【作者】 熊正；

【导师】 林荣澄；

【作者基本信息】 厦门大学 ， 水生生物学， 2008， 硕士

【摘要】 观赏水族界流传着一句名言:“始于孔雀,精于七彩,终于孔雀。”由此可知孔雀鱼的魅力远远胜过任何种类鱼。孔雀鱼作为一种商品化的观赏鱼,与雌鱼比较,雄鱼拥有更加艳丽的颜色和优美的体型,所以雄鱼更加畅销,并且价格比雌鱼高出许多。如何提高雄鱼产量是生产养殖上迫切需要解决的问题。一般来说基因操作和激素处理是鱼类养殖中性别控制的主要方法。近年来,已有多位学者对孔雀鱼进行了外源激素的不同处理,并取得一定成果。但是激素处理需要技术熟练人员和昂贵的开支,并且容易导致内分泌紊乱。所以急需寻找一种更加温和,廉价,操作方便且持久的新方法来取代传统的方法。本文通过活体解剖证明孔雀鱼成鱼的性腺类型与其第二性征呈一一对应的关系。通过对孔雀鱼仔鱼的胚胎发育和胚后发育的温度单因子实验证明,温度对孔雀鱼仔鱼的性腺发育方向确实有很大的影响,并且影响期主要是在胚后发育阶段,仔鱼的雄性比例与温度成明显的正相关,R~2=0.968。随着温度的升高,雄性比例明显上升,雄鱼的平均比例在温度19℃、21℃、23℃、25℃、29℃、32℃、35℃分别为21.58%、23.44%、33.89%、51.38%、64.07%、75.87%、77.36%。在25℃下培养的仔鱼雌雄比例接近于1:1。虽然温度在孔雀鱼胚胎发育阶段对性别的发育方向影响不大,但是高温可以导致怀孕雌鱼和仔鱼胚胎的死亡,胚胎死亡率最高的出现在35℃温度下,为42.11%。为了进一步弄清楚孔雀鱼发育过程中性腺的变化情况,以及孔雀鱼性腺的结构及其发育过程,我们对其不同发育时期的性腺进行了显微和超显微结构观察,结果发现孔雀鱼的卵细胞的发育可分为6个时相。卵巢的发育除了相应的6个时期外,还根据胚胎在体内发育的特点,在第Ⅴ期后增加1个怀胎期,因此卵巢的发育共分为7个期。解剖发现孔雀鱼只有1个卵巢,卵巢的卵巢壁由体腔膜、白膜及生殖上皮组成。孔雀鱼的成熟卵子具多油球,油球分散排列于卵膜下面,卵黄颗粒液化,不可见。通过光镜观察孔雀鱼卵巢发育的组织切片表明,卵黄开始积累的区域并不是首先出现在细胞核或细胞膜周围,而是在细胞核与细胞膜的中间部位,并围绕细胞核呈环状分布,然后才逐渐往细胞核和细胞膜两边扩散。根据孔雀鱼精巢内生殖细胞的分布和发育特点,初步判定其精巢类型应为泄苄汀？兹赣愕木卜⒂嘈臀中⒂?成熟精巢包含精原细胞、初级精母细胞、次级精母细胞、精子细胞、成熟精子在内的所有类型生殖细胞。根据精巢形态、组织学分期和精子的发生过程,我们将孔雀鱼精巢的发育分为5个时期。孔雀鱼成熟精巢的基本单位为精小囊,精小囊由支持细胞包裹生殖细胞而成。精小囊在后期发育成卵胎生鱼类精巢中特有的结构——精包,成熟精子以精包为单位由输精管排出体外。本文对孔雀鱼的精包结构进行了扫描电镜和透射电镜观察,发现其形状和外观很像蚕茧,其外由薄膜包裹,成熟的精子在其中呈放射状排列,头部朝外,尾部朝内。精子头部无顶体,形状似饼状,与其他许多鱼类的圆球形头部有所区别。结合以上的研究和养殖经验,经过一年的试验摸索出一整套的高档孔雀鱼养殖模式,不但适用于小规模的家庭化养殖,亦适用于扩大化的工厂化养殖,有利于下岗职工和渔业转产人员的过渡性产业调整。更多还原

【Abstract】 The guppy Poecilia reticulata is a popular aquarium species, with the male commending much higher price due to its long and colorful tail. In this study, we tested the feasibility of producing higher proportions of male fish by increasing rearing temperature. When the fry produced from the female broodstock that gave birth a week prior (the females can use stored sperm to fertilize the eggs) and cultured under 19, 21, 23, 25, 29, 32 and 35℃, respectively, % male of the fry produced increased from 21.58 to 77.36% with increasing temperature. Although the death rate was higher at the two highest temperature levels (32 and 35℃). On the other hand, when the fry produced from the female broodstock that were about to give birth and subjected to the same temperature treatments as above, % male of the fry produced was similar (48.57 to 53.78%) among the temperature treatments, confirming that thermal treatment must begin at an early development stage to influence the sex change in the species.To further clarify the changes of guppy gonads’ development, and the structure of guppy gonads, we observed the microscopic and ultra-microstructure of different stages of their gonads, found that the oocyte can be divided into six phases. In addition to the development of ovarian the corresponding period of six, also in accordance with the development of embryos, add a gravid period after the V period, so the development of ovary divided into seven period. Anatomizing found there is only one ovary in guppy’s, surface of the ovary was composed of the film, body cavity wall and reproductive epithelium. the mature oocyte with much oil sphere, oil sphere dispersed below the egg membrane, yolk particles liquefied, invisible. Microscopic observation of the guppy ovarian showed that the accumulation of yolk is not first began in the region which surrounding of the membrane or the nucleus, but in the middle part of the cell membrane and the nucleus, and arounding for a ring, and then gradually dispersed to both sides of the nucleus and the of cell membrane.According to the characteristics of guppy’s germ cells in the testes, confirming their testes are tubular type. Guppy mature testis was composed of Spermatogonium, Primary spermatocyte, Secondary spermatocyte, Spermatid and Sperm.The basic unit of the guppy was Spermato-genic cyst. Spermato-genic cyst developing into the unique structure of Livebears fish- Spermatophore, mature sperm expeled from the testis in this structure. We observed the spermatophore ultra-structure with scanning electron microscopy and transmission electron microscopy, found their shape and appearance much like Cocoon, wrapped film, in which mature sperm are arranged in actinomorphy.Colligating the above research and breeding experience, after a year study we worked out a set of high-grade guppy breeding system, applies not only to the families of small-scale aquaculture, also apply to the expansion of factory farming, help the transition of industrial restructuring of fisheries and laid-off workers.更多还原