Phylogeny of coral-inhabiting barnacles (Cirripedia; Thoracica; Pyrgomatidae) based on 12S, 16S and 18S rDNA analysis

The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 52900, Israel.
Molecular Phylogenetics and Evolution (Impact Factor: 3.92). 10/2007; 44(3):1333-41. DOI: 10.1016/j.ympev.2007.03.026
Source: PubMed


The traditional phylogeny of the coral-inhabiting barnacles, the Pyrgomatidae, is based on morphological characteristics, mainly of the hard parts. It has been difficult to establish the phylogenetic relationships among Pyrgomatidae because of the apparent convergence of morphological characteristics, and due to the use of non-cladistic systematics, which emphasize ancestor-descendant relationships rather than sister-clade relationships. We used partial sequences of two mithochondrial genes, 12S rDNA and 16S rDNA, and a nuclear gene, 18S rDNA, to infer the molecular phylogeny of the pyrgomatids. Our phylogenetic results allowed us to reject previous classifications of Pyrgomatidae based on morphological characteristics. Our results also suggested the possibility of paraphyly of the Pyrgomatidae. The hydrocoral barnacle Wanella is not found on the same clade as the other pyrgomatids, but rather, with the free-living balanids. The basal position of Megatrema and Ceratoconcha is supported. The archeaobalanid Armatobalanus is grouped with Cantellius at the base of the Indo-Pacific pyrgomatines. Fusion of the shell plate and modification of the opercular valves are homoplasious features that occurred more than three times on different clades. The monophyly of the "Savignium" group, comprising four nominal genera, is also not supported, and the different taxa are placed on different clades.

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Available from: Noa Simon-Blecher
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    • "Previous phylogenies have focused almost exclusively on the evolution of morphological characters (e.g. Ross and Newman, 1973; Newman and Ross, 1976; Anderson, 1992; Simon-Blecher et al., 2007). The evolutionary history of host specificity and switching has, however, rarely been explored in the coral barnacles . "
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    ABSTRACT: Coral-inhabiting barnacles (Thoracica: Pyrgomatidae) are obligatory symbionts of scleractinian and fire corals. We attempted to reconstruct the phylogeny of coral-inhabiting barnacles using a multi-locus approach (mitochondrial 12S and 16S rRNA, and nuclear EF1, H3 and RP gene sequences, total 3532 bp), which recovered a paraphyletic pattern. The fire-coral inhabiting barnacle Wanella milleporae occupied a basal position with respect to the other coral inhabiting barnacles. Pyrgomatids along with the coral-inhabiting archaeobalanid Armatobalanus nested within the same clade and this clade was subdivided into two major lineages: Armatobalanus + Cantellius with species proposed to be the ancestral stock of extant coral barnacles, and the other comprising the remaining genera studied. Ancestral state reconstruction (ASR) suggested multiple independent fusions and separations of shell plates and opercular valves in coral barnacle evolution, which counters the traditional hypothesis founded on a scheme of morphological similarities. Most of the coral barnacles are restricted to one or two coral host families only, suggesting a trend toward narrow host range and more specific adaptation. Furthermore, there is a close linkage between coral host usage and phylogenetic relationships with sister taxa usually being found on the same coral host family. This suggests that symbiotic relationships in coral-inhabiting barnacles are phylogenetically conserved and that host associated specialization plays an important role in their diversification.
    Full-text · Article · Aug 2014 · Molecular Phylogenetics and Evolution
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    • "archaeobalanid genus Armatobalanus is considered to be morphologically closest to the pyrgomatids, and thus it is thought to represent either the ancestor of, or the sister clade to the pyrgomatids (Hiro, 1938; Ross & Newman, 1973; Healy & Anderson, 1990; Anderson 1992; Ross & Newman, 2000a; Simon-Blecher et al., 2007). Armatobalanus (∼12 species) is comprised of both obligate coral associates and free-living species, and is diagnosed by six tall, conical wall plates and the presence of teeth on the third or fourth pair of cirri (Zullo, 1963). "
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    ABSTRACT: Pyrgomatid barnacles are a family of balanomorphs uniquely adapted to symbiosis on corals. The evolution of the coral-dwelling barnacles is explored using a multi-gene phylogeny (COI, 16S, 12S, 18S, and H3) and phenotypic trait-mapping. We found that the hydrocoral associate Wanella should be excluded, while some archaeobalanids in the genus Armatobalanus should be included in the Pyrgomatidae. Three well supported clades were recovered: clade I is the largest group and is exclusively Indo-West Pacific, clade II contains two plesiomorphic Indo-West Pacific genera, while clade III is comprised of East and West Atlantic taxa. Some genera did not form reciprocally monophyletic groups, while the genus Trevathana was found to be paraphyletic and to include members of three other apomorphic genera/tribes. The highly unusual coral-parasitic hoekiines appear to be of recent origin and rapidly evolving from Trevathana sensu lato. Pyrgomatids include six-, four-, and one-plated forms, and exhibit convergent evolutionary tendencies towards skeletal reduction and fusion, loss of cirral armature, and increased host specificity. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, ●●, ●●–●●.
    Full-text · Article · Aug 2014 · Biological Journal of the Linnean Society
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    • "Please cite this article as: Rubio-Portillo, E., et al., Eukarya associated with the stony coral Oculina patagonica from the Mediterranean Sea, Mar. Genomics (2014), (i.e., two or more distinct species classified as single species based on morphological similarities) (Blanquer and Uriz, 2007; Simon-Blecher et al., 2007). In such cases, the incorporation of molecular tools could help to solve the problem, as our data suggest. "
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    ABSTRACT: Oculina patagonica is a putative alien scleractinian coral from the Southwest Atlantic that inhabits across the Mediterranean Sea. Here, we have addressed the diversity of Eukarya associated with this coral and its changes related to the environmental conditions and coral status. A total of 46 colonies of O. patagonica were taken from Alicante coast (Spain) and Pietra Ligure coast (Italy) and analyzed using denaturing gradient gel electrophoresis (DGGE) of the small-subunit 18S rRNA and 16S plastid rRNA genes, internal transcribed spacer region 2 (ITS 2) analyses, and electron microscopy. Our results show that Eukarya and plastid community associated to O. patagonica change with environmental conditions and coral status. Cryptic species, which can be difficult to identify by optical methods, were distinguished by 18S rRNA gene DGGE: the barnacle Megatrema anglicum, which was detected at two locations, and two boring sponges related to Cliona sp. and Siphonodictyon coralliphagum detected in samples from Tabarca and Alicante Harbour, respectively. Eukaryotic phototrophic community from the skeletal matrix of healthy corals was dominated by Ochrosphaera sp. while bleached corals from the Harbour and Tabarca were associated to different uncultured phototrophic organism. Differences in ultrastructural morphologies of the zooxanthellae between healthy and bleached corals were observed. Nevertheless, no differences were found in Symbiodinium community among time, environments, coral status and location, showing that O. patagonica hosted only one genotype of Symbiodinium belonging to clade B2. The fact that this clade has not been previously detected in other Mediterranean corals and is more frequent in the tropical Western Atlantic, is a new evidence that O. patagonica is an alien species in the Mediterranean Sea.
    Full-text · Article · Jun 2014 · Marine Genomics
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