahrungspräferenzen yon Karpfen-Jungfischen wurden im Verhätnis zur qualitativen und quantitativen Abundanz des Planktons in fünf Kultursystemen mit unterschiedlichen Managementprotokollen untersucht. (Lebendfutter, gedüngt, Wasseraustausch mit Düngung, kombiniertes System, Kontrollsystem). Wärend das Phytoplankton weitgehend vermieden wurde (wie aus dem Selektionsindex hervorgeht), stellten Cladoceren die wichtigste Nahrungsquelle für juvenile Karpfen in allen Kultursystemen dar. Positive Selektion konnte auch für die Cladoceren im gedüngten System und für Rotiferen im Lebendfuttersystem nachewiesen werden, obwohl im erstgenannten System Coepoden und im letztgenannten Cladoceren jominierten. Während in den Kultursystemen mit fer Zeit eine graduelle Zunahme in der relativen Abundanz der Copepoden in der Nabrung auftrat, nahmen die Cladoceren entsprechend mit zunehmendem Alter der jungen Karpfen im gedüngten System ab.

Acute toxicity of ammonia to common carp fry

Two recirculation bioassays were conducted for 168 h each to determine the median lethal concentration (LC50) of unionized ammonia (NH 3) to fry of common carp ( Cyprinus carpio L.) for different exposure times. In the first trial duplicate groups of carp fry (mean weight 299 mg, SE ± 14.2) were exposed to seven concentrations of ammonia. The 48-, 96- and 168-h LC50's for exposure to unionized ammonia were 1.76 (95% CL 1.67 – 1.85), 1.74 (95% CL 1.65 – 1.84) and 1.64 (95% CL 1.53 – 1.76) mg l −1 NH 3-N respectively. Similarly, in the second trial duplicate groups of fry (mean weight 206 mg, SE ± 8.4) were exposed to seven concentrations of ammonia. The 48-, 96- and 168-h LC50's of unionized ammonia were 1.87 (95% CL 1.82 – 1.93), 1.84 (95% CL 1.78 – 1.91) and 1.78 (95% CL 1.71 – 1.86) mg l −1 NH 3-N respectively. Acute toxicity ceased after 24 and 48 h, respectively, in the first and second trials, and the two 96-h LC50 values obtained were not significantly different.

The pathogenicity and development within the host fish of Myxobolus cyprini Doflein, 1898

Myxobolus cyprini has, until now, been considered an ‘organo-cosmopolitan’ parasite of the common carp (Cyprinus carpio) and less frequently of other carps, producing spores in various organs in small plasmodia and possible in cysts. The present observations of naturally infected common carp fry and two-summer carp have revealed that M. cyprini is a specific muscle parasite, developing intracellularly in the muscle fibres of the skeletal muscle. The sarcoplasm of the infected muscle fibres is filled with developmental stages, followed by spores of M. cyprini, which are held together in a 1–1·5 mm long pseudocyst by the sarcolemma of the muscle fibre. After maturation of the spores and disintegration of the pseudocysts the spores are transported in the bloodstream to different parts of the body where they are retained in the capillaries.

Tryptophan requirement of common carp (Cyprinus carpio L.) fry

ZusammenfassungDer Tryptophanbedarf von KarpfenbrutZur Ermittlung des Tryptophanbedarfs von Karpfenbrut wurden Wachstumsstudien durch‐geführt. Als Eiweißkomponente wurde Zein mit Zusatz von freien Aminosäuren verwen‐det.Auf Grund des Gewichtszuwachses wurde ein Bedarf an L‐Tryptophan von 0,133% in der Futter‐TS festgestellt. Zu etwa gleichen Ergebnissen kam man, wenn man den Zuwachs an Körper‐TS oder Körperprotein zugrundelegte. Die entsprechenden Bedarfszahlen lau‐ten 0,126%o und 0,1 34% der Futter‐TS. Dabei wird die D‐ und L‐Form von Tryptophan vom Karpfen anscheinend gleich gut verwertet.Die Erfassung des Tryptophangehaltes im gesamten Fischkörper brachte keine zusätzliche Aussage über den Tryptophanbedarf.Variierende Tryptophangaben über das Futter führten zu sigmfikanten Veränderungen in der Konzentration von anderen freien Aminosäuren im Fischkörper. Mangelhafte Tryptophanversorgung hatte einen Anstieg der freien Aminosäuren mit Ausnahme von Histidin zur Folge. Die Zulage von unterschiedlichen Mengen an Tryptophan zu Zein führte zu einem Abfall von freiem Lysin, Arginin und Histidin im Fischkörper im Vergleich zu Karpfen, die mit einem handelsüblichen Karpfenfutter gefüttert wurden.

Vulnerability of prey to predation by freshwater prawn, Macrobrachium malcolmsonii

The vulnerability of four prey species to predation by the freshwater prawn, Macrobrachium malcolmsonii, was found to be in order of decreasing vulnerability: tadpoles of frog ( Rana cyanaphyctis) > minnow ( Aplocheilus lineatus) > common carp fry ( Cyprinus carpio) > Tilapia mossambica fry. The weight of the prey consumed per day was, respectively, 12.48 ± 1.45 g, 6.02 ± 1.15 g, 5.61 ± 0.40 and 2.89 ± 0.26 g; and the estimated 50% predation time was 1.25 ± 0.26 days, 1.66 ± 0.33 days, 2.0 ± 0.17 days, and 3.54 ± 0.72 days, respectively.

A study of the application of proteolytic enzymes to fish food

A study was carried out to determine the effect of adding bovine trypsin to the diet of common carp fry. When added in the same and three times the quantity normally found in natural foods it increased the proteolytic activity by the same proportion. After 58 days of the experimental diet there was no deleterious effect on the survival of fish. Food utilization, stated in terms of feeding coefficient, apparent net protein utilization (NPU), protein efficiency ratio (PER) and NPU was from 1.63 to 1.79, 19.3 to 21.3, 1.32 to 1.46 and 46.0 to 50.5 respectively. The percentage composition of bond amino acid in all fish groups was found to be the same after the experiment. However, a considerable decrease in the total proteolytic activity in the hepatopancreas was observed for these fish which were given bovine trypsin in the diet. These results, with other recently published material suggest the possibility of a new approach to the study of the application of proteolytic enzymes to fish food.

Studies on the role of exogenous proteolytic enzymes in digestion processes in fish

Studies were carried out on the proteolytic activity of the fry of common carp, rainbow trout, grass carp, and whitefish, as well as on the activity of digestive organs of adult common carp and rainbow trout. Activity of exogenous enzymes in relation to endogenous ones was assessed on the basis of the proteolytic value of fish food and the activity of digestive organs. It was found that the share of proteolytic enzymes of natural food in the digestion process in fish was high. Beginning from a weight of 50–100 g for common carp and 10 g for rainbow trout, the relation between the daily enzymatic ration and the weight of fish indicates the cooperation of an approximately constant amount of exogenous enzymes.

飼育用水温の急變化が鯉仔魚に及ぼす影響に就て

In two sets of the Seno-Tauti's thermostat, the compartments were so prepared as to be maintained each at about 9, 12, 15, 18, 20, 22, 27, 30, 33, 35 and 39°C and in each of them were placed 2 or 3 vials, each containing about 60cc. of clear water. The fry of common carp just hatched, or (in the second of the four series of experiments carried out) those 4-days old, were first put in the vials placed in three compartments at about 15, 22 and 30°C for about 12 hours, and then transferred each into one of the vials at several temperatures above stated. 12 and 24 hours after that time, the number of dead fry in each vials was examined. The results thus gained may be summarized as follows: - (1) The critical change of the water temperature, which is mortal for the carp fry varies according as the original temperature, as shown in the next table: - (2) Abrupt fall of the water temperature from the original one at about 22°C has more distinct mortal influence on the carp fry than the sudden rise. (3) No difference was appreciable between the fry just hatched and those 4-days old as to their resistance to the sudden change of water temperature.