Multi-loci approached to the molecular phylogeny of reef-building coral, Montipora (Cnidaria; Scleractinia)
Date Issued
2004
Date
2004
Author(s)
Chang, Chao-Ching
DOI
en-US
Abstract
Montipora is the second speciose genus of scleractinians with 75 species currently described. In order to accommodate this speciose genus, species groups were adopted to cluster morphologically similar species based on either the final skeleton structure of coenosteums or the colony growth forms. These conventional groupings, however, do not imply any taxonomic affinity. Four major coenosteums and three growth forms including, glabrous-foveolate, papillae, tuberculae, verrucae, and laminar, encrusting-massive, and branches were used, either respectively or jointly, to define the species groups and species in the literatures. However, the results were usually conflict. In addition, more than one growth form was often observed within a single colony that confused identification of Montipora. In this study, we examined two taxonomical grouping hypotheses: (1) coenosteum hypothesis, groups based on glabrous-foveolate, papillae, tuberculae and verrucae, and (2) growth form hypothesis, groups based on laminar, encrusting-massive, and branches. Molecular phylogenies of 32 Montipora species were constructed using three independent loci, including mitochondrial intergenic region 3 (mtigr3, 472bp) spanning between cytochrome b (Cytb) and NADH dehydrogenase subunit 2 (ND2) genes, nuclear ribosomal internal transcribed spacer (ITS; ITS1+ITS2, 393bp), and an intron spanning between exon 2 and 3 of the calmodulin gene (CaM-II, 270bp). Species phylogeny analysis of the three independent loci using nested clade analysis (NCA) and phylogenetic trees with neighbour-joining, maximum-parsimony, maximum-likelihood, and Bayesian-likelihood approaches were largely corresponded with coenosteum structures groups, but not with growth forms. The NCA and phylogenetic trees based on mtigr3 and CaM-II loci could distinguish three coenosteum monophyletic groups consisted of “glabrous-foveolate”, “papillae-tuberculae” and “verrucae”, but the ITS can only divided glabrous-foveolate coenosteum from the others. Combining the three molecular markers suggested that growth forms did not contribute to resolve the taxonomic complexity of species groups for genus Montipora. Instead, with a few exceptions, the phylogenetic analyses tended to support the grouping based on coenosteum structures, which divided the genus into three major groups, included glabrous-foveolate, papillae-tuberculae and verrucae. This result highlighted not only the phylogenetic significance but also the utility of coenosteum structures in the future revision of species group and species taxonomy in genus Montipora.
Subjects
表孔珊瑚
分子親緣關係
造礁珊瑚
Scleractinia
molecular phylogeny
Montipora
Type
thesis