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Palythoa caesia (Dana1846)

Sea Mat Anemone

Ka Hei Charlotte Chan (2013)


Fact Sheet



Physical Description




Biogeographical Distribution

Local Distribution & Habitats

Life History & Behaviour

Anatomy & Physiology

External Morphology

Internal Anatomy

Cell Biology

Toxicity (Experiment)


Evolution & Systematics

Conservation & Threats

References & Links

 Evolution & Systematics 

(Fig 1. Phylogenetic tree of the mitochondrial sequences from Sinniger 2005)

(Fig 2. Phylogenetic tree constructed by Daly 2003)

Molecular sequences and morphological characteristics are used to determine the evolution of organisms. Previous phylogeny studies were conducted to examine the phylogeny relationship between Anthozoa. Based on the arrangement of the septa, the Zoanththaria can be divided into 2 suborder, Macrocnemina and Brachycnemina (Spinniger 2005). Within the Brachycnemina, Palythoa and Protopalythoa can closely related. Based on the result from Daly; Burnett 1997 and Spinniger 2005, the picture above show the evolutionary link among these species. Morphological characteristics such as the number of tentacles and septa, colour, the shape and position of sphincter muscle and the size and distribution of different nematocysts are the key characteristics to discriminate species (Spinniger 2005). In recent study, their result indicated that there were no clear phylogenetic distinction can be may between P.tuberculosa and P.caesia, however they have shown that P.tuberculosa and P.caesia are phylogenetically more related than P.tuberculosa and P.mutuki (Hibino 2013).


(Fig 3a & b. (a)Maximum likelihood trees of mitochondrial 16s rDNA sequences, (b) mitochondrial cytochrome oxidase subunit 1 sequences, both tree constructed by Hibino 2013)

(Fig 4. Maximum likelihood trees of nuclear ITS-rDNA sequences constructed by Hibino 2013)