Nóh Quiñones Virginia Elena, Torres Villegas Julián René, Brulé Thierry, Montero Muñoz Jorge L, Valdez-Montiel Uriel Fernando
Rev Biol Trop. 2017 Mar;65(1):293-303. doi: 10.15517/rbt.v65i1.22995.
Studies of fish reproductive biology often involve quantitative estimates based on histological sections of the ovaries. Prior characterization of gonad oocyte distribution patterns in females is fundamental to these studies. Heterogeneous distribution requires a standardized sampling protocol to prevent bias in data such as fecundity estimations. In contrast, homogeneous distribution allows sampling of any portion of the gonads with no risk of bias. A preliminary study was done of gonad oocyte distribution mode in a hogfish Lachnolaimus maximus population in the southern Gulf of Mexico. A total of 23 sexually-active females were selected and classified by reproductive stage. Six histological sections were taken from the anterior, middle and posterior regions of the left and right ovary lobes of each individual. Digital image processing (AxioVision and Image ProPlus programs) was used to estimate oocyte density per unit area in different development stages. Contingency tables were used to analyze oocyte distribution frequencies between the regions of each lobe and between the lobes of each ovary. This was supported with a Pearson’s χ2 test for goodness-of-fit and a replicated G test to confirm distribution heterogeneity. Oocyte type distribution was homogeneous in almost all the females regardless of ovary region or lobe. This was particularly the case for females in the actively spawning reproductive subphase. Females in this subphase are normally used to estimate batch fecundity in fish species such as L. maximus, which have asynchronous oocyte development and batch spawning. However, heterogeneity was present in tertiary vitellogenesis oocytes in the right lobe of females in the spawning capable reproductive phase. In these cases, it is preferable to take histological sections from any region of the left ovary lobe to ensure unbiased estimation of fecundity and adequate characterization of this species’ sexual cycle.
鱼类生殖生物学研究通常涉及基于卵巢组织切片的定量估计。对雌性性腺卵母细胞分布模式进行前期特征描述是这些研究的基础。分布不均需要标准化的采样方案，以防止在诸如繁殖力估计等数据中出现偏差。相比之下，分布均匀则允许对性腺的任何部分进行采样而不存在偏差风险。对墨西哥湾南部的大西洋猪齿鱼种群的性腺卵母细胞分布模式进行了一项初步研究。总共挑选了23只性活跃的雌性，并按生殖阶段进行分类。从每个个体的左右卵巢叶的前部、中部和后部区域各取6个组织切片。使用数字图像处理（AxioVision和Image ProPlus程序）来估计不同发育阶段每单位面积的卵母细胞密度。列联表用于分析每个叶的不同区域之间以及每个卵巢的叶之间的卵母细胞分布频率。通过Pearson拟合优度χ2检验和重复G检验来支持这一分析，以确认分布的不均一性。几乎所有雌性的卵母细胞类型分布都是均匀的，无论卵巢区域或叶如何。处于活跃产卵生殖亚阶段的雌性尤其如此。在诸如大西洋猪齿鱼这种具有卵母细胞异步发育和分批产卵的鱼类中，通常使用处于该亚阶段的雌性来估计分批繁殖力。然而，处于可产卵生殖阶段的雌性右叶中的三级卵黄发生期卵母细胞存在不均一性。在这些情况下，最好从左卵巢叶的任何区域获取组织切片，以确保对繁殖力进行无偏差估计，并充分描述该物种的性周期。
