Search

Currently, 24 species of Encotyllabe Diesing, 1850 (Monogenea: Capsalidae), are recorded as parasites on teleost fishes, but the validity of many species has been questioned due to deficient or incomplete descriptions. Almost all species in the genus have been described from one host species or closely related host species, suggesting host specificity, but some species, specifically Encotyllabe spari Yamaguti, 1934, have been reported from at least 19 species belonging to nine families in two orders (Perciformes and Scorpaeniformes) from Japan, Arabian Gulf and Brazil. Concerning Brazilian records of Encotyllabe spari and Encotyllabe cf. spari, seven species belonging to four families and two orders have been reported as hosts for this species. The aim of this study was to describe two new species of Encotyllabe from Brazil, previously considered as E. spari. Morphological and morphometric (multivariate analysis of proportional measurements standardized by total length) and molecular analysis (LSU rRNA and cox1 gene) were performed in order to identify the collected monogeneans. The description of two new species, namely Encotyllabe bifurcatum n. sp. and Encotyllabe parvum n. sp., parasitizing Pagrus pagrus and Orthopristis ruber, respectively, is the result of the three approaches. The main morphological differences from the most related species include a combination of body size, shape of the male copulatory organ, size and position of the testes. Our results suggest host specificity for members of Encotyllabe and specimens previously recorded as E. spari, other than those from the original description, must be revisited. [ABSTRACT FROM AUTHOR]

Incomplete original descriptions, the unavailability or poor conditions of specimens and the lack of detailed redescriptions have caused the validity of several species of the genus Encotyllabe Diesing, 1850 to be questioned. To date, seven of the recognized species were described upon one or two specimens, hindering study of intraspecific variations. This was made worse by considering few morphoanatomical differences sufficient to erect new species. Among Encotyllabe spp. occurring in Mediterranean waters, E. vallei was first described from the gilt-head bream Sparus aurata (Sparidae) off Italy. Although beautifully illustrated for a paper from that century, morphometric data for E. vallei from the type-host S. aurata remain unavailable. Previous records of E. vallei provided either morphometrical or molecular data, and its validity was questioned. We provide a redescription of E. vallei based on newly collected specimens from the S. aurata from the southwestern Mediterranean (off Algeria) using integrative taxonomy. Analysis of cox 1 sequences of E. vallei from S. aurata , compared to sequences from other sparid hosts, mainly Pagellus bogaraveo , revealed a divergence not exceeding 2%, suggesting a stenoxenic specificity for this monogenean. Given that P. bogaraveo is the type-host for Encotyllabe pagelli , we were tempted to suggest a synonymy between E. vallei and E. pagelli. We refrained from doing so because E. pagelli was first described from the Atlantic coast off Brest, France. Morphological data for Encotyllabe from P. bogaraveo are warranted assessing the host specificity of E. vallei and whether there might be a species complex within individual sparid fish species. [ABSTRACT FROM AUTHOR]

Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The capsalid monogeneans are important pathogens that generally infect marine fishes and have a substantial impact on fish welfare in aquaculture systems worldwide. However, the current mitogenome information on capsalids has received little attention, limiting the understanding of their evolution and phylogenetic relationships with other monogeneans. This paper reports the complete mitochondrial genomes of Capsala katsuwoni and Capsala martinieri for the first time, which we obtained using a next-generation sequencing method. The mitogenomes of C. katsuwoni and C. martinieri are 13,265 and 13,984 bp in length, respectively. Both species contain the typical 12 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a control region. The genome compositions show a moderate A+T bias (66.5% and 63.9% for C. katsuwoni and C. martinieri, respectively) and exhibit a negative AT skew but a positive GC skew in both species. One gene block rearrangement was found in C. katsuwoni in comparison with other capsalid species. Instead of being basal to the Gyrodactylidea and Dactylogyridea or being clustered with Dactylogyridea, all species of Capsalidea are grouped into a monophyletic clade. Our results clarify the gene rearrangement process and evolutionary status of Capsalidae and lay a foundation for further phylogenetic studies of monogeneans. [ABSTRACT FROM AUTHOR]

We detected Neobenedenia girellae infections in 40 species belonging to 12 families of imported marine ornamental fish from a public aquarium in the Mexican state of Yucatan. A total of 348 fish specimens were examined for monogeneans in January 2018 to December 2020. Monogeneans were corroborated morphologically and molecularly with a partial sequence of 28S (region D1–D3) ribosomal DNA and analyzed in a molecular phylogenetic context in combination with other N. girellae sequences available in GenBank. The phylogenetic tree revealed that the specimen found consistently belonged to the N. girellae clade. High infection parameters were detected of N. girellae in most hosts. This identification is relevant to aquarists and aquaculturists in the Gulf of Mexico because N. girellae is considered highly pathogenic in confined fish. This work demonstrates that the importation of ornamental fish coupled with deficient sanitary measures (lack of quarantine areas in distribution centers) contributes to spread of parasites and their establishment within Mexico. [ABSTRACT FROM AUTHOR]

Currently, 24 species of Encotyllabe Diesing, 1850 (Monogenea: Capsalidae), are recorded as parasites on teleost fishes, but the validity of many species has been questioned due to deficient or incomplete descriptions. Almost all species in the genus have been described from one host species or closely related host species, suggesting host specificity, but some species, specifically Encotyllabe spari Yamaguti, 1934, have been reported from at least 19 species belonging to nine families in two orders (Perciformes and Scorpaeniformes) from Japan, Arabian Gulf and Brazil. Concerning Brazilian records of Encotyllabe spari and Encotyllabe cf. spari, seven species belonging to four families and two orders have been reported as hosts for this species. The aim of this study was to describe two new species of Encotyllabe from Brazil, previously considered as E. spari. Morphological and morphometric (multivariate analysis of proportional measurements standardized by total length) and molecular analysis (LSU rRNA and cox1 gene) were performed in order to identify the collected monogeneans. The description of two new species, namely Encotyllabe bifurcatum n. sp. and Encotyllabe parvum n. sp., parasitizing Pagrus pagrus and Orthopristis ruber, respectively, is the result of the three approaches. The main morphological differences from the most related species include a combination of body size, shape of the male copulatory organ, size and position of the testes. Our results suggest host specificity for members of Encotyllabe and specimens previously recorded as E. spari, other than those from the original description, must be revisited.

Annually, more than 2500 ornamental fish species are traded worldwide. Forty percent of these are from marine water. Some 98% of marine species are wild-caught from their natural habitat, and the majority subsequently exported. Wild fish frequently carry pathogens, which could induce diseases after the stress of capture. Neobenedenia melleni is a platyhelminth that mainly attaches to the skin and eyes of the host. It provokes dermal inflammation, epidermal loss, skin depigmentation, reduction in the number of mucous cells, and, consequently, decreased mucus protection, and declining immunological barriers. This makes fish susceptible to secondary infections. A total of 47 wild reef fish from a retailer were examined, suspected to be infected with ectoparasites. The morphological identification revealed N. melleni as a monogenean agent. One monogenean specimen was collected from the eye of each of the 40 fish analyzed to evaluate possible bacterial secondary infections using the matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF MS) technique. The MALDI-TOF MS identified that 59% of monogenean collected from the eyes had bacteria, including some pathogenic to fish. This led us to believe that the ectoparasite can be a possible mechanical vector of pathogenic bacteria for fish culture and maintenance. The use of praziquantel as an antiparasitic agent is also discussed. [ABSTRACT FROM AUTHOR]

During a study of the monogeneans of four sparid fishes (Diplodus vulgaris, Pagellus bogaraveo, Pagrus pagrus and Sparus aurata) from the Western Mediterranean off Algeria, a large collection of parasites was characterised molecularly (28S rRNA and cox1 genes). A total of 46 partial sequences (23 for each gene) were generated from 38 isolates of monogeneans which included four species (Atrispinum acarne, Microcotyle erythrini (sensu stricto), Sparicotyle chrysophrii and Prostatomicrocotylinae gen. sp.) of the family Microcotylidae, two putative species of the family Capsalidae (Encotyllabe spp.), and one species (Choricotyle chrysophryi) of the family Diclidophoridae. Our study provides (i) the first molecular data for the Capsalidae in the Mediterranean; (ii) the first record of a member of the Prostatomicrocotylinae in the Mediterranean and in a sparid fish (D. vulgaris); (iii) the first cox1 sequences for A. acarne; (iv) the second record of M. erythrini (s.s.) from P. pagrus; and (v) the second confirmed by molecular data record of S. chrysophrii in wild populations of S. aurata. The first phylogenetic hypotheses for the family Microcotylidae developed here, revealed the monophyly of the subfamily Prostatomicrocotylinae and the genus Microcotyle but the relationships among the subfamilies were still largely unresolved with the best represented subfamily Microcotylinae being polyphyletic. Our results highlight the importance of molecular methods in the assessment of monogenean diversity and the need for a thorough taxon-sampling approach to increase the accuracy of phylogenetic reconstruction of the relationships of the large and taxonomically complex polyopisthocotylean family Microcotylidae.

A parasitological survey searching monogeneans infesting marine fish was carried out during June 2018 and January 2020 from the coastal zone of Puerto Pizarro, Tumbes (northern Peru) and from the coastal zone of Chorrillos, Lima (central Peru). The gills, skin, nasal cavities, or branchial gill-cover of seven species were sampled. Ten monogenean species assigned to six families and nine genera were identified. The monogeneans Callorhynchocotyle callorhynchi (Manter, 1955); Capsala biparasiticum (Goto, 1894) Price, 1938; Euryhaliotrema sagmatum Kritsky & Boeger, 2002; Listrocephalos kearni Bullard, Payne &Braswell, 2004; Magniexcipula lamothei Bravo-Hollis, 1981; Nasicola klawei (Stunkard, 1962) Yamaguti, 1968; and Pseudorhabdosynochus anulus Violante-Gonzalez & Rojas-Herrera, 2011 are registered for the first time in Peru. While Capsala gregalis (Wagner & Carter, 1967) Chisholm & Whittington, 2007; Heterocotyle margaritae Chero, Cruces, Sáez, Santos & Luque, 2020; and Monocotyle luquei Chero, Cruces, Iannacone, Sanchez, Minaya, Sáez & Alvariño, 2016 have been previously registered in Peruvian waters, however, the region of Tumbes (northern Peru) represent a new locality record for these species.

Phototaxis is the common behavioral response exhibited by the oncomiracidia of various monogeneans. However, the changes in the oncomiracidial swimming behavior in response to light cues are not well understood. Here, we investigated the light responses of four monogeneans that are important pathogens in mariculture, namely Benedenia epinepheli, Benedenia seriolae, Neobenedenia girellae, and Heteraxine heterocerca. The swimming trajectory and speed of oncomiracidia of each species were assessed in a glass Petri dish with an LED light placed adjacent to it, based on three different light responses: LED light in the off position (normal swimming), LED light in the on position (phototactic behavior), and immediately (< 5 s) after switching the LED light off (photophobic behavior). The oncomiracidia of all four species exhibited positive phototactic and photophobic responses; however, the change in swimming speed between each response differed among the species. The oncomiracidia of three species (B. epinepheli, N. girellae, and H. heterocerca) exhibited high swimming speed, as a phototactic response; in contrast, the oncomiracidia of B. seriolae exhibited reduced swimming speed when moving toward the light source. Benedenia epinepheli and H. heterocerca exhibited the highest swimming speed during the phototaxis phase, whereas B. seriolae and N. girellae exhibited the highest swimming speed during the photophobic phase. These light responses are considered adaptive traits to increase the chance of encountering and infecting suitable hosts in nature, and such responses could potentially be applied to the control of parasite infections in aquaculture. [ABSTRACT FROM AUTHOR]

• Temperature changes altered fish ectoparasite reproductive traits. • Neobenedenia girellae laid larger, more nutritionally-rich eggs under cool conditions. • Reproduction rates increased under warm conditions. • Egg volume showed strong, positive correlations with several high-energy materials. This study quantified the effects of temperature on reproduction and maternal provisioning of the ectoparasite, Neobenedenia girellae (Platyhelminthes: Monogenea), a species known to cause detrimental impacts to aquaculture fishes in tropical and subtropical environments worldwide. At 20 and 25 °C, parasites exhibited relatively slower production of larger eggs that were energy-dense. In contrast, parasites at 30 °C attained sexual maturity faster, were reproductively active over a shorter period, grew to a smaller size and laid smaller, less energy-rich eggs at a faster rate. As such, parasites exhibited two distinct reproductive patterns in response to temperature: parasites at lower temperatures produced larger eggs with higher energy content, while those at the higher temperature had a higher rate of egg production. Larger eggs produced under cooler conditions were better provisioned with energetic reserves and important, membrane-bound lipids that would likely facilitate larval longevity and development success. This is commensurate with previous observations of epizootics of this parasite species in aquaculture systems during winter. Meanwhile, eggs produced at 30 °C contained higher proportions of saturated fatty acids compared with polyunsaturated fatty acids, likely reflecting metabolic regulation of cell membrane fluidity, which is necessary for larvae to survive warm conditions. This study demonstrates that fish ectoparasites have evolved substantial reproductive and metabolic flexibility to maximise infection success under variable environmental conditions. [ABSTRACT FROM AUTHOR]

Monogenean capsalids of the genus Neobenedenia are widespread parasites of wild and farmed marine fish, and represent a potential threat to mariculture due to their pathogenicity and ability to cause mortality in fish maintained in controlled conditions. The identification of Neobenedenia species and, consequently, the definition of their host specificity is often problematic due to their highly conserved morphology; therefore, in order to establish their specific identity, microscopic observation should be complemented with molecular analysis. The present work aims at characterizing Neobenedenia specimens infecting the skin of cage reared gilthead seabream Sparus aurata from Portugal. Parasite samples obtained from caged fish were processed for morphological analysis, through observation in light and scanning electron microscopy, and for molecular analysis, through amplification and sequencing of 28S rDNA and cytB, aimed at identifying them to the species level. Our results showed that the collected parasites belonged to the species Neobenedenia girellae; the susceptibility of S. aurata towards this pathogenic capsalid monogenean highlighted in the present work represents an important risk in the farming of this valuable fish species.

Mexicana rubra sp. nov. and Encotyllabe cf. spari are described from the gills of the marine fish Orthopristis ruber (Haemulidae) caught off Rio de Janeiro, Brazil. Morphological, ultrastructural and genetic data are provided. The main diagnostic features of this new species of ectoparasite are a posteriorly bipartite testis, a ventral bar with three deep bowed projections and a dorsal bar with two deep, conspicuous, antero-lateral indentations. Genetic data on Mexicana rubra sp. nov. are based on the ITS1, 5.8S and partial 18S and 28S rDNA. This is the sixth known species of Mexicana Caballero & Bravo-Hollis, 1959, a key to which is also presented. Encotyllabe cf. spari Yamaguti, 1934 is described from the same host, with new ultrastructural data and new partial 18S and 28S rDNA sequences. A phylogenetic analysis based on partial 18S and 28S sequences is undertaken for both species.

Seriola rivoliana cultivated in Mexico are infected by Neobenedenia sp. (Monogenea: Capsalidae), resulting in dermal ulceration and subsequent bacterial invasion that can cause fish death. This study assesses the effects of temperature over hatching success, oncomiracidia longevity, and infection success. The experimental design consisted of culturing the parasite at temperatures ranging between 16 and 32 °C. The oncomiracidia infection success, time to sexual maturity, and size at sexual maturity of Neobenedenia sp. were examined only at three temperatures (20 °C, 24 °C, and 30 °C). Experiments were conducted under controlled conditions in the laboratory. The oncomiracidia development was found to be faster at warmer temperatures (4–5 days between 24 and 30 °C) than in colder treatments (7–11 days between 18 and 20 °C). Hatching success and oncomiracidia longevity were higher at 24 °C and 26 °C. At 20 °C, 24 °C, and 30 °C, infection success was greater than 90%. Additionally, the laid eggs were observed at 9, 12, and 15 days at 30 °C, 24 °C, and 30 °C, respectively. The results of this study will allow for improving the temporal schedule of applications of treatments against Neobenedenia sp. by the function of temperatures. In conclusion, it is recommended to treat fish more frequently if the temperature in cultures is higher than 24 °C, because Neobenedenia sp. development is faster. As an alternative, the fish could be moved to deeper and cooler waters. [ABSTRACT FROM AUTHOR]

The infection dynamics and distribution of the ectoparasitic fish monogenean Neobenedenia sp. (Monogenea: Capsalidae) throughout its development was examined on barramundi, Lates calcarifer (Bloch) (Latidae), by labelling transparent, ciliated larvae (oncomiracidia) with a fluorescent dye. Replicate fish were each exposed to approximately 50 fluorescent oncomiracidia and then examined for parasites using an epifluorescence stereomicroscope at 10 time intervals post-exposure (15, 30, 60, 120 min, 24, 48 h, four, eight, 12, and 16 days). Fluorescent labelling revealed that parasites attached underneath and on the surface of the scales of host fish. Parasite infection success was 20% within 15 min, and peaked at 93% two days post-exposure, before gradually declining between four and sixteen days. Differences in parasite distribution on L. calcarifer over time provided strong evidence that Neobenedenia sp. larvae settled opportunistically and then migrated to specific microhabitats. Parasites initially attached (

Graphical abstract Highlights • The majority of specimens in this study (82%) fell into a single clade. • These specimens were morphologically indistinguishable from Neobenedenia melleni. • The only taxon in Neobenedenia which fits this profile is Neobenedenia girellae. • These specimens were collected from 24 host species of fish from nine countries. • Inclusion of Neobenedenia girellae back into the genus is recommended. Abstract Accurate identification of parasite species and strains is crucial to mitigate the risk of epidemics and emerging disease. Species of Neobenedenia are harmful monogenean ectoparasites that infect economically important bony fishes in aquaculture worldwide, however, the species boundaries between two of the most notorious taxa, N. melleni and N. girellae , has been a topic of contention for decades. Historically, identifications of Neobenedenia isolates have overwhelmingly been attributed to N. melleni , and it has been proposed that N. girellae is synonymous with N. melleni. We collected 33 Neobenedenia isolates from 22 host species spanning nine countries and amplified three genes including two nuclear (Histone 3 and 28S rDNA) and one mitochondrial (cytochrome b). Four major clades were identified using Maximum Likelihood and Bayesian inference analyses; clades A-D corresponding to N. girellae , N. melleni , N. longiprostata and N. pacifica, respectively. All unidentified isolates and the majority of Neobenedenia sequences from GenBank fell into clade A. The results of this study indicate that N. girellae is a separate species to N. melleni , and that a large proportion of previous samples identified as N. melleni may be erroneous and a revision of identifications is needed. The large diversity of host species that N. girellae is able to infect as determined in this study and the geographic range in which it is present (23.8426°S and 24.1426°N) makes it a globally cosmopolitan species and a threat to aquaculture industries around the world. [ABSTRACT FROM AUTHOR]

We herein redescribe Allobenedenia dischizosepta (Suriano, 1975) n. comb. (Monogenoidea: Capsalidae) based on light microscopic analysis of the holotype and 18 paratypes from the gill of Acanthistius brasilianus (Cuvier, 1828) (Perciformes: Serranidae) along with light and scanning electron microscopy of 25 newly collected specimens from the gill of Acanthistius patachonicus (Jenyns, 1842) (new host record) in the southwestern Atlantic Ocean off Argentina. Contradicting the original description of this species and its generic diagnosis, all specimens had 5 loculi (2 anterior plus 3 posterior loculi) plus 5 corresponding haptoral septa only (central loculus absent). The original description of this species erroneously specified 6 loculi, including 2 small anterolateral loculi. Because A. dischizosepta was the type species for Tetrasepta Suriano, 1975 and because it fits the diagnosis of Allobenedenia Yamaguti, 1963, the genus therefore is regarded a junior synonym of Allobenedenia. Allobenedenia dischizosepta differs from its congeners by lacking a haptoral peduncle as well as by having 5 haptoral loculi, accessory sclerites that lack a conspicuous dorsal protuberance and that are weakly bifid, by posssesing robust anterior hamuli that are strongly recurved for half of their total length, by having a male accessory gland reservoir in the extreme posterior portion of the penis sac and lateral to the vitelline reservoir abutting the ovary, and by the presence of a straight (not coiled) proximal portion of the ejaculatory duct within the penis sac. [ABSTRACT FROM AUTHOR]

Neobenedenia pacifica (Monogenoidea: Capsalidae) is redescribed from the skin and eye of the striped mullet Mugil cephalus and white mullet Mugil curema from localities off Florida and Mississippi. The capsalid is confirmed as a member of Neobenedenia, and its occurrences off Florida and Mississippi represent new distribution records for the species. [ABSTRACT FROM AUTHOR]

Copyright of Instituto Oceanografico de Venezuela (Boletin) is the property of Universidad de Oriente and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Seto Inland Sea, the largest inland sea in Japan, is a rich fishery with high biodiversity and productivity. Monogeneans have been studied for more than 120 years, and 58 nominal species have been recorded in the Seto inland Sea. This study provided DNA information on five species of Benedenia sensu lato (Capsalidae) from marine fishes from the sea, and one of them, Benedenia kobudai n. sp., is described from Semicossyphus reticulatus (Perciformes: Labridae). This new species differs from the other congeners by the hooded appearance between the anterior attachment organs, the morphology of the penis, the absence of the lobe near the vaginal pore and the common genital pore, the position of the vaginal pore, the germarium lying near the slightly hexagonal testes, the morphology of the haptor, and the shape and position of the hamuli. Phylogenetic analysis showed B. kobudai n. sp. in a separate clade from the other Benedenia species, B. epinepheli , B. hoshinai , B. sekii , and B. seriolae collected from the sea. Each of the newly provided DNA sequences (28S rDNA, ITS1‐5.8S-ITS2, cox1) of the above four species are based on specimens obtained from the type hosts and/or type localities and are considered important for future taxonomic re-examination and confirmation of the reliability of the registered sequences. Furthermore, these four species are important causes of fish diseases in aquaculture, and it is expected that information on the distribution, host range, and occurrence of fish diseases for each capsalid secured by molecular identification will be accumulated. The Life Science Identifier (LSID): urn:lsid: zoobank.org :pub:26C15D17-CFD1-450D-9FCE-EFFF692D2133. [Display omitted] • Benedenia kobudai n. sp. is described from Semicossyphus reticulatus from Japan. • Other four Benedenia species were collected from the type hosts and/or localities. • DNA sequences and phylogenetic trees of those Benedenia species were provided. [ABSTRACT FROM AUTHOR]

The infection dynamics and distribution of the ectoparasitic fish monogenean Neobenedenia sp. (Monogenea: Capsalidae) throughout its development was examined on barramundi, Lates calcarifer (Bloch) (Latidae), by labelling transparent, ciliated larvae (oncomiracidia) with a fluorescent dye. Replicate fish were each exposed to approximately 50 fluorescent oncomiracidia and then examined for parasites using an epifluorescence stereomicroscope at 10 time intervals post-exposure (15, 30, 60, 120 min, 24, 48 h, four, eight, 12, and 16 days). Fluorescent labelling revealed that parasites attached underneath and on the surface of the scales of host fish. Parasite infection success was 20% within 15 min, and peaked at 93% two days post-exposure, before gradually declining between four and sixteen days. Differences in parasite distribution on L. calcarifer over time provided strong evidence that Neobenedenia sp. larvae settled opportunistically and then migrated to specific microhabitats. Parasites initially attached (<24 h) in greater mean numbers on the body surface (13 ± 1.5) compared to the fins (4 ± 0.42) and head region (2 ± 0.41). Once larvae recruitment had ceased (48 h), there were significantly higher mean post-larvae counts on the head (5 ± 3.4) and fins (12 ± 3) compared to previous time intervals. Neobenedenia sp. aggregated on the eyes, fins, and dorsal and ventral extremities on the main body. As parasites neared sexual maturity, there was a marked aggregation on the fins (22 ± 2.35) compared to the head (4 ± 0.97) and body (9 ± 1.33), indicating that Neobenedenia sp. may form mating aggregations. [ABSTRACT FROM AUTHOR]

Eleven known species of Monogenoidea were found parasitizing six different species of scombrid fishes collected from Rio de Janeiro coast, Southwestern Atlantic Ocean: Capsala biparasitica, Capsala katsuwoni, Capsala notosinense, Nasicola brasiliensis, Nasicola klawei, Allopseudaxinoides euthynni, Sibitrema poonui, Hexostoma albsmithi, Hexostoma euthynni, Hexostoma keokeo and Hexostoma sibi. Katsuwonus pelamis is reported as a new host to A. euthynni and Thunnus obesus to H. albsmithi. Capsala notosinense, A. euthynni, H. albsmithi and H. sibi are referred for the first time in Brazil, Southwestern Atlantic Ocean. Morphological and morphometric features are presented for each species. [ABSTRACT FROM AUTHOR]

This study on the eggs of the tropical monogenean Neobenedenia girellae presents the first detailed quantitative biochemical information of a marine parasite species’ eggs. Moisture and protein composed the majority of the contents of freshly laid eggs (79.12 ± 0.82 and 11.51 ± 0.49% respectively) followed by lipid (2.50 ± 0.15%). Lipids were composed of approximately equal amounts of saturated, monounsaturated, and polyunsaturated fatty acids and the predominant lipid class was triacylglycerol (33.82 ± 1.20%). This study represents a fundamental step towards a better understanding of the early life biology of this important species of parasite. [ABSTRACT FROM AUTHOR]

Abstract: Specimens of Neobenedenia girellae, recognized as one of the most important pathogen of fish, were collected in order to find evidence of the nitric oxide synthase (NOS) and its possible role in haptor control. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western Blotting technique were used on a homogenate of parasites; immunohistochemistry technique was applied on whole mount parasites, which were thereby investigated with confocal laser scanning microscope. Images obtained by immunohistochemistry show a strong evidence of the enzyme presence in the posterior body of N. girellae specimens, colocalizing with α-tubulin; focusing on the distribution one could speculate that the constitutive form of NOS is expressed. Samples investigated with Western Blotting show a moderate evidence of NOS presence too. The investigation of the role of NOS in regulating the most important attaching structures of N. girellae is important not only from the standpoint of biochemical knowledge but also in terms of development of new pharmacological strategies for the eradication of these parasites from aquacultures. [Copyright &y& Elsevier]

Abstract: Relationships between the three classes of Neodermata (parasitic Platyhelminthes) are much debated and restrict our understanding of the evolution of parasitism and contingent adaptations. The historic view of a sister relationship between Cestoda and Monogenea (Cercomeromorphae; larvae bearing posterior hooks) has been dismissed and the weight of evidence against monogenean monophyly has mounted. We present the nucleotide sequence of the complete mitochondrial (mt) genome of Benedenia seriolae (Monogenea: Monopisthocotylea: Capsalidae), the first complete non-gyrodactylid monopisthocotylean mt genome to be reported. We also include nucleotide sequence data for some mt protein coding genes for a second capsalid, Neobenedenia sp. Analyses of the new mt genomes with all available platyhelminth mt genomes provide new phylogenetic hypotheses, which strongly influence perspectives on the evolution of diet in the Neodermata. Our analyses do not support monogenean monophyly but confirm that the Digenea and Cestoda are each monophyletic and sister groups. Epithelial feeding monopisthocotyleans on fish hosts are basal in the Neodermata and represent the first shift to parasitism from free-living ancestors. The next evolutionary step in parasitism was a dietary change from epithelium to blood. The common ancestor of Digenea+Cestoda was monogenean-like and most likely sanguinivorous. From this ancestral condition, adult digeneans and cestodes independently evolved dietary specialisations to suit their diverse microhabitats in their final vertebrate hosts. These improved perspectives on relationships fundamentally enhance our understanding of the evolution of parasitism in the Neodermata and in particular, the evolution of diet. [Copyright &y& Elsevier]

Abstract: The morphological based taxonomy of highly derived parasite groups is likely to poorly reflect their evolutionary relationships. The taxonomy of the monogenean family Capsalidae, which comprises approximately 180 species of flatworm parasites that predominantly attach to external surfaces of chondrichthyan and teleost fishes, is based mainly on six morphological characters. The phylogenetic history of the family is largely unknown. We reconstructed the phylogenetic relationships of 47 species in 20 genera from eight of the nine subfamilies, from nucleotide sequences of three unlinked nuclear genes, 28S ribosomal RNA, Histone 3 and Elongation Factor 1 α. Our phylogeny was well corroborated, with 75% of branches receiving strong support from both Bayesian posterior probabilities and maximum likelihood bootstrap proportions and all nodes showed positive partitioned likelihood support for each of the three genes. We found that the family was monophyletic, with the Gyrodactylidae and Udonellidae forming the sister group. The Capsalinae was monophyletic, however, our data do not support monophyly for the Benedeniinae, Entobdellinae and Trochopodinae. Monophyly was supported for Capsala, Entobdella, Listrocephalos, Neobenedenia and Tristoma, but Benedenia and Neoentobdella were polyphyletic. Comparisons of the distribution of character states for the small number of morphological characters on the molecular phylogeny show a high frequency of apparent homoplasy. Consequently the current morphological classification shows little correspondence with the phylogenetic relationships within the family. [Copyright &y& Elsevier]

Three species of the genus Capsala including Capsala naffari n. sp., C. neothunni (Yamaguti, 1968) and C. nozawae (Goto, 1894) are recorded and described from the buccal cavity of mackerel tuna Euthynnus affinis caught from Emirate coasts. Capsala naffari can be differentiated by its lateral spiniform teeth, which extend posteriorly, small measurements compared with the closely resembled C. gotoi and relatively large testes. This is the first record of the genus Capsala from Arabian Gulf fishes and E. affinis is a new host record. [Copyright &y& Elsevier]

The cleaner fish Labroides dimidiatus affected the pigmented monogenean parasite Benedenia lolo on the fish Hemigymnus melapterus (Labridae) held in aquaria. The effect of cleaner fish varied with the size class of fish; only small fish [a posteriori size class <11·5 cm standard length (LS)] exposed to cleaner fish had fewer monogeneans compared with fish not exposed to cleaner fish. The abundance of monogeneans on large fish (a posteriori size class >11·5 cmLS ) was not affected by cleaner fish. The size-frequency distributions of monogeneans on both size-classes of H. melapterus were affected by cleaner fish. Fish exposed to cleaner fish had fewer large (>3 mm) and more small (<1 mm) monogeneans than fish not exposed to cleaner fish, suggesting cleaner fish selectively removed larger monogeneans. This difference was more pronounced on large fish. In the absence of cleaner fish, small fish had almost as many monogeneans as large fish; they also had more small monogeneans than the large fish, suggesting small fish were more vulnerable to infection by monogeneans than larger fish. This suggests that the cleaner fish L. dimidiatus has the potential to control benedeniine monogeneans on captive fish and highlights the importance of taking into account fish size in studies of the effect of cleaner fish on ectoparasites. Copyright 2002 The Fisheries Society of the British Isles. Published by Elsevier Science Ltd. All rights reserved. [Copyright &y& Elsevier]