【作者】 李志国；

【导师】 富惠光；

【作者基本信息】 河北农业大学 ， 水产养殖， 2010， 硕士

【摘要】 本文作者对秦皇岛水域栖息的青鳉进行了为期四年的观察研究,作者详细调查了该湿地的生态环境,总结了秦皇岛水域青鳉生存的环境特点。同时进行了不同盐度条件下青鳉的部分繁殖生物学指标研究,重点研究了不同盐度下青鳉存活情况、性行为表现、卵的受精率、受精卵的孵化率及初孵仔鱼畸形率,并同步测量了受精卵的卵径及初孵仔鱼的全长。通过对不同盐度条件下青鳉的部分繁殖生物学指标研究,我们初步得出了适宜青鳉繁殖的盐度范围。为我国的青鳉保护工作提供一定的理论支持。对秦皇岛水域栖息的青鳉的生态学研究发现：水域西面村庄流出的污水增加了该湿地开阔水域的营养水平,但在香蒲和芦苇地带营养水平却是降低的。香蒲和芦苇地带的浮游动物比开阔水域更少。由笼网捕获的样品显示,青鳉在香蒲和芦苇地带数量很大,鲫鱼、麦穗鱼及泥鳅则占据湿地的开阔水域。该水域还发现少量的圆尾斗鱼(中国圆尾斗鱼),另外,在所有采样点中,仅在水厂通往湿地的渠道内发现有日本沼虾的存在。室内水族试验表明：野生青鳉与家养鱼类相似,很容易用商业饲料来饲养。作者用该湿地捕获的野生青鳉为材料,对野生青鳉在淡水(0‰)、5‰、15‰、20‰、纯海水(30‰左右)等盐度下的繁殖生物学进行了一系列研究。结果表明：青鳉在各盐度下均能正常存活,试验期间各盐度组亲鱼的死亡率不大,且大部份是在暂养期间由于网伤发生死亡；5‰盐度组的亲鱼性行为出现最早；随着盐度的升高,性行为现象越加明显,但海水中(3‰)亲鱼的性行为却没有其它组表现明显。在试验期内,15‰组总产卵量最多,其次是5‰、20‰、海水(30‰)、淡水(0‰),淡水中亲鱼产卵量明显少于其它盐度组；在受精率方面：5‰盐度组受精率最高,为76.34%,其次为：淡水(0‰)、15‰、20‰及海水(30‰)盐度组,分别为60.91%、51.97%、41.06%及17.45‰。卵径长度：各组之间没有明显差异(P>0.05),各组卵径平均长度从大到小分别为：1.0124mm(淡水0‰)、0.9932mm(海水30‰)、0.9904mm(20‰)、0.9742mm(15‰)、0.9712mm(5‰)；孵化率方面：5‰盐度组孵化率最高,为73.80%,其次为15‰、淡水、20‰盐度组,分别为70.78%、42.50%及17.19%,而海水组(30‰)仅有2条鱼苗孵出,孵化率为0.67%,多数胚胎在发育到心跳期并可见明显的血液循环时,陆续发生死亡；初孵仔鱼畸形率方面：除海水(30‰)组外,20‰盐度组最高,为5.51%,其次为15‰、5‰盐度组,分别为：0.80%和0.60%。初孵仔鱼全长：除海水(30‰)组外,5‰及15‰与其它两个盐度组之间具有显著差异(p<0.05),各盐度组初孵仔鱼全长从大到小依次为3.1888mm(淡水)、3.1184mm(20‰)、2.9184mm(15‰)、2.8952mm(5‰)。综合以上结果：其他条件相似的情况下,适当的提高盐度对青鳉的繁殖有着十分明显的促进作用。通过本实验我们得出5-15‰是青鳉繁殖的适宜盐度。更多还原

【Abstract】 We researched medaka(Oryzias latipes) which habited in a marsh of Qin-huangdao,Hebei,China last four years.We surveyed ecological environment and got some environmental characters of medaka (Oryzias latipes) lived in the marsh. At the same time, We also researched a part of breeding biology of medaka within diverse sanity, which mainly include the brood survival rate; performance of sexual behavior; fertilization rate of egg; rate of hatchability of fertilized egg; deformity rate of fry; meanwhile We also measured the diameter of fertilized egg and the overall length of fry. By studying the part of breeding biology of medaka within different environmental sanity, we can get the proper range of sanity for medaka to breed. We hope to provide some theory’s support for medaka protection of our country. We founded by studying the ecology of medaka habited in a mash of Qinhuangdao that sewage release from a village increased nutrient levels in open water areas of the marsh, while in cattail (Typha angustifolia) and reed (Phragmites communis) beds the nutrient levels were decreased. Zooplanktons were fewer in the cattail and reed beds compared with that in open water areas. Sampling of fishes with trap nets showed that medaka (Oryzias latipes) lived in dense populations in the cattail and reed beds, while the other three fish species, wild goldfish (Carassius auratus), topmouth gudgeon (Pseudorasbora parva), and mud loach (Misgurnus bipartitus), occuppied the open water areas in the marsh. A little amount of paradise fish (Macropodus chinensis) was also found in the marsh. Japanese freshwater shrimps (Macrobrachium nipponense) were found only in the influx canal from waterworks. Indoor aquarium experiments showed that wild medaka in this marsh was easily cultured with commercial feed similar to domesticated strain.The author use the medaka captured in the marsh of Qinhuangdao as experimental material to study its part of breeding biology within different sanity included freshwater(0‰)、5‰、15‰、20‰、seawater. Results indicate that medaka can survive normally in all sanity. Brood death rate was 8% during experiment and without significant difference among all sanity group. Moreover, most of brood dead because of injure of net in the time of temporary foster. Sexual behavior of brood within 5‰sanity group was first came up. The performance of sexual behavior become more and more obvious with sanity increased. However, the performance sexual behavior of brood in seawater with 30‰is not more obvious than other groups. During experiment,the number of egg spawned of 15‰group is maximum and others is 5‰、20‰、seawater (30‰)、freshwater(0‰) group respectively. The number of egg spawned of freshwater group is minimum. The fertilization rate of egg of 5‰group is maximal with 76.34% and others is freshwater(0‰)、15‰、20‰、seawater (30‰) group with 60.91%、51.97%、41.06%及17.45‰respectively。The diameter of fertilized egg among all groups has not significant difference (P>0.05). The average diameter of fertilized egg all groups is 1.0124mm(freshwater 0‰)、0.9932mm(seawater 30‰)、0.9904mm(20‰)、0.9742mm(15‰)、0.9712mm(5‰) respectively from maximum to minimum. In the aspect of hatching rate, 5‰sanity group is highest about 73.80% and others are 15‰、freshwater and 20‰groups with 70.78%、42.50%及17.19%respectively. However, there are only two fry hatched in seawater group and hatching rate is only 0.67%. Most embryos happen to die gradually when they develop to the stage of heart beat and obvious blood cycle. In the aspect of deformity rate of fry,20‰group is highest about 5.51% and others are 15‰and 5‰groups with 0.80%和0.60% apart from seawater group. Apart from seawater group, the overall length of fry of 5‰and 15‰groups has not significant difference with the other two groups. The overall length of fry is 3.1888mm(freshwater)、3.1184mm(20‰)、2.9184mm(15‰)、2.8952mm(5‰) respectively from maximum to minimum. Include all the results, we can say that it is helpful for medaka to breed to improve the sanity at some tense, when other case are the same. We can get that 5-15‰is the ideal sanity range for medaka to breed by this experiment.更多还原