Predicting the distribution of Omalonyx (Mollusca: Pulmonata: Succineidae) species from literature review, museum databases and new sampling efforts in Brazil

Abstract

Accurate distributional information is crucial for studies on systematics, biodiversity and conservation. To improve the knowledge regarding the geographical distribution of Omalonyx in South America, we present updated information based on data from a literature review, institutional collections and malacological surveys. All this information composed the dataset used to predict species distribution employing the Maximum Entropy Algorithm (MaxEnt). The model was run using data on species distribution, altitude and bioclimatic variables (WorldClim database). The model had consistent performance, and areas presenting similar conditions to areas where the species were recorded were considered areas of occurrence. The predicted occurrence areas included those that were already surveyed and those that are considered potential occurrence areas. The results demonstrate that the genus has widespread distribution in the Neotropical region and occurs in the tropical, temperate and arid regions of South America and Lesser Antilles. Omalonyx spp. were recorded in all South American countries and hydrographic regions. However, in some countries, there were only isolated records (ex: Colombia and Ecuador). Here, we also present the first record of Omalonyx spp. in four Brazilian States (Acre, Rondônia, Piaui, and Amapá). The genus was found in all hydrographic regions within Brazil and among 27 federative unities; it was absent from only two unities (Roraima State and Distrito Federal). This work contributes to the knowledge on Omalonyx spp. distribution and provides an important basis for the work of ecologists and taxonomists.

The mitochondrial genome of the semi-slug Omalonyx unguis (Gastropoda: Succineidae) and the phylogenetic relationships within Stylommatophora

“…They are also natural and potential intermediate hosts for parasites of the genus Leucochloridium Carus, 1835 (Trematoda) and Angiostrongylus Kamensky, 1905 (Nematoda), respectively [ 24 – 27 ]. Based on morphological characteristics of the reproductive system, six species are currently recognized within Omalonyx [ 28 , 29 ], including Omalonyx unguis (d’Orbigny, 1836) which inhabits the Paraná River basin [ 28 , 30 ].…”

New records of the sponge Radiospongilla inesi (Porifera: Spongilidae) and the slug Omalonyx matheroni (Gastropoda: Succineidae) in the Vale do Paraíba, southeast Brazil

“…Species of the genus Omalonyx have broad distribution on the Central and South Americas, found in swamps and lake banks, or under the emergent vegetation of the freshwater systems (Poi De Neiff & Casco, 2003). The slugs Omalonyx matheroni present records especially in the Amazonian region, with some feel reports to Central West, Southeaster and South regions (Coscarelli et al, 2018). Despite some records of Omalonix sp.…”

“…They are distributed over the Neotropical area, in the West Indies and South America. According Coscarelli et al (2018) (Tillier, 1981).…”

First record of the semi-slug Omalonyx unguis (d’Orbigny, 1837) (Gastropoda, Succineidae) in the Misiones Province, Argentina

“…Recently, Coscarelli et al (2018) made predictions on the potential distribution area of 5 Omalonyx species, where Misiones Province is indicated as a suitable area for the occurrence of O. unguis and O. convexus. Nonetheless, although more than 150 years have passed since both species were described, these species continue to be poorly represented for Misiones Province and occurrence data are almost lacking in the literature for the area.…”

“…According to potential distribution models for Omalonyx species in South America, the Argentine province of Misiones represents a suitable area for the occurrence of O. unguis and O. convexus (Heynemann, 1868) (Coscarelli et al 2018). Both species occur in the Paraná river basin and are typical inhabitants of hygrophilous environments Vidigal 2011, Coscarelli et al 2018).…”