Trypanorhynch Cestode Research Articles

Larvae trypanorhynch (Cestoda) infecting the dusky flounder, Syacium papillosum (Paralichthyidae: Pleuronectiformes) in the continental shelf of the Yucatan Peninsula, Mexico.

Trypanorhynch cestode larvae were found parasitizing specimens of dusky flounder Syacium papillosum (Linnaeus, 1758) in the Southeastern Gulf of Mexico (s-GoM). Plerocercoids were recovered from a total of 194 flatfish, embedded in the intestine and stomach wall. Trypanorhynch were identified using morphology and a molecular phylogeny using newly sequenced partial 28S (region D1-D3) ribosomal DNA in combination with data derived from other species of trypanorhynchs available from GenBank. Larvae representing three genera of trypanorhynch cestodes, Nybelinia Poche, 1926; Kotorella Euzet & Radujkovic, 1989 and Oncomegas Dollfus, 1929 were found in dusky flounder specimens in the s-GoM. These plerocercoids represent six species: Nybelinia sp. 1, Nybelinia sp. 2, Nybelinia sp. 3, Nybelinia sp. 4, Kotorella pronosoma (Stossich, 1901) and Oncomegas wageneri (Linton, 1890) Dollfus, 1929. All cestode specimens in this study represent new locality records for their respective species.

Trypanorhynch cestode larvae parasitizing Hyporthodus niveatus (Valenciennes, 1828) (Actinopterygii) collected from fish markets in the municipality of Niterói, RJ, Brazil

This study is a continuation of the survey about helminths parasitizing the white grouper, Hyporthodus niveatus, a marine fish purchased from fish markets in the municipality of Niterói, Rio de Janeiro State, Brazil. Specifically, this study reports the results of an investigation concerning trypanorhynch cestodes parasitizing this host. A total of 20 fish specimens were caught by professional fishermen off the coast of Rio de Janeiro State. The fish were measured and necropsied, and their organs were investigated for trypanorhynch cestodes. A total of 13 H. niveatus were parasitized by 67 specimens of trypanorhynch cestode plerocerci that were found infecting the visceral serosa, stomach, intestine, and abdominal musculature. The taxonomic identification of these parasites was based on morphological and morphometric characters using bright-field and scanning electron microscopies. Five trypanorhynch species were identified: Pintneriella gymnorhynchoides, Grillotia (Christianella) carvajalregorum, Pterobothrium crassicolle, Callitetrarhynchus gracilis, and Callitetrarhynchus speciosus, and their parasitic indices were presented. This is the first report on the occurrence of P. gymnorhynchoides in the Western Atlantic Ocean. Apart from the repugnance, the presence of cestode plerocerci is worrisome because of the potential risk of allergic reactions, thereby reinforcing the hygienic-sanitary significance of monitoring these parasites.

Confocal laser scanning microscopy (CLSM) as a new tool for morphological characterisation of both newly collected and museum voucher specimens of the Trypanorhyncha Diesing, 1863 (Platyhelminthes: Cestoda).

Taxonomic issues within Trypanorhyncha, e.g., the inaccurate light microscopic visualisation of the hook patterns, are solvable by confocal laser scanning microscopy (CLSM). We applied CLSM imaging to study Trygonicola macropora (Shipley et Hornell, 1906) and Dollfusiella michiae (Southwell, 1929) from Neotrygon caeruliopunctata Last, White et Séret from Bali, Indonesia. To illustrate the strength and limitations of CLSM, images of Otobothrium cysticum (Mayer, 1842) and Symbothriorhynchus tigaminacantha Palm, 2004, both permanent mounts from a collection, were also processed. The CLSM created image stacks of many layers, and edited with IMARIS Software, these layers resulted in three-dimensional images of the armature patterns and internal organs of both species. BABB (benzylalcohol and benzylbenzuolate) clearing was applied to T. macropora. We conclude that trypanorhynch cestodes stained with Mayer-Schuberg's acetic carmine permanently mounted in Canada balsam are suitable for CLSM, allowing detailed analyses of museum type-material as well as freshly collected and processed worms. BABB resulted in imaging the testes in detail, suggesting other stains to be used for CLSM in trypanorhynch cestode research. Application of CLSM for studies of other cestode groups is highly recommended.

Elasmobranchs from Indonesian Waters: Feeding Ecology and Trypanorhynch Cestode Fauna Composition to Support Efforts in Shark and Ray Conservation

PurposeThe stomachs and spiral valves of sharks and rays were examined for their trypanorhynch (Cestoda) parasite fauna and dietary items to infer feeding ecology. In Indonesia, sharks and rays have been experiencing increasing awareness and conservation in the recent years due to high fisheries activities and to avoid future species extinction.MethodsThe samples were collected in 2009 from two different sampling sites at the southern coasts of Java and Bali in Indonesia. The parasite fauna was studied for 41 elasmobranch fishes. Amongst these, three shark species, Carcharhinus sorrah, Carcharhinus sp. I and Squalus megalops and seven ray species, Brevitrygon heterura, B. cf. heterura, Gymnura zonura, Maculabatis gerrardi, Mobula kuhlii, Neotrygon cauruleopuncatata and Rhinobatos penggali were studied. Four additional specimens, belonging to the shark species Carcharhinus sp. II and Mustelus cf. manazo and the ray species Maculabatis gerrardi were studied from the waters of South Bali.ResultsAnalyses of the feeding ecology of the ray M. gerrardi revealed distinct differences between both sampling sites, indicating the presence of ecological differences between the geographically independent regions. A total of 11 different trypanorhynch species/taxa belonging to the five families Eutetrarhynchidae (5), Gilquiniidae (1), Lacistorhynchidae (1), Pterobothriidae (1) and Tentaculariidae (3) were found. Ten trypanorhynch species from Penyu Bay and four species from South Bali could be identified. Two taxa that might represent new species were collected: Dollfusiella sp. from Brevitrygon heterura and Prochristianella sp. from Maculabatis gerrardi.ConclusionsThe present paper gives insights in using the trypanorhynch cestode community in combination with feeding ecology analyses to support conservation of elasmobranchs in Indonesian waters.

Marine parasite in a freshwater wetland: new host and geographical records of Progrillotia dasyatidis (Cestoda: Trypanorhyncha) from Gasterosteus aculeatus (Actinopterygii: Gasterosteidae) in Bulgaria, with comments on its life-cycle.

Plerocerci of the trypanorhynch cestode Progrillotia dasyatidis Beveridge, Neifar & Euzet, (Progrillotiidae) were isolated from the gallbladder of the three-spined stickleback Gasterosteus aculeatus from a small freshwater marsh in the Lake Atanasovsko Wetlands, a coastal area adjacent to the Black Sea coast, Bulgaria. The parasite was recorded in five out of 134 fish individuals studied (prevalence 3.73%, intensity 1-7, mean intensity 2.40 ± 1.17 and mean abundance 0.09 ± 0.06). A description of the plerocerci is presented, expanding data on intraspecific variation. The present report is the first record of P. dasyatidis from G. aculeatus (new host record) and from Bulgaria (new geographical record). Recording only plerocerci with evaginated scoleces in the sticklebacks is consistent with the hypothesis that teleosts are paratenic hosts and not intermediate hosts of P. dasyatidis.

Three methods to measure parasite aggregation using examples from Australian fish parasites

Abstract The distribution of parasites in host populations is integral to simulations of parasite populations. We compared three methods to measure parasite aggregation, namely the Hoover, coefficient of variation and I10 indices, using field data from a range of fish parasites. These included anisakid nematodes, trypanorhynch cestodes and polyopisthocotylean monogeneans from 10 previously published studies and one unpublished study. Positive correlations among the three methods were high. Standard errors and estimated biases obtained by bootstrap methods were smallest for the Hoover index. There was no evidence for a bias–variance trade‐off. The analyses suggest that the Hoover index is to be preferred as a measure of aggregation although difficulties remain in deriving theoretical and operational definitions of aggregation.

A new genus and two new species of trypanorhynch cestodes (Tentaculariidae) from the sharksCarcharhinus sorrah(Müller & Henle) andSphyrna lewini(Griffith & Smith) from off the coasts of Malaysia and Mexico.

Two new tentaculariid species were found infecting carcharhiniform sharks from off the coasts of Malaysian Borneo and the southwestern coast of the Baja California Sur, Mexico. Both new species exhibit a homeoacanthous heteromorphous basal and a homeoacanthous homeomorphous metabasal armature. Since this hook arrangement is unique within the tentaculariids and the taxonomy in this group deeply depends on the tentacular armature, Reimeriella n. g. is erected to accommodate R. varioacantha n. sp. ex Carcharhinus sorrah (Müller & Henle) and R. mexicoensis n. sp. ex Sphyrna lewini (Griffith & Smith). Unlike R. mexicoensis n. sp., R. varioacantha n. sp. has a pars bothrialis not overlapping the pars bulbosa and the number of testes is higher. Reimeriella mexicoensis n. sp. possesses very large uncinate to falcate hooks in the basal armature, while in R. varioacantha n. sp. these hooks are almost the same in size as the remaining hooks in both the basal and metabasal armature. The latter species is the first tentaculariid species where the metabasal armature very closely resembles an eutetrarhynchid with a heteroacanthous typical homeomorphous metabasal armature and a high number of spiniform hooks per half spiral row (10-11 vs 6-7 in R. mexicoensis n. sp.) in the metabasal and apical armature. This pattern provides further morphological evidence for the close relationship of the Eutetrarhynchoidea and the Tentacularioidea. Reimeriella varioacantha n. sp. enriches the trypanorhynch fauna from off the coast of Malaysian Borneo while R. mexicoensis n. sp. is a novel record of a tentaculariid trypanorhynch from the Mexican Pacific.

Trypanorhynch cestodes parasitizing Mugil liza (Mugiliformes: Mugilidae) commercialized in the state of Rio de Janeiro, Brazil.

The aim of the present study was to identify, through morphological and morphometric analyses, the species of trypanorhynch cestodes found as plerocerci in the intestinal serosa of Mugil liza and to determine their parasitic indices. One hundred and fifty specimens of this mullet collected off the coast of the state of Rio de Janeiro were necropsied and the trypanorhynch cestodes found were fixed and preserved as whole mounts for morphological analysis. The plerocerci were identified as Callitetrarhynchus gracilis and Pterobothrium crassicole, both with a prevalence of 0.67%, an intensity of 1 and abundance of 0.0067, in single infections. This is the first record of a trypanorhynch cestode parasitizing M. liza in Brazil. Although the parasitic indexes were low, from a hygienic-sanitary perspective the plerocerci of these species are visible to the naked eye, and thus can disgust consumers and make marketing the fish unfeasible.

Phylogeny, genetics, and the partial life cycle of Oncomegas wageneri in the Gulf of Mexico.

Despite the diversity and ecological importance of cestodes, there is a paucity of studies on their life stages (i.e., complete lists of intermediate, paratenic, and definitive hosts) and genetic variation. For example, in the Gulf of Mexico (GoM) 98 species of cestodes have been reported to date; however, data on their intraspecific genetic variation and population genetic studies are lacking. The trypanorhynch cestode, Oncomegas wageneri, is found (among other places) off the American Western Atlantic Coast, including the GoM, and has been reported as an adult from stingrays and from several teleost species in its larval form (as plerocerci). This study represents the first report of 2 previously unregistered definitive hosts for O. wageneri, namely the Atlantic sharpnose shark Rhizoprionodon terraenovae and the southern stingray Hypanus americanus. In this work, partial sequences of the 28S (region D1–D2) ribosomal DNA were analyzed to include O. wageneri within an eutetrarhynchoid phylogenetic framework. All O. wageneri individuals (which included plerocerci and adults) were recovered as monophyletic and Oncomegas celatus was identified as the sister species of O. wageneri. Furthermore, population genetic analyses of O. wageneri from the southern GoM were carried out using DNA sequences of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene, which reflected high genetic variation and a lack of genetic structure among the 9 oceanographic sampling sites. Based on these results, O. wageneri is panmictic in the southern GoM. More extensive sampling along the species entire distribution is necessary to make more accurate inferences of population genetics of O. wageneri.

Callitetrarhynchus gracilis (Rudolphi, 1819) Pintner, 1931 (Cestoda: Trypanorhyncha) parasitizing the musculature of Sardinella brasiliensis (Steindachner, 1879) (Actinopterygii) off the coast of the state of Rio de Janeiro, Brazil.

Cestodes of the order Trypanorhyncha can frequently be found infecting the muscles of several marine fish species, and lead to a repugnant aspect of the fish and rejection by consumers. The Brazilian sardinella, Sardinella brasiliensis, occurs from the Gulf of Mexico and the Caribbean to northern Uruguay. In southeastern Brazil, fishing for the species is very intensive since it generates significant revenue as one of the most commonly consumed fish and an important element of the canned fish industry. The aims of the present study were to identify and report the occurrence of tiny cestodes (3 mm—6.6 mm) in the musculature of Brazilian sardinella that were purchased in the São Pedro fish market in the municipality of Niterói, state of Rio de Janeiro, Brazil. From October 2013 to November 2016, 75 specimens of S. brasiliensis were investigated. The trypanorhynch cestodes encountered were identified as plerocerci of Callitetrarhynchus gracilis using morphological, morphometric and molecular data. Parasitic indices were calculated, and the cestodes infection of the musculature of Brazilian sardinella had the following values: prevalence, 40%; mean intensity, 3.47; mean abundance, 1.39; and range of infection, 1–18, specimens. The presence of this trypanorhynch cestode in the musculature of Brazilian sardinella is an important indicator of fish hygiene.

Grillotia (Cestoda: Trypanorhyncha) plerocerci in an anglerfish (Lophius piscatorius) from the Tyrrhenian Sea.

Trypanorhynch cestodes are common parasites of marine fish with complicated life cycles which have been suggested as model taxa to study the evolution of marine helminth parasites and their life cycles. Among the Trypanorhyncha, the genus Grillotia includes 18 valid species, of which only four have been found in Mediterranean fish hosts. Morphological, histopathological, and molecular data are presented on a massive Grillotia plerocercus infection in an anglerfish (Lophius piscatorius) from the Tyrrhenian Sea. BLAST analysis of the 28S rDNA sequences revealed 99% similarity between specimens here found and a G. (Bathygrillotia) rowei sequence available in GenBank with a total of six nucleotide site differences. A morphological study suggested that the Grillotia sp. here reported did not match important characters to those previously reported from the Mediterranean Sea. Taking in account these differences, we prefer to place these specimens within Grillotia sensu lato until more material is available for study including sequences from adult specimens of Grillotia spp. from the Mediterranean Sea.

Occurrence of larvae of trypanorhynch cestodes in snappers (Lutjanidae) from northeast Brazil.

Three species of snappers from artisanal, small-scale fisheries were examined for the presence of parasites. A total of 139 lutjanid fish were collected: 69 specimens of Lutjanus analis, 47 specimens of Lutjanus vivanus, and 23 specimens of Lutjanus synagris. Encysted plerocercoid of trypanorhynch cestodes found at necropsy in the viscera of snappers were sampled for parasitological analysis. These plerocercoid larvae belong to the genera Floriceps, Pseudogrillotia , and Oncomegas. Although these parasites do not have any zoonotic potential, fish with heavy loads of plerocercoids are rejected during inspection as they compromise meat hygiene. Our findings suggest that light larval cestode infections in lutjanids would not lead to consumer rejection of the food product. The occurrence of Floriceps sp. in L. analis and in L. synagris, of Pseudogrillotia sp. in L. vivanus and in L. synagris , and of Oncomegas sp. in L. synagris are new findings in these fish species. These parasites are new to these fish species and have not been reported in snappers from the northeast coast of Brazil. The results contribute to the existing body of knowledge about the parasitic fauna of fish and its distribution along the coastline of Brazil.

Detection of Grillotia erinaceus (Cestoda: Trypanorhyncha) in Megalaspis cordyla (Linnaeus, 1758) (Perciformes: Carangidae) from the Persian Gulf

Cestode species of the genus Grillotia Guiart, 1927 are among the most commonly encountered trypanorhynch cestodes, either as the adult in elasmobranchs or as the plerocercus (larval stage) in teleost fishes. In this study, we report Grillotia erinaceus (Cestoda: Trypanorhyncha) from a teleost fish, Torpedo scad, Megalaspis cordyla (Linnaeus, 1758), from the Persian Gulf for the first time. The specimens of G. erinaceus were obtained from subcutaneous tissues of Torpedo scad collected from a fish market in Bandar Abbas, Iran. No reaction, inflammation or exudate was seen in examined tissues.

Larvas de nematoides e cestoides de importí­¢ncia higiênico-sanitária em Lopholatilus villarii (Actinopterygii) no Estado do Rio de Janeiro, Brasil

O peixe batata, Lopholatilus villarii, ocorre do Brasil í­Â Argentina e possui carne apreciada e comercialmente importante. O objetivo deste estudo foi identificar as larvas de nematoides Anisakidae e Raphidascarididae e cestoides Trypanorhyncha em espécimes de L. villarii obtidos em mercados de pescado do municí­­pio de Niterói, Estado do Rio de Janeiro, Brasil, calcular seus í­­ndices parasitários e apresentar os sí­­tios de infecção. De agosto de 2015 a setembro de 2016 foram investigados 31 espécimes de L. villarii. Os peixes foram necropsiados e suas ví­­sceras e musculatura, analisadas. Os helmintos encontrados foram processados de acordo com as técnicas em helmintologia para permitir a identificação taxonômica. Dos 31 peixes analisados, 28 (90,3%) estavam parasitados com larvas de nematoides anisaquí­­deos e rafidascaridí­­deos: Anisakis sp., Terranova sp., Pseudoterranova sp. e Hysterothylacium deardorffoverstreetorum (L3 e L4) e plerocercos de cestoides Trypanorhyncha: Otobothrium sp. Seus í­­ndices parasitários foram calculados. Os helmintos estavam parasitando, principalmente, as serosas do intestino, estômago e fí­­gado e H. deardorffoverstreetorum estava também na musculatura abdominal de um peixe. Este é o primeiro registro de nematoides anisaquí­­deos e rafidascaridí­­deos e cestoides Trypanorhyncha em L. villarii. Aspectos higiênico-sanitários foram discutidos.

Caracteres morfológicos e significí­¢ncia higiênico sanitária de Tentacularia coryphaenae em Coryphaena hippurus do Brasil

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 própria peixaria do clube, devido í­Â 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 significí­¢ncia higiênico-sanitária. 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 sí­­tios de infecção a musculatura, mesentério, estômago e serosa do fí­­gado. Além da repugní­¢ncia destes parasitos, a presença de plerocercoides é um fator preocupante, porque há o risco de reações alérgicas em humanos, salientando-se, então, a significí­¢ncia higiênico-sanitária no monitoramento destes parasitos.

Larval trypanorhynch cestodes in teleost fish from Moreton Bay, Queensland

During a helminthological examination of teleost fish of Moreton Bay (Qld, Australia), 976 fish from 13 orders, 57 families and 133 species were examined and nine species of trypanorhynch metacestodes were identified. Callitetrarhynchus gracilis (Rudolphi, 1819) was the most frequently encountered species, found in 16 species of fish, with Callitetrarhynchus speciosus (Linton, 1897), Pterobothrium pearsoni (Southwell, 1929), Otobothrium alexanderi Palm, 2004, Otobothrium mugilis Hiscock, 1954, Otobothrium parvum Beveridge & Justine, 2007, Proemotobothrium southwelli Beveridge & Campbell, 2001, Pseudotobothrium dipsacum (Linton, 1897) and Heteronybelinia cf. heteromorphi Palm, 1999 occurring in fewer host species and at lower prevalences. Comparisons are made with studies elsewhere in the world and specifically within the South-west Pacific. Of the best studied regions in the South-west Pacific (Heron Island, Lizard Island, New Caledonia and now Moreton Bay), the fauna from Moreton Bay was found to be the most distinctive, with fauna from the three reef locations sharing 35–48% of species between sites and just 12–24% with Moreton Bay. The fauna of trypanorhynch cestodes from Lizard Island and New Caledonia was found to be the most similar.

Prochristianella clarkeae Beveridge, 1990 (Eutetrarhynchidae): a species complex or a species with intraspecific variation in the distribution of its tegumental microtriches?

The microthrix pattern of common forms of the trypanorhynch cestode Prochristianella clarkeae Beveridge, 1990 on which the microscopically visible microtriches almost extended to the posterior end of the scolex was described using SEM and compared to other forms for which this pattern was different. The proximal bothrial surface and the scolex peduncle of all the examined specimens were covered with palmate spinitriches and papilliform filitriches. Unlike the common specimens of P. clarkeae, on the surface of those specimens with unusual distributions of microtriches as well as those on which the microscopically visible microtriches were not observable, palmate spinitriches extended to the mid-pars vaginalis and not to the posterior end of the scolex. Statistical tests did not detect any significant difference in the measurements of the specimens possessing different microthrix patterns. Furthermore, the partial 28S rDNA confirmed that the different forms were conspecific and that P. clarkeae possesses an intraspecific variation in the distribution of palmate spinitriches. Pastinachus sephen as a new host record was also established for Prochristianella clarkeae reported for the first time from the Persian Gulf.

A historical and contemporary consideration of the diet of the reef manta ray (Manta alfredi) from the Great Barrier Reef, Australia

The preserved stomach contents from the manta ray, collected in 1935, that provided the basis for the 2009 taxonomic resurrection of the species Manta alfredi, were examined. The majority of the material comprised calanoid copepods (61.7%) and trypanorhynch cestodes (34.6%), with minor contributions by arrow worms, a barnacle larva and a nematode. Comparison of the size-frequency distributions of stomach contents with that of zooplankton from the Great Barrier Reef region suggest that this manta ray preferentially ingested large copepods, or that the filter mechanism used to extract prey from the water was selective for prey items over 0.8mm in length. This is the first description of the diet of M. alfredi from stomach contents, and is consistent with previous inferences about what this species consumes.

Review of the genus Shirleyrhynchus Beveridge & Campbell, 1988 (Trypanorhyncha: Shirleyrhynchidae), with the resurrection of S. butlerae Beveridge & Campbell, 1988 and the description of S. panamensis n. sp.

A new species of trypanorhynch cestode is described from two species of stingrays, the Panamic stingray Urotrygon aspidura (Jordan & Gilbert) and the Pacific chupare Himantura pacifica (Beebe & Tee-Van) collected in the Golfo de Montijo in the Eastern Pacific Ocean off the coast of Panama. Shirleyrhynchus panamensis n. sp. represents an important addition to the family, which until now consisted of two monotypic genera. The new species is characterised by an elongate scolex with four, ovate bothria, presence of prebulbar organs, absence of gland cells within the muscular bulbs and an oncotaxy with a typical heteroacanthous, heteromorphous tentacular armature, a characteristic basal armature and the presence of a slight basal swelling. It is readily distinguished from its congeners by a smaller scolex and features of the oncotaxy, such as dissimilar hooks on opposing principle rows, a commencement of hook rows from the bothrial to the antibothrial surface and a much shorter basal armature. Although described only on the basis of immature worms lacking a strobila, the new species adds information on features of the oncotaxy within Shirleyrhynchus Beveridge & Campbell, 1988. Observation of the holotype of Shirleyrhynchus aetobatidis (Shipley & Hornell, 1906) revealed apparent differences from Australian specimens that have been described as Shirleyrhynchus butlerae Beveridge & Campbell, 1988 but which were later synonymised. Observations of type-specimens of S. butlerae also revealed differences from the original description and some morphological characteristics are amended. Shirleyrhynchus butlerae is herein resurrected and an amended generic diagnosis and a key to the identification of species are provided. The molecular voucher specimen of 'S. aetobatidis' utilised in previous molecular phylogenetic studies was re-observed which revealed a misidentification of the specimen with Parachristianella indonesiensis Palm, 2004.

Metazoan parasites of blue jack mackerel Trachurus picturatus (Perciformes: Carangidae) from Portuguese mainland waters.

Blue jack mackerel, Trachurus picturatus, is a carangid fish which constitutes an important commercial resource in the north-east Atlantic. Its metazoan parasite community from Portuguese mainland waters was investigated here for the first time. Nine parasite taxa were found, most of which are common parasites of Trachurus spp. The parasite community was broadly similar to that of the Atlantic horse mackerel, T. trachurus, from the same region, but two digenean species were detected in blue jack mackerel, Monascus filiformis and Tergestia sp., which did not occur in horse mackerel from this region. A comparison with the two previous studies of T. picturatus parasite communities shows that continental-shelf regions are characterized by higher prevalences of digenean trematodes and an absence of trypanorhynch cestodes, in contrast with oceanic regions.