Boca de Siri was a capoeirista from Santo Amaro da Purificação who trained alongside the legendary Besouro Mangangá in the early 20th century. His name, meaning "Crab's Mouth", was also later adopted as the name of a capoeira technique - a takedown where the practitioner grabs the cuffs of both legs of the opponent's pants.
According to Professor Leiteiro, Boca de Siri was among the companions of Besouro alongside Paulo Barroquinha, Noca de Jacó, Doze Homens, and Canário Pardo. All were residents of Trapiche de Baixo - described as "the poorest neighborhood of Santo Amaro" - and "were his companions in the memorable capoeira rodas that hypnotized anybody who would go by".
These Sunday gatherings in Trapiche de Baixo and at folk parties were where the young Besouro first made a name for himself. The group formed what some sources call a "gang of capoeira resistance fighters" who trained together during an era when capoeira was still criminalized under the 1890 penal code.
Nothing else is recorded about Boca de Siri - not his full name, his fate, or his individual deeds. Like many of his contemporaries, he exists in history only as a name in the oral tradition, one of the circle of practitioners who helped shape the legendary era of Bahian capoeira in Santo Amaro.