The present work describes the reproductive biology of the white marlin (Kajikia albida) caught in the southwestern and equatorial Atlantic Ocean. The gonads of 924 fish were collected by observers on board Brazilian tuna longliners, between November 2004 and December 2006. The spawning season was assessed by the monthly frequency distribution of distinct stages of maturity and monthly mean female gonadosomatic index GSI. Sixty-one percent (n = 656) of the fish examined were female, with a Lower Jaw Fork Length (LJFL) between 83 and 236 cm (mean = 155.5 ± 16.63). The 268 males had a LJFL between 90 and 220 cm (mean = 152.3 ± 34.62). Although the northeastern region of Brazil does not appear to be a significant spawning area for the species, the results suggest a higher reproductive activity in the third quarter of the year. Using a Bayesian logistic model approach, length at 50% maturity was estimated at 145.04 cm (credibility interval of 95%, 143.94–146.09 cm), for females, and at 140.03 cm (credibility interval of 95%, 137.28–142.52 cm), for males.

中文翻译：

---

西南和赤道大西洋白枪鱼（Kajikia albida）的生殖生物学

目前的工作描述了在西南和赤道大西洋捕获的白枪鱼（Kajikia  albida）的生殖生物学。2004 年 11 月至 2006 年 12 月期间，巴西金枪鱼延绳钓船上的观察员收集了 924 条鱼的性腺。产卵季节通过不同成熟阶段的月频率分布和月平均雌性性腺指数 GSI 进行评估。百分之六十一 ( n = 656) 检查的鱼是雌性，下颚叉长度 (LJFL) 介于 83 和 236 厘米之间（平均值 = 155.5 ± 16.63）。268 名男性的 LJFL 介于 90 到 220 厘米之间（平均值 = 152.3 ± 34.62）。尽管巴西东北部地区似乎不是该物种的重要产卵区，但结果表明，今年第三季度的繁殖活动更高。使用贝叶斯逻辑模型方法，估计女性在 50% 成熟度时的长度为 145.04 厘米（可信区间为 95%、143.94-146.09 厘米）和 140.03 厘米（可信区间为 95%、137.28-142.52 厘米）、对于男性。