Intraspecific genetic lineages of a marine mussel show behavioural divergence and spatial segregation over a tropical/subtropical biogeographic transition. | - CCMAR -

Journal Article

TitleIntraspecific genetic lineages of a marine mussel show behavioural divergence and spatial segregation over a tropical/subtropical biogeographic transition.
Publication TypeJournal Article
AuthorsZardi, GI, Nicastro, KR, McQuaid, CD, Castilho, R, Costa, J, Serrão, EA, Pearson, GA
Year of Publication2015
JournalBMC Evol Biol
Volume15
Date Published2015 May 31
Pagination100
ISSN1471-2148
KeywordsAfrica, Southern, Animals, Biodiversity, Biological Evolution, Bivalvia, Ecosystem, Gene Flow
Abstract

BACKGROUND: Intraspecific variability is seen as a central component of biodiversity. We investigated genetic differentiation, contemporary patterns of demographic connectivity and intraspecific variation of adaptive behavioural traits in two lineages of an intertidal mussel (Perna perna) across a tropical/subtropical biogeographic transition.RESULTS: Microsatellite analyses revealed clear genetic differentiation between western (temperate) and eastern (subtropical/tropical) populations, confirming divergence previously detected with mitochondrial (COI) and nuclear (ITS) markers. Gene flow between regions was predominantly east-to-west and was only moderate, with higher heterozygote deficiency where the two lineages co-occur. This can be explained by differential selection and/or oceanographic dynamics acting as a barrier to larval dispersal. Common garden experiments showed that gaping (periodic closure and opening of the shell) and attachment to the substratum differed significantly between the two lineages. Western individuals gaped more and attached less strongly to the substratum than eastern ones.CONCLUSIONS: These behavioural differences are consistent with the geographic and intertidal distributions of each lineage along sharp environmental clines, indicating their strong adaptive significance. We highlight the functional role of diversity below the species level in evolutionary trends and the need to understand this when predicting biodiversity responses to environmental change.

DOI10.1186/s12862-015-0366-5
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/26026663?dopt=Abstract

Alternate JournalBMC Evol. Biol.
PubMed ID26026663
PubMed Central IDPMC4449970