FIGURES 9 15 - uploaded by Margarita Ostrowskide Núñez
Content may be subject to copyright.
Stephanoprora uruguayense Holcman Spector et Olagüe, 1989. (9) Adult from experimentally infected chicks, 11 days PE; scale bar 400 m. (10) Head collar; scale bar 100 m. (11) Miracidium, live specimen; scale bar 30 m. (12) Sporocyst 130 days PE, with 2 mother rediae; scale bar 100 m. (13) Redia with immature cercariae; scale bar 200 m. (14) Cercaria, fully developed body; scale bar 100 m. (15) Cercaria, body with tail; scale bar 300 m.
Source publication
The life cycle of Stephanoprora uruguayense Holcman et Olagüe, 1989, was experimentally resolved. In an artificial pond in the Zoological Garden in Buenos Aires City, Argentina, Heleobia parchappei (Hydrobiidae) was found to be releasing large-tailed cercariae with a prepharyngeal body, but lacking collar spines and corpuscles in the excretory syst...
Similar publications
In vivo and in vitro encystment of the cercariae of Echinochasmus liliputanus and biological activity of the metacercariae were studied. In vivo encystment of cercariae occurred in the gills of goldfish, the second intermediate host. However, the cercariae also encysted in vitro in Locke solution (0.6x to 1.2x strength), 0.7-1.2% NaCI, artificial g...
Thehealth status of red swamp crayfish, Procambarus clarkii and mosquito fish, Gambusia affinis collected from Elmansoria canal, Giza, Egypt was investigated. The canal is known to receive lofty loads of pollutants from diverse anthropogenic sources. 113 bacterial isolates were obtained from the investigated fish specimens. Isolates were phenotypic...
Axenic primary cultures of Himasthla elongata rediae harvested from hepatopancreas of naturally infected marine prosobranch snail Littorina littorea were maintained in Leibovitz's L-15 medium (osmolarity of approximately 780 mOsm, pH 7.8, temperature 14 degrees C under normal atmospheric conditions). Cultured rediae were active, motile and demonstr...
From December 2012 to November 2014, 267 fish belonging to the family Profundulidae (representing nine of the 11 species of the genus Profundulus) were collected in 26 localities of Middle-America, across southern Mexico, Guatemala, and Honduras, comprising the distribution range of the genus, and analyzed for helminth parasites. Additionally, a da...
A new species, Stephanoprora aylacostoma is described and its life cycle was resolved experimentally. The prosobranch snail Aylacostoma chloroticum Hylton Scott, collected in the Yacyretá dam, Province of Misiones, Argentina, was found naturally infected with large-tailed cercariae possessing a prepharyngeal body and corpuscles in the excretory sys...
Citations
... Cercariae are released in aquatic environments to search for fishes that serve as second intermediate hosts. In particular, in the gill filament, the encysted cercaria become in a metacercaria, which are ingested by appropriate definitive hosts [6,35,43]. ...
... However, the first intermediate host remains unknown. In Argentina, this life cycle was elucidated by Ostrowski de Núñez (2007), indicating the aquatic snail Heleobia parchappei as the first intermediate host. This genus of snail is also present in Chile (Valdovinos 1999), therefore, surveying these mollusks could elucidate the life cycle in the country. ...
Helminths are an important component of biodiversity with over 24,000 species parasitising wild birds globally, with this figure on the rise given the growing interest in wildlife parasitology. The present study aimed to establish an updated baseline of the helminthological surveys on wild birds from Chile. Thus, available publications were reviewed to build a parasite-host association checklist and also to discuss the state of knowledge regarding these parasites. As a result, 92 publications were counted between the years 1892 and 2019. With regard to helminth parasites, 174 taxa belonging to 3 phyla and 37 families were recorded. However, 114 taxa have been identified to species level, with the rest remaining incompletely described. Also, 4 taxa corresponded to new genera and 16 to new species for science. The most reported parasites were platyhelminthes (53.9%) followed by nematodes (36.2%) and acanthocephalans (9.2%). Sixty-five avian species from 19 orders have been recorded as hosts, with most of them having been studied only once (64.6%). Out of these, the order Charadriiformes had the highest number of publications (n=23). In the case of the avian species present in the country, 14.2% of native, 40% of endemic and 22.2% of exotic species have been recorded hosting helminths. Regarding heteroxenous parasites, only 2 species have had their life cycles elucidated. Among the methodologies used for parasitic identification, 48.9% of the studies used morphological tools, 5.4% used molecular tools and 4.3% used both tools. For that reason, there are evident gaps in the data concerning the hosts sampled, methodologies and issues related to the biology of parasites such as life cycles, among others. In this sense, the need for specialists and cooperative research becomes indispensable to improve our understanding of helminths.
... However, the first intermediate host remains unknown. In Argentina, this life cycle was elucidated by Ostrowski de Núñez (2007), indicating the aquatic snail Heleobia parchappei as the first intermediate host. This genus of snail is also present in Chile (Valdovinos 1999), therefore, surveying these mollusks could elucidate the life cycle in the country. ...
Helminths are an important component of biodiversity with over 24,000 species parasitising wild birds globally, with this figure on the rise given the growing interest in wildlife parasitology. The present study aimed to establish an updated baseline of the helminthological surveys on wild birds from Chile. Available publications were reviewed to build a parasite-host association checklist and also to discuss the state of knowledge regarding these parasites. A total of 92 publications were found between the years 1892 and 2019. Regarding helminth parasites, 174 taxa belonging to 3 phyla and 37 families were recorded, 114 taxa were identified at species level, with the rest remaining incompletely described. Also, 4 taxa corresponded to new genera and 16 to new at species for science. The most reported parasites were platyhelminthes (53.9%) followed by nematodes (36.2%) and acanthocephalans (9.2%). Sixty-five avian species from 19 orders have been recorded as hosts, with most of them having been studied only once (64.6%). Out of these, the order Charadriiformes had the highest number of publications (n=23). In the case of the avian species present in the country, 14.2% of native, 40% of endemic and 22.2% of exotic species have been recorded hosting helminths. Regarding heteroxenous parasites, only 2 species have had their life cycles elucidated. Among the methodologies used for parasitic identification, 48.9% of the studies used morphological tools, 5.4% used molecular tools and 4.3% used both tools. For that reason, there are evident gaps in the data concerning the hosts sampled, methodologies and issues related to the biology of parasites such as life cycles, among others. In this sense, the need for specialists and cooperative research becomes indispensable to improve our understanding of helminths.
... showed a marked peak only in site 4. Due to the complex life-cycles displayed by digeneans, their abundance is strongly associated with host densities (Blasco-Costa et al., 2013;de Montaudouin and Lanceleur, 2011). Most species of larval trematodes found in C. decemmaculatus display allogenic life cycles, using birds as definitive hosts; the unique exception is A. gnerii, with an autogenic life cycle and a siluriform fish as definitive hosts (Ostrowski de Núñez, 2007). Regarding first intermediate hosts, with the exception of P. nanum that parasitizes the ancylid Uncancylus concentricus (Ostrowski de Núñez, 1973), the rest of species share the same species of snail hosts (Helobia parchappei and H. piscium) (Ostrowski de Núñez, 1999Núñez, , 2007, being H. ...
... Most species of larval trematodes found in C. decemmaculatus display allogenic life cycles, using birds as definitive hosts; the unique exception is A. gnerii, with an autogenic life cycle and a siluriform fish as definitive hosts (Ostrowski de Núñez, 2007). Regarding first intermediate hosts, with the exception of P. nanum that parasitizes the ancylid Uncancylus concentricus (Ostrowski de Núñez, 1973), the rest of species share the same species of snail hosts (Helobia parchappei and H. piscium) (Ostrowski de Núñez, 1999Núñez, , 2007, being H. ...
Parasites have proven to display high responsiveness to anthropogenic stress, having, therefore a considerable value as bioindicators. We analysed the variability in the structure of parasite populations and assemblages of the poeciliid Cnesterodon decemmaculatus caught at partially urbanized stream along a unidirectional gradient with the aim of evaluating their utility as indicators of the effect of urbanization. A total of 209 fish were examined for parasites; some physical parameters of the stream, including the percentage of urbanization (UR) were also recorded. Data were analyzed at the levels of parasite populations and assemblages discriminated by host sex. Fish condition factor was negatively affected by UR, possibly related to flashing hydrology, but it was not related to parasite abundance. Different combinations of variables explained the distribution of parasite populations and assemblages along the creek, with UR being recurrently identified among the best predictors of parasite loads at all levels of analyses. Whereas densities of mollusc first intermediate hosts were considered of little relevance for parasite distribution, distribution of definitive hosts, as well as the presence of pollutants and increased flashiness in urbanized sections of the creek were retained as possible explanations to the observed patterns. As these factors can act simultaneously, the mechanisms driving differences in parasite dynamics of urban streams are difficult to individualize, but the effect of urbanization on both hosts and parasites was clearly identified. Parasites found, with abundances clearly related to UR, can be considered as good ecological indicators, since they are broadly distributed in the region, easy to observe and count, their prevalence and abundance allow reliable quantitative comparisons and are sensitive to variations of environmental stress and/or ecological conditions at small spatial scales. Consequently the susceptibility of fish-trematode systems to variations in both biotic and abiotic stressors makes them a promising tool for detecting urbanization-related disturbances in streams.
... In 2005, during a revision of Echinostomatidae, Kostadinova [1] divided the genus Stephanoprora into two subgenera, Stephanoprora and Monilifer. Studies conducted on the life cycle of Stephanoprora species have shown that its cercariae have a long tail [10][11][12]. Based on this structural feature of cercariae, Kostadinova included some species from Echinochasmus, which have long-tailed cercariae in Stephanoprora. ...
... Cercariae and adult life stages of the described species correspond to Stephanoprora. Long-tailed cercariae of the described worm are morphologically similar to those of S. denticulate (Rudolphi, 1802), S. uruguayense Holcman-Spector et Olague, 1989, and S. aylacostoma Ostrowski de Nunez et Quintana, 2008 [10][11][12]. Adult worms have similar organ composition and topology to other representatives of Stephanoprora, and bear 22 collar spines (with the exception of the species S. ornata Odhner, 1902, which has 26 spines). The main difference between S. chasanensis n. sp. and other species is the position of the vitellarium. ...
Echinostomatoidea is a large, globally distributed and heterogeneous group of hermaphroditic digeneans that parasite, as adults, vertebrate hosts of all classes. Species of this group have received attention from researchers as they can cause diseases in wildlife and humans. Here we describe the biological and molecular phylogenetic characteristics of Stephanoprora chasanensis n. sp. (Digenea: Echinochasmidae). The life cycle of this fluke was experimentally completed by the use of hosts, i.e. Stenothyra recondite Lindholm, 1929 snail (the 1st intermediate), Rhynchocypris percnurus mantschuricus (Berg, 1907) freshwater fish (the 2nd intermediate) and Gallus gallus chicken (the definitive host). In the adult worms, vitelline follicles were distributed anteriorly to the mid-level of the ventral sucker in our specimens whereas they did not reach the level of anterior testis in other species of Stephanoprora previously reported. Phylogenetic analysis based on 28S rDNA revealed that Stephanoprora and Echinochasmus with 20–22 collar spines grouped together in a single cluster. In addition, we showed that Stephanoprora chasanensis n. sp. was closely related to Echinochasmus milvi Yamaguti, 1939. Cercariae of these two echinostomes commonly have a long tail.
... Site of infection: Intestine Locality: Valdivia Prevalence: 1 of 14 (7.1 %) Mean intensity: 2.0 (2) Comments: Only two ovigerous trematodes were isolated, both with total loss of the cephalic spines. According to Sutton et al. (1982) (Nasir & Rodríguez, 1969;Sutton et al., 1982;Torres et al., 1983;Torres et al., 1991b;Etchegoin & Martorelli, 1997;Ostrowski de Núñez et al., 2004;Ostrowski de Núñez, 2007;Ostrowski de Núñez & Quintana, 2008;Brandao et al., 2013). Regard the morphology and measurements, the present specimens are in agreement with S. uruguayense of Torres et al. (1983) and Ostrowski de Núñez et al. (2004). ...
The goal of the present survey was to improve the scarce knowledge regard the endoparasites of raptors in Chile and South America. Thus, necropsy was performed on 14 chimango caracara Milvago chimango temucoensis from Los Ríos Region, Chile. From all examined birds, 78.6% were positive to helminths. The species identified were Capillaria tenuissima, Pterothominx sp., Baruscapillaria falconis, Cosmocephalus obvelatus, Skrjabinoclava sp., Synhimantus (Dispharynx) nasuta, Synhimantus (D.) sp., Synhimantus (Synhimantus) sp., Paracuaria adunca, Procyrnea spinosa, Porrocaecum depressum, Contracaecum rudolphii sensu lato, Stephanoprora sp. and Polymorphus mutabilis. All species listed, with the exception of C. tenuissima, P. spinosa and P. depressum, are new records for the chimango caracara. Furthermore C. obvelatus, Skrjabinoclava sp., S. (D.) nasuta, S. (D.) sp., P. adunca, C. rudolphii s. l., Stephanoprora sp. and P. mutabilis all are new records for Neotropical raptors.
... The larval stages of Psilochasmus oxyurus were first described from H. parchappii by Szidat (1957). Etchegoin (1997) and Ostrowski de Núñez (2007) found P. oxyurus in H. conexa in the Mar Chiquita coastal lagoon and in a pond in the Zoological Garden in Buenos Aires City (Argentina), respectively; the latter author did not provide a description. The cercaria found in this study, however, was smaller (Table II) than the ones described by Szidat (1957) and Etchegoin (1997). ...
... The morphologic features of the redia from the digestive gland and gonad of H. australis and the cercaria examined by us are consistent with the characteristics of the larval stages of S. uruguayensis as described by Ostrowski de Núñez (2007). The cercaria of this species has a head collar poorly developed without spines, a tail with brownish pigment on posterior fourth, longitudinal and circular muscle fibers, flattened spines on oral and ventral sucker (Figs 2E-F), a prepharyngeal body present, cystogenous cells with bar-shaped contents between pharynx and end of body, primary excretory ducts narrow without refractile granules, 16 flame cells, and a caudal excretory duct extending into the tail and bifurcating at the base of the tail into unequal branches ending blindly (Ostrowski de Núñez 2007). ...
... The morphologic features of the redia from the digestive gland and gonad of H. australis and the cercaria examined by us are consistent with the characteristics of the larval stages of S. uruguayensis as described by Ostrowski de Núñez (2007). The cercaria of this species has a head collar poorly developed without spines, a tail with brownish pigment on posterior fourth, longitudinal and circular muscle fibers, flattened spines on oral and ventral sucker (Figs 2E-F), a prepharyngeal body present, cystogenous cells with bar-shaped contents between pharynx and end of body, primary excretory ducts narrow without refractile granules, 16 flame cells, and a caudal excretory duct extending into the tail and bifurcating at the base of the tail into unequal branches ending blindly (Ostrowski de Núñez 2007). The cercariae of this species seem to exhibit a wide tolerance to salinity since the trematode has been recorded in the freshwater snail, H. parchappii, and for the first time in an estuarine snail, H. australis in our study. ...
Larval trematodes infecting the snail Heleobia australis (Cochliopidae) from the Bahía Blanca estuary, Argentina were surveyed for two years. A total of 7,504 snail specimens was dissected and the larval stages of 15 different trematodes were recovered and examined morphologically. These larvae included four species that had previously been reported from H. australis in Brazil, Uruguay, and Argentina: the heterophyid Ascocotyle (Phagicola) longa and the microphallids, Maritrema bonaerense, Maritrema orensense, and Microphallus simillimus. Three other species, the echinostomatid Stephanoprora uruguayensis, the microphallid Levinseniella cruzi, and the psilostomid Psilochasmus oxyurus are reported here for the first time as parasites of H. australis. Eight other trematodes found in H. australis are described and placed in the appropriate superfamilies, families or genera (Cryptogonimidae, Apocreadiidae, Aporocotylidae, Notocotylidae, Haploporidae, Renicolidae, Himasthla, and Renicola). The prevalence of the trematode taxa infecting H. australis in the Bahía Blanca estuary was low (<3%) with a single exception (M. simillimus; >20%). Microphallidae were the richest and the most prevalent family, probably because of the high abundance of crabs - the second-intermediate hosts of certain microphallid species - and the considerable diversity of gulls. Here we compare the parasite assemblage found in the H. australis from Bahía Blanca estuary with other parasite assemblages infecting Heleobia spp. and other rissooids from the rest of the world.
... Of these, S. anomala has been suggested as belonging to Ignavia Freitas, 1948 (see Ostrowski de Núñez, 1968), S. singularis was transferred to Echinoparyphium Dietz, 1909 (see Kohn & Fernandes, 1976), and S. dogieli and S. podicipei were considered synonymous with S. uruguayensis (see Ostrowski de Núñez et al., 2004). Nasir & Scorza (1968) described the life-cycle of a species which they identified as S. denticulata (Rudolphi, 1802), but the taxonomic status of their material requires confirmation due to differences between the descriptions of both larval and adult stages and European S. denticulata (see Køie, 1986;Ostrowski de Núñez, 2007;Ostrowski de Núñez & Quintana, 2008). ...
Five species of digeneans parasitic in the Magellanic penguin Spheniscus magellanicus (Forster) from off the Brazilian coast of the western Atlantic are reported for the first time from this host and described. These are Mesostephanus odhneri (Travassos, 1924) Lutz, 1935, Posthodiplostomum
macrocotyle Dubois, 1937, Stephanoprora
uruguayensis Holcman-Spector & Olagüe, 1989, Ascocotyle (Phagicola) longa Ransom, 1920 and Ascocotyle (Phagicola) sp. One other digenean, Cardiocephaloides physalis (Lutz, 1926) Sudarikov, 1959, was also recorded. The taxonomy of the species and available data on their life-cycles are commented upon in relation to the possible origins of digenean infections of the Magellanic penguin.
... D I S C U S S I O N Experimental infections of animals with trematode metacercariae have provided vital information on previously unknown life cycles (Viozzi et al. 2005 ; de Nunez, 2007 ), host-parasite biochemical and immune interactions (Toledo et al. 2005 ; Alcala-Canto et al. 2007 ; Raadsma et al. 2007), or the efficacy of vaccines and drugs against infection (GonzalezLanza et al. 2006 ; Reyes et al. 2008). However, the results of metacercarial infections are not independent of choices made by researchers during the design of the experiment. ...
Experimental studies of parasite transmission are essential for advances in basic and applied parasitology. A survey of the results of published experiments can identify the determinants of both variation among studies in experimental design and of parasite infection success. Here, analyses are conducted on data compiled from a total of 106 metacercarial infection experiments (35 on Echinostomatidae, 37 on Fasciolidae, 34 on other trematodes) obtained from 83 studies. All of these involved experimental oral infection of individual definitive hosts by a single known dose of metacercariae under controlled conditions. Across these studies, the metacercarial dose used (i) was typically about 10 times higher than the average natural dose that could be acquired by feeding on intermediate hosts (for taxa other than Fasciolidae), and (ii) showed a positive relationship with the body mass of the definitive host, although this relationship was only significant for Fasciolidae. Although the chosen dose was rarely justified, the larger the definitive host, the more metacercariae it received. Among Echinostomatidae and Fasciolidae, there was also a significant dose-dependent effect on infection success: the higher the dose used in an experiment, the smaller the proportion of metacercariae recovered from the host. This effect was mitigated by definitive host body mass, with infection success being generally lower in larger definitive hosts. For Echinostomatidae, the taxonomic identity of the definitive host also mattered, with metacercariae achieving higher infection success in mammals than in birds. The present findings suggest that the design of experimental infection studies requires greater consideration if their results are to yield useful biological insights.
... However, the life cycle and taxonomic status of S. denticulata as reported by Nasir and Scorza (1968) may be subject to revision because differences with the European S. denticulata suggest that it has been misclassified (Køie 1986) or that experimental results were misinterpreted (Ostrowski de Núñez 2007). S. aylacostoma is distinguished from the experimentally obtained adults of S. uruguayense of the same age (Ostrowski de Núñez 2007) only by its smaller body, tail and collar spines and larger eggs. The main differences between these species lay in the morphological and biological features of life cycle stages and in the intermediate hosts. ...
... The main differences between these species lay in the morphological and biological features of life cycle stages and in the intermediate hosts. S. aylacostoma exhibits the following distinctive features in comparison with S. uruguayense: adult body size is smaller (2,026 vs 2,770), live eggs are larger (95×57 vs 83×51), miracidia are larger (68 vs 52) and have a considerably longer life span (4 days vs 20 h); daughter rediae from natural infections are shorter and wider (836× 201 vs 976×150), and the pharynx is larger (71×66 vs 44× 50); the cercariae are larger (250 vs 183) and possess calcareous corpuscles in the excretory system, which are absent in the cercariae of S. uruguayense; the metacercaria cysts are larger (127×120 vs 108×69), the calcareous corpuscles are smaller (7×6 vs 17×9), and the head collar spines appear later (10 days vs 7 days) (Ostrowski de Núñez 2007). The first intermediate host of S. aylacostoma seems to be specific, as its miracidia are unable to infect H. parchappei, the host of S. uruguayense. ...
A new species, Stephanoprora aylacostoma is described and its life cycle was resolved experimentally. The prosobranch snail Aylacostoma chloroticum Hylton Scott, collected in the Yacyretá dam, Province of Misiones, Argentina, was found naturally infected with large-tailed cercariae possessing a prepharyngeal body and corpuscles in the excretory system but lacking collar spines. Metacercariae, which encysted on the gills of experimentally infected fishes Cnesterodon decemmaculatus (Jenyns) and Poecilia reticulata (Peters) (Poecilidae), developed collar spines after 10 days. Tetragonopterid fishes Moenckhausia dichroura (Kner), Astyanax erythropterus (Holmberg) and Hyphesobrycon serpae (Durbin in Eigenmann) were found infected naturally. Sexually mature adults were recovered from domestic chicks at day 7 post-exposure. Eggs shed in chick faeces developed to miracidia within 13-15 days; sporocysts were found on the gills of snails. The new species differs from other species of the genus in its larger eggs, in the smaller, slender body and smaller collar spines of the adult and in the morphological and biological features of the larval stages.
