Biological invasions pose significant challenges in the Anthropocene, impacting ecosystem biodiversity and functioning. Ecological Niche Modeling is widely used to evaluate potential areas at risk of invasions, aiding in the prevention of invasive-species expansion and guiding conservation efforts in freshwater ecosystems. The main objectives of this study were to model the ecological niche and evaluate remaining suitable habitat areas for the occurrence of five potentially invasive species of freshwater decapods in South America: Dilocarcinus pagei, Macrobrachium amazonicum, M. jelskii, M. rosenbergii, and Procambarus clarkii. Occurrence data from the Global Biodiversity Information Facility were complemented with a literature systematic review. Variables used in the models were obtained from the Worldclim and EarthEv databases. Ecological Niche Modeling was performed using the Biomod2 and sdm package algorithms. Our results indicated a suitable area of up to 11% of South America. Model evaluations yielded favorable TSS and AUC values (>0.7 and >0.8). The suitable areas projected for South America included several hydrographic basins and Protected Areas. The information generated in our study can help identifying areas susceptible to decapod invasion in South America and support local management and decisions.

We compiled taxonomic information about terrestrial gastropods in Brazil in an organized and user-friendly checklist that we hope will be useful for researchers and stakeholders alike. We also expect that it will serve as a springboard, garnering more interest and enabling a new wave of studies on this fauna, which has one the highest extinction rates of all animal groups while being essential ecosystem functioning and also includes species of importance to public health and agriculture. We list all species of terrestrial gastropods that occur in the country, with information regarding synonymized names and fossils. We also propose a few nomenclatural acts to address some pending issues of easy resolution. A total of 748 species of terrestrial gastropods are known in Brazil, including 33 exotic species that have been introduced to Brazil. A total of 48 families are present, the majority of which belong to Stylommatophora; only six families represent the Neritimorpha, Caenogastropoda and Systellommatophora. The most speciose families are Bulimulidae, Strophocheilidae, Cyclodontinidae, Streptaxidae, and Simpulopsidae. Changes in nomenclature proposed here are as follows: Drymaeus obliquus poecilogramma Ancey, 1901 is now reclassified as Sanniostracus poecilogramma (Ancey, 1901) comb. nov.; Helix uniplicata Férussac, 1827 as Clessinia uniplicata (Férussac, 1827) comb. nov.; Zonitoides parana Baker, 1914 as Miradiscops parana (Baker, 1914) comb. nov.; “Helix” circumplexa Deshayes, 1839 as Systrophiella circumplexa (Deshayes, 1839) comb. nov.; Bradybaena giovannalimae Lima & Cossignani, 2021 as Streptaxis giovannalimae (Lima & Cossignani, 2021) comb. nov.

Leiostracus Albers, 1850 was established to allocate land snails from Central America and Northern South America. Currently, approximately 19 species are considered valid. However, for most of them, the internal morphology is unknown. Leiostracus obliquus was described as a species of Bulimus from the state of Bahia based on shell characters. Until now, knowledge of this species has been scarce. The discovery of ethanol-preserved specimens from MZSP of this species allowed us to characterize, for the first time, the internal anatomy of this species and update its distribution. The shell of L. obliquus has seven to eight whorls and a wide pale-pink disrupted band all over the teleoconch. The rachidian tooth is small rectangular, symmetric, with round edges, and without differentiated cusps. After comparing the anatomy and radular characters between the shells of L. obliquus and L. carnavalescus, we found remarkable similarities in the morphology and color pattern.

The family Planorbidae comprises freshwater gastropods with planispiral, spiral and limpet-shaped shells. Subfamily Planorbinae sensu stricto, has a richness of almost 300 species, with some of the main genera being Biomphalaria Preston, 1910 and Drepanotrema Fischer & Crosse, 1880. Some Biomphalaria species are of concern to human health as they are intermediate hosts of blood flukes in Latin America. In Argentina, the family Planorbidae is represented by 15 species in four genera. In Northern Argentina (NOA region), records of the family are scarce, and most of them are a result of occasional collecting. We provide an updated checklist of Planorbinae in NOA resulting from fieldwork, material in malacological collections, and data in the literature. Nine species occur in the area: four species of Biomphalaria and five of Drepanotrema. Among Biomphalaria species, we recorded Biomphalaria straminea (Dunker, 1848), which is considered a natural host of the blood fluke Schistostoma mansoni Sambon, 1907, for first time in Salta province; the known geographic distribution of B. straminea is extended in the country.