Phylogenetic analysis of Anacaenini (Coleoptera: Hydrophilidae: Hydrophilinae) based on morphological characters of adults

Abstract.  The skeletal features of adults of fifty species of Anacaenini (Coleoptera: Hydrophilidae) and six outgroup taxa belonging to Hydrophilini and Laccobiini were examined. Eighty-one characters were selected and analysed cladistically. The resulting trees confirm the sister group relationship of Anacaenini and Laccobiini. Paracymus forms a clade within Laccobiini, as sister group of Oocyclus . Paranacaena is highly polyphyletic and, like Hebauerina , Grodum and Enigmata deeply nested within a complex formed mainly by Anacaena species ( Anacaena complex). The position of Gentilina remains ambiguous, but is also likely to be nested within this group. Notionotus is also part of this clade and clearly is monophyletic. Phelea , Crenitis and Notohydrus are distinctive groups which split off successively at the base of the Anacaena complex. On the basis of our results Enigmata Hansen ( syn.n. ), Gentilina Hebauer ( syn.n. ), Grodum Hansen ( syn.n. ) and Hebauerina Gentili ( syn.n. ) are synonymized with Anacaena Thomson.     

Sexual and reproductive traits of Hypania invalida (Polychaeta,Ampharetidae): a remarkable invasive species in Central European waterways

1. The Ponto‐Caspian polychaete Hypania invalida (Archiv für Naturgeschichte, 1860, 26, 109) is undergoing rapid range expansion in the Rhine and other central European waterways. We examined its reproductive traits in an attempt to account for its remarkable invasive success. 2. For the first time in this species, we found males, dioecy (gonochorism) and an exclusively sexual mode of reproduction; no indication for hermaphroditism or (unisexual) parthenogenesis, that could explain the rapid range expansion of H. invalida, was found. 3. Our experimental evidence shows that H. invalida reproduces by males discharging their sperm into the water column while eggs are retained and fertilised in the female dwelling tubes. This mode of ‘spermcast’ reproduction is common in sessile benthic animals on wave‐washed shores. 4. Fecundity of H. invalida ranged between 60 and 260 eggs per clutch and is increased by iteroparity (i.e. multiple cycles of oogenesis and egg‐laying per specimen). Offspring are brooded for about 2 weeks before they leave the maternal dwelling tubes and disperse in the water column. 5. After connection to a supply of Rhine water, sediments in flumes were rapidly colonised up to a density of 12 000 ind. m^?2 via the settlement of small larvae (<300 μm) from the water column; these reached sexual maturity approximately 12 weeks after settlement. 6. The reproductive traits of H. invalida give the species a high rate of dispersal. The capacity of its larvae to survive passage through pumps before settlement enables them to travel in the ballast water of ships. This might explain the upstream expansion of H. invalida in rivers. We conclude that further range expansion, and especially intercontinental transport of this polychaete, can only be prevented by improved ballast water treatment.     

Passerine diversity in the late Oligocene of Germany: earliest evidence for the sympatric coexistence of Suboscines and Oscines

A passerine avifauna from the late Oligocene ( c. 26–25 mya) of Germany was characterized by a high diversity of conspicuously small birds ranging in size from the smallest known Oscines to moderately small forms. The avifauna comprised both Oscines and Suboscines. Other passerine fragments showed such an unexpected mosaic of characters that it was impossible to assign them with certainty to any subordinate clade within the Passeriformes. The isolated remains of oscine passerines are the earliest evidence of this taxon in the Northern Hemisphere. Coexistence of oscine and suboscine passerines during the late Oligocene is also documented for the first time in the Northern Hemisphere. These finds reduce a major gap in the passerine fossil record and allow new insights into the composition and natural history of ancient avifaunas.     

Convergent evolution of shell shape in freshwater limpets: the African genus Burnupia

Convergent evolution of shell shape is a well known phenomenon in gastropods that has caused much confusion in taxonomic and systematic studies. A paradigm is the patelliform shell shape in several taxa of the order Basommatophora. Historically, most freshwater limpets were assigned to the family Ancylidae. Based on anatomical data, some taxa were subsequently moved to different families. However, there are still doubts about the monophyly of the remaining ancylids. This is also true for the African limpets and particularly for species of the genus Burnupia Walker, 1912. In the present paper, two independent molecular markers (COI, 18S rRNA) are used to (a) infer the position of Burnupia within the Basommatophora and (b) to test whether the shell shape of Burnupia evolved independently. Bayesian and maximum likelihood analyses of 12 genera of limnic Basommatophora indicate that Burnupia not only appears to be distinct from the Ancylidae, but also from all other representatives of the superfamily Planorboidea studied here. Based on a generally well-supported phylogeny and preliminary anatomical data, it is concluded that patelliform shell shapes evolved at least three times in the taxa studied here and that the shell shape of Burnupia represents another case of convergent evolution. Previously proposed functional and evolutionary scenarios for the evolution of patelliform shell and their relevance for freshwater limpets are discussed.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 577–586.