Predominant east to west colonizations across major oceanic barriers: Insights into the phylogeographic history of the hydroid superfamily Plumularioidea, suggested by a mitochondrial DNA barcoding marker

Abstract

We provide preliminary insights into the global phylogeographic and evolutionary patterns across species of the hydrozoan superfamily Plumularioidea (Cnidaria: Hydrozoa). We analyzed 1,114 16S sequences of 198 putative species of Plumularioidea collected worldwide. We investigated genetic connections and divergence in relation to present‐day and ancient biogeographic barriers, climate changes and oceanic circulation. Geographical distributions of most species are generally more constrained than previously assumed. Some species able to raft are dispersed widely. Human‐mediated dispersal explains some wide geographical ranges. Trans‐Atlantic genetic connections are presently unlikely for most of the tropical‐temperate species, but were probably more frequent until the Miocene–Pliocene transition, before restriction of the Tethys Sea and the Central American Seaway. Trans‐Atlantic colonizations were predominantly directed westwards through (sub)tropical waters. The Azores were colonized multiple times and through different routes, mainly from the east Atlantic, at least since the Pliocene. Extant geminate clades separated by the Isthmus of Panama have predominantly Atlantic origin. Various ancient colonizations mainly directed from the Indian Ocean to the Atlantic occurred through the Tethys Sea and around South Africa in periods of lower intensity of the Benguela upwelling. Thermal tolerance, population sizes, dispersal strategies, oceanic currents, substrate preference, and land barriers are important factors for dispersal and speciation of marine hydroids.

Genetic diversity and structure of circumtropical almaco jack, Seriola rivoliana: tool for conservation and management

“…Another mechanism that could account for divergent haplogroups within the Atlantic is secondary contact, a pattern characterized by the presence of shared haplotypes in different geographic locations caused by admixture between populations after long periods of geographic isolation (Avise, 2000). Colonization, isolation and recolonization of the Atlantic seems to be a common phenomenon in marine species and has occurred in a variety of taxa, across levels of biological organization [ e.g ., species of hydroids: Moura et al ., 2019; species of surgeonfish within the genus Acanthurus , Siqueira et al ., 2019; within species Carcharhinus plumbeus (Nardo 1827), Portnoy et al ., 2010]. For many taxa, the closure of the Tethys Sea (50–12 bp ) isolated the Atlantic and the Mediterranean Sea from the Indo‐West Pacific, and changing current regimes led to transatlantic colonization predominately from east to west through tropical waters (Hou & Li, 2018).…”

Some leptothecate hydroids (Cnidaria, Hydrozoa) from Hawaii, mostly from inshore and nearshore waters

“…Other characters distinguishing M. balei from the morphologically similar M. philippina Kirchenpauer, 1872 and M. phoenicea (Busk, 1852) have been noted by Schuchert (2003). These three species have been shown to be close genetically (Moura 2018(Moura , 2019 as well as morphologically.…”

“…In some works, Ventromma halecioides (Alder, 1859) has been assigned to Kirchenpaueria Jickeli, 1883. Evidence from molecular studies (Leclère et al 2007;Moura et al 2008Moura et al , 2018Moura et al , 2019Peña Cantero et al 2010;Maronna et al 2016) reveals that Ventromma Stechow, 1923(type species: Plumularia halecioides Alder, 1859 is clearly divergent from Kirchenpaueria Jickeli, 1883 (type species: Sertularia pinnata Linnaeus, 1758). Ventromma halecioides is therefore taken here to be the valid name of the species.…”

“…In addition to its occurrence in the Hawaiian Islands, this species has been reported several times from locations in the western Pacific (Stechow 1913;Rho 1967;Hirohito 1969Hirohito , 1983Hirohito , 1995Yamada 1981;Schuchert 2015;Galea 2020). Recent molecular studies have incorporated data on material attributed to L. nigra from the islands of Europa and Juan de Nova in the Mozambique Channel, from New Caledonia, and from Okinawa (Postaire et al 2016;Ronowicz et al 2017;Moura et al 2018Moura et al , 2019. Results of these studies indicate that this hydroid has a much closer relationship to species of Macrorhynchia Kirchenpauer, 1872 and Taxella Allman, 1874 than to Lytocarpia myriophyllum (Linnaeus, 1758), type species of Lytocarpia Kirchenpauer, 1872, and others of that genus.…”

“…Elsewhere. Korea (Rho 1967, as Lytocarpia niger;Park 1993, as Lytocarpia niger); Japan, including Okinawa (Hirohito 1995;Schuchert 2015); South China Sea (Xu et al 2014); New Caledonia (Galea 2020); provisional re-cords from the Mozambique Channel and New Caledonia (Postaire et al 2016;Ronowicz et al 2017;Moura et al 2018Moura et al , 2019.…”