Data from: Movement of a hybrid zone between lineages of the Australian glass shrimp (Paratya australiensis)

In 1993, a population of freshwater glass shrimp (Paratya australiensis)
was translocated from Kilcoy Creek to Branch Creek in the Conondale Range,
Queensland. Subsequent genetic analysis revealed that the translocated and
resident shrimp belonged to different mitochondrial DNA lineages (mtDNA)
that were capable of hybridising. Monitoring of the pools along Branch
Creek up until 2002 suggested that the translocated lineage had an
advantage in upstream pools, and the resident lineage dominated
downstream. Differential temperature tolerance and hybridisation barriers
such as hybrid inviability and mate selection were factors proposed to
explain hybrid zone structure. The major objective of this study was to
combine nuclear and mtDNA markers to identify the structure of the hybrid
zone in 2013 and identify any changes that had occurred since 2002.
Specifically, we used genetic data to test for evidence of hybrid zone
movement, and used FIS values to investigate whether mating was random in
the contact zone; where hybridisation barriers could be present. The
results revealed that the hybrid zone centre has shifted 510m downstream
since 2002. Increased rainfall in the region since 2010 could have
facilitated this. Secondly, mating appears significantly non-random in the
pools where both lineages occur; supporting the occurrence of
hybridisation barriers which appear to prevent the co-occurrence of the
two lineages in the same pool. This study reveals a complex and dynamic
hybrid zone, and exemplifies why multiple temporal studies are necessary
to understand hybrid zone structure.