An investigation on fingerling grass carp Ctenopharyngodos idella ectoparasites with the first occurrence of Tylodelphys clavata as a new locality record in northern Iran

The research aimed to determine the peculiarities of the formation of the parasitic system in herbivorous fish in the aquaculture of the North-Eastern and Eastern regions of Ukraine. In fish farms of the North-Eastern and Eastern regions of Ukraine, 26 species of parasites were found in herbivorous fish: 19 species in the silver carp (11 — protozoa, 1 — monogeneans, 4 — trematodes, 3 — parasitic crustaceans); 18 species in the grass carp (6 — protozoa, 1 — monogeneans, 4 — trematodes, 4 — cestodes, 3 — parasitic crustaceans); and 20 species in the bighead carp (10 — protozoa, 1 — monogeneans, 4 — trematodes, 2 — cestodes, 3 — parasitic crustaceans). 11 species (42.3%) of registered parasites were invasive; 18 species (69.2%) of the detected herbivorous fish’s parasites develop directly and 8 (30.8%) — with the participation of definitive and intermediate hosts; the fish is an additional (second intermediate) host in the life cycle of 6 species (23.1%) of parasites. Outbreaks of diseases caused by parasitic protozoa from the genera Myxobolus, Cryptobia, Chilodonella, and Ichthyophthirius have been reported in both fingerlings and two-year-olds. The protozoa from the genera Ichthyobodo, Trichodina, and Trichodinella were registered en masse only in fingerlings. Pathogens from the genus Dactylogyrus were more often registered among three-year-old silver and bighead carps. Metacercariae of Ichthyocotylurus variegatus were found en masse in fingerlings of the grass carp. Posthodiplostomum cuticola larvae in unfavorable farms were found with a high level of prevalence in fish of different age groups. Thong plerocercoids were more commonly recorded in two-year-old silver and bighead carps and fingerlings of the grass carp. The highest level of cestode infection with Bothriocephalus acheilognathi was recorded in fingerlings of the grass carp. Parasitic crustaceans Sinergasilus lieni with a high level of prevalence were registered in two-year-old and three-year-old fish. Crustaceans Lernaea cyprinacea massively affected two-year-old and three-year-old fish. Pathogens from the genera Trichodina, Cryptobia, and Chilodonella, and Dactylogyrus hypophthalmichthys, Posthodiplostomum cuticola, and Sinergasilus lieni were of the greatest epizootic significance for the silver carp; for the bighead carp — from the genus Myxobolus, (especially M. pavlovskii), Chilodonella piscicola, Ichthyophthirius multifiliis, Dactylogyrus aristichthys, Posthodiplostomum cuticola, Diplostomum spathaceum, Digramma interrupta, and Sinergasilus lieni; for the grass carp — Bothriocephalus acheilognathi, Ichthyocotylurus variegatus, Ligula intestinalis, Sinergasilus major, Lernaea cyprinacea, Ichthyobodo necator, and Ichthyophthirius multifiliis

Assessment of induced breeding of major Chinese carps at a large-scale hatchery in Hungary

Effect of population strategies on production of polyculture system

<em>Abstract</em>.—Numerous natural resource agency and media reports have alleged that Asian carps were introduced into the wild through escapes from commercial fish farms. This chapter traces the chronology associated with importations of Asian carps to North America and discusses the likeliest pathways of their introduction to the wild. The U.S. Fish and Wildlife Service first imported an Asian carp species, grass carp <em>Ctenopharyngodon idella</em>, in 1963. Since then, state and federal agencies, universities, and private fish farmers have interacted to import Asian carps, to develop production technologies, and to promote their use in both public and private sectors in a number of different states. These importations and stocking, whether in confinement or, in the case of the grass carp, sometimes in open waters, were purposeful and legal. Asian carps were introduced to take advantage of their unique food preferences (planktivory by silver carp <em>Hypophthalmichthys molitrix </em>and bighead carp <em>H. nobilis</em>, herbivory by grass carp, and molluscivory by black carp <em>Mylopharyngodon piceus</em>). The first known accidental release of diploid grass carp was in 1966 by the U.S. Fish and Wildlife Service in Stuttgart, Arkansas. Other early reports of grass carp in the wild were from waters in Alabama, Georgia, and Florida. Grass carp were reported from the wild in 1970, 2 years before the first private hatchery received grass carp. By 1972, grass carp had been stocked in open water systems in 16 different states. Silver carp and bighead carp were first imported purposely by a commercial fish producer in Arkansas in 1973. All silver and bighead carps were transferred to the Arkansas Game and Fish Commission by March 1974 where they first successfully spawned silver carp and bighead carp later that year. The first report of silver carp in the wild was in Arizona in 1972, although strong evidence suggests that this may have been a misidentification, followed by reports in Arkansas in the wild in 1975. The Arkansas report occurred 2 years before bighead carp and silver carp were returned to private hatcheries for commercial production. By 1977, silver carp and bighead carp had been introduced to Alabama, Arizona, Arkansas, Illinois, and Tennessee. Research and stockings of silver carp and bighead carp were conducted by at least six state and federal agencies and three universities in seven states in the 1970s and 1980s. Public-sector agencies, which were successful in encouraging development and use of Asian carps that today are in commercial trade, are the likeliest pathways for the earliest escapes of grass carp, silver carp, and bighead carp.

Carp is one of the most widely cultivated warm water fish, which has been introduced into many countries. It is essential for the manager of a carp farm to know the production costs and their evolution, showing the main inputs on which the cost reduction is worth effort. In Iran, carp farming is mainly based on common carp, silver carp, grass carp, and bighead carp, which were often reared in poly culture. Carp farming production reached a peak in 2006 with production of more than 77,000 tones. The characteristics of the carp farming industry in the main fish farming provinces, (overall more than 90% of total carp production) are considerably different. In years 1996 and 2001, a study of yield production, factor costs and profitability of farmed carp was carried out to help clarify carp production costs and their difference between the provinces. 153 farms in 1996 and 101 farms in 2001, overall, a total of 254 farms from the main carp farming provinces, including; Guilan, Mazandaran and Khuzestan were randomly selected, classified and studied. Results showed that the various producer provinces have different cost structures. Overall, feed and fertilizer with the highest level of variation accounted for 45% of total costs in 1996, declined to 23% in 2001. However, on average, cost of seed and labor increased from 7% and 10% to 23% and 17% of total costs over the 1996 and 2001, respectively. On average, benefit-cost ratio and the rate of farm income were closely related to location suggesting that farmers practiced more efficiently and have better conditions in Guilan in 1996, resulting in higher farm income per ha and per kg, changing to better conditions and more efficient by Mazandaran province in 2001. Overall, in the three main provinces, rate of farm income from an average of 20% in 1996, declined to 12% in 2001.

The full-length cDNA of grass carp (Ctenopharyngodon idellus) and silver carp (Hypophthalmichthys molitrix) uncoupling protein 2 (UCP2) was obtained from liver. The grass carp UCP2 cDNA was determined to be 1152 bp in length with an open reading frame that encodes 310 amino acids. Five introns (Intron 3, 4, 5, 6 and 7) in the translated region, and partial sequence of Intron 2 in the untranslated region of grass carp UCP2 gene were also obtained. Gene structure comparison between grass carp and mammalian (human and mouse) UCP2 gene shows that, the UCP2 gene structure of grass carp is much similar to that of human and mouse. Partial UCP2 cDNA sequences of bighead carp (Aristichthys nobilis) and mud carp (Cirrhinus molitorella), were further determined. Together with the common carp (Cyprinus carpio) UCP2 sequence from GenBank (AJ243486), multiple alignment result shows that the nucleotide and amino acid sequences of the UCP2 gene, were highly conserved among the five major Chinese carps that belong to four subfamilies. Using beta-actin as control, the ratio UCP2/beta-actin mRNA (%) was determined to be 149.4 +/- 15.6 (common carp), 127.4 +/- 22.1(mud carp), 96.7 +/- 12.7 (silver carp), 94.1 +/- 26.8 (bighead carp) and 63.7 +/- 16.2 (grass carp). The relative liver UCP2 expression of the five major Chinese carps, shows a close relationship with their food habit: benthos and detritus-eating fish (common carp and mud carp) > planktivorious fish (silver carp and bighead carp) > herbivorous fish (grass carp). We suggest that liver UCP2 might be important for Chinese carps to detoxify cyanotoxins and bacteria in debris and plankton food.

7 - The Common Carp and Chinese Carps

Invasive carp in China's plateau lakes.

Purpose. Conducting an analysis of parasitic diseases of different age groups of carps grown in specialized fish farms of Odesa region under different forms of ownership for 2014–2023. Methodology. The paper presents the generalized results of studies carried out during planned test catches in specialized fish farms of various forms of ownership located in Odesa region. Parasitological studies were carried out according to the Bykhovska-Pavlovska method. The study included: visual inspection; excision of skin and muscle tissue; microscopy of scrapings from the surface of the body, fins and gills; microscopy of eye lenses; pathological autopsy, search for parasites in the body cavity; compression microscopy of internal organs and muscle tissue; intestinal dissection; gallbladder microscopy; dissection and microscopy of the swim bladder walls. At the same time, the parasitic species were identified, and the extensiveness and intensity of the invasion were calculated. Parasites were identified using identification keys. Findings. The study was conducted by employees of the ichthyopathology laboratory of the Institute of Fisheries of the National Academy of Sciences in laboratory conditions and at sampling sites in the period from 2014 to 2023. The objects of the study were different age groups of common carp (Cyprinus carpio), hybrids of silver and bighead carps (Hypophthalmichthys spp.), grass carp (Ctenopharyngodon idella) and crucian carp. Parasitological analysis showed that carp were most often affected by monogeneans, the prevalence (P) was 50.6% of the studied fish, and infestation intensity (II) was an average of 10 parasites per fish. In addition, a large percentage of infection was caused by ciliates with P of 24% P, II was 9 parasites per fish. Grass carp, in turn, were most affected by ciliates — P 56.3% with an average II — 16 parasites per fish and monogeneans — P 36.4% with an average II — 12 parasites per fish and trematodes — P 25.4% with II 8 parasites per fish. Grass carp was the most affected by crustaceans, the P was 46.6%, and the II was 3 parasites per fish, trematode P 16.6% with an average II of 10 parasites per fish. In Prussian carp, infestation by monogeneans was most often detected, which reached 75% with II — 5 parasites per fish. In the period of 2019-2023, carp was most often affected by monogeneans, where P was 29.3%, and II was 3 parasites per fish, also a high percentage of infection was due to ciliates 24%, II was 6 parasites per fish. Chinese carps, in turn, was most affected by trematodes — P 59.1% at II — 60 parasites per fish. Grass carp was the most affected by diplostoma, where P was 45.5% with an average II of 45 parasites per fish. Crucian carp was most affected by lernea. Based on the analysis of data on parasitic diseases of freshwater fish, it can be concluded that both in the period 2014‒2018 and 2019‒2023, fish were most often affected by monogeneans and infusoria, but in the period 2019‒2023, the infestation of silver and grass carps by diplostomes and postodiplostomes increased significantly. Originality. An analysis of parasitic diseases of carp grown in specialized farms of various forms of ownership, located in the Odesa region for the period of over the past ten years has been presented. The results of these studies can be used for parasitological monitoring of water bodies as well as control of the spread of ecto- and endoparasites. Practical value. The obtained results can be used for a timely understanding of trends in the spread of parasitic diseases and allows using the obtained material for parasitological monitoring of fish farms. Keywords: fish, carps, parasites, prevalence, infestation intensity.

Trichodinids are probably the most commonly encountered protozoan parasites on fishes in marine and freshwater environments. They are typically found on the gills, skin and fins of fish. The aim of this study was to evaluate the prevalence and mean intensity of Trichodina sp. in freshwater fish from cyprinid aquaculture facilities in Macedonia. This study was carried out by seasons, in a period of three years. A total of 578 specimens of common carp (Cyprinus carpio, Linnaeus 1758), 76 specimens of grass carp (Ctenopharyngodon idella, Valenciennes 1844), 47 specimens of silver carp (Hypophthalmichthys molitrix, Valenciennes, 1844) and 53 specimens of bighead carp (Hypophthalmichthys nobilis, Richardson, 1845) from the most significant and larger cyprinid aquaculture facilities in Macedonia, including fish farms and reservoirs, were examined for parasitological investigations. Infestation with Trichodina sp. was found in 206 specimens of common carp in all aquaculture facilities examined, in all seasons, as well as, in 9 specimens of grass carp from two fish farms, only in autumn season. Total, the prevalence with Trichodina sp. was 11.84% (grass carp) and 35.67% (common carp), while the, mean intensity was 7.56 (grass carp) and 4.56 (common carp). The prevalence with Trichodina sp. in common carp by season was as following: spring – 11.82%, summer – 3.44%, autumn – 7.85%, winter – 7.05%, while the mean intensity was: spring – 4.55; summer – 4.67; autumn – 4.40; winter – 4.72. Our findings of Trichodina sp. in grass carp in the present study is considered as the first record in Macedonia. Also, this fish species is regarded as new host for Trichodina sp. in Macedonian waters.

Simple SummaryCarps include some of the most widely farmed fresh water species. In the present study, the incidence of skeletal malformations in the fingerlings of four carp species reared in semi-intensive conditions in Albania was assessed. The investigated species were the common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella) and bighead carp (Hypophthalmichthys nobilis). The incidence of skeletal malformations and body growth were much higher in the herbivorous silver carp, grass carp and bighead carp than in the omnivorous common carp. We hypothesized that (i) the feeding protocol, which included ingredients of animal origin, may have caused an abnormal increase in the body growth rate associated with an increase in skeletal malformations in the herbivorous carp species; (ii) more efficient broodstock management may help increase egg quality and reduce skeletal malformations.Cyprinids include some of the most widely farmed freshwater species. The aim of this study was to assess the incidence of skeletal malformations in carp species reared in semi-intensive systems in Albania: common carp (Cyprinus carpio), silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon idella) and bighead carp (Hypophthalmichthys nobilis). The common carp fingerlings had a mean total length of 28.9 ± 5.0 mm; the frequencies of individuals with at least one anomaly and at least one severe anomaly were 79.2% and 43.4%, respectively. The silver carp juveniles had a mean total length of 21.6 ± 2.1 mm; the frequencies of individuals with at least one anomaly and one severe anomaly were 93.1% and 57.5%, respectively. The grass carp fry had a mean total length of 33.5 ± 2.6 mm; all the analyzed specimens showed almost one anomaly and 86.4% showed at least one severe anomaly. The bighead carp juveniles had a mean total length of 34.4 ± 5.7 mm; the frequencies of individuals with at least one anomaly and at least one severe anomaly were 95.0% and 62.5%, respectively. The development of a more suitable feeding protocol for herbivorous species and the setting up of more efficient broodstock management protocols are suggested to reduce the high incidence of skeletal malformations.

In order to understand the stress encountered by freshwater fish as a result of thermal discharges into waters, we undertake thermal shock experiments study. The TL <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">50</sub> values of four freshwater fishes increased with increasing acclimation temperature. The UILT values for silver carp, bighead carp, grass carp and common carp were 37.1degC, 35.6degC, 37.7degC, 37.3degC, respectively. The results obtained showed similar type of heat acclimation for CTMax and LRR. Data of CTMax, LRR and TL <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">50</sub> indicate the importance of acclimation temperature relative to their upper thermal tolerance limits of fishes. In fish acclimated at 30degC , acute estimated final thermal optimum temperature was 29.9degC(silver carp), 31.2degC(bighead carp), 30.3degC (grass carp) and 30.1degC (common carp), respectively. The preferred temperature range of silver carp, bighead carp, grass carp, common carp was 28.0-32.0degC, 28.0-33.0degC, 27.0-34.0degC, 27.4-31.21degC.

Silver carp (Hypophthalmichthys molitrix), grass carp (Ctenopharyngodon piceus), bighead carp (Aristichthys nobilis), and black carp(Mylopharyngodon piceus) rank first, second, fourth, and seventh in world fish production. In China, the Yangtze River harbours the most important natural populations of these species. We performed a polymerase chain reaction - restriction fragment length poymorphism analysis on 365 juvenile fish representing three nursery grounds to provide a first assessment of the mitochondrial DNA diversity in these species and test the hypothesis that they are composed of more than one genetic stock. The mitochondrial DNA diversity was high in silver, bighead, and black carp, and much less in grass carp. Analysis of heterogeneity of genotype frequency, fixation indices, intersite molecular variance, and localization indices indicated that juvenile silver, bighead, and black carp from different nursery areas belong to genetically distinct populations. These results suggest that their population structure may be determined by the number of environmental settings that permit closure of their life cycle. They also imply that carp from the Yangtze River cannot be managed as a single unit and that human disturbance through exploitation and habitat modifications, in particular the construction of the Three Gorges Dam, will have differential impacts on fish abundance for different parts of the river.

Gut contents of six cultured cyprinid species were sampled and their chlorophyll and chlorophyll derivatives were measured to quantify fish feeding in a Chinese integrated fish culture pond. The densities of planktivorous (silver and bighead carp) and benthic-feeding (crucian and common carp) fish fry stocked in the pond were only 12% and 43%, respectively, of those in our previous pond study (TAKAMURA et al., 1993). High ratios of chl.b/chl.a or phaeophorbide a/chl.a were good indicators of the dependence on aquatic plants of herbivory or zooplanktivory, respectively. Phaeophytin a seemed to be a good index of herbivory on decomposing aquatic plants. Grass carp and blunt snout bream fed mostly on aquatic plants. The feeding habits of silver and bighead carp were very similar. These two planktivorous fish ingested zooplankton, phytoplankton and plant fragments derived from faeces of grass-eating carps. Silver carp were more dependent on zooplankton and bighead carp were less dependent on plant fragments in this pond as compared with those from the pond in our previous study (TAKAMURA et al., 1993). Common carp were largely dependent on plant fragments. Crucian carp utilized both plant fragments and zooplankton. The feeding habits of benthic carps did not differ from those in our previous pond study. Regardless of some changes in the feeding habits of planktivorous carps, both planktivorous and benthic-feeding cyprinids reared in this pond seemed to be supported by plant fragments, and were probably nourished by microorganisms attached to those plant fragments (IWATA et al., 1992).

Studies on the ecological effects of varying the size of fish ponds loaded with manures and feeds