Tamayoa decolorata
Authors: Salvador, Rodrigo B., Ferreira-Santos, Laura, Cavallari, Daniel C., Gallão, Jonas E., Bichuette, Maria E.
Type: Taxonomic treatment
Published: 2026-08-03
Keywords: Biodiversity, Taxonomy, Animalia, Mollusca, Gastropoda, Stylommatophora, Scolodontidae, Tamayoa, Tamayoa decolorata

<p><i>Tamayoa decolorata</i> (Drouët, 1859)</p><p>Figs 2 D, 4 E</p><p><i>Zonites decoloratus</i> Drouët, 1859: 50, pl. 1, figs 3–5.</p><p><i>Helix decolorata</i>: Pfeiffer 1868: 169.</p><p><i>Zonites</i> (<i>Hyalinia</i>) <i>decolorata</i>: Tryon 1886: 166, pl. 52, figs 69–71.</p><p><i>Scolodonta</i> (<i>Happia</i>) <i>decolorata</i>: Kobelt 1905–1906: 68, pl. 51, figs 14, 15.</p><p><i>Scolodonta decolorata</i>: Kobelt 1910: 146.</p><p><i>Happia decolorata</i>: Baker 1925: 23; Richardson 1989: 119.</p><p><i>Tamayoa</i> (<i>Tamayops</i>) <i>decolorata</i>: Tillier 1980: 106, pl. 5, fig. 1, figs 86–91.</p><p><i>Tamayoa</i> (<i>Tamayoa</i>) <i>decolorata</i>: Schileyko 2000: 759, fig. 988 A – C.</p><p><i>Happiella decolorata</i>: Chase and Robinson 2001: 49; Rosenberg and Muratov 2006: 140, tab. 2.</p><p><i>Tamayoa decolorata</i>: Massemin et al. 2009: 423, text fig., pl. 11, fig. B; Robinson et al. 2009: 640, figs 6 F, 9 B; Delannoye et al. 2015: 282, pl. 62; Charles 2016: 50, pl. 2, fig. 5; Sei et al. 2017: 705, tab. 2; Salvador 2021: 66; González-Guillén and Teruel 2022: 111; Wagner 2022: 24; Georgiev and Mishev 2025: 4.</p><p><b>Material examined.</b></p><p>LES 0031616 (Parauapebas, cave N 1_0174; ME Bichuette, JE Gallão & DF Torres leg., 22. viii. 2021) • LES 0031624, LES 0031625 (Canaã dos Carajás, cave SB_0049; JE Gallão, JS Gallo, DF Torres & VF Sperandei leg., 16. ii. 2022) • LES 0031656 (Parauapebas, cave N 1_0172; JE Gallão & DB Ribeiro leg., 05. iv. 2023) • LES 0031630 (Parauapebas, cave N 1_0174; JE Gallão, JS Gallo, DF Torres & VF Sperandei leg., 12. ii. 2022) • LES 0031654 (Parauapebas, cave N 1_0174; JE Gallão & DB Ribeiro leg., 04. iv. 2023) • LES 0031626, LES 0031627 (Parauapebas, cave N 1_0208; JE Gallão, JS Gallo, DF Torres & VF Sperandei leg., 19. ii. 2022) • LES 0031638, LES 0031642 (Parauapebas, cave N 3_0003; JE Gallão, JS Gallo, DF Torres & JEM Santos leg., 13. viii. 2022) • LES 0031617 (Parauapebas, cave N 3_0023; ME Bichuette, JE Gallão & DF Torres leg., 25. viii. 2021) • LES 0031628 (Parauapebas, cave N 3_0026; JE Gallão, JS Gallo, DF Torres & VF Sperandei leg., 18. ii. 2022) • LES 0031631 (Parauapebas, cave S 11 D_0013; JE Gallão, JS Gallo, DF Torres & VF Sperandei leg., 15. ii. 2022) • LES 0031659, LES 0031660 (Canaã dos Carajás, cave SB_0022; JE Gallão & DB Ribeiro leg., 06. iv. 2023) • LES 0031651, LES 0031652 (Canaã dos Carajás, cave SB_0049; JE Gallão & DB Ribeiro leg., 12. iv. 2023) • LES 0031632, LES 0031633, LES 0031634 (Canaã dos Carajás, cave SB_0051; JE Gallão, JS Gallo, DF Torres & VF Sperandei leg., 16. ii. 2022) • LES 0031644 (Canaã dos Carajás, cave SB_0051; JE Gallão, JS Gallo, DF Torres & JEM Santos leg., 17. viii. 2022) • LES 0031649 (Canaã dos Carajás, cave SB_0051; JE Gallão & DB Ribeiro leg., 12. iv. 2023) • LES 0031658 (Canaã dos Carajás, cave SB_0094; JE Gallão & DB Ribeiro leg., 06. iv. 2023) • LES 0031646, LES 0031647 (Canaã dos Carajás, cave ST_0016; JE Gallão & DB Ribeiro leg., 13. iv. 2023).</p><p><b>Identification.</b></p><p>The smooth shell, its size (~ 4 mm height, ~ 7 mm width, ~ 4 whorls), and profile, the slight constriction of the body whorl close to the aperture, and the whitish-yellow body (Fig. 2 D), with a distinct yellow tint on the visible mantle area, all support its identification as <i>Tamayoa decolorata</i> (Massemin et al. 2009; Delannoye et al. 2015). The present specimens could also fit in the description of <i>Scolodonta nitidula</i> (Dohrn, 1882) from the margins of the Amazon River in Pará. However, the original description lacks illustrations, the species has never illustrated since, and the type material is likely lost (Dance 1966). Considering the comparisons made by Dohrn (1882) between his species and <i>Tamayoa decolorata</i> and <i>Hapiella surinamensis</i> (Pfeiffer, 1872), it is very likely that his <i>Scolodonta nitidula</i> is synonymous with <i>Tamayoa decolorata</i>.</p><p><b>Distribution.</b></p><p>This species is known from French Guiana and is considered to have been introduced to the Antilles: Barbados, Dominica, Guadeloupe, Jamaica, and Martinique (Delannoye et al. 2015). The present record is the first report of this species from Brazil, although it is not the first time a land snail previously known from French Guiana has been recorded in northern Brazil (Salvador et al. 2018, 2020). A previous record of <i>T. decolorata</i> from southeastern Brazil (Esteves et al. 2025) has been considered erroneous (Salvador et al. 2026).</p><p><b>Remarks.</b></p><p>In the studied caves, <i>T. decolorata</i> was found from the entrance zone all to the aphotic zone. Individuals were found under rocks on humid or dry unconsolidated substrate, among roots, or rarely over bat guano (mixed guano of frugivorous and insectivorous bats). This species has also been recorded in anthropically disturbed areas in the nearby municipality of Parauapebas in Pará (Paulo Ricardo S. Coelho, pers. comm. 23 March 2026, species identity confirmed via photographs).</p>