Intertidal chitons (Mollusca: Polyplacophora) from the rocky coastline of Guerrero, México, with the description of a new species Author Reyes-Gómez, Adriana Author Flores-Garza, Rafael Author Galeana-Rebolledo, Lizeth Author Hernández-Vera, Gerardo Universidad de Guadalajara, Centro Universitario de Ciencias Biológicas y Agropecuarias, Departamento de Botánica y Zoología, Carretera a Nogales km. 15.5, Las Agujas Nextipac, Zapopan, Jalisco, C. P. 45110 México. Author Galván-Villa, Cristian M. Author Torreblanca-Ramírez, Carmina Author Flores-Rodríguez, Pedro Author García-Ibañez, Sergio Author Ríos-Jara, Eduardo text Zootaxa 2022 2022-06-23 5155 4 451 492 journal article 80415 10.11646/zootaxa.5155.4.1 2e18793c-3344-4542-92f3-1775f6276bb7 1175-5326 6691172 E6179D38-97E8-4EAB-8F28-8CF6E508C090 Stenoplax limaciformis (G.B. Sowerby I, 1832) Figures 2I–L , 9E–K , 10A–J Distribution. Isla Tiburón and Isla Carmen, Gulf of California, México to Inner Lobos Island, Perú , western coast of Central America ( Bullock 1985 ). Type specimens. Holotype BMNH 1980007 /1 ( in Kaas & Van Belle 1987 ). Type Locality. According to Kaas & Van Belle (1987) Inner Lobos Islands , Perú ; Central America at Guacomayo . Material examined . 115 specimens , maximum size of 33.5 mm long, 11.2 mm wide. K (n=12); L (n=10); M (n=8); N (n=12); D (n=12); B (n=9); F (n=10); A (n=8), U (n=13); J (n=5); G (n=5); H (n=7). Habitat. This species is present in a variety of habitats and represents one of the most common chitons found in our surveys. It is also distributed in the shallow subtidal ( 6–12 m ). Adult and juvenile specimens were found on medium-sized and smaller rocks, with crustose brown and red and filamentous green algae; it was occasionally found in tide pools and down to 12 m under stones in sand. It was found with C . lurida , C . albolineatus and occasionally with C . elenensis . Remarks. Stenoplax limaciformis displays a highly variable tegmentum color and sculpturing patterns. Our examination revealed individuals with ribs formed by aligned nodules, while others show irregular, uninterrupted ribs. Some specimens bear irregular nodules (in size and shape) at the periphery of the valve’s tegmentum, which progressively become more regular towards the apex. Other specimens have ribs that are strongly discontinuous at the periphery and show a zigzag pattern around the mucro and on the jugal areas of the head and tail valve.