【作者】 段晓伟；

【导师】 赵云龙；

【作者基本信息】 华东师范大学 ， 动物学， 2007， 硕士

【摘要】 本文应用生态学方法，初步研究了瘤背石磺的种群生态学；采用组织学和电镜方法，详细地研究了瘤背石磺生殖系统的发育；以及采用生物化学等方法，初步分析了生殖系统发育过程中各种营养因子的变化。主要研究结果如下：一、瘤背石磺种群生态学的研究于2005年9月至2006年9月，对上海市崇明岛堡镇北堡港(N31°38′23.4″，E121°41′02.2″)1000m长度范围内的瘤背石磺的种群数量、栖息环境、共栖生物、行为特征及生态因子对其生长和存活的影响进行了调查和研究。结果表明，瘤背石磺为雌雄同体、异体交配的软体动物，其生活史可分为胚胎(卵裂期、囊胚期、原肠期、卵内担轮幼虫、卵内面盘幼虫期)、浮游(开口期、大面盘幼虫期)和匍匐生活(附着期、匍匐幼虫期、成体)三个阶段(不经面盘幼虫)。瘤背石磺以泥滩上的底栖硅藻、有机碎屑、泥沙、腐殖质、潮汐涨落携带的小型生物等为食。周年调查发现，该群落4个季度中的生物量大小依次为晚春、初秋＞早春、秋末＞夏＞冬。各种生态因子，如盐度、温度、溶氧、污染物质、病害、捕食、动植物种类和数量、气候以及捕捞等对石磺的繁殖力、生长和存活都有影响。二、瘤背石磺生殖系统发育的研究瘤背石磺雌雄同体。生殖系统包括两性囊(卵睾ovotestis)、蛋白腺、卵黄腺、卵壳腺和雌、雄交接器。根据瘤背石磺两性囊的色泽、大小和生殖细胞的形态及两性囊成熟过程中的组织学特征，将其发育过程分为四个时期，即增殖期、生长期、成熟期、休止期(耗尽期)。根据卵细胞生长、发育的形态学特征及规律，把瘤背石磺卵子发育过程分为卵原细胞期、卵母细胞期、成熟卵母细胞期及退化的卵子。卵母细胞期又可根据其卵黄累积的情况进一步划分为卵黄合成前期、卵黄合成中期及卵黄合成后期即成熟期卵母细胞三个时期。雄性生殖细胞的发生过程可分为：精原细胞期、精母细胞期、前精子时期和精子几个时期。前精子时期是瘤背石磺特殊生殖方式的一种适应。精子尾鞭由轴丝(A)与侧鳍(Lf)缠绕形成，轴丝结构为典型的“9+2”型，侧鳍只位于轴丝的一侧，并围绕着轴丝而扭转。三、瘤背石磺生殖系统发育过程中各营养因子的变化对不同发育阶段的瘤背石磺各组织营养成分以及消化酶进行了分析。结果表明，各组织中生化成分的含量随性腺的发育而有较明显的变化。营养成分中以蛋白质含量相对较高，脂肪含量较低。在整个发育期肝胰腺组织蛋白质含量均低于肌肉组织，而脂肪含量高于肌肉组织，两种组织在成熟期前后蛋白质含量均表现出先降低后升高的趋势，但组织中灰分含量在不同发育期并无显著性变化(P＞0.05)。在整个性腺发育过程中，除牛磺酸和半胱氨酸外，瘤背石磺各组织均可检测出16种氨基酸，其中含必需氨基酸(essential amino acid，EAA)7种，半必需氨基酸(semi-essential amino acid，SEAA)3种，非必需氨基酸(nonessential aminoacid，NEAA)6种。各发育时期16种氨基酸中均以Glu的含量最高，平均含量达3.09％，Val最低，平均含量为0.10％。除Thr外含量由高到低依次为Asp、Leu、Lvs、Pro、Met、Arg、Ala、Gly、Ile、Phe、Tyr、Ser、His。Pro的变幅在三种组织中最大，变异系数在0.35-0.74之间，Ala的变异系数最小，在0.13-0.14之间。在整个发育过程中氨基酸总量大体呈“高-低-高”的变化趋势。瘤背石磺不同发育期各组织中共检出28种脂肪酸，其中饱和脂肪酸(SFA)10种，单不饱和脂肪酸(MUFA)8种，多不饱和脂肪酸(PUFA)10种。瘤背石磺体内的脂肪酸组成因不同生长发育期以及摄食不同食物而存在一定差异。两性囊中饱和脂肪酸含量从增殖期的55.96％显著下降到生长期时的最低值40.15％，随后开始逐渐升高到成熟期时又一高峰，单不饱和脂肪酸变化趋势与饱和脂肪酸有基本相似的变化趋势。卵黄腺中饱和及单不饱和脂肪酸总量具基本一致的变化趋势，在成熟期有最高值53.75％和36.55％，成熟前后含量相对较低，而多不饱和脂肪酸却呈与之相反的变化趋势。肝胰腺中饱和脂肪酸含量较前两种组织中低，各期含量无明显变化；单不饱和脂肪酸由增殖期的最高值34.88％显著降低至成熟期最低值15.39％，多不饱和脂肪酸则相反，由增殖期的最低值26.71％持续升高至成熟期最高值45.3％。肝胰腺中胰蛋白酶活力在各个发育期有显著性差异(P＜0.05)；两性囊中胰蛋白酶活力在发育各期没有显著性差异(P＞0.05)；卵黄腺中胰蛋白酶活力显著低于肝胰腺及两性囊中的活力(P＜0.05)，在休止期时达到最高，为0.114±0.008 U／mgprot，显著高于前几个时期(P＜0.05)。肝胰腺中淀粉酶活力在增殖期显著高于后几个时期的酶活力(P＜0.05)，两性囊中淀粉酶活力变化趋势与肝胰腺相似，也在增殖期显著高于后几个时期(P＜0.05)，卵黄腺中淀粉酶活力低于肝胰腺和两性囊中的活力，由生长期逐渐升高，并在休止期达到最高为0.112±0.008 U／mgprot。肝胰腺中脂肪酶活力呈降低趋势，但总体差异不显著(P＞0.05)，两性囊中脂肪酶活力在成熟期达最高为20.920±6.280 U／mgprot，显著高于成熟前后期该酶活力(P＜0.05)，卵黄腺中该酶在发育各期没有显著性变化(P＞0.05)，但显著低于肝胰腺和两性囊中该酶活力(P＜0.05)。分析表明，不同的消化酶在不同的部位其活性不完全相同，而且各消化酶的活性在瘤背石磺的不同发育阶段也发生变化，并随瘤背石磺的生长发育逐步演变和完善。更多还原

【Abstract】 The population ecology of Onchidium struma was studied by ecology method. The development of the reproductive systems was studied by the examination of histological methods and Electron Microscope. On the basis of morphological study, the sorts of nutriment during the different development were studied by the biochemical methods.1. Study on the population ecology of Onchidium strumaThe population number, inhabitaion, commensal, behaviour characteristics, ecological factor and the effect of growth and survive on Onchidium struma were studied on the basis of sample collected from Beibao harbor of Chongming from September 2005 to September 2006. The results showed that Onchidium struma is a kind of hermaphrodite allogamy mollusk, its life history can be divided into three phases:embryo(cleavage stage, blastula stage, coenteron stage, trochophore state inside ovum, veliger stage inside ovum), pelagic(Mouth-open stage, big veliger larva) and reptation (cling stage, reptation larva, adult). Onchidium struma feed on the benthic diatom, organic detritus, sediment, humus and minitype living things carried by tide. The biomass of Onchidium struma is late spring and early autumn > early spring, late autumn > summer>winter. All kinds of ecological factor can influence the reproductive capacity, growth and survive of Onchidium struma, such as salt, temperature, dissolved oxygen, pollutant, disease, preied on , the number and species of animals and plants, climate and catching. The results of the number and species of the community show that it is a kind of community with low species diversity and species abundance. And the species is distributed asymmetrically, and the degree of dominance is obvious.2. Study on the development of the reproductive systems of Onchidium strumaOnchidium struma is a kind of protandrous hermaphrodite marine pulmonate, reproductive system is composed of ovotestis, albumen gland, vitellarium, glandula conchae and copulatory organ. The reproductive cycle of Onchidium struma can be divided into four stages: proliferating stage, growing stage, maturing stage and degeneration stage (resting stage). By the morphological characters of oocytes and developmental rules, the course of oogenesis can be dividied into the phase of oogonium, oocyte and mature oocyte and degenerative ovum. The phase of oocyte can be dividied into previtellogenic oocytes. And the development of ovarian is divided into 3 phages: under-development phase, developing phase and phase of ovulation. By the course of meiosis of the spermatozoon, the course of spermatogenesis can be divided into spermatogonium, spermatocyte, pre-sperm and mature sperm. Pre-sperm is a special kind of stage adapting to its special method of reproduction. The sperm tail is composed of axial filament twisted with the lateral fin, and the axial filament is typical 9+2 structure of microtubule.3. Study on the change of sorts of nutriment during the different development of Onchidium strumaThe changes of nutrient ingredient and digestive enzyme in different development of Onchidium struma were analyzed by biochemistry method. The results show that the content of biochemical composition changed with the development of Onchidium struma. Onchidium struma has a high content of protein but low content of fat. The contents of protein in hepatopancreas are lower than those in muscle during the whole reproductive cycle. But the contents of fat in hepatopancreas are higher than those in muscle. The contents of protein and fat in both tissue change significantly(P<0. 05) before and behind the maturing stage. But the ash content in both tissue was not significant (P>0.05).Sixteen kinds of amino acids (AA) except Tau and Cystine of Onchidium struma were analyzed in different development stages, which contain7 essential amino acid, 3 semi-essential amino acid and 6 nonessential amino acid existed in each tissue. Among these amino acids, the content of Glu was the highest, the average content was 3.09, and the Val was the lowest, the average content was 0.10. The content of all the amino acids is Asp, Leu, Lys, Pro, Met, Arg, Ala, Gly, He, Phe, Tyr, Ser, His except Thr. The content of Pro changes obviously, and the coefficient of variability fluctuates from 0.35 to 0.74. And the coefficient of variability of Ala is the lowest, fluctuates from 0.13 to 0.14. The content of total AA has a trend of "high-low-high" with the development of the ovotestis. Twenty-eight kinds of fatty acids were analyzed in different development stages, which contain 10 SFA, 8 MUFA and 10 PUFA. The composition of total lipid is different in different development stages. The contents of SFA in ovotestis drop obviously from 55.96% in proliferating stage to 40.15% in growing stage, then rise gradually and reach to peak value in maturing stage.The MUFA has the similar trend with SFA. The SFA and MUFA in vitelline gland has similar trend. Both has the highest value 53.75% and 36.55% in maturing stage, and in other stages is low comparatively, but the PUFA has the contrary trend. The content of PUFA in hepatopancreas is lower than the other tissues, and the content has no significant different(P>0.05), the content of MUFA drop significantly from peak value 34.88% in proliferating stage to 15.39% in maturing stage, but the PUFA has different trend, rise from the lowest value 26.71% in proliferating stage to the highest 45.3% in maturing stage.The activities of digestive enzymes are different in different tissue and change with the development of ovotestis. The activity of trypsin in hepatopancreas changes significantly (P<0. 05) . The activity of trypsin in ovotestis was not significant (P>0.05). The activity of trypsin in vitelline gland is significantly lower than others (P<0.05), and the activity of trypsin in degeneration stage reach to peak value 0. 114 ±0. 008 U/mgprot, it is significantly higher than other stages(P<0.05). The activity of amylase in hepatopancreas in proliferating stage is significantly higher than other stages(P<0.05). The activity of amylase in ovotestis is similar with hepatopancreas, also significantly higher than other stages(P<0.05). The activity of amylase in vitelline gland is lower than the two other tissues, and begins to rise, and reaches to the peak value 0.112±0.008 U/mgprot. The activity of lipase in hepatopancreas has a trend to reduce, and was not significant (P>0.05) as a whole. The activity of lipase in ovotestis reaches to the peak value 20.920±6.280 U/mgprot in maturing stage, and significant higher(P<0.05) than degeneration stage. And The activity of lipase in vitelline gland was not significant (P>0.05), but significant lower than the two other tissues(P<0.05).更多还原