Population structure and identification of two matrilinear and one patrilinear mitochondrial lineages in the mussel Mytella charruana Thainara Oliveira de Souza a, 1 , Francisco Arimateia dos Santos Alves a, b, 1 , Colin Robert Beasley c , Luiz Ricardo Lopes de Simone d , Nelane do Socorro Marques-Silva a , Guilherme da Cruz Santos-Neto a, e , Claudia Helena Tagliaro a, * a Universidade Federal do Par a, Campus de Bragança, Instituto de Estudos Costeiros, Laborat orio de Conservaç~ ao e Biologia Evolutiva, Alameda Leandro Ribeiro, s/n, Bragança, PA, CEP 68600-000, Brazil b Instituto Evandro Chagas, Seç~ ao de Meio Ambiente, Laborat orio de Biologia Ambiental, Rodovia BR 316, Km 07, s/n, Levil^ andia, Ananindeua, PA, CEP 67030-070, Brazil c Universidade Federal do Par a, Campus de Bragança, Instituto de Estudos Costeiros, Laborat orio de Moluscos, Alameda Leandro Ribeiro, s/n, Bragança, PA, CEP 68600-000, Brazil d Museu de Zoologia da Universidade de S~ ao Paulo, Caixa Postal 42494, S~ ao Paulo, SP, CEP 04299-970, Brazil e Instituto Federal de Ci^ encia e Tecnologia do Par a, Campus de Abaetetuba, Rua Rio de Janeiro, 3322, Abaetetuba, PA, CEP 68440-000, Brazil article info Article history: Accepted 10 November 2014 Available online xxx Keywords: genetic diversity geographic isolation population genetics DUI Mytilidae abstract The mitochondrial gene cytochrome c oxidase subunit I (COI) was sequenced from Mytella charruana (N ¼ 243) at 10 Brazilian coastal localities to search for cryptic species, doubly uniparental inheritance and investigate genetic population structure and demography. Three haplogroups were found: two matrilinear (A and B) in males and females, and one patrilinear (C) found only in males. The p-distances were 0.0624 (A and B), 0.2097 (A and C) and 0.2081 (B and C). Coalescence of M. charruana occurred around 12.5 Mya, and the origins of the lineages were 3.4 and 4 Mya (matrilinear A and B) and 51.2 Mya (patrilinear), which split before the separation of the genera Perna and Mytella. All individuals from the northern coast of Brazil belonged to haplogroup A, whereas haplogroup B predominated among in- dividuals from the eastern and northeastern coasts, with one exception, Goiana. Haplogroup C was found in males from the northern to the eastern coast. GenBank sequences of M. charruana from Colombia, Ecuador and four populations introduced to the USA joined Brazilian haplogroup B. Nuclear gene 18S- ITS1 sequences confirmed that all specimens belong to the same species. Four populations from the northern coast of Brazil were homogenous with evidence of recent population expansion. All populations from the northeastern and eastern coasts of Brazil were significantly structured (pairwise F ST and AMOVA). The heterogeneity among Brazilian populations requires that relocation for aquaculture be preceded by genetic identification of the haplogroups. Differences in salinity and temperature may have selected for distinct lineages of mussels and changing conditions in coasts and estuaries may allow only resistant lineages of mussel to persist with the loss of others. In the light of global climate change, more detailed data on temperature, pH, salinity and local currents could help explain the genetic structuring observed among populations of Brazilian M. charruana. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Mytella charruana (d'Orbigny, 1842) (Mytilidae, Bivalvia), the charru mussel, is native to Central and South America where it ranges, along the Pacific coast, from Guayamas, Mexico to southern Ecuador and the Galapagos Islands (Rios, 1994; Cardenas and Aranda, 2000) and, along the Atlantic coast, from Colombia to Argentina (Keen, 1971). Introíni et al. (2010) listed the diverse synonyms attributed to M. charruana, including Mytella falcata d'Orbigny, 1846, Modiola falcata Von Ihering, 1897, Mytilus strigatus Von Ihering, 1900, Mytilus arciformis Dall, 1909, Mytilus munda- huensis Duarte, 1926 and Modiolus falcatus Morretes, 1949. * Corresponding author. E-mail address: tagliaro@ufpa.br (C.H. Tagliaro). 1 Both authors contributed equally to this research. Contents lists available at ScienceDirect Estuarine, Coastal and Shelf Science journal homepage: www.elsevier.com/locate/ecss http://dx.doi.org/10.1016/j.ecss.2014.11.009 0272-7714/© 2014 Elsevier Ltd. All rights reserved. Estuarine, Coastal and Shelf Science xxx (2014) 1e10 Please cite this article in press as: de Souza, T.O., et al., Population structure and identification of two matrilinear and one patrilinear mitochondrial lineages in the mussel Mytella charruana, Estuarine, Coastal and Shelf Science (2014), http://dx.doi.org/10.1016/j.ecss.2014.11.009