ABSTRACT

The genus Macrostomum (Platyhelminthes: Macrostomorpha) is a group of cosmopolitan free-living flatworms that occurs in a wide range of habitats. In our study, individuals of Macrostomum velastylum were collected from the Sagastume stream (33°38ʹ34ʺS; 58°49ʹ63ʺW) Entre Ríos Province, Argentina, during 2016. They were kept in laboratory at room temperature in order to study population parameters (1, fecundity; 2, hatching rate and hatching time; 3, male sexual maturation time; and 4, longevity). The results show that this species laid 1.5 eggs per day per individual, the hatching rate was 85% and most eggs hatched between the first and second week after laying. The maturation time showed an extensive range of time to reach sexual maturation. The average longevity was 96 ± 33 days. Considering the laboratory conditions and the scarce information on life cycles on Macrostomum species, these results are promising for future interspecific comparative studies.

摘要

Macrostomum属（扁形动物门：Macrostomorpha）是一群世界性的自由生活扁虫，出现在广泛的栖息地。在我们的研究中，Macrostomum velastylum的个体于 2016 年从阿根廷恩特雷里奥斯省的 Sagastume 溪流（33°38'34'S；58°49'63'W）收集。它们在室温下保存在实验室中，以研究种群参数（1，繁殖力；2，孵化率和孵化时间；3，男性性成熟时间；以及 4，寿命）。结果表明，该种个体每天产卵1.5个，孵化率为85%，大部分卵在产后第一周和第二周之间孵化。成熟时间表明达到性成熟的时间范围很广。平均寿命为 96 ± 33 天。考虑到实验室条件和关于Macrostomum物种生命周期的稀缺信息，这些结果对未来的种间比较研究很有希望。