Abstract
How species reach and persist in isolated habitats remains an open
question in many cases, especially for rapidly spreading invasive
species. This is particularly true for temporary freshwater ponds, which
can be remote and may dry out annually, but may still harbour high
biodiversity. Persistence in such habitats depends on recurrent
colonisation or species survival capacity, and ponds therefore provide
an ideal system to investigate dispersal and connectivity. 2. Here, we
test the hypothesis that the wide distributions and invasive potential
of aquatic snails is due to their ability to exploit several dispersal
vectors in different landscapes. We explored the population structure of
Physa acuta (recent synonyms: Haitia acuta, Physella acuta, Pulmonata:
Gastropoda), an invasive aquatic snail originating from North America,
but established in temporary ponds in Donana National Park, southern
Spain. In this area, snails face land barriers when attempting to
colonise other suitable habitat. 3. Genetic analyses using six
microsatellite loci from 271 snails in 21 sites indicated that (i)
geographically and hydrologically isolated snail populations in the park
were genetically similar to a large snail population in rice fields more
than 15 km away; (ii) these isolated ponds showed an
isolation-by-distance pattern. This pattern broke down, however, for
those ponds visited frequently by large mammals such as cattle, deer and
wild boar; (iii) snail populations were panmictic in flooded and
hydrologically connected rice fields. 4. These results support the
notion that aquatic snails disperse readily by direct water connections
in the flooded rice fields, can be carried by waterbirds flying between
the rice fields and the park and may disperse between ponds within the
park by attaching to large mammals. 5. The potential for aquatic snails
such as Physa acuta to exploit several dispersal vectors may contribute
to their wide distribution on various continents and their success as
invasive species. We suggest that the interaction between different
dispersal vectors, their relation to specific habitats and consequences
at different geographic scales should be considered both when attempting
to control invasive freshwater species and when protecting endangered
species.
Original language | English |
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Pages (from-to) | 88-99 |
Journal | Freshwater Biology |
Volume | 58 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2013 |
Keywords
- international