A novel two-step procedure for mass production of all-male populations of the giant freshwater prawn Macrobrachium rosenbergii
A novel two-step procedure for mass production of all-male populations of the giant freshwater prawn Macrobrachium rosenbergii
复制标题
DOI：
10.1016/j.aquaculture.2006.01.035
复制
发表时间：
2006-06-15
期刊：
影响因子：
4.5
通讯作者：
Sagi, A.
中科院分区：
文献类型：
--
作者：
Aflalo, E. D.;Hoang, T. T. T.;Sagi, A.
罗氏沼虾的雄性在收获时比雌性生长得更快，达到更高的体重，这一事实使得全雄性种群的养殖是可取的。所有的雄性种群都是通过交配性别反转的雄性产生的，即，新生女性和正常男性通过去除不成熟的M rosenbernitus雄性的雄腺（AG），产生能够交配和产卵的新雌体。开发基于这种操纵的技术的主要障碍是难以在足够早的发育阶段识别雄性。为了克服这个问题，我们开发了一种新的大规模显微手术雄腺切除术的两步计划。Ⅰ期后期幼虫在变态后25-60日龄（PL 25 -60）进行分离。获得的功能性性逆转的成功率较低（1.3%），导致所有雄性后代。鉴于成功率低和许多生殖发育异常的病例，引入了第二阶段，其中第一阶段的新雌性动物的后代（假定为雄性）在更早的年龄（PL 20 -30）被分离。这两个阶段的协议，使大量的少年男性被切除。在第二阶段，性反转动物（卵巢发育）的数量显著增加，成熟时间显著缩短。全雄群体与正常混合群体的比较表明，全雄群体的生长性能更高。这一优点与阶段H中较短的成熟时间一起打开了将系统按比例放大到现场条件的可能性。由于性二型生长模式在十足目甲壳动物中普遍存在，因此本研究结果对许多养殖物种具有应用意义。(c)2006 Elsevier B. V.保留所有权利。
Males of the giant freshwater prawn Macrobrachium rosenbergii grow faster and reach higher weights at harvest than females a fact which makes the culture of all-male populations desirable. All-male populations were produced by mating sex-reversed males, i.e., neofemales, with normal males. Neofemales capable of mating and spawning were produced by removal of the androgenic gland (AG) from immature M rosenbergii males. The main obstacle to developing a technology based on this type of manipulation is the difficulty of identifying males at a sufficiently early stage of development. To overcome this problem, we developed a novel two-step scheme for large-scale microsurgical andrectomy. Phase I post larvae were andrectornized at ages 25-60 days after metamorphosis (PL25-60). A low success rate of functional sex reversal, resulting with all male progeny was obtained (1.3%). In the light of the low success rate and a number of cases of abnormal reproductive development, a second phase was introduced in which the progeny (presumed males) of neofemales from phase I were andrectornized at earlier ages (PL20-30). This two-phase protocol enabled a large quantity of juvenile males to be andrectomized. In phase II there was a significant increase in the number of sex-reversed animals (developed ovaries) and a significant shortening of the time to maturation. Comparison of the all-male progeny with a normal mixed population showed higher growth performance of the all-male population. This advantage together with the shorter maturation time in phase H opens the possibility to scale-up the system to field conditions. Since sexual dimorphic growth patterns are common among decapod crustaceans, it is obvious that the results of this study will have applied significance for many aquacultured species. (c) 2006 Elsevier B.V. All rights reserved.