Studies on the diversity and creative mechanism of the reproductive mode in copulating teleost fishes

本研究对蝎形目棉铃虫进行了生态学和生理学研究，重点研究了精巢的产卵方式和功能形态作为交配行为进化的外适应特征。组织学观察表明，作为母性照顾和交配的两种鱼类，是潜在的多产卵生物。在实验上，这些物种的雌性在一个繁殖季节只在孵化前将卵块从水族箱中取出时产卵两次，但都只在雌性成功保护第一个卵块直到孵化时产卵一次。这些结果表明，在发育过程中，当第一窝卵被吃掉时，第二窝卵是为了补偿卵。组织学观察表明，塔拉内兹黄鼠和达杰维尼黄鼠的交配期和精巢中的精子束系统不同。R.Tarane…Tzi的交配时间为1月至7月的6个月，而R.darjevini的交配时间为9月至7月的10个月。与前者相比，后者的睾丸重量相对较重，精子以精子束的形式储存得更紧密。此外，在阴茎尖端开口附近设有小腔，腔内有结缔组织包裹。这些形态差异可能导致大量精子排入雌性生殖道，导致精子竞争激烈(交配期长)。在精子发生过程中，一种非交配的半硬膜海鞘会产生大量的无核精子。应用荧光染料和微卫星DNA多态技术对无精子症精子功能进行了研究。研究表明，精子在运动鞋的精液竞争中起到了中介作用。此外，实验还表明无核精子具有抗弥散作用。过去的研究表明，交配的棉铃虫是多产卵的，而非交配的棉铃虫是单产卵的。多次产卵给交配个体带来了很大的好处，但对非交配鱼类却没有好处。目前的研究对Radulinopsis物种进行了调查，表明上述概念可能不适用于至少母体护理和交配的鱼类。较少

The present studies carried out a ecological and physiological examination on Scorpaeniformes cottoid species, with the focus of the spawning mode and functional morphology of testes as out-adaptive traits for evolution of copulating behavior.1. Histological observation for investigation of on ovarian annual cycle showed that Radulinopsis taranetzi and R. darjevini, maternal care and copulating fishes, are potential multi-spawners. Experimentally, females of these species spawn two times in a breeding season only when the egg masses was taken out of aquarium tank before hatching, but both spawned only one time when the females succeefully protected the first egg mass until hatching. These results suggested that the second clutch of these cottids is for compensatory eggs when the first clutch was eaten during developing.2. Histological observation on testes showed that copulating period and sperm strage system in testicular organ differed between R. taranetzi and R. darjevini. R. tarane … More tzi copulates for six months from January to July, while R. darjevini for ten months from September to July. In the latter fish, testis weight is relatively heavier and sperm is stored more compactly as sperm bunch than those of the former. In addition small chamber, which is enclosed with connective tissues, is provided near the opening of the tip of penis. It is plausible that these morphological differences function to emit much sperm into female genital tract for intensive sperm competion (long copulaing period).3. A non-copulating sculpin, Hemilepidotus gilberti, produce much apyrene spermatozoa with plural nuclei during spermatogenesis. The function of apyrene sperm were investigated with fluorescent dye and microsatellite DNA polymorphism. It was showed that the sperm played as a broker toward sneaker's eusperm for sperm-competition. In addition it is experimentally showed that apyrene spermatozoa have antidispersive function.4. The past studies indicated that copulating cottoids are multispawers while non-copulating cottoids are single spawner. Multi-spawning brought much benefit for copulating individuals but not benefitial for non-copulating fishes. The present study investigated for Radulinopsis species, showed that the above concept may not adaptive for at least maternal care and copulating fishes. Less