Leptochiton setiger ( Nierstrasz, 1905 )

Sirenko, B. I., 2023, Indonesian chitons of the genera Belknapchiton Sirenko, Saito et Schwabe, 2022 and Leptochiton Gray, 1847 (Mollusca: Polyplacophora: Leptochitonidae), Ruthenica, Russian Malacological Journal 33 (2), pp. 79-94 : 91

publication ID	https://doi.org/ 10.35885/ruthenica.2023.33(2).4
DOI	https://doi.org/10.5281/zenodo.11172630
persistent identifier	https://treatment.plazi.org/id/1B1DC90A-E80D-0657-3BDC-FA0116EDFE8A
treatment provided by	Felipe
scientific name	Leptochiton setiger ( Nierstrasz, 1905 )
status

Treatment

Leptochiton setiger ( Nierstrasz, 1905) View in CoL

Lepidopleurus (Pilsbriella) setiger Nierstrasz, 1905:11 View in CoL , pl. 1, fig. 7, pl. 3, figs 60–65.

Leptochiton (Pilsbryella) setiger View in CoL . – Kaas, Van Belle, 1985: 161, fig. 74, map 22.

Type material. Lectotype ( ZMA.MOLL.138607) designated by Kaas and Van Belle [1985], and 2 paralectotypes ( ZMA.MOLL.138606, ZMA. MOLL.138625) (see below).

Type locality. Indonesia, Strait of Makassar, 0°34.6’N, 119°8.5’E, 1301 m. ( Siboga, St. 88) The paralectotypes were found in the Sea Bali, 7°15’S, 115°15’.6’E, 289 m ( Siboga, St. 12).

Distribution. Only known from the type locality of the lectotype.

Remarks. Sirenko [2020] already discussed the composition of the type specimens of this species. A thorough study of the lectotype and two paralectotypes revealed their morphological heterogeneity. The two paralectotypes differ from the lectotype in the arrangement of granules on the central areas in quincuncialy and in the absence of chitinous silky hairs between the valves, the main feature of this species, which served as the basis for the description of the subgenus Pilsbryella Nierstrasz, 1905 . They most likely belong to the genus Nierstraszella Sirenko, 1992 for a number of morphological features: 1) arrangement of false tegmentum granules in a quincunx pattern, 2) subcarinated valves, 3) elongated dorsal spicules-scales, 4) a tridentate cusp of the major lateral tooth, which is typical for juvenile individuals of Nierstraszella [ Sirenko, 1992] and 5) the paralectotypes were found on a piece of sunken wood which is a very typical substrate for Nierstraszella. By the way, two species of chitons: Leptochiton longisetosus Sigwart et Sirenko, 2012 and L. dykei Sigwart et Sirenko, 2012 [Sigwart, Sirenko, 2012] have long silky intersegmental bristles very similar to the hairs described by Nierstrasz for Lepidopleurus (Pilsbryella) setiger .