Worldwide genetic differentiation in the common fouling barnacle,Amphibalanus amphitrite

Abstract

Amphibalanus amphitrite is a common fouling barnacle distributed globally in tropical and subtropical waters. In the present study, the genetic (mitochondrial cytochrome oxidase subunit I) and morphological differentiation in A. amphitrite from 25 localities around the world were investigated. The results revealed three clades within A. amphitrite with a genetic divergence of ~ 4% among clades, whereas there were no diagnostic morphological differences among clades. Clade 1 is widely distributed in both temperate and tropical waters, whereas Clade 3 is currently restricted to the tropical region. The deep divergence among clades suggests historical isolation within A. amphitrite; thus, the present geographical overlaps are possibly a result of the combined effects of rising sea level and human-mediated dispersals. This study highlights the genetic differentiation that exists in a common, widely distributed fouling organism with great dispersal potential; future antifouling research should take into account the choice of lineages.

The diversity of acorn barnacles (Cirripedia, Balanomorpha) across Thailand’s coasts: The Andaman Sea and the Gulf of Thailand

“…Hence, we attempt to generate a checklist to understand the species diversification and how they distribute on intertidal rocky shores and sandy shores along the coast of Thailand. At least ten different forms of acorn barnacles were diagnosed so far that are classified into 6 genera and 3 families (Chthamalidae, Tetraclitidae and Balanidae), which can be distinguished based on their external shell morphology, including pattern of parietes, opercular plates, and arthropodal characters as described in previous literatures (Ross and Perreault 1999;Chan 2001;Chan et al 2007a, b;Chan et al 2009;Lozano-Cortés and Londoño-Cruz 2013;Chen et al 2014;Hayashi and Chan 2015;Chan and Cheang 2016). Our study also shows that the numbers of species found in the Andaman Sea (8 species) are more than those found in the Gulf of Thailand (6 species).…”

“…Shells exposed and eroded by heavy wave action showed no purple stripes on the external surface. The molecular analysis has confirmed its genetic differentiation which might be due to local adaptation and geographical isolation (Chen et al 2014). Due to hypothesis on human-mediated activities as the main cause of A. amphitrite's distribution across the globe, this species is considered as non-native or introduced species in these examined regions: Hawaii, California, North Carolina, and the Atlantic coast (Carlton et al 2011), whereas it is considered as native in tropical waters (e.g.…”

“…rocks, shells of oyster and green mussels, concrete walls of bridges and harbors, offshore vessels, dock pilling, and mooring robes). In previous records, this species distributes worldwide in both tropical and temperate regions including the Indo-West Pacific, and Western Australia (Jones 2004;Chen et al 2014) and it has been suggested that this wide range of distribution was due to human-mediated activities during global trade expansion (Chen et al 2014).…”

“…Due to hypothesis on human-mediated activities as the main cause of A. amphitrite's distribution across the globe, this species is considered as non-native or introduced species in these examined regions: Hawaii, California, North Carolina, and the Atlantic coast (Carlton et al 2011), whereas it is considered as native in tropical waters (e.g. Hong Kong, Thailand, Malaysia) supported by molecular study (Chen et al 2014). Despite the diverse morphology of A. amphitrite, another species in the same genus Amphibalanus reticulatus exhibits clear patterns of shell carrying both vertical and longitudinal striations on the external surface.…”

“…calcareous rock or limestone, mollusk shells, corals, sponges, mangrove roots, turtle shells, and whale skins) along intertidal zones of temperate and tropical coastlines worldwide, as sessile form throughout their adulthood (Frith et al 1976;Sophia Rani et al 2010;Brickner and Høeg 2010;Chen et al 2012;Hayashi 2013;Chen et al 2014;Yu et al 2016). It is known as a marine fouling or biofouling organism and it has been considered as a problematic or invasive species for oyster farming, aquaculture, the reforestation of mangrove swamps, and for the support structures of offshore oil rig platforms and ship transport (Santhakumaran and Sawant 1991;Rawangkul et al 1995;Molnar et al 2008;Sophia Rani et al 2010;Holm 2012).…”