Seasonal histopathological alterations caused by Bothriocephalus acheilognathi in Schizothorax niger of Kashmir valley

Liver and intestines affected by an cestode parasite viz., Bothriocephalus acheilognathi along with their host (Schizothorax niger) were collected randomly. Bothriocephalus acheilognathi causes damage to the intestinal tissues and induce complex host response; the affected fish were anemic and emaciated. The viscera were dark red on opening the abdomen. The intestinal contents showed lot of mucous and contained dark contents. The mucosal wall was red in colour and revealed necrotic surface. The histopathological changes were varied in severity with the season and parasitic burden. Intestinal infection of Bothriocephalus with Adenoscolex was usually seen together. Severe enteritis with heavy infilitration of inflammmtory cells and fibroblasts seen in lamina propia. Liver cells showed severe degenerative changes.

The synthesis of lipids and proteins in vitro in tissues of Cyprinus carpio infected with Bothriocephalus acheilognathi

The problem of the mechanisms of regulation of biochemical processes in carp Cyprinus carpio (Linnaeus, 1758) tissues and organs caused by infection with Bothriocephalus (Schyzocotyle) acheilognathi (Yamaguti, 1934) at different intensities of invasion remains practically unstudied. The purpose of this study was to dedetrmine the intensity of lipid and protein synthesis in vitro when [6-14C]glucose and [2-14C]lysine are used as their precursor in the tissues of the intestine, hepatopancreas and skeletal muscles of carp. The study was conducted on this-year carp with body weight 14.5–20.5 g, at different invasion rates of the helminth B. acheilognathi, which belongs to the family Bothriocephalidae of the Pseudophyllidae order of the Cestoda class of the Plathelminthes phylum. The examined carp were divided into three groups: 1st group of fish was free from intestinal helminths of B. acheilognathi (control); 2nd group of fish was weakly infected with helminths (intensity of invasion was 1–3 helminths per fish); the 3rd group of fish was highly infected (the invasion intensity was 4 worms and more per fish). Our results showed that in fish infected with the helminth B. acheilognathi in comparison to uninfected, the intensity of lipid synthesis in the intestinal wall, hepatopancreas, skeletal muscle was much lower when [6-14C]glucose was used as a predecessor than when [2-14C]lysine was used as a predecessor. In the examined tissues, significant decrease was observed in the synthesis of reserve lipids (mono-, di- and triacylglycerols) in comparison to the structural (phospholipids and cholesterol), which depends on the intensity of the B. acheilognathi invasion. In the metabolic processes in the wall of the intestine, hepatopancreas, skeletal muscle of this-year carp infectd with B. acheilognathi helminths, under in vitro conditions, [6-14C]glucose was used more than [2-14C]lysine. The intensity of protein synthesis in the intestinal wall, hepatopancreas, skeletal muscles of this-year carp infected with the helminth B. acheilognathi under in vitro conditions increased when [6-14C]glucose was added to the incubation medium, on average 7.1–28.3% and decreased when [2-14C]lysine was added, on average 7.8–25.7%.

The lipid metabolism in carp during invasion by the tapeworn Bothriocephalus acheilognathi

The changes in total lipids, their fatty acid composition and the ratio of individual classes were established in tissues of the intestine, hepatopancreas and skeletal muscles of carp (Cyprinus carpio Linnaeus, 1758), with body weight 14.5–20.5 g, at different rates of invasion by Bothriocephalus acheilognathi (Yamaguti, 1934) helminth, which belongs to the family Bothriocephalidae, of the Pseudophyllidae order, of the Cestoda class. The examined carp was divided into three groups: first group of fish was free from intestinal helminths of B. acheilognathi (control); second group of fish was weakly infected with helminths (intensity of invasion is 1–3 helminths per fish); the third group of fish was highly infected (the invasion intensity is 4 worms and more per fish). Our results showed that fish infected with helminth B. acheilognathi compared to uninfected fish had reduced total lipid level in the gut due to phospholipids, triacylglycerols, and also lipids were characterized by lower content of linoleic, linolenic, arachidonic, penta- and hexanoic fatty acids; decrease in the level of unsaturated and increase in the content of saturated fatty acids, which leads to an increase of the saturation factor. During the infection of carp with B. acheilognathi in the hepatopancreas, the content of total lipids, structural lipids – phospholipids and reserve energy sources – triacylglycerols is probably reduced, and lipids are characterized by a high content of saturated fatty acids (С14:0, С16:0, С18:0) and lower content of unsaturated: arachidonic (С20:4), linolenic (С18:3) and linoleic acid (С18:2), which is associated with a decrease in the source for the synthesis of a number of polyunsaturated fatty acids, especially docosahexaenoic (С22:6). The total content of lipids, triacylglycerols, free fatty acids and phospholipids in skeletal muscle of carp during the Bothriocephalus invasion decreased and the content of free cholesterol, mono- and triacylglycerols increased. Helminth B. acheilognathi has the effect of reducing the total lipids of the skeletal muscle content of С18-, С20-, С22-polyunsaturated fatty acids and increasing the content of saturated (С14:0, С16:0, С18:0) and monounsaturated (С16:1, С18:1) fatty acids. The obtained results prove that the parasite B. acheilognathi in the intestine of the carp significantly affects the nutrition processes of the host depending on the intensity of the damage by helminths, which is accompanied by impaired lipid metabolism.

Features of the parasitic system formation in common carp in the aquaculture of the north-eastern and eastern regions of Ukraine

The research aimed to determine the peculiarities of the formation of the parasitic system in common carp in the aquaculture of the North-Eastern and Eastern regions of Ukraine. According to the results of the research, 27 species of parasites were found in common carp (12 — protozoa, 6 — monogeneans, 3 — trematodes, 2 — cestodes, 4 — parasitic crustaceans). Three species (11.1%) of registered parasites were invasive. 22 species (81.5%) of detected common carp’s parasites develop directly and 5 (18.5%) — with the participation of definitive and intermediate hosts. 26 species (96.3%) of common carp’s parasitic fauna were found in crucian carp and 21 species (77.8%) in other coarse fish species (roach, rudd, bleak, perch). It has been established that among the protozoa, pathogens from the genera Trichodina, Chilodonella, and Ichthyophthirius were of epizootic importance for young common carp; Eimeria carpelli, Ichthyobodo necator, Myxobolus ellipsoides, and Myxobolus dogieli had relevance. The level of prevalence in common carp fingerlings during outbreaks of chylodonelosis was 72%, two-year-olds — 65%, three-year-olds — 27%, during outbreaks of ichthyoftiriosis — 45%, 56%, and 24%, respectively. Prevalence of Trichodina acuta and Trichodina nigra in common carp fingerlings was, respectively, 52% and 38%, Ichthyobodo necator — 16%, Eimeria carpelli — 22%, Myxobolus ellipsoides, and Myxobolus dogieli — 17–18%. Among the pathogens of helminthic diseases in the aquaculture, monogenetic suckers (Dactylogyrus anchoratus, Dactylogyrus extensus, Dactylogyrus vastator, Gyrodactylus cyprini, and Gyrodactylus katharineri), as well as cestodes (Bothriocephalus acheilognathi and Khawia sinensis) were the most epizootic significance for common carp. Prevalence of parasites from the genus Dactylogyrus reached 68–87% in fingerlings, from the genus Gyrodactylus — 21–36%. The highest level of Bothriocephalus acheilognathi infection (82%) was registered in fingerlings. The maximum prevalence of Khawia sinensis (62%) was observed in two-year-olds. Outbreaks of diseases caused by crustaceans Lernaea cyprinacea and Argulus foliaceus with a high level of prevalence have been reported in fish from fingerlings to three-year-olds. The level of prevalence of Lernaea cyprinacea was 69%, Argulus foliaceus — 22%

Features of the parasitic system formation in herbivorous fish in the aquaculture of the North-Eastern and Eastern regions of Ukraine

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

Distribución y patología causada por Bothriocephalus acheilognathi, Yamaguti 1934 (Cestoda: Bothriocephalidae). Revisión bibliográfica

La tenia asiática o tenia asiática de pez, Bothriocephalus acheilognathi, es oriunda de Asia Oriental y en las últimas décadas se ha extendido ampliamente a lo largo del mundo por diversas actividades humanas desarrolladas en todos los continentes. Ejemplos de tales actividades son los traslados de peces para satisfacer demandas de la piscicultura, el comercio de los ejemplares, la disputa por áreas acuáticas, el control de los mosquitos y más recientemente la pesca de peces. Además, las aves que se alimentan de peces infectados, pueden transportar huevos del cestode y diseminarlos a través de la defecación. Estimativamente, B. acheilognathi se ha reportado en unas 200 especies de peces de agua dulce, y este amplio rango de hospedadores colaboró en su establecimiento, aunque el parásito es principalmente reportado en las carpas salvajes y cultivadas. Ello constituye un problema para la acuacultura y se sospecha que afecta adversamente y pone en peligro a las especies silvestres. Es considerado como un patógeno de importancia regional (PRI) por el Servicio de Peces y Vida Silvestre de los Estados Unidos (US Fish and Wildlife Service, 2015). El principal vector de su propagación parece ser la introducción de su huésped natural, la carpa asiática Ctenopharyngodon idella, para su uso en acuacultura o para el control de vegetación acuática. En la actualidad, el principal vehículo de expansión de este parásito es la carpa común (koi carp, pez mosquito), aunque probablemente también intervengan otros peces. La tenia asiática es patógena para los peces de agua dulce, especialmente carpas jóvenes y alevines, pudiendo causar gran pérdida económica en los criaderos y granjas de peces. Tiene habilidad para colonizar nuevas regiones y adaptarse a un amplio espectro de peces hospederos. Ella representa uno de los ejemplos más impresionantes y deplorables de un parásito ampliamente diseminado por el hombre, asistido por movimientos de peces. El grado de diseminación y éxito de la colonización fue favorecido por la distribución cosmopolita de los huéspedes intermediario y definitivo