Do earthworms grow by adding segments?
Do earthworms grow by adding segments?
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DOI：
10.1086/280345
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发表时间：
1931-01-01
影响因子：
2.9
通讯作者：
Pratt, KC
中科院分区：
文献类型：
--
作者：
Sun, KK;Pratt, KC
对Helodrilus foetidus在不同发育阶段（出茧、无阴蒂的蠕虫和成熟蠕虫）的物种特征、节数和蠕虫长度的研究表明，没有证据表明出茧后继续分节。中期和成熟期的节段数量平均值之间没有统计学显著差异，但长度增加了34.5%。有统计学意义的差异（D。M.- r-P. E.氏盐M.= 7.06），但节数仅增加5.54%，体长增加78.62%。由于新孵化的蠕虫的节数的范围大于在后期阶段（一些新孵化的蠕虫有更多的节比任何成熟的蠕虫），它似乎可能是在成熟的节数是由选择性的环境因素，而不是继续分割。
Studies of species characteristics, number of segments and length of worm, of Helodrilus foetidus at different developmental stages (emergence from cocoon, worms without clitella and mature worms) present no evidence of continued segmentation after leaving the cocoon. There is no statistically significant difference between the means for number of segments of the intermediate and mature stages but there is a 34.5% increase in length. There is a statistically significant difference (D. of M.-r-P. E. of D. of M.=7.06) between the means for number of segments in newly hatched and intermediate stages but the increase in segments is only 5.54% whereas the increase in body length is 78.62%. Since the range in segment number of newly hatched worms is greater than in later stages (some newly hatched worms have more segments than any mature worms) it seems probable that segment number at maturity is determined by selective environmental factors rather than continued segmentation.