Family STYLONISCIDAE Vandel, 1952
Introduction
Members of Styloniscus Dana and Notoniscus Chilton typically inhabit litter and rotting wood in wet forests. Styloniscus also occurs in damp places in more open habitats (Green 1971) and is present in caves where both epigean and troglobitic species have been collected. One unnamed species has been found associated with ants. The family encircles the Southern Hemisphere with some remote islands included in its distribution. North of the equator it is less widespread. Two species of Styloniscus have been introduced to Britain.
Styloniscidae Vandel, 1952, is a replacement name for Patagoniscidae Verhoeff, 1939, and is conserved under ICZN Article 40. Dana (1853) established Styloniscus with two included species, S. magellanicus and S. longistylis. Jackson (1941) selected the latter as the type species and, although this subsequent designation is valid, the choice would create taxonomic havoc if followed. Styloniscus longistylis is now regarded as a member of Olibrinus Budde-Lund, 1913 (Olibrinidae) (Taiti & Ferrara 1991). Vandel's (1952) later designation of S. magellanicus as type species can not replace that of Jackson but, for practical reasons, this species rather than S. longistylis has been regarded as 'typical' (Green 1961). An application to the International Commission on Zoological Nomenclature (Lehtinen et al. 1994) to replace Jackson's type species with S. magellanicus, so as to reflect modern usage of the genus name, has not been acted on.
In spite of this, the genus is understood clearly and now includes 40 named species and others to be established. Modern authors follow the definition of Vandel (1952) who contrasted it with Trichoniscus.
Diagnosis
Animal does not conglobate. Head with supra-antennal line present, frontal line absent. Eye usually composed of 3 ommatidia, but may be reduced or absent. Antenna 2 flagellum with 3–10 articles in Australasian species. Mandible with molar process. Dactylar organ present on each pereopod. Male with single penis containing 2 ducts which join to lead to 1 median aperture. Pleopods 1 and 2 of male modified as copulatory structures. Pleopod 1 of male with protopod very large, operated by conspicuous muscles from sternite 1. Without pleopodal lungs. Telson trapezoidal.
General References
Dana, J.D. 1853. Crustacea. Part 2. United States Exploring Expedition during the years 1838, 1839, 1840, 1841, 1842, under the command of Charles Wilkes, U. S. N. 13(2): 686-1618 [Folio atlas of 96 plates]
Green, A.J.A. 1961. A study of Tasmanian Oniscoidea (Crustacea: Isopoda). Australian Journal of Zoology 9: 258-365
Green, A.J.A. 1971. Styloniscidae (Isopoda, Oniscoidea) from Tasmania and New Zealand. Papers and Proceedings of the Royal Society of Tasmania 105: 59-74
Jackson, H.G. 1941. Check-list of the terrestrial and freshwater Isopoda of Oceania. Smithsonian Miscellaneous Collections 99: 1-35
Lehtinen, P.T., Taiti, S., Ferrara, F. & Green, A.J.A. 1994. Case 2912. Styloniscus Dana, 1853 (Crustacea, Isopoda): proposed designation of Styloniscus magellanicus Dana, 1853 as the type species. Bulletin of Zoological Nomenclature 51: 1
Taiti, S. & Ferrara, F. 1991. New species and records of terrestrial isopods (Crustacea) from the Arabian Peninsula. Fauna of Saudi Arabia 12: 209-224
Vandel, A. 1952. Les Trichoniscides (Crustacés, Isopodes) de l'hémisphère austral, leur place systématique, leur interêt biogéographique. Mémoires du Muséum national d'Histoire naturelle, Paris [1936-1950] (A) Zoologie 6: 1-116
History of changes
Published | As part of group | Action Date | Action Type | Compiler(s) |
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05-Aug-2022 | 04-May-2011 | MODIFIED | ||
05-Aug-2022 | 29-Jun-2010 | MODIFIED | ||
12-Feb-2010 | (import) |