There are limited data regarding the reproductive biology of the scalloped hammerhead (Sphyrna lewini) in Ecuadorian waters, which limits the development of appropriate management measures of its populations. A total of 1664 S. lewini specimens were recorded in Manta, Ecuador in 2003–2009. Specimens were caught by local commercial fisheries and measured between 50–310 cm total length (TL). Females were more frequently caught, with a sex ratio of 1M:1.8F. The median size at maturity was 178.1 cm TL for males and 219.4 cm TL for females, which was larger compared with other localities. Gravid females, which measured 246–298 cm TL, contained 16–22 embryos. Embryos, which were observed from October–July, measured between 11.1–54.6 cm TL and the available data agreed with a gestation period of 10–11 months that starts in September and ends in June/July. Size at birth was 47–55 cm TL. Sampling data indicated that most fishing activity occurred in nearshore and around seamounts in the central-eastern Pacific Ocean, with much of the landed catch comprising immature individuals. This study documents the reproductive biology of S. lewini in the central-eastern Pacific Ocean and provides additional information to improve management and conservation measures for this species.

中文翻译：

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太平洋中东部扇贝双髻 (Sphyrna lewini) 的生殖生物学

关于扇形锤头鲨的生殖生物学的数据有限（石斑鱼) 在厄瓜多尔水域，这限制了对其人口的适当管理措施的发展。共有 1664 个S. lewini2003-2009 年在厄瓜多尔曼塔记录了标本。标本由当地商业渔业捕获，总长度（TL）在 50-310 厘米之间。女性更常被抓到，性别比为 1M:1.8F。成熟时的中位大小为雄性 178.1 cm TL，雌性 219.4 cm TL，与其他地区相比较大。怀孕的雌性，测量 246-298 厘米 TL，包含 16-22 个胚胎。从 10 月到 7 月观察到的胚胎测量长度在 11.1 到 54.6 厘米之间，可用数据同意从 9 月开始到 6 月/7 月结束的 10 到 11 个月的妊娠期。出生时的大小为 47-55 厘米 TL。抽样数据表明，大多数捕捞活动发生在太平洋中东部的近岸和海山周围，大部分上岸渔获包括未成熟个体。S. lewini在太平洋中东部地区，并提供更多信息以改进对该物种的管理和保护措施。