Studies On The Morphology And Genetics Of Temnopleurus And The Taxonomy Of Temnopleuridae Inshore Water Of China Sea

Temnopleurus, which widely distribute in Chinese coastal, belongs to Echinoidea,Camarodonta, Temnopleuridae. The phylogenetic relationships of Temnopleurus areanalysed by combining sequence data from mitochondrial16S rRNA and cytochromeoxidase subunitⅠgenes with morphological data.1. To distinguish the morphological differences between Temnopleurus hardwickii,Temnopleurus toreumaticus, and Temnopleurus reevesii, four meristic characters andfifteen morphometric characters are measured. The data were analyzed by PCA(principal component analysis) method, one-way ANOVA, multivariate analysismethod and discriminant method. The result shows that the morphological charactersof T. hardwickii and T. toreumaticus are similar, but are significantly different from T.reevesii. Through the discriminant method, the accurate discriminant formulas ofthree species are obteined separately, and the comprehensive discriminant rate is97.8%.2. To assess the phylogenetic relationship of Temnopleurus, the mitochondrialCOⅠ a nd16S rRNAfragments were amplified and analyzed. Alignments of threespecies (T. hardwickii, T. toreumaticus and T. reevesii) are consisted of459bp~462bpfor16S rRNA region and652bp for COⅠregion. Sequences polymorphism analysisindicate that the percentage of A+T content is higher than G+C. The variable sites rateof COⅠ(24.07%) is higher than16S rRNA(21.76%). Considering other tow speciesof Temnopleurus (Temnopleurus alexandri and Temnopleurus michaelseni), thegenetic distance based on16S rRNA and CO Ⅰ regions are calculated byKimura-2-parameter model. The genetic distance based on16S rRNA was0.076~0.182and was0.076~0.182based on COⅠ. Sequence analysis indicated thatthe nucleotide substitution rates of COⅠis higher than16S rRNA. For the fragmentof COⅠ, divergence rates is3.49%per million years, We calculated the divergenttime of the five species. It is inferred that T. hardwickii split from T. reevesii in about5.90million years ago, then split from T. michaelseni in about5.70million years ago,and at last, split from T. toreumaticus and T. alexandri in about5.0million years ago. All events occurred in the years of Late Miocene and Early Pliocene.3. Using Salmacis sphaeroides as a outgroup, phylogenetic trees are constructed basedon neighbor-joining, maximum parsimony and maximum likelihood methodsseparately. The results showed that the five species form into two clades. T.hardwickii，T. toreumaticus and T. alexandri show close genetic relationship, and thereis close genetic relationship between T. reevesii and T. michaelseni.The morphology of six species (Temnopleurus hardwickii, Temnopleurustoreumaticus, Temnopleurus reevesii, Temnotrema sculpta, Salmacis bicolor, andSalmacis sphaeroides) of family Temnopleuridae are descripted. Taking photographsat the test, ambulacral plates, interambulacral plates, apical system, and spines. Thisresearch compared the morphological characters descripted before and supplementedthe date of the taxonomy of Temnopleuridae.