The expression ‘you need to know to conserve’ is a well-known cliche among biologists. Documenting the richness of a group of organisms is the first step towards understanding biodiversity and preparing efficient conservation plans. In this context, many efforts have been made to quantify the number of species on Earth and estimate the number of species still unknown to science. A few countries have complete and integrated databases estimating the approximate number of species recorded for their territory, particularly in the Global South. In Brazil, a country of continental dimensions, revealing the richness of the second most diverse clade of invertebrates (=Mollusca) has been a goal of taxonomists. Recently, in an unprecedented, collective, and integrated effort among Brazilian malacologists, it was possible to estimate how many valid species of molluscs are there in Brazil. In this effort, more than 30 mollusc experts joined together to update the Taxonomic Catalogue of the Brazilian Fauna (TCBF), a governmental website that allows a quick and real-time updating of all Metazoan. So far, more than 5,000 updates have been made in TCBF, indicating the presence of 3,552 valid species of molluscs in Brazil, distributed among the main clades as follows: Caudofoveata (10 spp.), Solenogastres (6 spp.), Polyplacophora (35 spp.), Scaphopoda (43 spp.), Cephalopoda (92 spp.), Bivalvia (629 spp.) and Gastropoda (2,737 spp.). The present study, in addition to demonstrating for the first time the richness of Brazilian molluscs, also presents the state of the art of this important phylum of invertebrates highlighting its most representative and neglected groups.

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.

In this study, we provide the first data regarding seasonal variation and patterns along a fine-scale humidity gradient on the land snail community, including parameters such as richness and abundance, in the Sooretama Biological Reserve, Espírito Santo, Brazil. Our study was conducted from January 2017 to December 2018, covering all four seasons (summer, autumn, winter and spring). We used 24 plots of 250 m each, combined with subplots of 25 x 75 cm (to sample leaf-litter), following the RAPELD methodology. We collected 440 live specimens belonging to 35 species from 11 families. The snail species richness varied among seasons, with the highest mean values in summer and spring. The highest variation of richness occurred between summer and autumn, and the smallest variation occurred between spring and summer. Soil temperature, relative air moisture and soil moisture affected significantly the overall land snail abundance. The rainy season was hotter and wetter than the dry season and showed highest richness and abundance of species. Our results showed a clear compositional change along the moisture gradient, suggesting differences in species preference for moisture conditions even at a fine-scale.