粗糙沼虾Macrobrachium asperulum是中国台湾重要食用淡水虾种之一, 其经济价值高, 具人工繁养殖潜力,但是目前关于粗糙沼虾繁殖生物学的研究相当有限。研究从组织学的角度出发,对粗糙沼虾卵巢发育与其繁殖周期进行初步的观察。分别于四季前往中国台湾苗栗县后龙溪采集沼虾, 在实验室进行抱卵率、体重、性腺重、性腺成熟指数(gonadosomatic index, GSI)测定及母虾卵巢组织切片制作。结果显示, 粗糙沼虾的GSI在春季最高, 冬季最低。母虾抱卵率则在春季逐渐攀升, 秋季到达巅峰(79.17％), 而冬季急速降低。根据母虾生殖细胞尺寸与外观形态、细胞核染色体分裂情况以及细胞质是否出现油滴或卵黄颗粒等特征, 大致将母虾生殖细胞分为卵原细胞、初级卵母细胞、次级卵母细胞和成熟卵母细胞等4类。根据卵巢各类生殖细胞所占之比例, 进一步将粗糙沼虾卵巢发育分为增殖期、卵黄生合成前期、内源性卵黄生合成期、外源性卵黄生合成期、成熟期和产卵期等6期。研究结果可望为粗糙沼虾进行人工繁殖提供重要参考依据。

Macrobrachium asperulum is one of the major freshwater prawn species consumed by residents in Taiwan, China, and therefore is potentially valuable for aquaculture. However, little is known about its reproductive biology. The objective of the present study was to provide a preliminary characterization of the histological structure of the ovary throughout the repro-ductive cycle. Adult M. asperulum was collected in the River Houlong in Miaoli County of Central Taiwan seasonally during December 2007 and September 2008, which represented four seasons of winter, spring, summer and autumn. After sexual de-termination, female M. asperulum was sampled and followed by recording of gravid rate, body weight, and ovarian weight, as well as by determination of gonadosomatic index (GSI) value. Gonadal tissue section was then immediately prepared for his-tological study. The results showed that the highest GSI value was observed in spring while the lowest in winter. The gravid rate of the female prawn reached a maximum of 79.17% in autumn and then dropped sharply in winter. In addition, our results of histological study revealed that the germ cells of M. asperulum could be classified into four different cell types, including oogonia, primary oocytes, secondary oocytes, and mature oocytes, based on differences of size and morphology of cell, chro-matin patterns, and the amounts of lipid droplet and yolk granule. Furthermore, according to the number and type of predomi-nant germ cells presented, the ovarian cycle could be clearly divided into six stages as follows: Stages I and II were prolifera-tive and previtellogenic stages; Stages III and IV were endogenous and exogenous vitellogenic stages; and Stages V and VI were mature and spawn stages.