How big can a walking fish be?A theoretical inference based on observations on four land-dwelling fish genera of South Vietnam  

作　　者：Alexander N.KUZNETSOV 

机构地区：[1]Borissiak Paleontological Institute,Russian Academy of Sciences,Moscow,Russia

出　　处：《Integrative Zoology》2022年第5期849-878,共30页整合动物学（英文版）

摘　　要：Comparative study of terrestrial locomotion of 4fish genera including Anabas,Channa,Clarias,and Monopterus,was performed in experimental setting with the substrate surface of wet clay.No special adaptations for terrestrial locomotion were found.Everyfish uses for propulsion on land what it already has.Eel-shaped Monopterus crawls by body undulations in a serpentine or sidewinding technique,the latter of which was not previously observed beyond snakes.The other 3fish genera walk by body oscillations using stiff appendages as propulsors.When they are located anteriorly,as the serrate operculum in Anabas and the preaxial spine of the pectoralfin in Clarias,the propulsion is termed prolocomotor,when posteriorly,as the spiny analfin in Channa—metalocomotor.Channa is the heaviestfish walking out of water in our days,quite comparable in size withfirst Devonian tetrapods Acan-thostega and Tulerpeton.A theoretical calculation is suggested for the upper size limit of afish capable of terrestrial walking without special locomotor adaptations.It should be roughly 20 cm in the vertical dimension of the trunk,which is just a little above the known size of Devonian tetrapodomorphfishes Panderichthys and Elpistostege.The metalocomotor walking technique of Channa is suggested as the closest extant model for terrestrial locomotion at thefish-tetrapod transition.The major difference is that the metalocomotor propulsor in Channa is represented by the analfin,while in tetrapodomorphs by the pelvicfins.The sprawled pelvicfins were advantageous in respect of reduced requirement for side-to-side tail swinging.

关 键 词：fish-tetrapod transition metalocomotor propulsion prolocomotor propulsion SNAKEHEAD 

分 类 号：Q95[生物学—动物学]