Phylogeography and cryptic diversity of intertidal Ligia isopods (Crustacea, Isopoda, Ligiidae) across the southern Africa coastline
- Published
- Accepted
- Subject Areas
- Biodiversity, Biogeography, Evolutionary Studies, Marine Biology, Zoology
- Keywords
- South Africa biogeography, Oniscidea, Cryptic species, Ligiidae, Intertidal, Vicariance
- Copyright
- © 2017 Greenan et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Phylogeography and cryptic diversity of intertidal Ligia isopods (Crustacea, Isopoda, Ligiidae) across the southern Africa coastline. PeerJ Preprints 5:e3332v1 https://doi.org/10.7287/peerj.preprints.3332v1
Abstract
The extensive coastlines of South Africa and Namibia extends from the Atlantic to the Indian Ocean and encompass several major biogeographic provinces, each characterized by unique faunal and floral assemblages. Recent biogeographic studies have led to competing biogeographic models of the southern African coastline. This has stimulated phylogeographic work to determine whether the distribution of genetic diversity within coastal invertebrate species match the proposed biogeographic regions. The lack of congruence between studies and the discovery of cryptic diversity indicating the possible existence of cryptic species in coastal isopods in the region underscore the need for additional phylogeographic research in southern Africa, particularly for organisms that have been shown to both harbor cryptic diversity and to retain signatures of past geological and oceanographic processes in their phylogeographic patterns. Isopods in the genus Ligia exhibit several biological traits that suggest they may be informative on phylogeographic patterns. They inhabit patchy rocky beaches, are direct developers, avoid the open water, and exhibit several biological traits that severely constrain their dispersal potential (e.g. poor desiccation resistance). These traits are thought to lead to long term isolation of populations, the retention of geological and oceanographic signatures in phylogeographic patterns of Ligia, and the presence of cryptic lineages. In this study, we used mitochondrial and nuclear markers to characterize Ligia collected in 18 localities across Namibia to the KwaZulu-Natal region of South Africa. We report the presence of cryptic lineages within Ligia species in the region, as well as distributional patterns that differ from those reported from other coastal taxa, but that broadly matches a widely used biogeographic model for the region.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Alignment of COI gene sequences used in phylogenetic analyses
Identical sequences from different individuals were removed prior to analyses.