Abstract：
Macrobrachium amazonicum is a species of economic interest with a wide distribution in the Americas and high morphological and reproductive variability. Three phenotypes can be observed in this species: i) large-size amphidromous, ii) large-size and iii) small-size hololimnetic prawns. In the present work, the morphological, histochemical and ultrastructural aspects of ovarian development in the three phenotypes were comparatively analyzed. In addition, the interaction between the ovary and the hepatopancreas was investigated in these phenotypes through the use of gonadosomatic (GSI) and hepatosomatic (HSI) indices. Despite the morphological differences and different reproductive strategies adopted by the females, the macroscopic, histochemical and ultrastructural patterns of ovarian development showed no differences between the phenotypes. The ovaries were macroscopically classified into five stages of development (I to V). In early stages (I and II), the ovaries are full of oogonia, previtellogenic oocytes and oocytes in primary or endogenous vitellogenesis. At these stages, the rough endoplasmic reticulum (RER) produces a granular electron-dense material and sends it to the Golgi apparatus, where it will be modified, compacted and transformed into immature yolk granules. From stage III, secondary or exogenous vitellogenesis begins (with no interruption of endogenous vitellogenesis), where follicular cells nourish the oocytes and extracellular material is absorbed by endocytic vesicles, which fuse with immature yolk granules (forming mature granules) or with existing mature yolk granules. In stages IV and V, secondary vitellogenesis continues and mature yolk granules progressively occupy the cytoplasm. In M. amazonicum, the patterns of increase in oocyte diameter are quite similar between phenotypes, being greater in the small-size phenotype. This is related to the formation of larger oocytes/eggs and the production of large lipid reserves for their larvae. Changes in GSI and HSI during ovarian development show strong similarity between phenotypes, supporting the results obtained by histology and ultrastructure. Females in stages III and IV mobilize hepatopancreas reserves for ovarian maturation, which justifies the higher HSI values recorded in these stages. On the other hand, females in stage V show higher GSI and lower HSI values, indicating a mobilization of resources for the end of ovarian development as the females are ready to spawn.
摘要：
亚马逊沼虾是一种具有经济利益的物种，在美洲分布广泛，形态和生殖变异性高。在该物种中可以观察到三种表型：i）大型两栖动物，ii）大尺寸和iii）小尺寸的全息对虾。在目前的工作中,形态学,比较分析了三种表型中卵巢发育的组织化学和超微结构方面。此外,通过使用促性腺激素（GSI）和肝细胞（HSI）指数研究了这些表型中卵巢与肝胰腺之间的相互作用。尽管雌性动物的形态差异和生殖策略不同，宏观的，卵巢发育的组织化学和超微结构模式显示表型之间没有差异。卵巢从宏观上分为五个发育阶段（I至V）。在早期阶段（I和II），卵巢充满了卵骨，前卵黄形成的卵母细胞和初级或内源性卵黄形成的卵母细胞。在这些阶段,粗糙内质网（RER）产生颗粒状的电子致密物质，并将其发送到高尔基体，它将被修改，压实并转化为未成熟的卵黄颗粒。从第三阶段开始，次生或外源性卵黄发生开始（内源性卵黄发生没有中断），卵泡细胞滋养卵母细胞，胞外物质被内吞囊泡吸收，与未成熟卵黄颗粒（形成成熟颗粒）或现有成熟卵黄颗粒融合。在第四阶段和第五阶段，次生卵黄发生仍在继续，成熟的卵黄颗粒逐渐占据细胞质。在亚马逊M.表型之间卵母细胞直径增加的模式非常相似，在小尺寸表型中更大。这与较大的卵母细胞/卵的形成以及其幼虫的大量脂质储备的产生有关。卵巢发育过程中GSI和HSI的变化显示表型之间有很强的相似性，支持通过组织学和超微结构获得的结果。处于III期和IV期的女性动员肝胰腺储备用于卵巢成熟，这证明了在这些阶段记录的较高HSI值是合理的。另一方面,处于V期的女性表现出较高的GSI和较低的HSI值，表明当雌性准备产卵时，为卵巢发育的结束动员了资源。
