Shallow and deep-sea chitons of the genus Leptochiton Gray, 1847 (Mollusca: Polyplacophora: Lepidopleurida) from Peruvian and Chilean waters Author Sirenko, Boris text Zootaxa 2015 4033 2 151 202 journal article 10.11646/zootaxa.4033.2.1 5f83c37c-162d-42a0-9698-f35278de98b8 1175-5326 241610 46694533-415A-4469-866E-B968502198A7 Leptochiton laurae Schwabe & Sellanes, 2010 ( Figs 8 A–C, 9–16) Leptochiton cf. sykesi Sirenko & Gallardo 2005 : 89 [non Leptochiton sykesi ( Sowerby III, 1903 )] Leptochiton laurae Schwabe & Sellanes 2010 : 37 –41, Figs 1 J, 4, 5A–D. Type . Holotype ( ZSM Mol 20070760). Type locality. Chile , off Concepcion, 36º22.19’S 73º43.36’W , 846 m . Material examined. Chile . Near Valdivia, Punta Galera, 39º59’S 73º43’W , 450 m ; Canal Concepcion, 50°30’S , 74°55’W (depth unknown); Magellan Strait and Beagle Channel . RV Victor Hensen, st. 1045, EBS, 54°51.8’S , 69°55.6’W , 210 m , 2 spms, 0 4.11.1994 , leg. K. Linse; st. 1140, EBS, 54°54.9’S , 68°39.1’W , 310 m , 1 spm, 0 7.11.1994 , leg. K. Linse; st. 1270, EBS, 54°55.17’S , 70°45.15’W , 135 m , 1 spm, 21.11.1994 , leg. A. Brandt; RV Vidal Garmas, cruise 96, st. 41, AGT, 50°20.9’S , 74°49.3’W , 438 m , 3 spms, 25.10.1996 ; RV Vidal Garmas, cruise 97, st. 5, AGT, 53°03.6’S , 70°38.2’W , 88 m , 1 spm, 07.10.1997 ; South Orkney Islands . RV Evrika, cruise 22, dredge 18, 60°24’S , 46°09’W , 1200–1280 m , 1 spm, 0 9.02.1987, leg. I. Smirnov; dredge 32 60°28’S , 47°07.0’W , 285 m , 2 spms, 24.03.1987 , leg. I. Smirnov; South Shetland Islands . RV Eltanin, cruise 6, st. 432, Blake trawl, 62°52’S , 59°27’W , 884–935 m , 2 spms, 07.01.1963 ; RV Polarstern, ANT XVII/3, st. 149, AGT, 62°30.00’S , 56°55.08’W , 911 m , 2 spms, 24.04.2000 , leg. B. Sirenko; Kerguelen Islands , RV Skif, cruise 3, st. 170, 49°12.4’S , 68°23.5’E , 145–146 m , 2 spms, 4.1.1971 , leg. A. Pushkin; RV Fiolent, cruise 2, st. 82, 47°57’S , 69°02’E , 175 m , 5 spms, 21.10.1972 ; Crozet Islands . RV Skif., cruise 6, st. 45, 45°42.3’S , 49°35’E , 520–545 m , 4 spms, 6.12.1970 , leg. A. Pushkin. FIGURE 7 . Leptochiton medinae Plate, 1899 , (ZISP 2258). Magellan Strait, RV Victor Hensen st.884, BL—5 mm. A . Sutural needle; B . Dorsal scale; C . Marginal needle; D . Marginal scale; E . Ventral scale; F . Central and first lateral teeth; G . Heads of major lateral tooth; H . Aesthete group in central area. Scale bar 100 µm (A–G). Distribution. Chile from off Concepcion ( 36°22’S ) southwards to the Magellan Strait and Beagle Channel, South Orkney , South Shetland , Kerguelen and Crozet Islands, 88–1200 m . Remarks. The dorsal scales of this species are variable. The specimens from South Shetland Ids. ( Figs 9–11 ) have dorsal scales without ribs, whereas the specimens from the Beagle Channel ( Figs12–15 ) have scales with or without rib. Moreover small specimens of L. laurae ( Fig.16 ) are very similar to L. medinae . This species resembles Leptochiton sykesi ( Sowerby III, 1903 ) ( Figures 17–19 ) and L. medinae by longitudinal rows of granules in the central areas of the intermediate valves and features of the radula. L. laurae differs from L. sykesi in the number of aesthete pores ( 3 in L. laurae and 5 in L. sykesi ), in having dorsal scales which are rarely smooth or have one rib (girdle densely covered by numerous dorsal scales with three ribs in L. sykesi ). Leptochiton laurae differs from L. medinae in the number of aesthete pores ( 3 in L. laurae and 5 in L. medinae ), and L. medinae has dorsal scales with 6 ribs. Additionally the valves are subcarinated in L. laurae vs. rounded in L. medinae , quincuncially arranged granules in the lateral areas vs. radiating rows of granules and smooth marginal scales vs. ribbed marginal scales in L. medinae .