Phylogeography, cave invasion and diversification of the Philippine Sundathelphusa (Decapoda: Brachyura: Parathelphusidae)
Abstract
Availability of resources influences the opportunistic characters of animals to migrate and colonize a specific habitat while the organism’s geographic isolation causes speciation and diversification. Stable isotope signatures (δ13C and δ15N) elucidate the nutrient source of cavernicolous animals. Mitochondrial DNA sequences of the large subunit rRNA (16S rRNA) revealed multiple colonizations of caves by the genus Sundathelphusa as well as its phylogenetic relationships. Overall molecular phylogeny of the freshwater crabs recovered one major clade of the Philippine Sundathelphusa consisting nine clusters/subclades distributed to various regions in the archipelago. Molecular clock estimation based on the substitution rate of 0.88% per million years established for the grapsid crab genus Sesarma suggested that the diversification of Sundathelphusa species in the Philippines could have started during the late Miocene epoch ca. 5.92 mya. Speciation events coincide with the timing of the eustatic sea level fluctuation and geologic changes in the Philippine archipelago. The sea level fluctuation and subsequent geologic changes must have caused geographic isolation of the species. This appears to be the most plausible explanation for the high diversity of Sundathelphusa species in the Philippines where its congeners inhabit a wide range of habitats, ranging from epigean to hypogean domain.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.B33F0450H
- Keywords:
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- 0410 BIOGEOSCIENCES / Biodiversity;
- 0439 BIOGEOSCIENCES / Ecosystems;
- structure and dynamics;
- 0444 BIOGEOSCIENCES / Evolutionary geobiology