ON SYSTEMATICS AND ECOLOGY (LIFE-CYCLES, POPULATION DYNAMICS) OF TURBELLARIEN-GENUS PAROMALOSTOMUM . INVESTIGATIONS AT SANDY BEACH OF ISLAND SYLT

被引:21
作者
PAWLAK, R
机构
[1] II. Zoologisches Institut und Museum der Universität Göttingen, Göttingen
来源
HELGOLANDER WISSENSCHAFTLICHE MEERESUNTERSUCHUNGEN | 1969年 / 19卷 / 03期
关键词
D O I
10.1007/BF01611980
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
This paper contributes to the systematics, the ecology and the biology of sexual reproduction of psammobiontic macrostomid Turbellaria from a sandy beach on the eastern shore of the island Sylt. The anatomy of a new species, Paromalostomum proceracauda, is described. The cuticular structures of the genital apparatus of Paromalostomum fusculum Ax, P. dubium (de Beauchamp) and Haplopharynx rostratusMeixner are analyzed. P. fusculum is one of the most frequent turbellarians living in the sandy flats (Sandwatt) in front of the Litoralstation of the Biologische Anstalt Helgoland in List. This species shows obvious seasonal differences in it's vertical distribution. In summer, P. fusculum lives in the upper 4 cm of the sand while in winter, the animals move to the deeper strata of the sediment, were they are more protected from low temperatures. P. fusculum has an annual life-cycle. The period of reproduction lasts from May to July. The new generation hibernates in the state of male maturity and attains female maturity in spring. After the period of egg-shedding, large animals individuals are seldom found; it is supposed that they die after spawning. The mechanism of egg-shedding and the structure of the egg are described. The egg-shells of P. fusculum are distinguished from those of P. dubium by the presence of opercula. © 1969 Biologischen Anstalt Helgoland.
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页码:417 / &
相关论文
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