摘要
The taxonomic status of Bufo species in East Asia,particularly those closely related to B.gargarizans,has been controversial for over half a century,and recent molecular studies further fueled the dispute.Whether B.andrewsi,B.bankorensis,B.minshanicus,B.sachalinensis,B.tibetanus,and B.tuberculatus constitute valid species or are geographic or ecological variants of B.gargarizans is at the centre of the discussion.Most of these forms possess morphological diagnostic traits,but those differences are minimal and often inconsistent.Molecular data produced many contradictory patterns.Lack of clear diagnostic characters,different usage or definition of various names,mis-identified specimens,limited amount of data or samples,and frequent inter-specific hybridization may all have contributed to the current controversies.Some contradiction may also result from differences between similarity-based clustering and gene tree-based branching patterns.Nevertheless,a dominant allopatric differentiation pattern within this species complex is apparent,and several regional population groups have been identified.Some of the groups resemble old names(e.g.B.minshanicus,B.tibetanus),while others are new.These groups may represent geographic or ecological variants,incipient species,or valid species,and the current data do not warrant a convincing taxonomic revision.To move forward,a single study with comprehensive sampling and genomic data is needed to establish a solid framework,which will define naturally existing population clusters/lineages,and detect their levels of divergence and approximate geographic boundaries.Morphological and ecological examination will follow to understand their biology,determine their taxonomic status,and identify consistent diagnostic characters if necessary.
