Sampaio C M S, Silva R R, Santos J A, Sales S P
Laboratório de Carcinicultura, Centro de Ciências da Saúde, Universidade Estadual do Ceará, Fortaleza, CE 60740-903, Brazil.
Braz J Biol. 2007 Aug;67(3):551-9. doi: 10.1590/s1519-69842007000300022.
Macrobrachium amazonicum is considered a favorite Brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. The aim of this work is to describe the sexual cycle stages and determine maturation age of the female M. amazonicum, which was collected monthly from June, 2002 to May, 2003 in the Jaguaribe River, Itaiçaba, Ceará. A monthly sample of water was also collected to determine the following parameters: temperature, dissolved oxygen, pH and salinity. A monthly sample of females was selected among the individuals caught, to determine the total weight (W(T)), carapace length (L( C)) and abdomen+telson length (L(A+T)) and to register the number of non-ovigerous females (NOF) and ovigerous females (OF). Determining ovarian maturation stages of M. amazonicum was done in a laboratory by observing macroscopic characters such as coloring, size, location and appearance of ovarians examined by transparent carapace. The first maturation age was determined from the relative frequency of the total length (L(T)) of young and adult females. The environmental parameters of the Jaguaribe River did not hold any influence in the number of individuals collected. A total of 1,337 prawns were sampled, 513 males (38.4%) and 824 females (61.6%). The proportion between males and females in the studied population was of 1:1.6. Among the collected females, 492 (50.7%) did not carry eggs in their abdomens (NOF) and 332 (40.3%) carried eggs in their abdomens (OF). There was no record of intact females. Non-ovigerous females with mature ovaries were recorded throughout all the months of collection. The female ovaries were classified as immature (IM), rudimentary (RU), intermediary (IN) and mature (M). M. amazonicum females reach their first sexual maturity between 4.5 and 5.5 cm of total length.
由于亚马逊沼虾生长迅速且易于人工养殖，它被认为是巴西最受欢迎的淡水虾养殖品种。本研究旨在描述亚马逊沼虾的性周期阶段，并确定其雌虾的成熟年龄。研究对象为2002年6月至2003年5月每月从塞阿拉州伊塔伊萨巴的雅瓜里贝河采集的亚马逊沼虾。每月采集水样以测定以下参数：温度、溶解氧、pH值和盐度。从捕获的个体中每月选取雌虾样本，测定其总重量（W(T)）、头胸甲长度（L(C)）和腹节+尾节长度（L(A+T)），并记录未抱卵雌虾（NOF）和抱卵雌虾（OF）的数量。在实验室中，通过观察透明头胸甲下卵巢的颜色、大小、位置和外观等宏观特征来确定亚马逊沼虾的卵巢成熟阶段。根据幼虾和成虾雌虾的全长（L(T)）相对频率确定首次成熟年龄。雅瓜里贝河的环境参数对采集到的个体数量没有任何影响。总共采集了1337只虾，其中雄虾513只（38.4%），雌虾824只（61.6%）。研究种群中雌雄比例为1:1.6。在采集到的雌虾中，492只（50.7%）腹部未携带卵（NOF），332只（40.3%）腹部携带卵（OF）。没有完整雌虾的记录。在所有采集月份都记录到了卵巢成熟的未抱卵雌虾。雌虾卵巢分为未成熟（IM）、初级（RU）、中级（IN）和成熟（M）。亚马逊沼虾雌虾在全长4.5至5.5厘米之间达到首次性成熟。
