Merging scleractinian genera: the overwhelming genetic similarity between solitary Desmophyllum and colonial Lophelia

Abstract

BackgroundIn recent years, several types of molecular markers and new microscale skeletal characters have shown potential as powerful tools for phylogenetic reconstructions and higher-level taxonomy of scleractinian corals. Nonetheless, discrimination of closely related taxa is still highly controversial in scleractinian coral research. Here we used newly sequenced complete mitochondrial genomes and 30 microsatellites to define the genetic divergence between two closely related azooxanthellate taxa of the family Caryophylliidae: solitary Desmophyllum dianthus and colonial Lophelia pertusa.ResultsIn the mitochondrial control region, an astonishing 99.8 % of nucleotides between L. pertusa and D. dianthus were identical. Variability of the mitochondrial genomes of the two species is represented by only 12 non-synonymous out of 19 total nucleotide substitutions. Microsatellite sequence (37 loci) analysis of L. pertusa and D. dianthus showed genetic similarity is about 97 %. Our results also indicated that L. pertusa and D. dianthus show high skeletal plasticity in corallum shape and similarity in skeletal ontogeny, micromorphological (septal and wall granulations) and microstructural characters (arrangement of rapid accretion deposits, thickening deposits).ConclusionsMolecularly and morphologically, the solitary Desmophyllum and the dendroid Lophelia appear to be significantly more similar to each other than other unambiguous coral genera analysed to date. This consequently leads to ascribe both taxa under the generic name Desmophyllum (priority by date of publication). Findings of this study demonstrate that coloniality may not be a robust taxonomic character in scleractinian corals.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0654-8) contains supplementary material, which is available to authorized users.

Species delimitation in the coral genus Goniopora (Scleractinia, Poritidae) from the Saudi Arabian Red Sea

“…Unfortunately, scleractinian morphology exhibits extensive phenotypic plasticity, high variability, and/or evolutionary convergence that often obscure natural patterns of evolution (e.g., Gittenberger and Hoeksema, 2006;Fukami et al, 2004;Todd, 2008;Flot et al, 2011;Budd et al, 2012). The integration of molecular tools with morphological analyses has proven to be powerful in clarifying misleading and complex phylogenies, with recent examples in the genera Pocillopora (Schmidt Roach et al, 2014), Psammocora (Stefani et al, 2008;Benzoni et al, 2010), and Desmophyllium (Addamo et al, 2016). In the present study, a multi-locus genetic approach provides the basis for a reevaluation of evolutionary-informative morphological features to assess species boundaries in Goniopora.…”

Overview of the conservation status of Mediterranean anthozoa

“…The Mediterranean marine fauna and flora is consequently a combination of some relicts (paleo-endemic species) of the Tethys Sea and those species of Atlantic origin (the majority, about 60%), of boreal or subtropical origin, having entered through Gibraltar from either the African or the European portion of the Atlantic Ocean (Boero 2003;Blondel et al 2010). In more recent times, an additional group of species entered the Mediterranean Sea through the Suez Canal connecting the species from the Red Sea or through other means (e.g.…”

“…These species that look like sea anemones, are mostly known to colonise rocky shores, overhangs, artificial substrates, and can also be found attached to other sessile invertebrates, particularly on the shell of hermit crabs (Ates 2003).…”

“…Since the 1960s, at depths below 200 m and on the continental shelf throughout the Mediterranean basin, there are major commercial fishing grounds for red shrimps (Aristaeomorpha foliacea and Aristeus antennatus), Norway Lobster (Nephrops norvegicus) and other important multispecies fisheries such as for European Hake (Merluccius merluccius) or the Rose Shrimp Parapenaeus longirostris (Bas et al 1985). Here, the trawl fisheries use nonselective gears with small mesh sizes, generating by-catch that is thrown overboard, most of the time dead or dying (ICES 2007).…”

“…Near-shore species, such as the golden anemone Condylactis aurantiaca or the gorgonian Leptogorgia sarmentosa are exposed to increasing coastal disturbances and anthropogenic activities (such as dredging, land clearing, municipal and agricultural discharge, construction, and coastal development) which can alter water chemistry and increase turbidity and sedimentation (Airoldi 2003). The Cassidaigne canyon (France) receives massive disposal of bauxite residues expelled by an aluminium company inland, resulting in deep gorgonians (Acanthogorgia hirsuta) being smothered with the red mud residue and showing clear signs of tissue necrosis and patches of mud deposits (Fabri et al 2014).…”