On the presence of Chaetopleura hennahi(Gray, 1828) (Polyplacophora: Chaetopleuridae) in Chile

* Correspondence: jfaraya@u.uchile.cl Most of the chiton species from northern Chile were described in the 19th century, chiefly in some classical works reviewing the entire region of the southeastern Pacific (e.g., Frembly, 1827; Rochebrune and Mabille, 1885; Rochebrune, 1889; Pilsbry, 1892–1894; Plate, 1901, 1902; Thiele, 1906, 1911; Melvill and Standen, 1912). However, most of the subsequent works dealing with polyplacophorans have neglected the coast of northern Chile, and only a few works have included chitons from the area (e.g., Leloup, 1956; Kaas and Van Belle, 1985a, 1985b, 1987, 1990, 1994; Aguilera 2005a, 2005b; Aguilera and Navarrete, 2007; Camus et al., 2012; Sirenko, 2014, 2015). Even when considering the narrow intertidal zones of most of the coast of northern Chile, the diversity of species in the area is similar to that found in the central and southern areas of the country (Osorio and Reid, 2004; Aldea and Valdovinos, 2005; Osorio et al., 2005; Araya and Araya, 2015). Of the 29 extant Chaetopleura species, only 8 are found in the southeastern Pacific, from Peru to southern Chile. Most of these conspicuously sculptured, often hairy species live in shallow water, with some species (e.g., Chaetopleura peruviana (Lamarck, 1819)) having high local abundances on rocky beaches. In this report, as part of a series of works reviewing the molluscan species from northern Chile, we present the first confirmed records of Chaetopleura hennahi in Chile, based on two specimens collected from commercial fisheries, with commentaries on the records of this species in the southeastern Pacific. Systematics Phylum Mollusca Linnaeus, 1758 Class Polyplacophora Gray, 1821 Subclass Neoloricata Bergenhayn, 1955 Order Chitonida Thiele, 1909 Superfamily Chitonoidea Rafinesque, 1815 Family Chaetopleuridae Plate 1899 Genus Chaetopleura Shuttleworth, 1853 Type species Chiton peruvianus Lamarck, 1819, by subsequent designation. Chaetopleura hennahi (Gray, 1828) (Figures 1A–1C) Chiton hennahi Gray, 1828 6. Sowerby I, 1832: pl. 38, fig. 1. Gray, 1839: 148, pl. XL, fig. 1. Chiton jaspideus Gould, 1846: 143. Smith, 1977: 244. Ferreira, 1983: 210. Chaetopleura hennahi Pilsbry, 1892: 29, pl. 12, figs. 47, 48, 49; pl. 17, fig. 39. Thiele, 1908: 17. Dall, 1909: 180, 244. Leloup, 1956: 33, figs. 14, 15, 16. Ferreira, 1983: 220. Lyons, 1985: 42. Valdovinos, 1999: 122. Ramirez et al., 2003: 257. Kaas and Van Belle, 1987: 64, fig. 28, map 11. Álamo and Valdivieso, 1997: 4. Ramírez et al., 2003: 257. Material examined: Two specimens, attached to rocks, collected from commercial fisheries off Caldera (27°01′S, 70°48′W; 25 m depth), Región de Atacama, northern Chile. Measurements: 33 mm length, 24 mm width, 6 mm height Abstract: Chaetopleura hennahi (Gray, 1828) is a chiton species characterized by its low profile, a comparatively large and wide body with reddish brown valves, and the presence of short hairs only in the rather narrow mantle. This rare species has been previously cited from Peru and Chile, with a dubious record near Ringdove Inlet in Canal Smyth, southern Chile; however, no field records have confirmed its presence in Chile. Here we present the first confirmed record for C. hennahi in the country based on two specimens found attached to rocks collected from commercial fisheries off Caldera, northern Chile. Considering this record, a continuous presence of Chaetopleura hennahi from Isla Chincha Norte, Peru, to Caldera, northern Chile, is expected.