Data from: Bone-eating Osedax females and their 'harems' of dwarf males are recruited from a common larval pool

Extreme male dwarfism occurs in Osedax (Annelida: Siboglinidae), marine worms with sessile females that bore into submerged bones. Osedax are hypothesized to use environmental sex-determination (ESD), in which undifferentiated larvae that settle on bones develop as females, and subsequent larvae that settle on females transform into dwarf males. This study addresses several hypotheses regarding possible recruitment sources for the males: (1) common larval pool — males and females are sampled from a common pool of larvae; (2) neighborhood — males are supplied by a limited number of neighboring females; and (3) arrhenotoky — males are primarily the sons of host females. Osedax rubiplumus were sampled from submerged whalebones located at 1820 and 2893 m depths in Monterey Bay, California. Immature females typically did not host males, but mature females maintained male "harems" that grew exponentially in the number of males as female size increased. Allozyme analysis of the females revealed binomial proportions of nuclear genotypes, an indication of random sexual mating. Analysis of mitochondrial DNA sequences from the male harems and their host females allowed us to reject the arrhenotoky and neighborhood hypotheses for male recruitment. No significant partitioning of mitochondrial diversity existed between the male and female sexes, or between subsamples of worms collected at different depths or during different years (2002–2007). Mitochondrial sequence diversity was very high in these worms, suggesting that as many as 106 females contributed to a common larval pool from which the two sexes were randomly drawn.极端雄性矮化现象存在于骨虫属（Osedax，环节动物门：须腕动物科）中，这类海洋蠕虫的雌性个体营固着生活，可钻孔侵入沉没骨骼内。现有假说认为骨虫采用环境性别决定（environmental sex-determination, ESD）机制：未分化的幼虫沉降至骨骼表面后发育为雌性，而后续沉降至雌性个体上的幼虫则会特化为矮化雄性。 本研究针对雄性的潜在招募来源提出三项假说：（1）共同幼虫池假说：雌雄个体均采自同一幼虫种群；（2）邻域假说：雄性仅由有限数量的邻近雌性供应；（3）产雄孤雌生殖（arrhenotoky）假说：雄性主要为宿主雌性的子代。 研究团队于美国加利福尼亚州蒙特雷湾1820米与2893米水深的沉没鲸骨中采集了红羽骨虫（Osedax rubiplumus）。未成熟雌性通常不携带雄性，而成熟雌性则会维持雄性“后宫群体”，且雄性数量随雌性体型增大呈指数增长。 对雌性个体的同工酶分析（allozyme analysis）显示，其核基因型符合二项分布比例，表明存在随机有性交配行为。通过对雄性后宫群体及其宿主雌性的线粒体DNA序列（mitochondrial DNA sequences）进行分析，我们否决了产雄孤雌生殖与邻域这两项雄性招募假说。 雄性与雌性个体间的线粒体多样性无显著分化，不同水深或不同年份（2002—2007年）采集的蠕虫亚样本间亦无显著分化。该类蠕虫的线粒体序列多样性极高，表明多达106头雌性个体共同构成了一个共享的幼虫池，两性个体均从该池中随机招募而来。