Biogeography of Indo-Pacific Pontoniinae (Crustacea, Decapoda): a PAE analysis

Aim Pontoniid shrimps are one of the most abundant coral reef associated taxa in the Indo-Pacific. Although taxonomically well known, their ecology, life history and biogeography appears virtually unstudied. The object of the present contribution is to derive a basin wide biogeographical hypothesis, using a limited number of operational geographic units (OGU). Location Twelve OGU's were selected, spanning the entire Indo-Pacific, from the East coast of Africa and the Red Sea to the Tropical Eastern Pacific (TEP). Methods Analysis was based on a species by OGU matrix, in which presences (1) and putative occurrences (?) were coded. Parsimony analysis of endemicity (PAE) was applied to the data set, using Dollo and Wagner Parsimony. Results A hierarchical pattern of area relationships was derived, with the TEP occupying a basal position, Hawaii and French Polynesia occupy positions higher up in the cladogram, whilst the Melanesian OGU maintains a sister-area relationship to the crown clade. The latter consists of the Indo-Philippine area, the Australian and all Indian Ocean OGUs. Main conclusions Pontoniinae exhibit a clear hierarchical pattern of area relationships, which is congruent with previous biogeographical studies on coral reef and other taxa. The observed pattern can be explained by a combination of dispersal and vicariant events, whilst the importance of sea level changes is recognized.