Antimicrobial and anthelmintic effects of copper nanoparticles against Koi carp parasites and their toxicity.

This study investigated the in vitro antimicrobial and anthelmintic effect of copper nanoparticles (CuNPs) against the bacterium Aeromonas hydrophila, the monogeneans Dactylogyrus minutus, Dactylogyrus extensus, Gyrodactylus cyprini, and the cestode Schyzocotyle acheilognathi, as well as their toxicity to Cyprinus carpio Koi. In the antimicrobial in vitro test, the inhibition zone method and minimum inhibitory concentration (MIC) were performed. In order to determine the time and efficacy of monogenean parasite mortality, the parasites were exposed to CuNP concentrations of 20, 50, 100, 150, 200, and 300 mg L-1, and a control group with tank water and one with copper sulphate pentahydrate (CuSO4.5H2O) at a concentration of 0.3 mg L-1, performed in triplicate. The parasites were observed every 10 min for 300 min, and mortality was recorded. For the cestodes, parasites were immersed in CuNP concentrations of 50, 100, 150, and 300 mg L-1. At the end of the in vitro tests, the anthelmintic efficacy of each treatment was calculated. To assess the tolerance and toxicity in fish, they were exposed to CuNP concentrations of 0.6, 1.25, 2.5, 5, 10, 20, and 50 mg L-1 for 12 h. The MIC demonstrated that CuNPs effectively inhibited the growth of A. hydrophila up to a dilution of 12,500 mg L-1 and showed an inhibition zone of 14.0 ± 1.6 mm for CuNPs. The results of anthelmintic activity showed a dose-dependent effect of concentration for both groups of parasites, with the most effective concentration being 300 mg L-1 in 120 min. In the toxicity test, the carps showed tolerance to lower concentrations. The study indicated that CuNPs were effective against the studied pathogens. However, it proved to be toxic to fish at high concentrations. The use of low concentrations is recommended still requires further investigation.

Ornamental fish mortality reveals an old parasite introduction: A case study of Koi carp and fish louse.

Koi carp are globally known for their colors and cultural significance. The introduction of these fish to new environments poses a threat to local biodiversity, in addition to releasing parasites, such as argulid ectoparasites. This study presents a record of Argulus japonicus infecting carp in an artificial lake in Southern Brazil using morphological and molecular methods, with a 100% prevalence (n = 3) and a mean intensity of 21.6 parasites per host, distributed over the body surface. The invasion history of hosts in the study locality indicates that the introduction of A. japonicus occurred decades before its first formal record in Brazil.

Three new Dactylogyrus species (Monogenea: Dactylogyridae) and redescription of one other, gill parasites of five Labeo spp. (Cypriniformes: Cyprinidae) from the Sanaga basin (Cameroon, Central Africa)

Three new and one already known species of Dactylogyrus Diesing, 1850 are described from five species of Labeo (Cyprinidae) sampled in the middle section of the Sanaga hydrosystem (Centre Region-Cameroon): Dactylogyrus sanagaensis sp. nov. from Labeo sanagaensis Tshibwabwa, 1997, L. nunensis Pellegrin, 1929, L. camerunensis Trewavas, 1974 and L. annectens Boulenger, 1903; Dactylogyrus nachtigalensis sp. nov. and D. yassensis Musilová, Rehulková & Gelnar, 2009 from Labeo batesii Boulenger, 1911; and Dactylogyrus djimensis sp. nov. from Labeo camerunensis. Dactylogyrus sanagaensis sp. nov. is close to D. longiphalloides, D. longiphallus, D. leonis, D. marocanus, and D. dembae, however it can be easily distinguished from these species by the size of MCO. Dactylogyrus nachtigalensis sp. nov. is similar to D. dembae and D. sanagaensis sp. nov. but this new species can be mainly differentiated by the length of penis. Dactylogyrus djimensis sp. nov. mostly similar to D. omega can be differentiated from it by the penis diameter. Dactylogyrus yassensis collected from Cameroon doesn't significantly differ morphometrically from the original description, thus extends the distribution of this species to Sanaga basin. Monogenean species collected from Labeo spp. in the middle section of the Sanaga hydrosystem were classified into two morphological groups: the 'pseudanchoratus-like group' and the 'cyclocirrus-like group' newly defined herein. Phylogenetic relationships are suggested among Dactylogyrus species.

In vitro and in vivo antiparasitic action of essential oils of Lippia spp. in Koi Carp (Cyprinus carpio) fed supplemented diets

This study evaluated the in vitro antiparasitic activity of the essential oils of Lippia alba, L. origanoides and L. sidoides against monogenean parasites of koi carp Cyprinus carpio and its zootechnical performance in net cages. The oils were obtained from the leaves by hydro distillation, and the chemical composition was evaluated via gas chromatography. In vitro assays were performed with each essential oil separately and combined in binary (1:1) and tertiary (1:1:1) mixtures with the Lippia species at 10, 20, 40, 60, 80 and 100 mg L-1 and two control groups (grain alcohol and tank water). To determine zootechnical performance, L. sidoides oil was added to the feed at 0.00 (control), 0.25, 0.50, 0.75 and 1%, in triplicate and with 20 fish per net cage fed for 60 days. The best results in vitro against monogeneans were observed for L. sidoides (40 mg L-1 in 8 min), followed by L. origanoides (40 mg L-1 in 25 min) and L. alba (40 mg L-1 in 4 h). Reductions in weight gain, protein efficiency rate and specific growth rate were observed in diets containing 0.75% of L. sidoides oil in comparison to the control and the 0.25% diet. There were no significant differences in growth, individual mean feed intake, apparent feed conversion and parasitological indices. Based on our results, 0.25% L. sidoides oil showed the best zootechnical performance, but was not effective against koi carp parasites in vivo.

In vitro and in vivo antiparasitic action of essential oils of Lippia spp. in Koi Carp (Cyprinus carpio) fed supplemented diets

This study evaluated the in vitro antiparasitic activity of the essential oils of Lippia alba, L. origanoides and L. sidoides against monogenean parasites of koi carp Cyprinus carpio and its zootechnical performance in net cages. The oils were obtained from the leaves by hydro distillation, and the chemical composition was evaluated via gas chromatography. In vitro assays were performed with each essential oil separately and combined in binary (1:1) and tertiary (1:1:1) mixtures with the Lippia species at 10, 20, 40, 60, 80 and 100 mg L-1 and two control groups (grain alcohol and tank water). To determine zootechnical performance, L. sidoides oil was added to the feed at 0.00 (control), 0.25, 0.50, 0.75 and 1%, in triplicate and with 20 fish per net cage fed for 60 days. The best results in vitro against monogeneans were observed for L. sidoides (40 mg L-1 in 8 min), followed by L. origanoides (40 mg L-1 in 25 min) and L. alba (40 mg L-1 in 4 h). Reductions in weight gain, protein efficiency rate and specific growth rate were observed in diets containing 0.75% of L. sidoides oil in comparison to the control and the 0.25% diet. There were no significant differences in growth, individual mean feed intake, apparent feed conversion and parasitological indices. Based on our results, 0.25% L. sidoides oil showed the best zootechnical performance, but was not effective against koi carp parasites in vivo.(AU)

First record of the invasive tapeworm, Schyzocotyle acheilognathi (Pseudophyllidea; Bothriocephalidae) in native freshwater fish, Brazil.

Schyzocotyle acheilognathi is a tapeworm cestode commonly found in native freshwater fishes from Asia. This cestode has low host specificity and for that reason it has been registered parasitizing more than 200 cultured and wild fish species, besides amphibians, reptiles and birds from different regions of the world. With a high pathogenic potential, S. acheilognathi may cause mortalities in highly infected fish. In South America, Schyzocotyle was reported in Cyprinus carpio from a Brazilian fish farm at the municipality of Cornélio Procópio, northern Paraná State and from the natural environment in C. carpio from Neuquen River, Patagonia, Argentina. So far, there has been no report of this parasite in South American native fishes. Herein we report the first occurrence of the invasive tapeworm S. acheilognathi in Rineloricaria pentamaculata (Siluriformes, Loricariidae), a native armored freshwater catfish from southern Brazil.

Update on the distribution of the co-invasive Schyzocotyle acheilognathi (= Bothriocephalus acheilognathi), the Asian fish tapeworm, in freshwater fishes of Mexico.

The Asian fish tapeworm, Schyzocotyle acheilognathi (syn. Bothriocephalus acheilognathi) represents a threat to freshwater fish, mainly cyprinids, across the globe. This tapeworm possesses an extraordinary ability to adapt to different environmental conditions and, because of that, from its natural geographical origin in mainland Asia, it has colonized every continent except Antarctica. It is thought that this pathogenic tapeworm was first co-introduced into Mexico in 1965 from China, with the grass carp Ctenopharyngodon idella, although the first formal record of its presence was published in 1981. Over the past 35 years, the Asian fish tapeworm has invaded about 22% of the freshwater fish in Mexico. Because fish communities in Mexico are characterized by high species richness and levels of endemism, S. acheilognathi is considered as a co-introduced and co-invasive species. In this review, we update the geographic distribution and host spectrum of the Asian fish tapeworm in Mexico. Up until December 2016, the tapeworm had been recorded in 110 freshwater fish species (96 native and 14 introduced), included in 51 genera, 11 families and 4 orders; it was also widely distributed in all types of aquatic environments, and has been found in 214 localities. We present novel data from a survey aimed at establishing the distribution pattern of the tapeworm in native freshwater fishes of two rivers in north-central Mexico, and the genetic variation among individuals of this co-invasive species collected from different host species and localities. We discuss briefly the factors that have determined the remarkable invasive success of this parasite in freshwater systems in Mexico.

First record of the invasive Asian fish tapeworm Bothriocephalus acheilognathi in Honduras, Central America.

This paper provides the first report of the invasive Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti, 1934, in Honduras. The cestode was found in Profundulus portillorum (Cyprinodontiformes: Profundulidae), which represents a new host record, and which is a member of a genus faced with a variety of conservation challenges, now potentially complicated by the presence of this pathogenic cestode. Nearly complete sequence data from the ITS-1 5.8S and ITS-2 regions corroborate the determination based on morphological characteristics. Several species of carp were introduced to Honduras for aquaculture purposes in the early 1980s and the presence of the Asian fish tapeworm in Honduras may be related to these introductions. In addition, this report documents the currently known geographical distribution of this parasite in Central America, first recorded from Panamá and now from Honduras.

Investigations in associated protozoa-bacterial infections of cyprinids from a fish farm situated on the Jijia river in N-E of Romania / Investigações sobre infecções protozoárias-bacterianas associadas a ciprinídeos da exploração piscícola no rio Jijia, situado no NE da Romênia

In autumn 2011 in cyprinid farms located in Iasi on the Jijia river, several infections with bacterial strains and macroscopical external cysts on the skin were diagnosedwhich developed as a result of the stress induced by biotic and abiotic factors. On the examination of the cyst contents the presence of numerous spores was observed, mostly of the Dermocystidium sp genusThe samples were taken from the common carp (Cyprinus carpio) and crucian carp (Carassius auratus gibelio) species from the fish farm as well as from the Jijia River. 35 fish were examined, all of them showing cysts, fragmentation of their dorsal fin and congestion of the gills. Histological examination of the skin showed a field of multiple dermal cysts with round light eosinophilic formations (14-16µm) containing a central refractable body similar to that reported for Dermocystidium sp. Gills samples were taken from the affected areas for the SEM examination with the purpose of evaluating not only aspects of normal morphology, but also aspects of some modifications of the affected areas as well as the presence of the etiologically incriminated bacteria Pseudomonas fluorescens. The isolates were identified through phenotypic methods. All the strains that showed mobility and oxidase-positivity were tested using API 20 NE strip. Consequently, they were taxonomically grouped into the species Pseudomonas fluorescens. The scanning electron microscope (SEM) was used for the first time in the characterization of the bacterial lesions produced by Pseudomonas strains on Cyprinus carpio and Carassius auratus gibelio gills. The diagnosis of septicemia with conditional pathogen species of Pseudomonas fluorescens was correlated with the results of the physico-chemical investigations of water and the data concerning the breeding conditions of the investigated livestock...

No outono de 2011, em fazendas de ciprinídeos localizadas em Iasi, no rio Jijia, diversas infecções bacterianas e cistos externos macroscópicos na pele se desenvolveram como resultado do estresse induzido por fatores bióticos e abióticos. No exame do conteúdo dos cistos, a presença de diversos esporos foi observada, a maioria do gênero Dermocystidium sp. As amostras foram colhidas das seguintes espécies: carpa comum (Cyprinus carpio) e carpa cruciana (Carassius auratus gibelio) de fazenda piscícola, além do rio Jijia. Assim sendo, 35 peixes foram examinados, todos demonstrando cistos, fragmentação da barbatana dorsal e congestão das guelras. O exame histológico da pele mostrou um campo de múltiplos cistos dérmicos com formações circulares claras eosinofílicas (14-16µm) contendo corpo central refratado similar ao relatado para Dermocystidium sp. Amostras de guelras foram retiradas das áreas afetadas para exame MEV, com o propósito de se avaliar não apenas os aspectos da morfologia normal, mas também os aspectos de algumas modificações das áreas afetadas, além da presença da bactéria etiologicamente incriminada: Pseudomonas fluorescens. Os isolados foram identificados por meio de métodos fenotípicos. Todas as amostras que mostraram mobilidade e positividade-oxidase foram testadas usando-se fita API 20 NE. Consequentemente, estas foram taxonomicamente agrupadas na espécie Pseudomonas fluorescens. O microscópio eletrônico de varredura (MEV) foi usado pela primeira vez na caracterização de lesões bacterianas produzidas por Pseudomonas nas guelras de Cyprinus carpio e Carassius auratus gibelio. O diagnóstico de septicemia com espécies condicionais de patogênico de Pseudomonas fluorescens foi correlacionado com os resultados das investigações físico-químicas da água e de dados sobre as condições de reprodução dos animais investigados...

Investigations in associated protozoa-bacterial infections of cyprinids from a fish farm situated on the Jijia river in N-E of Romania / Investigações sobre infecções protozoárias-bacterianas associadas a ciprinídeos da exploração piscícola no rio Jijia, situado no NE da Romênia

In autumn 2011 in cyprinid farms located in Iasi on the Jijia river, several infections with bacterial strains and macroscopical external cysts on the skin were diagnosedwhich developed as a result of the stress induced by biotic and abiotic factors. On the examination of the cyst contents the presence of numerous spores was observed, mostly of the Dermocystidium sp genusThe samples were taken from the common carp (Cyprinus carpio) and crucian carp (Carassius auratus gibelio) species from the fish farm as well as from the Jijia River. 35 fish were examined, all of them showing cysts, fragmentation of their dorsal fin and congestion of the gills. Histological examination of the skin showed a field of multiple dermal cysts with round light eosinophilic formations (14-16µm) containing a central refractable body similar to that reported for Dermocystidium sp. Gills samples were taken from the affected areas for the SEM examination with the purpose of evaluating not only aspects of normal morphology, but also aspects of some modifications of the affected areas as well as the presence of the etiologically incriminated bacteria Pseudomonas fluorescens. The isolates were identified through phenotypic methods. All the strains that showed mobility and oxidase-positivity were tested using API 20 NE strip. Consequently, they were taxonomically grouped into the species Pseudomonas fluorescens. The scanning electron microscope (SEM) was used for the first time in the characterization of the bacterial lesions produced by Pseudomonas strains on Cyprinus carpio and Carassius auratus gibelio gills. The diagnosis of septicemia with conditional pathogen species of Pseudomonas fluorescens was correlated with the results of the physico-chemical investigations of water and the data concerning the breeding conditions of the investigated livestock.(AU)

No outono de 2011, em fazendas de ciprinídeos localizadas em Iasi, no rio Jijia, diversas infecções bacterianas e cistos externos macroscópicos na pele se desenvolveram como resultado do estresse induzido por fatores bióticos e abióticos. No exame do conteúdo dos cistos, a presença de diversos esporos foi observada, a maioria do gênero Dermocystidium sp. As amostras foram colhidas das seguintes espécies: carpa comum (Cyprinus carpio) e carpa cruciana (Carassius auratus gibelio) de fazenda piscícola, além do rio Jijia. Assim sendo, 35 peixes foram examinados, todos demonstrando cistos, fragmentação da barbatana dorsal e congestão das guelras. O exame histológico da pele mostrou um campo de múltiplos cistos dérmicos com formações circulares claras eosinofílicas (14-16µm) contendo corpo central refratado similar ao relatado para Dermocystidium sp. Amostras de guelras foram retiradas das áreas afetadas para exame MEV, com o propósito de se avaliar não apenas os aspectos da morfologia normal, mas também os aspectos de algumas modificações das áreas afetadas, além da presença da bactéria etiologicamente incriminada: Pseudomonas fluorescens. Os isolados foram identificados por meio de métodos fenotípicos. Todas as amostras que mostraram mobilidade e positividade-oxidase foram testadas usando-se fita API 20 NE. Consequentemente, estas foram taxonomicamente agrupadas na espécie Pseudomonas fluorescens. O microscópio eletrônico de varredura (MEV) foi usado pela primeira vez na caracterização de lesões bacterianas produzidas por Pseudomonas nas guelras de Cyprinus carpio e Carassius auratus gibelio. O diagnóstico de septicemia com espécies condicionais de patogênico de Pseudomonas fluorescens foi correlacionado com os resultados das investigações físico-químicas da água e de dados sobre as condições de reprodução dos animais investigados.(AU)

Biomphalaria straminea and Biomphalaria glabrata (Mollusca: Planorbidae) as new intermediate hosts of the fish eyefluke Austrodiplostomum compactum (Trematoda: Diplostomidae) in Brazil.

Austrodiplostomum compactum has been involved in cases of ocular diplostomiasis in several species of fish in Brazil, but the molluscan intermediate hosts of the parasite remain unknown. In the present study, malacological surveys were carried out at Pampulha Reservoir, Belo Horizonte, Minas Gerais, Brazil, between January 2009 and July 2012. A total of 16,119 specimens of Biomphalaria spp. were collected and examined, of which 68/14,948 specimens (0.45%) of Biomphalaria straminea and 6/541 (1.11%) of Biomphalaria glabrata were found harboring a strigeid cercariae. Groups of 5 specimens of Cyprinius carpio were experimentally infected with these cercariae (100 larvae/fish), and metacercariae were recovered from the eyes of the fish, 65 days after infection, with a mean intensity of infection of 10.4 (8-13) metacercariae/fish. Morphological study on cercariae and metacercariae identified them as A. compactum . This is the first record of cercariae of A. compactum in Brazil, and B. straminea and B. glabrata as new intermediate hosts for the parasite.

[Evaluation of 4 vermifuges against Bothriocephalus acheilognathi in carp]. / Evaluación de cuatro vermicidas contra Bothriocephalus acheilognathi en carpas.

With the aim to evaluate the efficacy of four vermicides, praziquantel, mebendazole, nitroscanate and triclorfon in the control of Bothriocephalus acheilognathi in carps, one hundred and sixty, two year-old carps (Ctenopharyngodon idellus) with an average weight of 120 g and a mean parasitic burden of 115.5 parasites/fish were used. Five groups of 30 fish each were randomly formed. Each group was then subdivided in three groups, each of 10 individuals/pond. The three subgroups of group A received 30, 50 and 70 mg/Kg of praziquantel, respectively. Groups B and C received 2.2, 4.4, and 6.8 mg/Kg of mebendazole suspension and mebendazole solution respectively; groups D and E received 10, 30, 50 mg/Kg; and 2.0, 4.0, 6.0 mg/Kg of nitroscanate and trichlorfon respectively. Group F of 10 fish remained as non-treated control. Praziquantel showed 100% of efficacy for all doses, therefore it was excluded from the statistical analysis. The subgroups B, C, D and E compared with the non-treated control were statistically significant (P < 0.01); showing in all treatments an additive effect, the higher the dose the better efficacy, except trichlorfon which showed a different tendency, having no explanation on that matter.