Phylogeography of Kauri Snails and their allies from Northland, New Zealand (Mollusca: Gastropoda: Rhytididae: Paryphantinae)

Abstract

The carnivorous snails of the family Rhytididae occur in parts of the continental remnants of Gondwana—southern Africa, Madagascar, Seychelle Islands, Australia, Indonesia, New Guinea, New Caledonia, and New Zealand—and on many islands in the tropical western PaciWc, including Caroline Is, Bismarck Is, Solomon Is, Vanuatu, Fiji, Tonga, and Samoa (Emberton, 1990; Solem, 1959). New Zealand has a particularly rich and diverse rhytidid fauna, with 10 genera, 32 species, and 9 further subspecies listed in Spencer et al. (2004). Some of the New Zealand species are large (the shell of Powelliphanta hochstetteri superba reaches 90 mm), with spectacularly colored shells, and many are now of conservation concern, mostly because of habitat degradation, but also from introduced predators such as pigs, rats, and brush-tailed possums (Brook, 2002a; EVord, 1998; Walker, 2003). The status of many of the nominal species of New Zealand rhytidids and the relationships among the various genera are currently unclear. The most recent attempt at resolving the higher classiWcation was by Climo (1977), who grouped the New Zealand genera in two subfamilies, Rhytidinae and Paryphantinae, on the basis of diVerences in reproductive anatomy. The latter subfamily comprised the endemic genera Paryphanta, Rhytidarex, Amborhytida (which Climo treated as a subgenus of Rhytidarex), and Schizoglossa. Only the last of these genera occurs naturally south of the Hunua Ranges, near Auckland, and most species are restricted to Northland and its various oVshore islands (Fig. 1). In this note we use genetic tools to investigate the relationships among the species Climo