Phylogenetic Study On Balanomorpha (Cirripedia: Seessilia)

In this study morphological characters , 18S rDNA sequences and the combined data of the two matrixes were used respectively to infer the phylogenetic relationships among Balanomorha taxa. And the fine structures of spermatozoa of balanomorphs were investigated and its significance in deducing phylogeny of Balanomorha was discussed.1. A cladistic analysis of the BalanomorphaThe list of characters comprised 37 shell and soft body features. Brachylepas, Verruca and Eochionelasmus were chosen as outgroups. Phylogenetic trees were estimated by the way of parsimony analysis. The monophyly of the Balanomorpha was confirmed. Coronuloidea,Balanoidea, Balanidae and Pyrgomatidae were strongly supported to be monophyletic. Archaeobalanidae appears to be paraphyletic while Chthamalidae and Tetraclitidae appear to be polyphletic. Chthamalidae branches off lowermost in the strict consensus tree of 96 most parsimony trees, while Archaeobalanidae lies between Balanidae and Pyrgomatidae. Coronuloidea appears as the sister group of Balanoidea.2. Phylogenetic study of Balanomorpha on 18S rDNA sequence analysisThe phylogeny of Balanomorpha was estimated from 18S rDNA sequences. Four sequences were included, Euraphia Withersi , Tetraclita japonica , Fustilobalanus kondokovi, Chirona amaryllis. These were combined with previously published sequences from Genbank. Verruca spengleri was chosen as outgroup. Phylogenetic analysis revealed the monophyly of Balanomorpha. The species from Chthamalidae , Tetraclitidae and Balanidae form a clade respectively. Coronuloidea is the basal member of the Balanomorpha.3. Phylogenetic study on morphological and molecular dataMorphological and molecular data were combined to deduce phylogenetic relationships among Balanomorpha taxa. The same topology of phylogenetic trees as that based upon the two data was gained. The monophyly of Balanomorpha wasconfirmed. Coronuloidea acts as the basal member of the Balanomorpha. The species from Chthamalidae , Tetraclitidae and Balanidae form a clade respectively. 4. Study on spermatozoa ultrastructure in BalanomorphaThe spermatozoa ultrastructures of 5 species in Balanomorpha were investigated. Out of them, 2 species belong to Balanidae, 1 to Chthamalidae, 1 to Tetraclitidae and 1 to Archaeobalanidae. The ultrastructure of these species can be summarized as: the nuclei of spermatozoa appear semicircle; in the middle part transverse section accessory droplet partially envelops the nucleus and associated axoneme; there is axoneme left on the section of the posterior end of spermatozoa; many granules paralleling to axoneme can be seen on the vertical section of the middle of the sperm.The spermatozoa ultrastructures of Chthamalidae are the simplest model, while those of Balanidae are the most complicated. As is congruent with the phylogenies based on cladistic analysis and 18S rDNA sequences.