Spermatangia formation and sperm discharge in the Japanese pygmy squid Idiosepius paradoxus.
Spermatangia formation and sperm discharge in the Japanese pygmy squid Idiosepius paradoxus.
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日本侏儒乌贼 Idiosepius paradoxus 的精囊形成和精子排出。
DOI：
10.1016/j.zool.2014.02.001
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发表时间：
2014
期刊：
影响因子：
2
通讯作者：
T. Kasugai & H. Munehara.
中科院分区：
文献类型：
--
作者：
Sato;N.;T. Kasugai & H. Munehara.
在头足类动物中，精子排出不仅是精子转移的重要过程，而且影响附着的精管（外移的精囊）的精子储存能力。为了研究日本侏儒乌贼（Idiosepius paradoxus）精子从精囊中排出和精子自然附着的情况，我们(i)研究了精子囊和精囊的形态，以及体外获得的精子囊外露和精子从精囊中排出的过程；（ii）观察交配后6、12、18、24和48 h雌乌贼自然附着的精管，观察自然附着的精管随时间的变化。精子包囊i。似是而非的细长圆柱形，由精子团、水泥体和射精器组成，类似于脂质鱿鱼。精囊呈鱼钩状，其远端开放而狭窄。精囊形成后，精子团逐渐移动到精囊的开口端，从那里释放精子。精子排出是一个快速的过程，在精子开始释放后立即释放，但在5分钟内变为断断续续的精子释放。尽管自然附着在单个个体上的精囊中残余精子的体积不同，但随着时间的推移，精囊空化的可能性增加。大多数自然附着的精子在交配后24 h内排出了几乎所有的精子，而在交配后48 h没有精子附着在雌性精子上。这些结果表明，精子从精囊转移到精囊必须在24小时内发生，并且精囊在侏儒乌贼中起着短暂的精子储存器官的作用。
In cephalopods, sperm discharge is an important event not only for sperm transfer but also influencing sperm storage capacity of attached spermatangia (everted spermatophores). To investigate sperm discharge from spermatangia and the condition of naturally attached spermatangia in Japanese pygmy squid (Idiosepius paradoxus) we (i) investigated the morphology of spermatophores and spermatangia, and the process of spermatophore evagination and sperm discharge from spermatangia obtained in vitro; (ii) observed spermatangia that were naturally attached to female squids at 6, 12, 18, 24 and 48 h after copulation to investigate alterations in naturally attached spermatangia with time. The spermatophore ofI. paradoxusis slender and cylindrical and consists of a sperm mass, a cement body and an ejaculatory apparatus, which is similar to those of loliginid squids. The spermatangium is fishhook-shaped, its distal end being open and narrow. After the spermatangium is formed, the sperm mass gradually moves to the open end of the spermatangium, from where sperm are released. Sperm discharge is a rapid process immediately after the beginning of sperm release, but within 5 min changes to an intermittent release of sperm. Although the volume of residual spermatozoa differed among spermatangia that were naturally attached to a single individual, the probability that spermatangia would be empty increased with time. Most naturally attached spermatangia discharged almost all of their spermatozoa within 24 h after copulation, and no spermatangia were attached to females 48 h after copulation. These results suggest that sperm transfer from the spermatangium to the seminal receptacle must occur within 24 h, and that the spermatangium functions as a transient sperm storage organ in pygmy squids.