Francisco Brusa

New Species of Gieysztoria (Platyhelminthes, Rhabdocoela) from Peruvian Amazon Floodplain with Description of their Stylet Ultrastructure

Abstract The free-living Platyhelminthes of the Amazon basin are poorly known. Presently only four turbellarian species have been mentioned from the Amazon river, a fact that confirms the lack of information on this kind of faunas in this huge basin. Three new species of Gieysztoria from Amazonian floodplain in Peru are described herein: G. chiqchi n. sp., G. kasasapa n. sp. and G. sasa n. sp. The samples were taken in the Pacaya-Samiria National Reserve (Peru) during September 2002. Besides the usual description of the stylet based on whole mounted specimens, we provide a complementary description using SEM, which allowed differentiation of the new species within the currently yet imperfect picture of the Amazonian turbellarian fauna. Although further research is desired, current findings are suggestive of high diversity of free-living Turbellaria in the surveyed region.

New freshwater interstitial Otoplanidae (Platyhelminthes: Proseriata) from the Paraná and Uruguay rivers, South America

This study describes two new freshwater otoplanid species (Platyhelminthes, Proseriata), Itaspiella parana n. sp. and Philosyrtis rauli n. sp., from interstitial habitats of the middle Paraná river (Argentina) and lower Uruguay river (Uruguay), respectively. Kata sp. from the Uruguay river is briefly characterized. This is the first report of otoplanids from freshwater environments of South America. The studied areas are particular biotopes. At present, only a few studies on the turbellarian fauna and its ecology have been carried out in the Paraná river and the records presented here are the first for the Uruguay river. The main difference between other known otoplanid species and Itaspiella parana, Philosyrtis rauli and Kata sp. is their ecological characterization. Until now the family Otoplanidae was known only from marine environments, with a few exceptions.

A new species of Gieysztoria (Platyhelminthes, Rhabdocoela) from Argentina and a kinship analysis of South American species of the genus

This study describes a new species of Gieysztoria found in lentic environments in Argentina. Gieysztoria falx sp. n. appears to be closely related to G. therapaina and G. intricata, and is differentiated principally by the presence of two strongly developed pincer‐shaped spines of the cuticular stylet. A preliminary analysis of the phylogeny among the South American species of this genus is undertaken, and the monophyly verified. This study constitutes the first approach to interpreting these relationships.

A new Paravortex (Platyhelminthes, Dalyellioida) endoparasite of Mesodesma mactroides (Bivalvia, Mesodesmatidae) from Uruguay

Many species of turbellarians (Platyhelminthes) are known to live associated with other organisms, especially invertebrates, as commensals or parasites. The family Graffillidae (Rhabdocoela) includes two genera that parasitize mollusks, Graffílla and Paravortex. Within the latter genus, six species were described as associated with mollusks. In other instances, unnamed Paravortex species were mentioned as parasites of other bivalves and of the body surface of fishes. In the present work, a new Paravortex species that was found in the intestine of Mesodesma mactroides from the Atlantic coast of Uruguay is described. In addition, a bibliographical revision of the known Paravortex species with their respective hosts, location, and distribution is made. Paravortex nicolli, described by Szidat for the Argentinean coast, is mentioned for the first time after the original description, and the authorship and date of description of Paravortex tapetis Noury-Sraïri 1989 are elucidated.

First report of Temnocephala brevicornis Monticelli 1889 (Temnocephalidae: Platyhelminthes) in Argentina

Temnocephala brevicornis Monticelli 1889, ectosymbiont of Hydromedusa tectifera Cope 1869, is reported for the first time for Argentina. Numerous temnocephalans from Arroyo Villoldo in the locality of Magdalena, Buenos Aires, Argentina were stained in toto to be studied. This commensal species in turtles was originally cited in association with Hydromedusa maximiliani (Mikan) and Hydraspis radiolata Mikan in Brazil. Afterwards, it was found on other fresh water turtle species in Brazil and Uruguay.

Paravortex panopea n. sp. (Platyhelminthes: Rhabdocoela) on clams from the northern Patagonian coast, Argentina: pathogeny and specificity

SummaryDuring a histopathological survey of the geoduck, Panopeaabbreviata (Hiatellidae), and the razor clam, Ensis macha (Pharidae), in northern Patagonian gulfs (Argentina), turbellarian worms were found in the intestine lumen. In this work, we described a new species of Paravortex (Platyhelminthes, Graffillidae). We collected the hosts by scuba diving and dissected alive for studying the turbellarians. In this new species, the pharynx continues in a short esophagus and the latter in a saccular intestine. Gravid specimens have from 2 to 8 twin embryos in the parenchyma. A short penis papilla arises from the seminal vesicle and the gonopore presents a strong sphincter. This species resembled P. nicolli Szidat, 1965, which was described paraziting Mytilus edulis platensis in Buenos Aires, Argentina. The new species can be differentiated from P. nicolli mainly by the presence of a penis papilla and a sphincter between genital atrium and gonopore. This turbellarian species was significantly more prevalent in geoducks (28 %, n = 210) than in razor clams (6 %, n = 480) (KW, p < 0.0001). For both host species, no evidence of direct physical damage caused by turbellarians was observed.

Composition of meiobenthonic Platyhelminthes from brackish environments of the Galician and Cantabrian coasts of Spain with the description of a new species of Djeziraia (Polycystididae, Kalyptorhynchia)

From 1997 to 1999, the fauna of free‐living Platyhelminthes of the rias ecosystem was studied along the Galician and Cantabrian coast in northern Spain. In total, 72 platyhelminth species are listed in this study. Forty‐two species represent new records for the Iberian Peninsula, three of which represent new genera records. A new species belonging to the genus Djeziraia (Polycystididae, Kalyptorhynchia), Djeziraia longistyla sp. nov., is described in this paper. In this broad‐scale study, a large data set (27 localities) of the estuaries of northern Spain allowed an analysis of the turbellarian species assemblages and the relation of species distributions to salinity, conductivity, oxygen, temperature, and sediment characteristics. Species assemblages (species diversity) of each habitat of the brackish water ecotone are shown. The present study contributes to knowledge on the ability of adaptation of free‐living Platyhelminthes to regimes of brackish water ecotones.

Morphology and DNA barcodes reveal the presence of the non-native land planarian Obama marmorata (Platyhelminthes : Geoplanidae) in Europe

Abstract. We report for the first time the occurrence of Obama marmorata in the Iberian Peninsula as an introduced species from the Neotropical Region. The species is also reported for the first time in Argentina. The identification was made on the basis of morphological evidence. The divergence levels of a fragment of the mitochondrial cytochrome c oxidase I gene from Argentinean and Iberian samples were studied. The morphology of samples from the two regions was the same and matched the original description of the species. A DNA barcoding matrix was constructed using new sequences from O. marmorata and sequences of related species taken from GenBank. Among the Geoplanidae, interspecific divergence ranged between 3.3 and 14.4%, while intraspecific divergence percentages were 0–1.2%, signalling the presence of a DNA barcoding gap. All O. marmorata sequences, irrespective of their geographic origin, form a well supported clade with an intraspecific divergence of 0–0.9 (average = 0.4%). These results indicate the utility of DNA barcoding to discover allochthonous species in this group of organisms.

Land Planarian Assemblages in Protected Areas of the Interior Atlantic Forest: Implications for Conservation

Land planarians are an interesting group of free-living flatworms that can be useful as bioindicators because of their high sensitivity to environmental changes and low dispersal capacity. In this study, we describe and compare assemblages of land planarians from areas with different conservation degrees of the Interior Atlantic Forest (Misiones, Argentina), and assess factors that could be related to their abundance and richness. Eight sites were tracked in search of land planarians in Reserva de Vida Silvestre Urugua-í (RVSU) and Campo Anexo Manuel Belgrano (CAMB). Diurnal and nocturnal surveys were performed in each site along nine sampling campaigns. We collected 237 individuals belonging to 18 species of the subfamily Geoplaninae. All sites were dominated by Geoplana sp. 1 and Pasipha hauseri. The richness estimators showed that there would be more species in RVSU than in CAMB. The abundance and richness of land planarians was high during the night and after rainfalls, suggesting an increased activity of flatworms under such conditions. The abundance and richness of land planarians were also related to the conservation condition of the sites. Disturbed sites showed less abundance and richness, and were segregated from non-disturbed ones by nmMDS analysis. Beta diversity between sites was higher than expected, indicating that the species turnover between sites contributed more to the total richness (gamma diversity) than the alpha diversity.

Choeradoplana crassiphalla sp. nov. (Platyhelminthes: Tricladida: Geoplanidae): a new species of land planarian from the Atlantic Forest of Argentina

A new species of land planarian from northeastern Argentina, Choeradoplana crassiphalla sp. nov., is described. This is the first report of Choeradoplana in the Atlantic Forest of Argentina and the second species of the genus for this country. Choeradoplana includes nine species of Neotropical land planarians. The new species is light brown with a thin clearer median stripe. The pharynx is bell-shaped. The copulatory apparatus presents a short and very high and thick penis papilla. Choeradoplana crassiphalla is compared with other species of the genus, especially with Ch. marthae, due to the similarity of the copulatory apparatus.