Sperm whales live in culture-based multilevel societies in which the fundamental social level is the nearly permanent social unit of females and immature individuals, and the largest level is the clan constituted by social units that share a common coda repertoire. This study describes the coda repertoire and vocal clans of sperm whales in Brazilian waters recorded between 2011 and 2016. Inter-click intervals of codas were used to quantify similarity between repertoires. The analysis showed two evident clans, in the north and the south, distinct in their repertoires. The clan of the north, termed the “5R” clan, presented a predominant production of codas containing five regularly spaced clicks, not found in the clan of the south, termed “D” clan, which repertoire was dominated by long codas with 10–13 clicks with descending inter-click intervals. Codas with five regularly spaced clicks with the same rhythm and tempo as those found in the “5R” clan of Brazil are also predominant in sperm whales recorded in the Island of Dominica, at a distance of approximately 2700 km from the north of Brazil, which corresponds to the extension of the areas of sympatric clans. The sharing of 5R type by the both distinct clans is likely the result of cultural transmission in which conformism through social learning homogenizes coda repertoire. The results of this study corroborated the hypothesis that social boundaries, here the clan level, are maintained by cultural identities.

抹香鲸生活在以文化为基础的多层次社会中，其中基本社会层次是雌性和未成熟个体的几乎永久的社会单位，最大层次是由拥有共同的尾声库的社会单位组成的氏族。这项研究描述了2011年至2016年之间在巴西水域中录制的抹香鲸的声母曲目和声乐氏族。使用声母的点击间隔来量化曲目之间的相似性。分析表明，在北部和南部有两个明显的氏族，它们的谱系不同。北部氏族称为“ 5R”氏族，主要生产包含五个规则间隔的click嗒声的鳕鱼，在南部氏族中找不到，称为“ D”氏族，其曲目全部由长尾鳕鱼组成，其中10-点击间隔为递减的13次点击。在巴西多米尼加岛上记录的抹香鲸中，距巴西北部约2700公里的地方，抹香鲸中也有5条规则间隔的咔哒声，它们的节奏和节奏与巴西的“ 5R”氏族相同。对应于同族氏族领域的扩展。两个不同氏族共享5R类型可能是文化传播的结果，在这种文化传播中，通过社会学习进行的顺应性使尾声库变得同质。这项研究的结果证实了这样的假说，即社会边界（这里是氏族）是由文化身份来维持的。距巴西北部约2700公里，相当于同族氏族地区的扩大。两个不同氏族共享5R类型可能是文化传播的结果，在这种文化传播中，通过社会学习进行的顺应性使尾声库变得同质。这项研究的结果证实了这样的假说，即社会边界（这里是氏族）是由文化身份来维持的。距巴西北部约2700公里，相当于同族氏族地区的扩大。两个不同氏族共享5R类型可能是文化传播的结果，在这种文化传播中，通过社会学习进行的顺应性使尾声库变得均匀。这项研究的结果证实了这样的假说，即社会边界（这里是氏族）是由文化身份来维持的。