The Observation Of External Morphology And The Skeleton Anatomy Of Glyptosternum Maculatum (Regan)

Glyptosternon maculatum(Siluriformes:Sisoridae),is one of the Glyptosternoid catfish species.G.maculatum,inhabiting in the cold-waters of plateau,distributes only in the middle-reach of Yaluzangbu River(the reach from Xietongmen to bomi) in Tibet. There are some reports about G.maculatum mainly focued on its taxology,biogeography and the phylogeny of Glyptosternoid fishes.Fewer reports on the skeleton system of G. maculatum have been found.The external morphology and skeleton system of two population of G.maculatum that come from Linzhi and Rikaze part have been studied in the paper,to estimate if there are some differences between them owing to reproductive isolation.The main results of the paper as follows:1.There is no difference between the two places,and principal components analyses indicates that Linzhi part are included the Rikaze's.2.It is existed the structure of fontanella,but without circumorbital series.The author arrived at the result during the process of dealing with the data that the fishes whose circumorbital series are developed but whose fontanella are degenerated or disappeared,to reverse,the fishes whose fontanella are developed but whose circumorbital series are degenerated or disappeared.3.There is no posttemporal fossa in the Neurocranium.4.It is found that there are two specialized bones which are jaw bone and basibone, both of which have not been reported during the former research.5.Every other premaxilla can be divided into three parts by boiled water.The premaxillas,the dentaries and articulars are comformed the mouth of G.maculatum.6.There are advanced opercular series,including not only operculars,preoperculars,interoperculars,suboperculars but also basal-operculars which are not existed in the other fishes,all of which are consisted of the tough scutum of the back head of G.maculatum.7.The dentition strip of G.maculatum is G.maculatum type and its dentition shape is needle type,the suspend mode of jowl is metahyostyly.8.Tail fin is the standard homocercal fin constituted by 1 urostyle and 3 hypuras.9.The partition of the G.maculatum's vertebra:former body vertebra(1-13),main body vertebra(14-18),back body vertebra(19-37).