| Leech (or hirudo) is the common name of hirudinea in Annelida. Leech has a very long applied history in China as traditional Chinese medicine. The main mechanism is that hirudin can facilitate blood circulation and reduce blood viscosity. At present, European and North American countries mainly use Hirudo medicinalis for medical treatment by in vitro blood-sucking, because hirudin has blood coagulation function produced by Hirudo medicinalis salivary gland. Three species of leech, Whitmania pigra (Whitman,1884), Whitmania acranulata (Whitman,1886) and Hirudo nipponia (Whitman,1886) were recorded in Chinese Pharmacopoeia. Whitmania pigra (Whitman,1884) is the leech species mostly applyed in medicine nowadays. Species in Whitmania feed on mollusks, and the living habit obviously differs from the species in Hirudo sucking blood of human and vertebrate. The question whether species in Whitmania would secrete hirudin is undiscovered. So taxonomic research on Whitmania pigra (Whitman,1884) and Whitmania acranulata (Whitman,1886) to detect whether they are synonyms or totally different species, is important not only in taxonomy but also in using pharmaceutical exactly and expanding the medicial source.The progression of leech taxonomy is reviewed, and the classifying problem of higher category of Hirudinea, as well as leech synonyms in China are discussed. The specimens of Whitmania pigra, Whitmania laevis in this study were collected from Shaanxi province, Inner Mongolia, Hubei province and Hunan provice. According to morphological characters in Oka's paper and Fauna Sinica, the specimens were identified into Whitmania pigra, Whitmania laevis and Whitmania sp, which are similar to them. This study aims to discuss synonyms and phylogenetic relationship of Whitmania pigra, Whitmania laevis and similar species, which has a dispute in category, by using numerical taxonomy and molecular phylogeny methods based on the specimens above.Seven standard points on the ventral side of specimen were choosed, to obtains six numerical characters, and the numerical characters were converted into three proportional numbers, then combining with the structure of ejaculatory bulb and seminal vesicle for cluster analysis. In the molecular phylogenetic analysis, partial sequences of ND1 gene and partial sequences of tRNA-Leu gene, which are adjacent to each other, and 12SrRNA were used. Alignment of the sequences was done by using Clustal X. The result calculated in MEGA5 by statistic analysis, in JModelTest by assessing appropriate model. MEGA5 and PAUP4 were used to test phylogenetic signal, and NJ, MP, BI were applied to reconstruct the phylogenetic relationship.The conclusions were as follows:1,The result of morphological character using clustering analysis is that taxonomic character choosen by Oka is steady in Whitmania pigra, but the character in Whitmania laevis is insufficient. The rate of ejaculatory bulb area to seminal vesicle area can not be a steady character to classify them in this study, the reason may that this character is prone to influence by individual physiological and environmental condition.2,The evidence of reconstructing phylogeny based on the arithmetic of NJ, MP, BI using ND1 gene and 12SrRNA as molecular markers strongly supported that Whitmania pigra and Whitmania laevis were distinctly different species. And the species having 4 rings on the dorsum and 5 rings on the ventral cluster with other species whose position of gonopore is not on the annuli, explaining that Whitmania laevis is more variable in morphological structure.3,The phylogenetic tree based on the sequences of gene 12SrRNA sequencing from the specimens in Whitmania in this study and the sequences of other leech downloading from NCBI, Whitmania and Hirudo has close phylogenetic relationship. On this evidence, we can conclud that:Whitmania may be derivated from Hirudo. So the mechanism of anticoagulation in Whitmania need more further research. |
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