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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.

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Coryphaena hippurus, or dolphinfish, is a popular species of fish pursued by sport fishing tournaments of the Yacht Club of Rio de Janeiro, wich markets then in its own fish market, because of its desirable flesh. However, the presence of helminths, including in the musculature, results in commercial losses due their repugnant appearance. The aim of this investigation was to identify taxonomically these helminthes using morphometrical and morphological data from analyses using optical and scanning electron microscopy, and to determine their hygienic-sanitary significance. Seven specimens of C. hippurus collected in January and November 2014 were necropsied and had their organs investigated. The helminths encountered included plerocercoids of Tentacularia coryphaenae, a trypanorhynch cestode. The seven specimens of C. hippurus were parasitized by a total of 204 plerocercoids, with infection sites being musculature, mesentery, stomach and liver serosa. Beyond the repugnance of these parasites, the presence of plerocercoids is worrisome because of the potential risk of allergic reactions by humans, thereby reinforcing the hygienicsanitary significance of monitoring for these parasites.

Coryphaena hippurus, ou dourado é uma espécie popular de peixe pescada em torneios de pesca esportiva do Iate Clube do Rio de Janeiro, a qual é comercializada na sua própria peixaria, devido à apreciação de sua carne. Contudo a presença de helmintos, inclusive na musculatura, resulta em perdas comerciais devido ao seu aspecto repugnante. O objetivo desta investigação foi identificar taxonomicamente estes helmintos utilizando dados de análises morfométricas e morfológicas através das microscopias ótica e eletrônica de varredura e determinar sua significância higiênicosanitária. Em janeiro e novembro de 2014, sete espécimes de C. hippurus foram necropsiados e seus órgãos investigados. Os helmintos encontrados foram identificados como plerocercoides de Tentacularia coryphaenae, um cestoide Trypanorhyncha. Os sete espécimes de C. hippurus estavam parasitados por um total de 204 plerocercoides, tendo como os sítios de infecção a musculatura, mesentério, estômago e serosa do fígado. Além da repugnância destes parasitos, a presença de plerocercoides é um fator preocupante porque há o risco de reações alérgicas em humanos, por isto salienta a sua significância higiênico-sanitária no monitoramento destes parasitos.

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Coryphaena hippurus, or dolphinfish, is a popular species of fish pursued by sport fishing tournaments of the Yacht Club of Rio de Janeiro, wich markets then in its own fish market, because of its desirable flesh. However, the presence of helminths, including in the musculature, results in commercial losses due their repugnant appearance. The aim of this investigation was to identify taxonomically these helminthes using morphometrical and morphological data from analyses using optical and scanning electron microscopy, and to determine their hygienic-sanitary significance. Seven specimens of C. hippurus collected in January and November 2014 were necropsied and had their organs investigated. The helminths encountered included plerocercoids of Tentacularia coryphaenae, a trypanorhynch cestode. The seven specimens of C. hippurus were parasitized by a total of 204 plerocercoids, with infection sites being musculature, mesentery, stomach and liver serosa. Beyond the repugnance of these parasites, the presence of plerocercoids is worrisome because of the potential risk of allergic reactions by humans, thereby reinforcing the hygienicsanitary significance of monitoring for these parasites.(AU)

Coryphaena hippurus, ou dourado é uma espécie popular de peixe pescada em torneios de pesca esportiva do Iate Clube do Rio de Janeiro, a qual é comercializada na sua própria peixaria, devido à apreciação de sua carne. Contudo a presença de helmintos, inclusive na musculatura, resulta em perdas comerciais devido ao seu aspecto repugnante. O objetivo desta investigação foi identificar taxonomicamente estes helmintos utilizando dados de análises morfométricas e morfológicas através das microscopias ótica e eletrônica de varredura e determinar sua significância higiênicosanitária. Em janeiro e novembro de 2014, sete espécimes de C. hippurus foram necropsiados e seus órgãos investigados. Os helmintos encontrados foram identificados como plerocercoides de Tentacularia coryphaenae, um cestoide Trypanorhyncha. Os sete espécimes de C. hippurus estavam parasitados por um total de 204 plerocercoides, tendo como os sítios de infecção a musculatura, mesentério, estômago e serosa do fígado. Além da repugnância destes parasitos, a presença de plerocercoides é um fator preocupante porque há o risco de reações alérgicas em humanos, por isto salienta a sua significância higiênico-sanitária no monitoramento destes parasitos.(AU)

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The enemy release hypothesis is frequently used to explain the success of invaders, postulating that introduced species have escaped from their native enemies, including parasites. Here, we tested this hypothesis for the tucunaré (Cichla piquiti), a predatory cichlid, and its endoparasites. First, the parasites and their influence on the condition of the hosts in the native environment, the Tocantins River (TO), were compared to an environment where the fish was introduced, the Paraná River (PR). Then, comparisons of the abundances of Diplostomidae eye flukes and Contracaecum sp. larval nematodes were made between the introduced tucunaré and two predators native to the PR, Hoplias malabaricus and Raphiodon vulpinus. Nine species of endoparasites were recorded in total, five of which occurring in both localities. Total species richness did not differ between localities, and fish condition was negatively affected by the cestodes Sciadocephalus megalodiscus only in the TO. In the PR, abundance of Contracaecum sp. did not differ between natives and invaders; however, eye flukes were more abundant in the native fish H. malabaricus, which may represent an advantage to the invader if they were competing for prey. These results did not support the idea that the escape from parasites favoured the establishment of C. piquiti in the PR. Instead, the escape from the parasites' effects seems a better explanation, and further studies examining effects on host physiology and/or fitness in the native and introduced ranges are needed.

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The Brazilian savannah-like area, the Cerrado region, covers large areas of the country and provides a habitat for a multitude of different animal species. The giant anteater (Myrmecophaga tridactyla) is geographically widespread and one of the typical inhabitants of the Cerrado. They are listed as vulnerable by the International Union for Conservation of Nature and Natural Resources. A population loss of at least 30 % over the past 10 years has been estimated based on local extinctions, habitat loss and deaths caused by fires, roadkills and hunting. Little is known about ecological and in particular parasitic conditions of this highly specialised insectivore species. During September and November 2010 we examined three roadkilled giant anteater for the presence of metazoan ecto- and endoparasites. Besides the cestode species Oochoristica tetragonocephala and the tick species Amblyomma nodosum, we found for the first time the flea Tunga penetrans. Beside morphological flea species identification, we compared a fragment of the 16S rRNA gene of eggs, a molecular method utilised for the first time in this combination. The identification of T. penetrans in M. tridactyla represents a new host record and expands the host and distribution range of the zoonotic flea species.

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We evaluated the relationship between infection by proteocephalid cestodes and the sex and weight classes of tucunaré (Cichla piquiti) captured between August 1999 and June 2001 in the Volta Grande Reservoir, Minas Gerais, Brazil. A total of 96 fish, 75.9 ± 9.3% males and 88.9 ± 6.4% females, were parasitized by Proteocephalus macrophallus and P. microscopicus, with total mean intensities of 76.6 ± 23.9 and 145.2 ± 36.7, respectively, during this period. In the majority of the months analysed, males showed 71.4-100% prevalence of parasitism and females 80-100%. Although there was no significant difference, females showed a higher mean intensity of infection (145.2 ± 36.7) than males (76.6 ± 23.9). Fish weighing 300-800 g showed a higher mean abundance of parasites (P < 0.05) compared with the biggest specimens weighing 801-2750 g. Analysing both males and females together, the greatest mean intensities of infection were found in October and December (P < 0.05) independent of the year, which coincides with the months of highest rainfall. These results show that fish living in reservoirs may be more susceptible to intermediate hosts than those that live in rivers.

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From February to October 2007, thirty specimens of the king mackerel, Scomberomorus cavalla (Cuvier, 1829) were purchased from markets in the municipalities of Niterói and Rio de Janeiro. The fishes were measured, filleted and further had their organs investigated for helminths. Ten out of the thirty fish specimens were parasitized with anisakid nematodes represented by Anisakis sp. and Contracaecum sp. with prevalence of 1% and 16%, mean intensity of 2 and 3.31 and mean abundance of 0.02 and 0.53, respectively. The infection range with Contracaecum sp. was 1-9. The sites of infection were the stomach serosa and mesentery. Seventeen fish specimens (53%) out of the 30 investigated were parasitized with Trypanorhyncha metacestodes, identified as Callitetrarhynchus gracilis, Pterobothrium crassicole, Callitetrarhynchus speciosus and Tentacularia coryphaenae in the mesentery, with prevalence of 26, 20, 6, 3%, intensity and mean intensity of 3.25, 3.5, 1, 2 and mean abundance of 0.86, 0.7, 0.06 and 0.06, respectively. The infection range due to C. gracilis and P. crassicole were of 1-5 and 1-20, respectively. Anisakis sp., C. speciosus and P. crassicole are reported in S. cavalla for the first time. Considerations on the zoonotic potential of the parasites and their rules in sanitary inspection are presented.

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This paper reports the parasites found in three commercially exploited bivalve molluscs (Mytella guyanensis, Anomalocardia brasiliana and Iphigenia brasiliana) of an estuarine region of Ilhéus, south of Bahia, Brazil (14 degrees 48'23''S; 39 degrees 02'47''W). Samples of 20 individuals of each species were collected fortnightly from August 2005 to August 2006. A total of 1480 individuals was collected and processed by standard histologic techniques; the histologic sections were stained with Harris haematoxylin and eosin and examined with light microscope. The water temperature in the study area varied from 24 to 30.5 degrees C and the salinity from 0 to 23ppt. Remarkable differences were found in the parasitic community between the three mollusc species involved in the study, which occupied different habitats in the estuarine region of the Cachoeira river. The following parasites were found: intracellular rickettsia-like colonies in digestive epithelia; intracellular gregarine Nematopsis sp. in gills, mantle, gonad, digestive gland and foot muscle; sporocysts of a Bucephalidae trematode in gonads, mantle, gills, digestive gland and foot; unidentified digenetic metacercariae in digestive gland and gonad; metacestodes of Tylocephalum sp. in connective tissue in the digestive gland and in gonad; and an unidentified metazoan in mantle and intestinal lumen. No significant temporal variation in the prevalence of any parasite was detected, which could be due to the narrow temperature range of the region and the absence of patterns of salinity and rainfall variation through the year. The infestation by sporocyst was the only pathological threat detected for the studied populations because of its potential for host castration. The low infection intensity and/or prevalence of the other parasites and the lack of obvious lesions suggest that there is no other serious pathological risk for the studied mollusc populations.

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Specimens of fleas Ctenocephalides felis felis (1052 female symbol/448 male symbol), obtained from 150 dogs in Centro de Controle de Zoonoses de Belo Horizonte, Minas Gerais, Brazil, were dissected and examined for endosymbionts. Three protozoan, Nolleria pulicis, a gregarine (Actinocephalidae) and Leptomonas sp., together with one cestode, Dipylidium caninum were identified. Infections by N. pulicis and Leptomonas sp. occurred mainly in the warm-rainy period. The prevalence and distribution of these endosymbionts in fleas derived from Brazil and South America, and the their variation according to sex and season, are reported for the first time.

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Recombinant DNA studies have been focused on developing vaccines to different cestodes. But few studies involving Dipylidium caninum molecular biology and genes have been done. Only partial sequences of mitochondrial DNA and ribosomal RNA gene are available in databases. Any molecular work with this parasite, including epidemiology, study of drug-resistant strains, and vaccine development, is hampered by the lack of knowledge of its genome. Thus, the knowledge of specific genes of different developmental stages of D. caninum is crucial to locate potential targets to be used as candidates to develop a vaccine and/or new drugs against this parasite. Here we report, for the first time, the sequencing of a fragment of a D. caninum expressed gene.

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