Open AccessDiscovery of populations endemic to a marine biogeographical transition zone
Author(s) -
Golla Tirupathi Rao,
Pieterse Leishe,
Jooste Candice M.,
Teske Peter R.
Publication year - 2020
Publication title -
diversity and distributions
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.918
H-Index - 118
eISSN - 1472-4642
pISSN - 1366-9516
DOI - 10.1111/ddi.13162
Subject(s) - biological dispersal , biogeography , phylogeography , ecology , endemism , fauna , population , biology , subtropics , geography , phylogenetics , biochemistry , demography , sociology , gene
Aim Biogeographical transition zones are areas of overlap between the faunas of adjacent biogeographical entities. Particularly the well‐defined transition zones along linear coastlines are interesting natural laboratories to study dispersal and incipient speciation. Few studies have explored whether marine biogeographical transition zones harbour biodiversity that is distinct from that of the biogeographical entities they separate. The Wild Coast in eastern South Africa is a poorly studied transition zone between the region's warm‐temperate and subtropical faunas, and is generally considered to be an area of faunal overlap. Location The South African portion of the Western Indian Ocean. Methods Sequences of the DNA barcoding marker COI were generated from 306 estuarine sandprawns ( Kraussillichirus kraussi ) collected at 13 sites. Genetic structure and evolutionary history were assessed using a haplotype network and a Bayesian discrete phylogeographic analysis. Result Two populations were identified whose ranges are centred on the Wild Coast, a rare one in the northern portion and a more common one in the central and southern portion of this biogeographical transition zone. These populations are not closely related to each other, but descend from subtropical and warm‐temperate sister populations, respectively. Although genetic distances between populations were low, they exceeded within‐population distances, indicating the presence of a "barcoding gap." Conclusions This is the first study to indicate that the Wild Coast marine biogeographical transition zone is not merely an area of faunal overlap, and one of very few studies to have discovered genetically unique populations within a marine biogeographical transition zone. The Wild Coast may harbour additional unique biodiversity that remains to be discovered, including rare species that require protection. More research is required to understand how this environmentally dynamic marine biogeographical transition zone differs from the adjacent biogeographical provinces.