Forty-seven specimens of Neotropical cormorants, Phalacrocorax brasilianus, from Lago Guaíba, Guaíba, State of Rio Grande do Sul, Brazil (30° 00' S, 51°15' W), were examined for helminth parasites between 1999 and 2003. Twenty species of helminth parasites were found: ten digeneans: Austrodiplostomum mordax, Austrodiplostomum compactum, Clinostomum sp., Drepanocephalus olivaceus, Drepanocephalus spathans, Hysteromorpha triloba, Ignavia olivacei, Paryphostomum segregatum, Prosthogonimus ovatus, and Ribeiroia ondatrae; one cestode: Paradilepis caballeroi; eight nematodes: Contracaecum rudolphii, Eucoleus contortus, Eustrongylides sp., Ornithocapillaria appendiculata, Syngamus sp., Syncuaria squamata, Tetrameres (Gynaecophila) sp., and one undetermined capillariid (genus and species); and one acanthocephalan: Andracantha tandemtesticulata. The length and weight of male and female birds, as well as their sexual maturity (juvenile or adult), did not show significant difference regarding the helminth fauna; the standard length did not influence the helminth parasite indices. The prevalence of I. olivacei was higher in larger birds while the intensity of infection by this digenean species was higher in females. The abundance of P. caballeroi was higher in male birds. A. mordax and H. triloba showed higher prevalence and abundance in juvenile hosts, while O. appendiculata was more abundant in juveniles. The remaining species did not have their parasite indices influenced by the host parameters studied. The present work records the richest helminth fauna for any bird of the genus Phalacrocorax and is the first study to evaluate the influence of length, weight, sex, and maturity state on parasitism.

Urbanization drastically alters natural ecosystems and the structure of their plant and animal communities. Whereas some species cope successfully with these environmental changes, others may go extinct. In the case of parasite communities, the expansion of urban areas has a critical effect by changing the availability of suitable substrates for the eggs or free-larval stages of those species with direct life cycles or for the range of hosts of those species with complex cycles. In this study we investigated the influence of the degree of urbanization and environmental heterogeneity on helminth richness, abundance and community structure of rufous-bellied thrushes (Turdus rufiventris) along a rural-urban gradient in the metropolitan region of Porto Alegre, State of Rio Grande do Sul, Brazil. This common native bird species of southern Brazil hosts 15 endoparasite species at the study region. A total of 144 thrushes were collected with mist nets at 11 sites. The degree of urbanization and environmental heterogeneity were estimated by quantifying five landscape elements: buildings, woodlands, fields, bare lands, and water. Landscape analyses were performed at two spatial scales (10 and 100 ha) taking into account home range size and the potential dispersal distance of thrushes and their prey (intermediate hosts). Mean parasite richness showed an inverse relationship with the degree of urbanization, but a positive relationship with environmental heterogeneity. Changes in the structure of component communities along the rural-urban gradient resulted from responses to the availability of particular landscape elements that are compatible with the parasites' life cycles. We found that the replacement of natural environments with buildings breaks up host-parasite interactions, whereas a higher environmental (substrate) diversity allows the survival of a wider range of intermediate hosts and vectors and their associated parasites.

The present report is part of a larger study on the helminth fauna of Neotropical Cormorants, Phalacrocorax brasilianus (Gmelin, 1789) in Brazil, particularly, in the southernmost State of Rio Grande do Sul. The nematodes which were found loose in the proventriculus/ventriculus or in groups of adults of different ages and of L3 and L4 larval stages, forming eosinophylic granulomas had a prevalence of 100% in 47 Neotropical cormorants from Lago Guaíba, Municipality of Guaíba. The morphology of the labia/interlabia, the distribution pattern of the caudal papillae in males examined under scanning electron microscopy (SEM), and the tips of the spicules allowed determination of the species as Contracaecum rudolphii Hartwich, 1964 sensu lato (s. l.). This is the first record of C. rudolphii in southern Brazil.

Sixty specimens of the "cururu" toad, Rhinella icterica (Spix 1824) (Bufonidae), were collected in Campo Belo do Sul, State of Santa Catarina, Brazil, between May 2009 and January 2011, and were examined for the presence of helminth parasites. Nine species of adult helminths were found: Catadiscus cohni, Rudolphitrema rudolphii, Cylindrotaenia sp., Rhabdias fuelleborni, Strongyloides sp., Cosmocerca rara, Cosmocerca brasiliensis, Aplectana elenae, and Oxyascaris sp., in addition to an unidentified adult nematode species. Females of cosmocercid nematodes, proteocephalan plerocercoid, and acanthocephalan cystacanth were found but not identified for lack absolute of taxonomic characters. The sex of the anurans had no influence on prevalence, abundance, and richness of helminth species. Length and body mass of hosts did not influence the prevalence and richness of helminths, while the abundance of R. fuelleborni was significantly correlated with both parameters.

The interface Eurytrema coelomaticum/Bradybaena similaris was studied by quantifying the amount of glucose on the hemolymph and the content of glycogen in the cells of the digestive gland and the cephalopedal mass of infected and uninfected snails. Samples were analyzed on days 0, 30, 90 and 150 post-infection. The infected snails had less glucose in the hemolymph, with a reduction of 67.05 por cento at 30 days, and 62.09 por cento at 90 days post-infection. The reduction in glycogen content was 86.41 por cento in the digestive gland and 79.1 por cento in the cephalopedal mass at 30 days, and 92.71 por cento and 90.89 por cento in these organs respectively at 90 days post-infection. It is proposed that the sporocysts absorb glucose directly from the hemolymph

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A new species of the genus Temnocephala Blanchard, 1849 is described from southern Brazil, ectosymbiont on Aegla serrana Buckup & Rossi, 1977, an anomuran crustacean, collected in a creek and a reservoir of the highlands in the State of Rio Grande do Sul. All crustaceans examined were positive for this species of Temnocephala and carried eggs in different regions of the ventral side: perioral area, pleural strips, esternal plates, pereiopods and chelipods; to a lesser extent in the dorsal side of the cephalothorax and dorsal side of the uropods; as well as adult and young specimens. The most distinctive characters of the new species are: 1) cyanophilous glands forming an irregular-shaped, grape-like, bunch of approximately 10-15 cells, deeply staining with hematoxylin; 2) shape and size of the cirrus and its introvert section; 3) number, size and distribution of the rhabdite glands and 4) shape and position of the post tentacular, 'excretory' syncytial plates, with the off-centered nephridiopore

Ninety specimens of Rhinella fernandezae , collected in Imbé, State of Rio Grande do Sul, Brazil, from August 2006 to April 2007, were examined for presence of helminth parasites; all were infected by at least 1 species. Thirteen species of parasites were found: 4 digeneans, 2 cestodes, 2 acanthocephalans, and 5 nematodes. Rhinella fernandezae represents a new host record, as well as for Gorgoderina festoni , Cylindrotaenia americana , Acanthocephalus lutzi , Aplectana meridionalis , and Strongyloides carinii . The nematodes Cosmocerca parva and A. meridionalis occurred with a prevalence of 79.1%, and, as in other Rhinella species, the nematodes dominated the parasite community. Host gender had no influence on either abundance or prevalence of the helminths, and neither the length nor weight of the hosts influenced the richness of the parasitic helminths of these burrowing toads. Only A. meridionalis and Centrorhynchus sp. (both cystacanths) exhibited a significant correlation between host length and abundance of helminths; only A. meridionalis showed a relationship between host length and prevalence.