摘要
关于云南省的枝角类,迄今只有陆鼎恒(1939)、张玺与易伯鲁(1945)分别就该省中部的洱海和滇池所产者作过专文报导。此外,萧之的(1949)、黎尚豪等(1963)曾在中部的高原地带进行了湖泊调查,并记述了部分种类。至于该省南部热带地区的枝角类,尚无调查研究。
The present faunistic study of Cladocera is based upon the material collected fromHsi-Song-Pang-Na and vicinity, Yunnan Province, by the Institute of Zoology and theInstitute of Hydrobiology, Academia Sinica in 1957 and 1963 respectively. From thematerial, 36 species (listed in Table 1) have been identified, including two new species.Macrothrix brevicornis (Macrothricidae) and Kurzia yunnanensis (Chydoridae) and twonew records (Daphniidae) from China, Daphnia lumholtzi Sars and Simocephalus acutiro-stratus (King). In the present paper, the diagnoses of the new species and some notes on the newrecords and rare species are given. An attempt is also made to analyze the characteristicsof the fauna under investigation. Diagnoses of the Two New Species1. Macrothrix brevicornis, sp. nov. (Text figs. 20-23) Material examined: 4 ? ? (Cat. No. YN-570299), Menghai, March 17, 1957,water temp. 21.5℃, pH value 6.0. 2 ? ? (Cat. No. YN-570319), Szemao, May 3, 1957, water temp. 21.5℃, pH value7.2. 2 ? ? (Cat. No. YN-570309), Puwen, Apr. 28, 1957, water temp. 23.0℃, pHvalue 5.0. Holotype ? (Cat. No. YN-570299A), Menghai, while the remainder are paratypes,deposited in the Institute of Hydrobiology, Academia Sinica, Wuhan. Characters of female: Shell 0.58 (0.51-0.62) mm in length, longer than high,elliptical and transparent, marked with oblique fine striae. Crest on head and shell.Dorsal margin finely serrated from the sucking disk to the posterior dorsal angle, ventralborder finely and irregularly incised and provided anteriorly with 5--6 plumose setae ex-tending horizontally to both sides. Head broad, smoothly rounded on dorsum, with theventral border obliquely straight and serrated. Rostrum short and blunt. Labrum tongue-shaped and serrated along its median keel. First antenna very short, with rudimentaryolfactory setae distally. Second antenna with the swimming setae arranged as in theformula 0-0-1-3/1-1-3. Post-abdomen short, dorsal border with a series of postanal spinulesand about 8 anal spinules. Abdominal setae long and plumose distally. Terminal clawshort, without basal spine. Intestine curved but not convoluted. Brood pouch usuallycontaining 4-5 eggs. Comparison: It can be readily distinguished from the known species of the genusby having a pair of very short first antennae, which are provided each with a group of rudimental olfactory setae distally.2. Kurzia yunnanensis, sp. nov. (Text figs. 24-26) Material examined: Holotype ?, paratypes 4 ? ? (Cat. No. YN-630002), Yuen-chinghong, August 16, 1963, deposited in the Institute of Hydrobiology, Academia Sinica,Wuhan. Characters of female: Shell 0.42 (0.39-0.45) mm in length and spherical in formand transparent, resembling Alonella in general appearance. Shell as high as long, dorsalmargin strongly arched, with a distinct crest, posterior margin vertical and short, aboutone-half the height of the shell, ventral margin almost straight and scarcely setose, butbecoming spinulose towards the posterior ventral angle. Head small. Rostrum short.First antenna long, bearing a tactile seta on the anterior border and a cluster of longolfactory setae at the extremity. Second antenna with the swimming setae arranged asin the formula 1-1-3/0-0-3. Post-abdomen abruptly narrowed distally, with 13-15 pairs ofpreanal spinules along the dorsal margin and about 10 clusters of spinules on the lateralside. Terminal claw very long, the basal half spinulated and the distal half pectinated.Basal spine about one half as long as the terminal claw, bearing 4 long setae at the baseand a series of shorter ones at the distal. Intestine convoluted with a caecum near thedistal end. Brood pouch usually containing 2 eggs. Comparison: This new species closely resembles Kurzia latissima (Kurz), but dif-fers chiefly from the latter by the characters as shown in the following table: Discussion: Judging from the height of the shell, the presence of a crest on the dor-sum of the shell and the terminal claw being spinulated and pectinated along the innerborder, this species may be considered as a new member of the genus
