Based on a review and our own data, we present an overview of the ecological impacts on the trophic web of Mediterranean wetlands by an introduced Decapod Crustacean, the red swamp crayfish (Procambarus clarkii). P. clarkii lacks efficient dispersal mechanisms but is very well adapted to the ecological conditions of Mediterranean wetlands (fluctuating hydroperiods with regular intervals of drought). As an opportunistic, omnivorous species, which adapts its ecology and life history characteristics, such as timing and size at reproduction to changing environmental conditions, it became readily established in most of the Mediterranean wetland environments. High reproductive output, short development time and a flexible feeding strategy are responsible for its success as an invader. Like most crayfish, it occupies a keystone position in the trophic web of the invaded system and interacts strongly with various trophic levels. It efficiently grazes on macrophytes and is one of the main factors, besides the impact of flamingos, cattle and introduced fish, of the change of many water bodies from a macrophyte dominated, clear water equilibrium to a phytoplankton driven turbid water balance. Juveniles feed on protein rich animal food with the corresponding impact on the macroinvertebrate community in competition with other crayfish or fish species. At the same time, it serves as a prey for mammals, birds and fish. Due to its predatory and grazing activity, it efficiently canalises energy pathways reducing food web complexity and structure. Feeding also on detritus it opens, especially in marshlands, the detritic food chain to higher trophic levels which results in an increase of crayfish predators. As a vector of diseases, it has a severe impact on the preservation and reintroduction of native crayfish. P. clarkii accumulates heavy metals and other pollutants in its organs and body tissues and transmits them to higher trophic levels. Due to the long history of its presence, the complex interactions it established within the invaded ecosystems and the socio-economic benefits it provides to humans, prevention and control seem the most promising management measures to reduce the negative impact of this crayfish species. Biological Invasions (2005) 7: 49-73 Ó Springer 2005 ) High fecundity ++ Short generation and juvenile development times ++ Fast adaptation to environmental stress +++ High tolerance to environmental heterogeneity +++ Desirability to and association with humans (edibility, game species) +++ Additional features Omnivory +++ Brood care +++

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Invertebrate propagules may survive internal and external transports by waterbirds, thus facilitating their dispersal between aquatic habitats. However, field data on such transport remain limited, especially for exozoochory. We quantified and compared the rates of internal and external invertebrate transports simultaneously in a wintering population of teal (Anas crecca) in the Camargue (southern France). We inspected lower gut (rectum) contents of birds that had been shot (N = 366) and washed birds that had been live-trapped (N = 68) during the winters 2006-2007 and 2007-2008. At least one propagule was recorded in 2.5% and 10.3% of internal and external samples, respectively. Cladoceran, ostracod, plumatellid bryozoan and anostracan propagules were all recorded in both internal and external samples. Hatching confirmed their viability, except for anostracan eggs. At least three cladoceran species and two ostracod species were recorded, none of which had previously been shown to be dispersed by birds. Amongst external samples, we recorded a significant seasonal trend in 1 year with most propagules recorded before December, keeping with a seasonal decline in the availability of propagules on the water surface. This study provides evidence that teal may be important vectors of invertebrate dispersal both within the Camargue and along migratory flyways.

Danielopolina kornickeri sp. n. is described from an anchialine cave in Western Australia. This is the first Danielopolina species occurring outside of the Western Hemisphere (Atlantic and Eastern Pacific Oceans and Islands). A cladistic analysis indicates that this species is a primitive taxon of the anchialine cavernicolous clade; the deep‐sea dwelling species Danielopolina carolynae appears more primitive and does not cluster with the other Danielopolina species. The ecological environment of D. kornickeri is described. Detailed discussions consider: (1) the shell ornamentation and its relevance to the phylogeny of the Thaumatocyprididae; (2) the antero‐dorsal node of the Permian Thaumatomma (hypothesized here to be an ocular lens which regressed in the post‐Palaeozoic thaumatocypridids); (3) the distal chaetotaxy of the antennae (hypothesized to perform the chemosensorial function known in the aesthetascs of other myodocopids or podocopids); (4) palaeobiogeographical arguments for a shallow marine origin of cavernicolous species Danielopolina.

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