【摘要】 <正> R.W.Kiser氏于1948年首先发表了奇异尖额溞(Alona eximia),但他仅描述了该种的雌体。至于该种的雄性,一直是不清楚的。1962年秋,作者等于江西省瑞洪镇鄱阳湖采到奇异尖额溞时,首先发现该种的雄性,后于广东肇庆七星岩采集的样品中亦有见到。更多还原

【Abstract】 In 1948, R. W. Kiser described the female of the new chydorid, Alona eximia,from the Pearl River in Canton, China, and Green (1962) found also the female of thesame species from the River Sokoto in England. The male of this species has hereto-fore remained unknown. Since the last autumn, several specimens of the undescribedmale have been observed from the material collected by the authors from Po-Yang Hu,Kiangsi Province, and also from Qi-Xing-Yan, Shiu-hing, Kwangtung Province. It maybe described as follows. Body (Fig. 1) comparatively smaller than that of the female, measuring 0.34-0.37 mm in length, being about 80% of the body length of the female. Shell rectangu-lar in form, translucent, yellowish in colour and longitudinally striated. Dorsal marginof the shell evenly arched and the ventral setose throughout. Length of the posteriormargin more than one half the length of the shell. Rostrum very short and blunt. An-tennules short and thick, reaching almost to the tip of the rostrum. One of the olfac-tory setae very long, being about twice as long as the others. Two sensory setae op-positely located at distal one-third of the antennules. Both dorsal and ventral rami ofthe antennae 3-segmented; formula of the setae: 0-1-3/0-0-3. Intestine convoluted. Thefirst pair of thoracic legs each bearing a hook-like appendage. Post-abdomen (Fig. 2) shortand broad, with the dorsal margin convex at the middle region and bearing about 8clusters of minute fascicles on the lateral side, but without any anal spinules on the freemargin. In order to show diagnostic distinctions between Alona eximia Kiser, A. intermediaG. O. Sars and A. rectangula G. O. Sars, a comparison is made of the male post-abdo-men of the three closely allied species (Table 1, Figs. 2-4).更多还原