Indo-Pacific molecular biogeography of the coral-dwelling snapping shrimp Alphes lottini Decapoda: Caridea: Alpheidae

The species of snapping shrimp Alpheus lottini contains two highly distinct groups (A and B), which should be recognized at the species level. Only group A were found in the Indian Ocean, and this group corresponds to Alpheus lottini sensu stricto. Within A. lottini s.s. mtDNA sequence data suggest that there are four genetically differentiated groups. A clade is found in the Indo-West Pacific and can be further divided into Indian Ocean and West Pacific groups. Indian Ocean haplotypes are genetically distinguished from all Pacific haplotypes by a single fixed transversion out of 564 bp of cytochrome oxidase I sequence. This difference, although small, means that no haplotype occurred in both oceans, consistent with the presence of a biogeographic boundary between the Indian and Pacific Oceans. The estimated timing of the split between biogeographic regions, based on rates of evolution in Alpheus species across the isthmus of Panama, lies within the late Pleistocene. Within the Indian Ocean, populations of A. lottini are genetically similar despite long distances among them. A second clade in A. lottini s.s consists of the Central-East Pacific populations which can also be divided into two groups - coastal (Panama) and offshore (Clipperton & Moorea) populations. These patterns of molecular biogeography suggest that vicariant events have played an important role in shaping the broad scale genetic structure of A. lottini.
Williams S , Knowlton Nancy , Weight L .
shrimp, Population Genetics, mtDNA, Indian Ocean, Larval dispersal, Marine Crustacea