Geographical and temporal origins of Neocaridina species (Decapoda: Caridea: Atyidae) in Taiwan

Abstract

AbstractBackgroundThe freshwater species on Taiwan Island have been documented to have originated from mainland China and the Japanese islands from multiple events and by multiple colonization routes. Moreover, the sequences from the mitochondrial DNA cytochrome c oxidase subunit I (COI) have been used for DNA barcoding to identify the species. This study used the COI sequences to identifyNeocaridinaspecies in Taiwan and to examine their geographical and temporal origins.ResultsIn total, 479 specimens were collected from 35 localities, which covered almost all rivers in Taiwan. In addition, some sequences were downloaded from GenBank. The maximum likelihood (ML) tree displayed that all sequences were sorted into 13 taxa (clades), and all sequences in Taiwan were sorted into four clades. The Bayesian skyline plots revealed that these fourNeocaridinaspecies have declined recently in Taiwan.ConclusionsAll results support that (1) there are fourNeocaridinaspecies in Taiwan, which areN. davidi,N. saccam,N. ketagalanand an undescribedNeocaridinaspecies (N.sp.); (2) these four species colonized Taiwan Island in four colonization events; (3)N.sp. colonized Taiwan first; (4) after the island reached its shape,N. ketagalanandN. saccamcolonized Taiwan from the Japanese islands and mainland China, respectively; (5)N. davidicolonized northern Taiwan last; and (6) the cyclic glacial and landform changes in East Asia shaped the colonization events and population structures of theNeocaridinaspecies.