不同形态型雄性罗氏沼虾的交配能力

Mating capacity of male Macrobrachium rosenbergii with different morphotypes

从行为生态学角度,对采自孟加拉国库尔纳专区羌纳县布苏尔河罗氏沼虾原产地池塘种群中3种不同形态型雄虾的繁殖行为及交配能力进行了初步研究.结果表明:社群中蓝螯型(BC)、橙螯型(OC)和小型(SM)雄性罗氏沼虾的交配行为模式没有明显的区别,但BC、OC和SM雄虾在交媾前守卫、交媾及精荚传递和交媾后守卫3个典型行为中投入的时间存在明显差异.BC雄虾交媾前守卫、交媾及精荚传递用时明显比OC、SM雄虾短,而交媾后守卫用时明显比OC、SM雄虾长.SM雄虾在交媾前守卫和精荚传递上投入的时间最长,而交媾后守卫用时最短.在雌虾体质量为雄虾体质量的80%,且♀∶♂为8∶1性比条件下,BC、OC和SM雄虾在120h内平均交媾次数分别为4.6、2.2、1.3,BC雄虾具有较强的连续交媾能力.罗氏沼虾的交配能力与其体质量相关,雄、雌虾的体质量相匹配才能保证成功交媾.否则会出现"假交"现象.

From the viewpoint of behavioral ecology,a pilot study was made on the mating capacity of male Macrobrachium rosenbergii with different morphotypes（blue claw,BC;orange claw,OC;runt or small male,SM） native to the Pusur River in Chalna County of Khulna Division,Bangladesh.No significant differences were observed in the mating behavioral modes among the male morphotypes,but the time invested in such typical mating behaviors as pre-/postcopulatory mate-guard and copulation/spermatophore transfer for BC,OC and SM had distinct difference.BC spent much less time than OC or SM on precopulatory guard（PG） and spermatophore transmission（ST）,but much more time on post-copulatory guard.SM spent the longest time on PG and ST,and the shortest time on postcopulatory guard.The average frequencies of successive copulation in 120 h were respectively 4.6,2.2,and 1.3 at the sex ratio of 8：1（♀：♂） in BC,OC and SM when the body mass of the females was 80 percent of the males.BC possessed much stronger capacity of successive copulation.The mating capacity of male M.rosenbergii was not only related to its own body mass,but also related to the body mass of female M.rosenbergii.Only when the males and females matched to some extent in their body mass,could the copulation be guaranteed in success.Otherwise,false copulation would occur.