Abstract

Age, growth and length-at-maturity of the red porgy Pagrus pagrus were studied off the southeastern coast of Brazil. A total of 798 otoliths from specimens sampled from the hook-and-line commercial landings between January and December 2017 were used. Age and growth were estimated by counting and measuring increments in sectioned sagitta otoliths, and length-at-maturity was estimated based on macroscopic gonadal analysis. The annual periodicity of opaque zones was validated by marginal increment analysis. Growth curves were estimated by fitting von Bertalanffy growth model to the observed length-at-age data. A single annulus was laid down in summer, from November to February, associated with coastal upwelling of the subtropical South Atlantic Central Water (14.9–18.0°C) and with the onset of reproductive activity. The maximum age observed was 11 years in females and 12 years in males. The parameters of the von Bertalanffy model were: males (L_∞ = 419.9 mm, k = 0.347 year⁻¹, t₀ = – 0.199), females (L_∞ = 503.8 mm, k = 0.253 year⁻¹, t₀ = – 0.154) and sexes combined (L_∞ = 461.0 mm, k = 0.290 year⁻¹, t₀ = – 0.260). The mean length and age at first maturity was estimated at 258 mm (2.5 years) for males and 274 mm (3.0 years) for females. For both sexes, maturity precedes size and age at which specimens are fully recruited to hook-and-line fisheries at age 4 (327 mm).

中文翻译：

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来自巴西东南部的红色红麻古草（Sparidae）的年龄，生长和成熟度

摘要

红海豚Pagrus pagrus的年龄，生长和成熟期在巴西东南沿海进行了研究。2017年1月至2017年12月期间，从钩钓商业登陆点取样的样本中总共使用了798耳石。通过计数和测量切面人耳耳石的增量来估计年龄和生长，并基于宏观的性腺分析来估计成熟时的长度。通过边际增量分析验证了不透明区域的年度周期性。通过将von Bertalanffy生长模型拟合到观察到的年龄长度数据来估算生长曲线。夏季（11月至2月）放置了一个环形空间，与亚热带南大西洋中央水域（14.9-18.0°C）的海岸上升以及生殖活动的开始有关。观察到的最大年龄是女性11岁，男性12岁。大号_∞ =419.9毫米，ķ =0.347年^-1，吨₀ = - 0.199），女性（大号_∞ =503.8毫米，ķ =0.253年^-1，吨₀ = - 0.154）和性别合并（大号_∞ =461.0毫米，k = 0.290 year ^-1，t ₀ = – 0.260）。男性的首次成熟平均长度和年龄估计为258毫米（2.5岁），女性为274毫米（3.0岁）。对于男女而言，成熟度要早于大小和年龄，在4岁（327毫米）时，将标本完全招募到钩钓渔业中。