Drymaeus magus, commonly known as the magician snail, is a species of tropical air-breathing land snail, a pulmonategastropodmollusc in the family Bulimulidae found in regions of southeastern Brazil. For nearly two centuries, this species was rarely revisited in scientific literature and was mysteriously absent from scientific collections, often being confused with other members of the genus Drymaeus. Recent studies have revealed that, although it has been poorly documented in the literature, the species is more common than previously thought.[1]
The shell of Drymaeus magus has a typical bulimoid shape and displays a distinctive pattern, with a beige or light-brown base color and sinuous axial streaks (running from base to apex) in darker shades. Two morphological variants have recently been recognized in this species: The typical morphotype has larger shells (22–25 mm in length), with continuous streaks and a duller coloration; and the red-banded morphotype has smaller shells (15–17 mm), more vibrant colors, patterns interrupted by spiral lines, and a reddish area around the umbilicus.[1] Recent micro-computed tomography (micro-CT) reconstructions of internal anatomy have revealed notable adaptations, such as an exceptionally large albumengland and a reduced penis, distinguishing it from closely related species like Drymaeus castillensis. The radula features tricuspid teeth (1 rachidian tooth and 63–72 pairs of lateral teeth), with gradual variations toward the margins—a trait shared with D. papyraceus but differing in the structure of the central cusp.[1]
The magician snail occurs predominantly in semi-deciduousAtlantic Forest fragments and Cerrado (savanna) areas within the states of São Paulo, Minas Gerais, Rio de Janeiro, and Paraná. Isolated records from Rondônia and Mato Grosso do Sul, though intriguing, are likely the result of accidental introductions, given the absence of natural biogeographic connections.[1] This species is arboreal, often found on tree trunks and foliage at night, particularly during the rainy season. Field observations have documented its preference for humid habitats, though it also tolerates disturbed areas such as coffee plantations and urban parks. This ecological plasticity may explain its broad yet long-overlooked distribution.[1]
Phylogeny
Molecular analyses based on mitochondrial (COI) and nuclear (H3, ITS2/28S) genes placed D. magus within a well-supported clade alongside D. papyraceus and D. castillensis, corroborating their morphological similarities. This group shares a common ancestor with species from the genera Mesembrinus and Antidrymaeus, as illustrated in the cladogram below:[1]
The close relationship between D. magus and D. papyraceus is further supported by shared radular traits (e.g., tricuspid teeth) and shell morphology. However, D. magus exhibits distinct anatomical adaptations (e.g., reduced penis, enlarged albumen gland), likely reflecting divergent ecological pressures.[1]
Conservation status
Despite its apparent resilience to disturbed environments, habitat loss due to deforestation cannot be discarded as a potential threat to the magician snail. While the species has not yet been assessed by the IUCN Red List, its broad distribution and occurrence within protected areas, such as Furnas do Bom Jesus State Park (São Paulo), are considered favourable factors for its conservation.[1]
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