Angiostoma margaretae n. sp (Nematoda: Angiostomatidae), a parasite of the milacid slug Milax gagates Draparnaud collected near Caledon, South Africa Jenna L. Ross • Antoinette P. Malan • Elena S. Ivanova Received: 26 November 2010 / Accepted: 22 December 2010 Ó Springer Science+Business Media B.V. 2011 Abstract Angiostoma margaretae n. sp. (Angiostom- atidae) is described from the oesophagus of the slug Milax gagates Draparnaud collected near Caledon in the Western Cape Province of South Africa. The new species closely resembles another parasite of a milacid slug, A. milacis Ivanova & Wilson, 2009, with a similar head, stoma and spicule shape, the presence of distally outstretched ovaries, coiled oviducts, the same number of caudal papillae and enlarged rectal glands. However, A. margaretae differs from the latter by having: a shorter, wider tail with a rounded vs pointed tip; the distal parts of both ovaries with a particular hook-like shape due to an expansion closely following the short initial zone; ovoviparous females; and a different arrangement of male papillae. A. margaretae is compa- rable with A. limacis Dujardin, 1845, A. asamati (Spiridonov, 1985), A. coloaense (Pham Van Luc, Spiridonov & Wilson, 2005) and A. stammeri (Mengert, 1953), which have a similar stoma shape and size, but can be readily differentiated by the presence of distally outstretched vs reflexed ovaries and the presence vs lack of enlarged rectal glands. The new species has a similar arrangement of the ovaries to A. kimmeriense Korol & Spiridonov, 1991 and A. zonitidis Ivanova & Wilson, 2009, but is clearly differentiated by the lack of an off- set lip region and presence of a large bowl-shaped vs tubular stoma and less numerous male caudal papillae (seven pairs vs nine in A. kimmeriense and 10 in A. zonitidis). Introduction The nematode family Angiostomatidae Blanchard, 1895 is currently known from 16 species, 12 of which are associated with terrestrial gastropod molluscs (slugs and snails) and four are described from the intestine and bronchi of amphibian and reptile hosts (Chitwood, 1933; Bursey & Goldberg, 2000; Bursey & Manire, 2006; Falco ´n-Ordaz et al., 2008). In the main, molluscan angiostomatids are parasites of the intestine, although A. glandicola Ivanova & Spiridonov, 2010 has been found in the hepatopancreas and A. aspersae Morand, 1986 has been recovered from the pallial cavity of these hosts (Ivanova & Spiridonov, 2010; Morand, 1986). International surveys reveal that molluscan angiostomatids are present in Europe (Ivanova & Wilson, 2009; Ross et al., 2010a, b), North America (Ross et al., 2010a, b), South-East Asia (Pham J. L. Ross (&) Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK e-mail: jenna.ross@abdn.ac.uk A. P. Malan Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa E. S. Ivanova Centre of Parasitology, A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Science, Leninskii prospect 33, 119071 Moscow, Russia 123 Syst Parasitol (2011) 79:71–76 DOI 10.1007/s11230-011-9294-y