鳋科(寄生桡足类)二新种

TWO NEW SPECIES OF ERGASILIDAE(PARASITIC COPEPODA)FROM CHINA

我们在整理西北地区收集的淡水鱼寄生桡足类标本时,发现鳋科(Ergasilidac)的二个新种,现记述于下。模式标本保存于中国科学院昆明动物研究所。

The present paper deals with two new species of Ergasilidae from Xizang and Xinjiang,China.Type specimens are deposited in the Kunming Instituteof Zoology,Academia Sinica.Ergasilus yaluzangbus,sp.nov.Holotype,no.80820,Paratypes 10,no.80821.Hosts:Gymnocypris(Oxygymnocypris)stewartii,Schizopygopsis stoliczkai,Tetrostichodon o’connori.Distribution:Xigaze county(Nianchu River)and Nyingchi county(Niyong River),Xizang.Measurements(mm):Total length 1.36-1.55;cephalothorax 0.78-0.80,its width 0.46-0.53;genital segment 0.13-0.15,its width 0.15-0.17;caudal rami 0.046-0.058;egg sac 1.0-1.18,5th leg 0.057-0.066.Diagnosis:The new species resembles E.amblycephalus Kuang,but differs from the latter in having a conic process on the edge of coxopod between exopod and endopod of leg 1 to 4,in the arrangement of spines and setae of leg 1 and leg 3 and in the number and position of cub-like sencilla at 1st antenna.Ergasilus xinjiangensis,sp.nov.Holotype,no.80822,Paratypes 6,no.80823.Host:Schizothorax(Schizopyge)argentatus.Distribution:Shuiding,Huocheng county,Xinjiang.Measurements(mm):Total length 0.89-0.98;cephalothorax 0.58-0.65,its width 0.51-0.61;genital segment 0.087-0.094,its width 0.131-0.145;egg sac 1.24-1.33.Diagnosis:Allied to E.argulus Cressey,the new species is distinguished from it by the following characters(1)the 3-segmented endopod of leg 1 as against 2-segmented in E.argulus,(2)the arrangement of spines and setae on legs,(3)the shape and series number of spinules on the genital and abdominal segments,(4)the egg sacs being much larger 1.24-1.33 mm in length than that of E.argulus being 0.4 mm only.