Phylogeographic structure of the caridean shrimp Palaemon peringueyi in South Africa: further evidence for intraspecific genetic units associated with marine biogeographic provinces

摘要

Recent genetic studies have shown that most widelydistributed, passively dispersing invertebrates insouthern Africa have regional intraspecific units thatare associated with the three main marine biogeographic provinces (cool-temperate, warm-temperateand subtropical). The caridean shrimp Palaemonperingueyi also occurs in all three provinces, but thefact that it can disperse both actively and passively (i.e.larval drifting, adult walking/swimming and potentialadult rafting by means of floating objects) suggeststhat the amount of gene flow between regions may betoo high for evolutionary divergence to have takenplace. Samples of P. peringueyi were collected throughout South Africa and an intraspecific phylogeny was reconstructed using mitochondrial COI and 16S rRNAsequences. Three major clades were recovered, whichwere broadly associated with the three biogeographicregions. This suggests that, even though P. peringueyican disperse actively, the fact that neither larvae noradults are strong swimmers has resulted in geneticsubdivisons comparable to those of passively dispersing coastal invertebrates in southern Africa.