Phylogenetic analysis of the Camaenidae (Mollusca: Stylommatophora) with special emphasis on the American taxa

The monophyly of the land snail family Camaenidae has been in doubt due to a disjunct bihemispheric distributional pattern and to the lack of morphological synapomorphies. A cladistic analysis is presented using an ingroup composed of representatives of the three subfamilies distributed in Australia and 52 other species with American distribution. Bradybaenidae, Helicidae and Helminthoglyptidae were used as outgroups. Fifty morphological characters were treated as unordered and analysed using Pee-Wee ver. 2.9, a program for parsimony analysis using implied weights. The results of the analysis support Camaenidae as a monophyletic family (synapomorphies: oval genital orifice, absence of penial sheath). Two of the three Australasian subfamilies, Sinumeloninae and Camaeninae, are monophyletic in the strict consensus tree. The American taxa are classified in eight genera and arranged into two main clades. Caracolus is proposed as the sister group of the American Continental Camaenidae. The genus Solaropsis , previously excluded from this family by different authors, is reassigned to Camaenidae. Shell characters proved to be phylogenetically informative in defining Pleurodonte , Caracolus , Solaropsis , Isomeria and Labyrinthus . © 2003 The Linnean Society of London, Zoological Journal of the Linnean Society, 2003, 138, 449–476.     

ULTRASTRUCTURE OF THE MATURE SPERMATOZOA OF THE LAND SNAIL EPIPHRAGMOPHORA TUCUMANENSIS (DOERING, 1874) (GASTROPODA: HELICOIDEA)

The ultrastructure of the sperm of Epiphragmophora tucumanensis(Doering), a pulmonate land snail belonging to the family Xanthonychidae,was examined. The results showed that this spermatozoon presents a similarmorphology to the other advanced stylommatophoran sperm described.The most peculiar characteristic is the form of the nucleus,which is straight instead of helically coiled. An acrosome ispresent, composed of an apical vesicle and an acrosomal pedestal.The connecting piece or neck region is formed by a basal bodyplus a centriolar derivative. It is also the point of originof coarse fibres that accompany the axoneme. Thus, the axonemalcomplex exhibits a 9+9+2 pattern. The midpiece is an elongatedregion composed of paracrystalline and matrix materials (collectively,the mitochondrial derivative) enclosing a single glycogen helixand the axoneme. The mitochondrial derivative extends to theposterior tip of the spermatozoon. As observed in other stylommatophorans,both an annulus and a glycogen piece are absent. (Received 25 October 1993; accepted 4 February 1994)