Vicentini R N, Araújo F G
Universidade Federal Rural do Rio de Janeiro, Brazil.
Braz J Biol. 2003 Nov;63(4):559-66. doi: 10.1590/s1519-69842003000400003. Epub 2004 Mar 15.
Sex ratio and size structure constitute basic information in assessing reproductive potential and estimating stock size in fish populations. One hundred fifty-one individuals of Micropogonias furnieri caught by experimental otter trawls, in three zones (inner, central, and outer) of Sepetiba Bay between October 1998 and September 1999 were examined. Males outnumbered females (1.3:1.0) in all zones but no significant differences were detected. Only in the outer zone (5.0:1.0) were male/female rates significantly different according to the chi-square test. No temporal differences were observed in sex ratio. Fish size ranged from 81 to 244 mm total length (TL) with significant differences in 155 to 185 mm TL size classes, where males predominated, and a slightly higher number of females were observed for the smaller size class (TL = 95-150 mm). Size distribution varied according to the zone, with juveniles predominating in the inner and adults in the outer zone. Spatial difference in size structure observed in this study indicates that the inner bay is a rearing ground during the first life-cycle period, and movement toward the sea occurs as fish increase in size.
性别比例和大小结构是评估鱼类种群繁殖潜力和估计种群数量的基本信息。对1998年10月至1999年9月间在塞佩蒂巴湾三个区域（内湾、中湾和外湾）通过实验性底拖网捕获的151尾福氏无鬚鲷个体进行了检查。所有区域雄性数量均多于雌性（1.3:1.0），但未检测到显著差异。根据卡方检验，仅在外湾（5.0:1.0）雌雄比例存在显著差异。在性别比例上未观察到时间差异。鱼的全长范围为81至244毫米，在155至185毫米的全长尺寸组中存在显著差异，该尺寸组中雄性占主导，而在较小尺寸组（全长=95 - 150毫米）中观察到雌性数量略多。大小分布因区域而异，内湾以幼鱼为主，外湾以成鱼为主。本研究中观察到的大小结构空间差异表明，内湾是鱼类第一个生命周期阶段的育幼场，随着鱼体长大，会向海洋移动。
