水生肉食亚目(Hydradephaga)系统发育学研究简论

水生肉食亚目(Hydradephaga)属于鞘翅目Coleoptera,是一类具有水生习性的食肉性真正水生甲虫(True water beetles)。在真正水生甲虫的系统分类中存在三种假说,一种是肉食亚目(Adephaga)位于该系统的基部,一种是多食亚目(Polyphaga)位于该系统基部,第三种是藻食亚目(Myxophaga)位于该系统基部。最近研究结果更多倾向第一种假说。目前水生肉食亚目大约有5 500个种,200多个属,含8个科。水生肉食亚目的科间水平系统发育关系虽被广泛研究,但观点仍不统一。有代表意义的有三个假说,一是豉甲科(Gyrinidae)位于系统基部,接下来是龙虱科(Dytiscidae)、两栖甲科(Amphizoidae)、水甲科(Hygrobiidae)、小粒龙虱科(Noteridae)与沼梭科(Haliplidae);二是沼梭科位于系统的基部;三是豉甲科位于系统的基部,接下来是沼梭科和龙虱总科(Dytiscoidea),其中龙虱总科由两栖甲科、水甲科、龙虱科、小粒龙虱科组成。目前根据形态学的分类,并结合分子系统学研究方法,第三种假说更符合水生肉食亚目的系统分类,也支持了水生肉食亚目作为一个单系,其祖先来自陆生的假说。

The simple exposition of phylogenetic study in Hydradephaga

Hydradephaga belonging to the Coleoptera, is a kind of true water beetles with aquatic flesh-eating habits. In the classification system in the true water beetles, there are three hypotheses, one is suborder Adephaga at the base of the system, the second is suborder Polyphaga at the base, and the third is suborder Myxophaga at the base. More recent studies tend to the first hypothesis. At present, Hydradephaga are about 5 500 species, more than 200 genera, with 8 families. Although the phylogenetie relationships of Hydradephaga have been extensively studied, the view is not uniform. There are three representative hypothesis, first, Gyrinidae is at the base of the system, followed by Dytiseidae, Amphiziodae, Hygrobiidae, Noteridae and Haliplidae; Second, Haliplidae is at the base; Third, Gyrinidae is at the base, followed by Haliplidae and Dytisct）idea, of which is made up of Dytiseidae, Amphiziodae, Hygrobiidae and Noteridae. At present, according to the morphological and molecular classification methods, the third hypothesis is more than representative in the classification system of Hydradephaga, and also supports a hypothesis which their ancestors as a monophyletie groups is from land.