Digenea and acanthocephala of elasmobranch fishes from the southern coast of Brazil.

New records for helminth species recovered from elasmobranch fishes in Brazil are established. Digenean and acanthocephalan parasites of elasmobranch fishes are reported from the southern coast of Brazil: Otodistomum veliporum (Creplin, 1837) Stafford, 1904 (Digenea: Azygiidae) in the stomach and spiral valve of Dipturus trachydermus and in the spiral valve of Squatina sp. Cystacanths and juveniles of the acanthocephalans Corynosoma australe Johnston, 1937 and Corynosoma sp., in the spiral valve of Squatina sp., Galeorhinus galeus and Hexanchus griseus and in the stomach of Squalus megalops; a juvenile of Gorgorhynchus sp., in the spiral valve of Sphyrna zygaena. Dipturus trachydermus and Squatina sp. are new host records for O. veliporum. Digeneans and acanthocephalans are reported for the first time parasitizing elasmobranch fishes in Brazil.     

Molecular phylogenetics and diagnosis of Anisakis, Pseudoterranova, and Contracaecum from northern Pacific marine mammals

Individual specimens of Anisakis, Pseudoterranova, and Contracaecum collected from marine mammals inhabiting northern Pacific waters were used for comparative diagnostic and molecular phylogenetic analyses. Forty-eight new sequences were obtained for this study of 14 Anisakis taxa, 8 Pseudoterranova taxa, 4 Contracaecum taxa, and 4 outgroup species. Partial 28S (LSU) and complete internal transcribed spacer (ITS-1, 5.8S, ITS-2) ribosomal DNA was amplified by the polymerase chain reaction and sequenced. Sequences of ITS indicated that Pseudoterranova specimens from Zalophus californianus (California sea lion), Mirounga angustirostris (northern elephant seal), Phoca vitulina (harbor seal), Enhydra lutris (sea otter), and Eumetopias jubatus (Steller's sea lion) exactly matched P. decipiens s. str., extending the host and geographic range of this species. Anisakis from northern Pacific marine mammals were most closely related to members of the A. simplex species complex. Comparison of Anisakis ITS sequences diagnosed the presence of A. simplex C in 2 M. angustirostris hosts, which is a new host record. Anisakis specimens from Phocoena phocoena (harbor porpoise), Lissodelphis borealis (Pacific rightwhale porpoise), and E. jubatus included 3 ITS sequences that did not match any known species. Contracaecum adults obtained from Z. californianus were most closely related to C. ogmorhini s.l. and C. rudolphii, but ITS sequences of these Contracaecum specimens did not match C. ogmorhini s. str. or C. margolisi. These novel Anisakis and Contracaecum ITS sequences may represent previously uncharacterized species. Phylogenetic analysis of LSU sequences revealed strong support for the monophyly of Anisakinae, Contracaecum plus Phocascaris, Pseudoterranova, and Anisakis. Phylogenetic trees inferred from ITS sequences yielded robustly supported relationships for Pseudoterranova and Anisakis species that are primarily consistent with previously published phenograms based on multilocus electrophoretic data.     

The value of external morphology in the identification of larval anisakid nematodes: a scanning electron microscope study

We studied larval nematodes of four genera of the Anisakidae using a scanning electron microscope (SEM). The anterior and posterior extremities and cuticular structures of the 3rd-stage larvae (L3) of Anisakis type I, Pseudoterranova decipiens, Contracaecum type B and Hysterothylacium were examined. The 4th-stage larvae (L4) of Anisakis type I, P. decipiens, recovered after infection into laboratory rats, and the L3 and L4 of Anisakis type I larvae from human were also examined in the same way. There were generic differences in the shape and size of the lip bulges, external papillary structures, the appearance of the boring tooth, the width and depth of the grooves and ridges of the cuticle and the caudal structures of the L3. In Anisakis type I and P. decipiens L3, changes were seen in the anterior extremity, cuticle and posterior extremity after molting to the L4. Similar changes can be expected in larvae infecting man. The L4 of Anisakis type I from rat and man were similar, while the L4 of Anisakis type I and P. decipiens showed differences. These ultrastructural differences might be of value in the identification of fragments recovered during endoscopy in man.     

Molecular detection of sibling species in anisakid nematodes

The number of sibling species of anisakid nematodes detected over the last two decades has been increased, fuelled by the use of genetic/molecular methodologies. In the present review, we summarize the biological species discovered within most of the nominal species belonging to the genera Anisakis, Contracaecum and Pseudoterranova by the use of allozyme (20-24 loci studied) and recently confirmed by us using mitochondrial cox-2 gene sequence analysis (mtDNA cox-2). Ecological evidence relating to the distributional range of the genetically detected sibling species and their host preferences, which represent data sets that can be utilized for species delimitation and definition, are summarized.     

Infection status of the sea eel (Astroconger myriaster) purchased from the Noryangjin fish market with anisakid larvae]

Although the sea eel (Astroconger myriaster) is suspected as one of the most important fish host for human anisakiasis in Korea, no report has been made on the infection status of the sea eel with anisakid larvae. In the present study, 26 sea eels (Astroconger myriaster) were purchased from the Noryangjin fish market in Seoul, and anisakid larvae were collected from their viscera, muscle, head and skin. The collected larvae were classified by their morphological types. A total of 1,351 anisakid larvae were collected from 15 of 26 fish examined. Among them, 1,269 were recovered from the viscera, 66 from the muscle, and 16 from the head and skin. Morphologically, most of the anisakids were classified into 6 known larval types, Anisakis type I (564 larvae) of Berland (1961), Contracaecum type A (409) and type D (5) of Koyama et al. (1969), Contracaecum type C' (83) and type D' (117) of Chai et al. (1986), and Contracaecum type V (1) of Yamaguti (1935). Remaining 172 specimens were new in the available literature, hence, designated as Contracaecum type A' (new type). The present results revealed that the sea eels caught in the Korean waters are heavily infected with anisakid larvae, not only in their viscera but also in the muscle, and Anisakis type I was the most common among the 7 larval types.     

Restriction fragment length polymorphisms of Anisakinae larvae

The analysis of restriction fragment length polymorphisms (RFLPs) was applied to distinguish several kinds of Anisakinae larvae, Anisakis larvae (type I) collected from two different paratenic hosts, Anisakis larvae (type II) and Contracaecum larvae. The patterns of the two different paratenic host-derived DNA of Anisakis larva (I) were exactly the same in hybridized fragments generated by six endonucleases. The quite different patterns in RFLPs of genomic DNA were observed among the Anisakis larva (I), Anisakis larva (II) and Contracaecum larvae. The results suggest that the RFLPs analysis may be useful for distinguishing Anisakinae larvae and clarifying the relationships between Anisakis larvae and their adult worms.     

Helminths parasitizing larval fish from Pantanal, Brazil

Fish larvae of 'corvinas' (Pachyurus bonariensis and Plagioscion ternetzi) from Sinhá Mariana Lagoon, Mato Grosso State, were collected from March 2000 to March 2004, in order to determine the parasitic fauna of fishes. Larvae from the two species were parasitized by the same endoparasites: Contracaecum sp. Type 2 (larvae) (Nematoda: Anisakidae) in the mesentery and Neoechinorhynchus (Neoechinorhynchus) paraguayensis (Acanthocephala: Neoechinorhynchidae) in the stomach and the terminal portion of the intestine. Statistical analysis showed that there was a significant positive correlation between the standard length of hosts and the abundance of acanthocephalans and nematodes, and that the prevalence of nematodes presented a significant positive correlation with the standard length of the two species of hosts, indicating the presence of a cumulative process of infection. The present study constitutes the first record of nematodes and acanthocephalans parasitizing larval fish, as well as the first record of endoparasites in fish larvae in Brazil. In addition, it lists a new locality and two species of hosts for Contracaecum sp. Type 2 (larva) and N. (N.) paraguayensis.     

A COPROLOGICAL SURVEY OF HELMINTH PARASITES OF THE HAWAIIAN MONK SEAL FROM THE NORTHWESTERN HAWAIIAN ISLANDS

In conjunction with an Hawaiian monk seal, Monachus schauinslandi , breeding enhancement program, fecal samples were examined for the presence of helminth parasite products (eggs, larvae, and proglottids). Eighty-two samples were examined from four island groups in the northwestern Hawaiian Islands: 38 from Kure Atoll, 32 from French Frigate Shoals, 11 from Laysan Island, and one from Lisianski Island. Identified helminth products include those of Diphyllobothrium sp., D. cameroni, Contracaecum turgidum, Anisakis sp., Corynosoma rauschi , and Trematoda. In addition, eggs from Halarachne laysanae (Atari) were found in 3 samples. Eggs of C. turgidum were present in the highest percentage (>64%) of samples from all locations. Eggs of Anisakis sp. and Trematoda are reported from this host for the first time.     

Allozyme and morphological identification of shape Anisakis,Contracaecum and Pseudoterranova from Japanese waters (Nematoda,Ascaridoidea)

Allozyme markers were used to identify anisakid nematodes from marine Japanese waters, morphologically assigned to three species complexes: Anisakis simplex (s. l.), Contracaecum osculatum (s. l.) and Pseudoterranova decipiens (s. l.). Samples assigned to A. simplex (s. l.) were found to correspond genetically to A. simplex sensu stricto, those of C. osculatum (s. l.) to C. osculatum A. No morphological characters are yet available to distinguish sibling species of these two complexes. As to the P. decipiens complex, two distinct species were detected: the first corresponded to P. decipiens C, previously recovered in the northern Atlantic, the second to P. decipiens D from Japan. The two species are genetically well differentiated, with five of the 19 loci tested showing distinct fixed alleles. Their reproductive isolation was proved by the lack of hybrids or recombinants in sympatric samples recovered from the same definitive host, Erignathus barbatus. P. decipiens D was found to correspond morphologically to Porrocaecum azarasi, previously considered a synonym of P. decipiens. Accordingly, the name Pseudoterranova azarasi (Yamaguti & Arima, 1942) n. comb. is proposed for P. decipiens D. Similarly, P. decipiens C fits in general morphology, type-locality and host with Ascaris bulbosa, also previously considered a synonym of P. decipiens. The name Pseudoterranova bulbosa (Cobb, 1888) n. comb. is proposed for P. decipiens C.     

Allozyme and PCR-RFLP markers in anisakid nematodes,aethiological agents of human anisakidosis

In the framework of the researches granted by MURST COFIN97, studies on anisakid nematodes, aethiological agents of human anisakidosis, were carried out. The project was aimed to implement the knowledge on the systematics, genetics, ecology and epizootiology of species of the genera Anisakis and Pseudoterranova by applying genetic markers obtained from multilocus allozyme electrophoresis and from PCR-based techniques. The results obtained by allozyme studies allowed to extend the geographic distribution and to detect new definitive and intermediate/paratenic hosts of two sibling species of the A. simplex complex, i.e. A. simplex s.s. and A. pegreffii and to characterise the species A. simplex C, a new sibling species within the A. simplex complex as well as a new species belonging to the genus Anisakis, A. ziphidarum. Combined allozyme and morphological analyses provided markers for the identification of the four sibling species of the Pseudoterranova decipiens complex and their nomenclatural designations. New markers based on PCR-RFLP analysis were used for the identification of sibling species of the Anisakis simplex complex and of another four species of the genus. Genetic markers based on three diagnostic restriction enzymes allowed the identification as A. pegreffii of a larva obtained by endoscopy in a case of human anisakidosis in Southern Italy.     

The Florida amphioxus (Cephalochordata) hosts larvae of the tapeworm Acanthobothrium brevissime: natural history,anatomy and taxonomic identification of the parasite

Plerocercoid larvae of a tapeworm are frequently found in the hindgut lumen of the Florida amphioxus (Branchiostoma floridae) in central west Florida. About three‐quarters of the adult amphioxus are parasitized. On average, each adult amphioxus hosts about five tapeworm larvae. The residence time of the parasites in the amphioxus gut appears to be in the order of several months, which is considerably shorter than the potential lifetime of the host. The living larvae range in length (when fully extended) from 300 to 850 µm and are approximately cone‐shaped, tapering to a point posteriorly and bearing a single large sucker anteriorly. Toward the anterior end of the body are four hookless bothridia, each indented by three loculi plus an inconspicuous accessory sucker. The larvae initiate the early stages of hook formation when they are cultured for a few days in urea‐saline (mimicking the gut fluid of the definitive host, which is an elasmobranch). The tapeworm larvae are identifiable to genus and species on the basis of correspondences between their nuclear ribosomal DNA genes and those of adult specimens of Acanthobothrium brevissime recovered from the spiral valve of a stingray from the same environment.     

A new anisakid species parasitizing the imperial cormorant Phalacrocorax atriceps from the North Patagonian Coast, Argentina

The anisakid species Contracaecum chubutensis n. sp. was found parasitizing the imperial cormorant Phalacrocorax atriceps at 2 different localities, Bahía Bustamante (45 degrees 11'S, 66 degrees 30'W) and Puerto Madryn (42 degrees 47'S, 65 degrees 02'W) on the Patagonian coast. Morphometrical analysis and further studies of adult specimens of C. chubutensis n. sp. and fourth-stage larvae of Contracaecum sp. were done using light and scanning electron microscopy. The possession and disposition of 7 pairs of tail papillae differentiate this new species from C. osculatum, C. radiatum, C. plagiaticium, and C. mirounga. Double-sized spicules separate it from C. variegatum and C. pelagicum. Moreover, the paracloacal papillae disposition and tail shape differentiate this new species from C. travassosi. The presence of bifurcated interlabia separate it from C. ogmorhini and C. margolisi. Three well-marked lip notches, a sharp tail shape, and the of the transversal paracloacal papillae disposition distinguishes C. chubutensis n. sp. from C. magnipapillatum and C. septentrionale. The species here described can be differentiated from C. caballeroi by its bifurcated interlabia, longer spicules, and for possessing more precloacal papillae pairs. It can be separated from C. rudolphii by a thinner interlabia at the base, deeper lip notches, a sharper tail, the disposition of transversal paracloacal papillae, and greater distance between both papillae of the first subventral distal papillae pair. In addition, fourth-stage larvae recovered from the same host and localities were identified and described as Contracaecum sp. Prevalence of adult parasites was 66.7 %, mean intensity was 4.0, and mean abundance was 7.1.     

Infection status of larval anisakids in Astroconger myriaster collected from the Southern Sea near Pusan]

A study was presented on the anisakid larvae in Astroconger myriaster which were caught at the Southern Sea and saled at Pusan area. The nematodes were morphologically classified into Anisakis sp. and Contracaecum sp. after fixation in 70% ethanol and clearing in lactophenol. Total of 1,768 larval anisakids were collected from 259 (67.8% positive rate) out of 382 examined A. myriaster. Total 642 larvae of Anisakis sp. were obtained from 94 (24.6%) and 1,126 Contracaecum sp. were recovered from 165 (43.1%) fish. The average number of worms per infected fish was 4.6. The infection rate increased according to the length of fish, and all of the fish over 71 cm were found infected. The numbers (proportions) of recovered worms by the organs were 1,440 (80.5%) in the omentum, 166 (9.4%) in the intestine, 107 (6.0%) in the stomach, 32 (1.8%) in the skin, 18 (1.0%) in the muscle, 13 (0.7%) in the liver, and 2 (0.1%) in the head. The larvae in the muscle may infect the humans who are enjoying raw sliced meat of the fish.     

Gastrointestinal helminths of Cuvier's beaked whales, Ziphius cavirostris, from the western Mediterranean

We examined the gastrointestinal helminth fauna of 2 Cuvier's beaked whales, Ziphius cavirostris, stranded on the Spanish Mediterranean coast. Information regarding intestinal parasites of this species is provided for the first time. Six helminth taxa were identified. Thirty type II larvae of the nematode Anisakis sp. were found in the stomach and the intestine of both hosts; 2 type I larvae of Anisakis sp. were found in the intestine of 1 host. One juvenile of the acanthocephalan Bolbosoma vasculosum was found in the intestine; the metacestode Scolex pleuronectis was found mainly in the terminal colon and the anal crypts of both hosts; adult cestodes of Tetrabothrius sp., which may represent a new species, were collected from the duodenum of 1 host. Composition of the intestinal parasitic community is similar to that of other oceanic cetaceans, which mostly include species of Bolbosoma and tetrabothriids (Cestoda).     

Multiple primer PCR for the identification of anisakid nematodes from Taiwan Strait

There were six major larval anisakid species found in commercial marine fishes caught in the Minnan fishing ground in the Taiwan Strait: Anisakis physeteris, Anisakis pegreffii, Raphidascaris trichiuri, Contracaecum aduncum, Contracaecum muraenesoxi, Contracaecum sp. For rapid identification of the parasite species above, a single and a multiple primer PCR (multiplex PCR) method, using specific primers based on aligned sequences of the internal transcribed spacer ITS-1, 5.8S, and ITS-2 of nuclear ribosomal DNA, were jointly used for the rapid identification of these anisakid larvae. The primers yielded distinct PCR products for each of the anisakid nematodes, providing rapid and accurate tools for identifying anisakid nematodes with distinct geographical distribution.     

Record of Diglyphus walker (Hymenoptera: Eulophidae) species in Brazil

Leafminers (Diptera: Agromyzidae) are pests of various crops, mainly in greenhouses, and have Diglyphus spp. as important leafminer larval parasitoids. Until recently, only Diglyphus insularis (Gahan) had been reported in Brazil. In here we report the first records of Diglyphus begini (Ashmead), D. intermedius (Girault) and D. isaea (Walker) in Brazil. These parasitoids were found parasitizing leafminer larvae on cultivated and spontaneous plants in some areas of Minas Gerais state, Brazil.     

Entedoninae wasps (Hymenoptera, Chalcidoidea, Eulophidae) associated with ants (Hymenoptera, Formicidae) in tropical America, with new species and notes on their biology

Three new species of Eulophidae associated, or presumed to be associated with ants are described: two species of Horismenus Walker and one species of Microdonophagus Schauff. Information on the biology is also included. The two Horismenus species are from Chiapas, Mexico. Horismenus myrmecophagussp. n. is known only from females and is a gregarious endoparasitoid in larvae of the weaver ant Camponotus sp. ca. textor. The parasitoids pupate inside the host larva, and an average of 6.7 individuals develops per host. This is the second time a species of genus Horismenus is found parasitizing the brood of a formicine ant of genus Camponotus. Horismenus microdonophagussp. n. is described from both males and females, and is a gregarious endoparasitoid attacking the larvae of Microdon sp. (Diptera: Syrphidae), a predator on ant brood found in nests of Camponotus sp. ca. textor. The new species of Microdonophagus, Microdonophagus tertius, is from Costa Rica, and known only from the female. Nothing is known about its biology but since another species in same genus, Microdonophagus woodleyi Schauff, is associated with ants through its host, Microdon larva (with same biology as Horismenus microdonophagus), it is possible that also Microdonophagus tertius has this association. A new distributional record for Microdonophagus woodleyi is also reported, extending its distribution from Panama and Colombia to Brazil.     

Checklist of helminth parasites of the cane toad Bufo marinus (Anura: Bufonidae) from Mexico

Thirty-four adult cane toads Bufo marinus L. (12 males and 22 females) collected from 2 localities in Mexico (Cerro de Oro and Temascal Dams, Oaxaca) in September 2003 were examined for helminth parasites. In total, 14,749 helminths belonging to 14 taxa were collected. Included were 2 adult digeneans (Choledocystus hepaticus, Mesocoelium monas); 1 larval cestode (an unidentified pseudophyllidean); and 11 nematodes, including 3 species of larvae (Contracaecum sp., Physaloptera sp., Physocephalus sexalatus) and 8 species of adults (Aplectana itzocanensis, Cosmocerca sp., Cruzia morleyi, Ochoterenella digiticauda, Oswaldocruzia sp., Raillietnema sp., Rhabdias americanus, and Rhabdiasfuelleborni). Higher species richness was recorded in B. marinus from Cerro de Oro (12 taxa versus 9 in those from Temascal); hosts from both localities shared 7 taxa. There were 25 new locality records, and 2 taxa were registered in Mexico for the first time. To date, 112 helminth species have been recorded parasitizing B. marinus along its native and introduced range of distribution, with 40.5% of them reported from Mexico.     

First record in South America of Didymosulcus palati and Didymosulcus philobranchiarca (Digenea, Didymozoidae) with new hosts records and pathological alterations

Two species of Didymozoidae, Didymosulcus palati (Yamaguti 1970) and Didymosulcus philobranchiarca (Yamaguti 1970) were reported for the first time in South America, Atlantic Ocean, parasitizing three different tuna species from the coast of Rio de Janeiro, Brazil: Thunnus atlanticus (Lesson), Thunnus albacares (Bonnaterre) and Thunnus obesus (Lowe). Pairs of D. philobranchiarca were found on gill arches of T. albacares and T. obesus, in longitudinal rows of yellow cysts located inside grooves in the hard denticle palate (new site) of the three hosts species studied, and as disperse groups of cysts in the operculum (new site) and gill arches of T. atlanticus (new host record). D. palati occurred as disperse groups of encysted worm pairs in the gill arches of T. albacares and T. obesus and in gill arches and operculum of T. atlanticus (new host record). The pathological alterations induced by D. philobranchiarca in the palate of T. atlanticus are described for the first time. Original measurements and figures are presented.