Molecular and morphological phylogenetics of the Faviidae (Scleractinia) in Singapore

Abstract

Faviidae constitutes one of the most important yet taxonomically challenging families of hermatypic corals. DNA barcoding holds enormous potential for species identification and resolution of evolutionary relationships among species. However, its efficacy for non-bilaterians has not been empirically assessed. Here, I present a comprehensive analysis of COI variabilities in Porifera and Cnidaria (Anthozoa + Medusozoa). Variation within and among species was found to be much lower in Porifera and Anthozoa compared to Medusozoa. Low identification success and substantial overlap between intra- and interspecific COI distances render the Anthozoa, and hence Scleractinia, unsuitable for DNA barcoding. Consequently, I relied solely on conventional taxonomic traits to reconstruct its phylogeny using two mitochondrial genes and 21 morphological characters. Phylogenetic trees based on both data types are incongruent and did not recover traditional classification. Results clearly show that conventional taxonomy has masked morphological convergence and reticulate evolution in this family.