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The reproductive cycle of non-native species is indicative of their capacity for dispersal, invasion, and competition, and the alteration in biodiversity. Corbicula spp. are successful invaders of aquatic ecosystems. We studied the reproductive cycle of Corbicula largillierti from a Pampean stream, Argentina, at its southern distribution in South America. Specimens were collected monthly from January 2003 to April 2005 and processed using traditional histological techniques. Three gonadal stages (active gametogenesis, mature, and spawned) were recognized. In the studied population, most individuals were hermaphroditic with a dominant female gonadal portion. The three gonadal stages were observed during the whole sampling period with rapid gonadal recovery; no resting period was observed. Five oocyte spawning events were recognized, occurring in autumn and spring. Expanding the knowledge of reproductive features of the Corbicula largillierti allows the understanding of current distributions. The results highlight the difficulty of identifying patterns of gamete release and spawning behavior in this invasive species, as it is recorded for other Corbicula spp. [ABSTRACT FROM AUTHOR]

Avian schistosomes are blood flukes parasitizing aquatic birds and snails, which are responsible for a zoonotic disease known as cercarial dermatitis, a hypersensitive reaction associated to the cutaneous penetration of furcocercariae. Despite its worldwide distribution, its knowledge is fragmentary in the Neotropics, with most of data coming from Argentina and Brazil. In Chile, there are only two mentions of these parasites from birds, and one human outbreak was associated to the genus "Trichobilharzia". However, the identity of such parasites is pending. The aim of this study was to identify the furcocercariae of avian schistosomes from Southern Chile using an integrative approach. Thus, a total of 2283 freshwater snails from different families were collected from three different regions. All snails were stimulated for the shedding of furcocercariae, but only Chilina dombeyana (Chilinidae) from the Biobío region was found to be parasitized. The morphology and phylogenetic analyses of 28S and COI genes stated two lineages, different from Trichobilharzia, shared with Argentina. This study provides new information on Neotropical schistosomes, highlighting the need for major research on these neglected trematodes, which are considered to be emerging/re-emerging parasites in other parts of the globe as consequence of anthropogenic disturbances and climatic change. Highlights: 1. Two different lineages (Lineage I and II) were described and molecularly characterized (28S and COI genes); 2. Cercaria chilinae I y II are proposed as a synonymous of Lineage II. Thus, a total of four different lineages of avian schistosomes are related to Chilina spp.; 3. Chilina spp. represents an important intermediate host for avian schistosomes in South America, constituting a reservoir de schistosomes with zoonotic potential; 4. Coinfection between the two different lineages was found, a finding previously not reported for avian schistosomes; 5. Expansion in the geographic distribution of Nasusbilharzia melancorhypha from its original record in Argentina, with Chilina dombeyana as an additional intermediate host. [ABSTRACT FROM AUTHOR]

The Atlantic Forest is a highly fragmented biodiversity hotspot, which in Argentina is represented by the Paranaense Forest, covering a wide area of the province of Misiones. In conservation studies, groups of vertebrates, plants and arthropods are generally used together but other invertebrates scarcely used. In the present work, we aim to provide information on new species of freshwater gastropods, from protected and unprotected areas. Specimens were collected in a protected area (Yabotí Biosphere Reserve) and in two unprotected areas (Alba Posse city and Centro de Investigaciones Antonia Ramos -CIAR-). The shell, radula, internal anatomy and the molecular information of the partial sequence of mitochondrial cytochrome c oxidase subunit I (COI) were analysed. The phylogenetic trees were obtained using Maximum Likelihood and Bayesian Inference analyses. Altogether, the anatomical, shell, and genetic studies allow us to differentiate six new species of the genus Potamolithus from the others present in Argentina and the surrounding areas. These new species raise the number of freshwater gastropods for the malacological province Río Uruguay to 64. Three of the new species have been found within a protected area, while other three at unprotected areas. The presence of invasive species, such as Limnoperna fortunei (Dunker 1857) and Melanoides tuberculata (Müller, 1774), as well as the possible creation of a hydroelectric dam, may modify the environment inhabited by the new endemic fauna. [ABSTRACT FROM AUTHOR]

Callyntra is a genus of tenebrionid beetles endemic to the Southern Cone region of South America, with 23 species occurring in Chile and one shared with Argentina. The recent descriptions of new species were commonly based on the male genitalia structure, underestimating the utility of the female genitalia for this purpose. Analysis of the ovipositor structure of a series of females assigned to Callyntra carbonaria from the Bío-Bío and Araucanía in Southern Chile, have resulted in the discovery of a new species, Callyntra femina sp. nov., which was corroborated through molecular analysis using COI and 16S gene fragments. The phylogenetic analysis recovered C. femina as sister to a clade composed of C. rossi, C. carbonaria and C. riverai, being genetically more similar to C. rossi.