Gross anatomy of the muscle systems and associated innervation of Apatemon cobitidis proterorhini metacercaria (Trematoda: Strigeidea), as visualized by confocal microscopy.:Strigeidea), as visualized by confocal microscopy

The major muscle systems of the metacercaria of the strigeid trematode, Apatemon cobitidis proterorhini have been examined using phalloidin as a site-specific probe for filamentous actin. Regional differences were evident in the organization of the body wall musculature of the forebody and hindbody, the former comprising outer circular, intermediate longitudinal and inner diagonal fibres, the latter having the inner diagonal fibres replaced with an extra layer of more widely spaced circular muscle. Three orientations of muscle fibres (equatorial, meridional, radial) were discernible in the oral sucker, acetabulum and paired lappets. Large longitudinal extensor and flexor muscles project into the hindbody where they connect to the body wall or end blindly. Innervation to the muscle systems of Apatemon was examined by immunocytochemistry, using antibodies to known myoactive substances: the flatworm FMRFamide-related neuropeptide (FaRP), GYIRFamide, and the biogenic amine, 5-hydroxytryptamine (5-HT). Strong immunostaining for both peptidergic and serotoninergic components was found in the central nervous system and confocal microscopic mapping of the distribution of these neuroactive substances revealed they occupied separate neuronal pathways. In the peripheral nervous system, GYIRFamide-immunoreactivity was extensive and, in particular, associated with the innervation of all attachment structures; serotoninergic fibres, on the other hand, were localized to the oral sucker and pharynx and to regions along the anterior margins of the forebody.

Neuroactive substances and associated major muscle systems in Bucephaloides gracilescens (Trematoda : Digenea) metacercaria and adult

Cholinergic, serotoninergic and neuropeptidergic components of the nervous system were examined and compared in the progenetic metacercaria and adult gasterostome trematode, Bucephaloides gracilescens in order to provide baseline information on neuronal control of the musculature involved in egg-assembly. Enzyme cytochemistry and indirect immunocytochemical techniques interfaced with confocal scanning laser microscopy demonstrated all three classes of neuroactive substance throughout the central and peripheral nervous systems. A comparable orthogonal arrangement of the central nervous system (CNS) and peripheral array of nerve plexuses was observed in both metacercaria and adult. Staining patterns for cholinergic and peptidergic substances showed significant overlap, while the serotoninergic system was confined to a separate set of neurons. Immunostaining for FMRFamide-related peptides (FaRPs) was strong in the CNS and peripheral innervation to the attachment apparatus of metacercaria and adult but was only found in the innervation of the ootype in ovigerous adults, implicating FaRPs in neuronal control of the muscle of the female reproductive tract during egg-assembly.

The use of parasites in discriminating stocks of Pacific halibut (Hippoglossus stenolepis) in the northeast Pacific

The use of parasites as indicators of the stock structure of Pacific halibut (Hippoglossus stenolepis) in the northeast Pacific was investigated by using 328 adult (>55 cm fork length) halibut from 15 composite localities ranging from northern California to the northern Bering Sea and 96 juvenile (10–55 cm) halibut from five localities ranging from the northern Queen Charlotte Islands to the Bering Sea. Counts of eight selected parasite species (the juvenile acanthocephalans Corynosoma strumosum and C. villosum, the metacestode Nybelinia surmenicola, the digenean metacercaria Otodistomum sp., and the larval nematodes Anisakis simplex, Pseudoterranova decipiens, Contracaecum sp., and Spirurid gen. sp.) that produce infections of long duration, do not multiply in the host, and that have a relatively high abundance in at least one geographic locality were subjected to discriminant function analysis. Juvenile Pacific halibut showed no separation and, even though they were not heavily infected with parasites, the analysis suggested that juveniles could be a mixed stock. Three groups of adults were identified: fish from California to the southern Queen Charlotte Islands, those from the northern Queen Charlotte Islands to the central Bering Sea, and those from the central and north-ern Bering Sea. These groups suggest that the single stock concept be more thoroughly evaluated.

Study ectoparasite infestation of 10 common imported freshwater ornamental fish species

In the present study, ectoparasite infestation of common freshwater ornamental fish species imported into Iran including: Dwarf gourami (Colisa lalia), Angelfish (Pterophyllum scalare), Oscar (Astronatus ocellatus), Red eye Tetra ( Moenkhansia Sanctaefilomenae), Barb( Capoeta tetrazona), Arowana (Osteoglossum bicirrhosum), Goldfish(Carassius auratus), Red fin Shark (Lebeo elythrurus, Catfish (Hypostomus plecostomus) and Pangasius sutchi ( Pangasius hypophthalmus) from May until April was investigated.A total of 6 specimens sample of each fish species) randomly were obtained and taken alive to the lab. After observing gill and skin wet smear under the microscope , gill was dissected and examined carefully .Photo and films were taken from the isolated parasites and parasite identification was performed according to Yamaguti AP1), Bychowsky (■Y).From a total of examined fishes 1\ ► sample (YY.V.) were parasitized .Parasite groups that were observed consisting ciliated protozoan myxosporidian , monogenean Digenean metacercaria and crustacean .The only non-parasitized fish was Barb. Monogenea Trianchoratus sp. , Cleidodiscus sp. , Ancylodiscoides sp. , Thaparocleidus sp. , Centrocestus formosanus metacercaria and Myxobolus longisporus report for the first time in ornamental fish which imported from Southeast of Asia to Iran. According to the results, it seems that severe quarantine and sanitary rules are necessary.

Development in vitro of the neuromusculature of two strigeid trematodes, Apatemon cobitidis proterorhini and Cotylurus erraticus

Confocal microscopy interfaced with cytochemical procedures has been used to monitor development of the major muscle systems and associated serotoninergic (5-HT, 5-hydroxytryptamine) and peptidergic (FaRP, FMRFamide-related peptide) innervation of the strigeid trematodes, Apatemon cobitidis proterorhini and Cotylurus erraticus during cultivation in vitro. Sexually undifferentiated metacercariae were successfully grown to ovigerous adults using tissue culture medium NCTC 135, chicken serum and egg albumen. Eggs were produced after 5 days in culture but had abnormal shells and failed to embryonate. 5-HT and FaRP (the flatworm FaRP, GYIRFamide) were localised immunocytochemically in both central and peripheral nervous systems of developing worms. During cultivation, the central serotoninergic and FaRPergic neuronal pathways of the forebody became more extensive, but retained the same basic orthogonal arrangement as found in the excysted metacercaria. Longitudinal extensor and flexor muscles of the hindbody provide support for the developing reproductive complex. The male reproductive tracts were established in advance (day 3) of those of the female system (day 4); completion of the latter was marked by the appearance of the ootype/egg chamber. The inner longitudinal muscle fibres of the female tract appeared prior to the outer and more densely arranged circular muscles. Circular fibres dominate the muscle complement of both alimentary and reproductive tracts. 5-HT- and GYIRFamide-immunoreactivities were demonstrable in the central nervous system (CNS) and subtegumental parasympathetic nervous system (PNS) throughout the culture period, but innervation of the developing reproductive structures was reactive just for 5-HT. Only at the onset of egg production was FaRP-IR observed in the reproductive system and was expressed only in the innervation of the ootype, a finding consistent with the view that FaRPs may regulate egg assembly in platyhelminths.

FASCIOLA-HEPATICA - ULTRASTRUCTURAL-CHANGES TO THE TEGUMENT OF JUVENILE FLUKES FOLLOWING INCUBATION IN-VITRO WITH THE DEACETYLATED (AMINE) METABOLITE OF DIAMPHENETHIDE

Ultrastructural changes to the tegument of 5-week-old, 3-week-old and freshly-excysted Fasciola hepatica following in vitro incubation with the deacetylated (amine) metabolite of diamphenethide (DAMD, 10 mu gml(-1)) were examined by transmission electron microscopy, A similar sequence of tegumental changes occurred in all three age groups of fluke, although, with increasing fluke age, the time before onset increased and the damage became more extensive. The 5-week-old flukes showed an initial stress response after 3 h, typified by blebbing of the apical plasma membrane, formation of microvilli and an accumulation and accelerated release of secretory bodies at the tegumental apex, as well as swelling of the basal infolds, The swelling increased in extent with progressively longer periods of incubation in DAMD, leading to extreme edema and sloughing of the tegument after 9 h. The 3-week-old flukes showed a stress response and swelling of the basal infolds after only 1.5 h, although sloughing of the tegument did not occur until after 9 h. In the freshly-excysted metacercaria, a stress response and some sloughing of the tegument were evident after only 0.5 h. At all stages of development, the ventral tegument was more severely affected than the dorsal, Changes also occurred to the tegumental cells which were indicative of a disruption in the synthesis and release of tegumental secretory bodies: the amount of GER became reduced, the cisternae became swollen and their ribosomal covering decreased, the Golgi complexes disappeared from the cells and the numbers of secretory bodies in the cells also decreased, The heterochromatin content of the nuclei increased and eventually the tegumental cells began to break down, Again, the changes became apparent more rapidly at the earlier stages of development. The ultrastructural changes to the tegument are linked to a possible mode of action for diamphenethide as an inhibitor of protein synthesis. In turn, the results may help to explain the drug's high efficacy against juvenile stages of F. hepatica.

Sphincterodiplostomum musculosum (Digenea, Diplostomidae) infectando Steindachnerina insculpta (Characiformes, Curimatidae) no reservatório de Chavantes, Sudeste do Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The helminth community of Geophagus proximus (Perciformes: Cichlidae) from a tributary of the Paraná River, Ilha Solteira Reservoir, São Paulo State, Brazil

This study aimed to evaluate the helminth parasites of Geophagus proximus from the São José dos Dourados River, a tributary of Paraná River, Ilha Solteira Reservoir, São Paulo State, Brazil. From May 2006 to May 2007, 116 G. proximus specimens were examined and seven different taxa of helminth were collected and identified: proteocephalidean plerocercoids (Cestoda); metacercariae of Austrodiplostomum compactum, Clinostomum heluans and Clinostomum sp. (Trematoda); and Raphidascaris (Sprentascaris) hypostomi, and larvae of Raphidascaris sp. and Contracaecum sp. (Nematoda). All parasites presented the typical aggregated pattern of distribution, as well as the presence of a high number of larval stages, an absence of influence of the host sex and seasonality upon community parameters, as well as a correlation between species richness and host body weight. Moreover, with the exception of A. compactum metacercariae, all helminths found in this study are reported for the first time in G. proximus. Copyright © Cambridge University Press 2012.

New host records and a checklist of fishes infected with Austrodiplostomum compactum (Digenea: Diplostomidae) in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)