An RAPD (random amplified polymorphic DNA) analysis of genetic population structure of Balea biplicata (Gastropoda: Clausiliidae) in fragmented floodplain forests of the Elster/Saale riparian system

Morphological trends and genetic divergence in anacondas, genus Eunectes Wagler, 1830 (Serpentes: Boidae)

The genus Eunectes Wagler, 1830 is divided into four nominal species: E. murinus (Linnaeus, 1758), E. notaeus Cope, 1862, E. deschauenseei Dunn and Conant, 1936, and E. beniensis Dirksen, 2002 (E. barbouri Dunn and Conant, 1936 being a synonym of E. murinus). We analyze multivariate morphological traits (scalation, coloration pattern, and body shape), sequences of one mitochondrial and five nuclear genes, and genetic patterns of randomly amplified DNA (RAPD) markers of historical geographical samples representing all known taxa. We show that the genus consists of two distinct evolutionary lineages, ‘big-bodied’ (only E. murinus) and ‘small-bodied’ anacondas. The latter group includes three morphologically distinct allopatric forms, E. notaeus, E. deschauenseei, and E. beniensis. Both phenotypically and genotypically, E. beniensis is more distant from E. notaeus and E. deschauenseei than the two latter species are from each other. However, the three nominal species of small-bodied anacondas did not show clear reciprocal monophyly and did not reach the stage of complete lineage sorting. Instead, genetic data support the presence of three incipient species of small-bodied anacondas.

Selfing and brooding in Alinda biplicata (Gastropoda: Pulmonata: Clausiliidae) – life history traits of a good coloniser

Alinda biplicatais capable of uniparental reproduction (selfing). The snails need 18 to 24 weeks to reach their ultimate size, and the first reproduction takes place 26 to 39 weeks after shell growth completion. Besides giving birth to juveniles, which is typical ofA. biplicata(39% of litters), the uniparentally reproducing individuals laid egg batches (38%) as well as mixed batches (eggs and juveniles; 23%). Within a few days the eggs decomposed, and in mixed batches they were often consumed by the accompanying neonates. In the next season, 70% of the remaining 20 snails reproduced (all of which had reproduced in the previous season). In the first season the neonate:egg proportion was 54:46, in the second 74:26. The egg-laying should be regarded as an anomaly – getting rid of eggs which were not fertilised or in which embryos died at early cleavage stages. The combination of selfing and brooding may explain the wide distribution and wide range of habitats occupied byA. biplicata.

Genetic reconstruction of the population dynamics of a carnivorous marsupial (Antechinus flavipes) in response to floods

Human activities such as regulating river flows, logging and removing fallen timber adversely affect floodplain ecosystems around the world. Studies of the dynamics of floodplain-dwelling populations will help to understand the effects of altered flood regimes and to manage and restore floodplains. The yellow-footed antechinus (Antechinus flavipes) is the only small, native, carnivorous mammal (Marsupialia) on many degraded floodplains in south-eastern Australia, where its abundance appears to increase with proximity to floods, which is partly due to enhanced survival (as inferred from increased abundance of second-year females). We analysed population genetic patterns and maternity among samples collected following the period of postnatal dispersal, in the years preceding and following planned floods, at different distances from flood locations along the Murray River. Our genic and genotypic analyses of mitochondrial DNA (mtDNA) control region haplotypes and 11 microsatellite loci demonstrated high immigration rates into sites in close proximity to floods. All sampled males emigrated from their natal sites to points of capture, while some females were philopatric. There were high rates of dispersal of males among all sites within a partially flooded forest, while females dispersed more to locations closest to inundations rather than to distant places. These results suggest that environmental flows are beneficial to antechinus both by enhancing adult survival and promoting dispersal of females.