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本文报道了霍氏半管藻雄配子形成过程中，减数分裂前后的精母细胞期、双鞭毛体期及精子期细胞的超微结构。各期细胞具有一些共同的细胞器－线粒体、色素体和核糖体。高尔基体在配子的整个发育过程中，均未见到。双鞭毛体后期和精子中出现了溶酶体，观察了各期细胞核形态、结构的变化。鞭毛器轴纤丝具９＋０的微管构型，基体微管排列成“车轮”状，过渡区有一基板。 相似文献
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为探讨星康吉鳗(Conger myriaster)精子的超微结构和形态,应用扫描电镜和透射电镜对星康吉鳗精子结构进行观察。结果表明,精子由头部、中段和鞭毛3部分组成,有其独特的结构,总长度为35.75± 1.15µm。精子头部为新月形,主要由细胞核构成,细胞核内有核泡,无顶体结构。精子头部的质膜内包含单一的线粒体。精子头部长为3.33±0.16 um,头宽为1.12±0.13 um。在精子头部的凸面上,有4条从中段到头端的条纹。精子中段伸出一支根,支根位于精子的中段末端。精子中段长度为0.55±0.05 um,支根长度为1.38±0.08 um、直径为90.48±6.06 nm。精子尾部鞭毛细长,鞭毛横切面呈圆形,无侧鳍,鞭毛的轴丝结构为“9+0”型;一些鞭毛的末端呈现卷曲状,发育机制尚不明确。精子鞭毛长为31.16±1.51µm,鞭毛直径为0.17±0.01µm。通过比较分析发现精子的这些形态学特征不仅表现在星康吉鳗精子,还表现在鳗鲡目其他属的精子;表明是鳗鲡目精子的共同特征。本研究揭示了星康吉鳗精子的形态结构,为突破星康吉鳗人工繁殖技术提供了理论参考。 相似文献
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为了解硬骨鱼许氏平鲉精子体内受精以及精子在雌性体内保持长期存活的特性，本研究应用扫描电镜与透射电镜对体内受精卵胎生硬骨鱼许氏平鲉与体外受精卵生大菱鲆的精子进行超微结构观察，并使用计算机精子分析系统比较精子激活后运动参数差异。结果显示，这两种鱼的精子均由头部，中段和尾部构成，无顶体，尾部轴丝为“9+2”微管结构。许氏平鲉精子特点：头部呈短棒状，细胞核呈长锥状；中段不对称，约30—40个线粒体呈垛叠状紧密排列在中段；轴丝质膜延伸形成的侧鳍较为发达。大菱鲆精子特点：头部呈椭圆形，头部和鞭毛结构松散，含有大量囊泡状结构；精子中段较短，向外突出的线粒体包裹鞭毛形成“半袖套”结构且尾部鞭毛侧鳍不发达。许氏平鲉精子密度和体外激活寿命均显著高于大菱鲆精子，而激活后精子的平均曲线速度（VCL）、平均直线运动速度（VSL）、平均路径速度（VAP）显著低于大菱鲆精子。研究表明，上述精子结构差异主要表现在精子头部与中段：体内受精硬骨鱼精子大多具有细长的头部，发达的中段，线粒体数量较多；体外受精硬骨鱼具有圆形或椭圆形的头部，中部不明显，线粒体较少。 相似文献
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超低温保存前后太平洋牡蛎精子(Crassostrea gigas (Thunberg))超微结构观察 总被引：1，自引：0，他引：1
应用扫描电镜和透射电镜技术 ,研究超低温冷冻前后太平洋牡蛎精子形态与超微结构。结果发现 ,受伤精子被膜肿胀、皱褶、破裂 ;顶体变形、囊泡化 ,顶体膜肿胀、局部断裂 ;核膜肿胀、破裂 ,核空泡化 ;线粒体嵴变形、消失 ,基质电子密度降低 ,结构模糊 ;精子鞭毛被膜膨胀 ,鞭毛自精子基部或主、末段断裂。结果表明 ,超低温冷冻和升温解冻 ,对牡蛎精子的膜结构损伤严重 ,导致精子活力和受精能力下降 相似文献
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为了解香鱼(Plecoglossus altivelis)精子的形态结构特点,采用扫描和透射电镜技术观察了香鱼精子的超微结构,并与鲤形目及鲑形目其他鱼类精子结构进行了比较。结果表明,香鱼精子由头部、中段和尾部组成,全长约23.5μm。头部呈弹头形,由细胞核外包质膜构成,长约1.8μm、宽约0.8μm;细胞核从后端中央向前深凹至核的近前端,形成植入窝,使核呈倒U字形,核的前端无顶体;植入窝内有中心粒复合体及小段起始的鞭毛,中心粒复合体由近端中心粒和远端中心粒(基体)组成,两者之间夹角约135o。中段为"半袖套"结构,长约0.5μm,其内部为一较大的"半套筒"形线粒体。鞭毛起始于远端中心粒,由轴丝及外包轴丝的质膜组成,轴丝为典型的"9+2"微管结构;鞭毛两侧有质膜向外突起形成侧鳍。研究显示,香鱼精子与典型的鲤形目(Cypriniformes)鱼类精子卵圆形或圆球形头部及细胞核、不对称的袖套及尾部鞭毛无侧鳍等结构特征不同,也与鲑形目(Salmoniformes)鱼类精子卵圆形或椭圆形头部及马蹄形或浅U形细胞核、两中心粒相互平行或垂直、袖套结构完整等结构特征不同。香鱼精子结构具有种的特异性。 相似文献
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中国对虾精子和卵子受精能力的初步研究 总被引：5，自引：1，他引：5
１９７３年，Ｃｌａｒｋ等以褐对虾（Ｐｕｎａｅｕｕｓ ａｚｔｅｃｕｓ）为实验材料，将解剖的卵子和精子混合，首次在非鞭毛型不动精子的人工授精研究中获得受精卵，受精率为１０％［２］。１９８６年，Ｍｉｎ－ＮａｎＬｉｎ等在雌虾产卵时，将精子滴入产卵池中使卵子受精，孵化率高达６３．１１［４］。关于中国对虾（Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ）精子和卵子受精能力的研究还未见报道。精卵的受精能力直接决定受精率，而受精率的高低影响苗种生产。因此．进行对虾精子和卵子受精能力的研究有利于对受精过程的进一步了解，以使更好… 相似文献
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罗氏沼虾人工繁殖期的占区与雌雄配对行为的研究 总被引：1，自引：0，他引：1
雄性罗氏沼虾对设置的人工巢穴具明显的占区本能，占区领域主要由雄虾个体大小决定。本实验中占区的最小安全领域是一个直径约为３５ｃｍ的立体空间，雄性占区后绝不允许同性入内，对性腺未成熟之雌虾亦加拒绝。但能稳定接纳１尾以上性腺已完全成熟、即将蜕壳的雌虾并与其配对，最多时１尾雄虾可稳定与８～１０尾这样的雌虾配对。在占区和配对过程中，虾的视觉起重要作用。人工繁殖时，捕虾作业不会对占区和雌雄配对产生不利影响。一昼夜１尾雄虾在人工巢穴中最多能与２０尾雌虾交配。 相似文献
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模仿雄性锯缘青蟹第一腹肢,根据其在交配中的作用机制,采用常规滴管为材料,利用酒精灯灼热拉制一个前端弯曲、侧扁、管径大小接近第一腹肢的人工交接器.以无钙离子的人工海水作为青蟹人工授精的缓冲液,缓冲液中加入适量庆大霉素.首次对青蟹采用类似硬壳交配的方式,将成熟雄蟹贮精囊内的精荚和精液成功移植至雌蟹纳精囊中.结果表明精荚的人工移植不会破坏成熟雌蟹纳精囊的内环境,其内精子具正常受精能力.未交配雌青蟹精荚的人工移植没有正常产卵,但性腺得以促进发育,并能进行正常的生殖脱皮. 相似文献
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波纹巴非蛤性逆转时生殖腺的组织学变化 总被引：4，自引：0，他引：4
波纹巴非蛤由雌性逆转为雄性时，其生殖腺雌性滤泡内卵细胞败育，逐渐退化分解吸收。同时，分布于滤泡壁上的原始精原细胞开始生长发育。残留的雌性生殖细胞与发育的雄性生殖细胞共同存在于滤泡腔内，即为波纹巴非蛤的雌雄间性过渡阶段。随着滤泡内卵细胞的退化吸收，精细胞与雄性泡逐渐形成。波纹巴非蛤雄性个体是由雌性个体通过性反转发育而来，这种性别的转化是双方向的。此外，波纹巴非蛤雌雄同体存在两种滤泡结构类型。 相似文献
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中国对虾精子的内部结构分为棘部、中间部和主体部。棘部由质膜、顶体囊膜和顶体物构成 ;中间部由质膜和顶体囊膜围绕顶体囊腔和顶体物构成 ;主体部则由细胞质带围绕细胞核构成。细胞质带中有线粒体衍生物、环状片层体、粗面内质网和一些泡状结构等 ,细胞核膜不完整 ,核物质絮状 ,核仁 1～ 2个。中国对虾雄虾体内与雌虾纳精器中的精子形态结构有明显的不同。雄虾体内精子外形似“梨形”,棘部短粗 ,中间部不明显 ,精子棘部基端物质呈螺旋状 ,主体部内质网发达 ,有线粒体衍生物。而雌虾纳精器中的精子外形似“葫芦”形 ,棘部细长 ,中间部明显 ,精子棘部上端物质呈螺旋状 ,内质网浓缩为团块状 ,未发现线粒体衍生物 相似文献
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Sex‐related differences in size,function and regeneration of the major cheliped in the hermit crab Pagurus filholi 
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下载免费PDF全文 Pagurus hermit crabs have a well‐developed right cheliped (major cheliped) and in some species the major cheliped of males is longer than that of females. This paper describes sex‐related differences in major cheliped length and regeneration pattern of the major cheliped in the hermit crab Pagurus filholi. We also examined the function of the major cheliped in male–male competition. Major cheliped length of males was longer than that of females in P. filholi. Males regenerated larger chelipeds than females at the first molt after experimentally induced autotomy. Body size growth in males of the regeneration group was less than that in intact males of the control group while there was no significant difference in body size growth of females between regeneration and control groups. Major cheliped length was included in the best model to explain the outcome of male–male competition and thus sexual selection appears to be a causative factor in the sex‐related difference of the major cheliped length. Sex‐related differences in the regeneration pattern may reflect differences in evolutionary pressures on males for large major chelipeds and females for large body size. 相似文献
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J. A. Colman 《新西兰海洋与淡水研究杂志》2013,47(2):351-370
Growth of the sand flounder, Rhombosolea plebeia (Richardson), and the yellow‐belly flounder, Rhombosolea leporina Günther, in the Hauraki Gulf is described. In both species females grow more quickly than males. At 2 years of age male and female sand flounders reach mean total lengths of 17 cm and 23 cm respectively, and male and female yellow‐belly flounders reach mean total lengths of 24 cm and 29 cm respectively. 相似文献
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Mating behavior strategies of brachyuran crabs are flexible depending on the habitat and social context. We evaluate pre-copulatory guarding in Neohelice granulata and describe the unusual copulatory behavior. Laboratory experiments were conducted to test whether factors such as male size, presence of burrows, a male-biased operational sex ratio (OSR) and female mating history affect the copulation duration in two different study areas. Females initiated a searching behavior approximately 20–26 h before they became receptive by assessing large male burrows and displaying a courtship behavior (“flirting”) in its entrance. Once the female entered inside the male burrow, pre-copulatory guarding was observed until the female became receptive and successful copulation occurred immediately after. This species shows some very unusual copulatory behavior involving eyestalk grasping not seen in any other varunid crab. The copulation duration was independent of male size and the presence of burrows, although it was dependent on the study area, the OSR and the female mating history. Thus, copulation duration is a flexible character in this species which varies with habitat and biological factors such as mating history and sex ratio. 相似文献
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龙须菜是中国重要的人工栽培海藻,主要用途是琼胶生产原料和鲍鱼饵料。目前龙须菜大规模栽培采用的是人工夹苗的方式,而其孢子采苗的生产方式也得到越来越多的关注。本文将人工培育的由四分孢子萌发长成的一对龙须菜雌、雄配子体进行受精,测试了雌雄配子体藻枝部位、温度、硝酸盐浓度等因素对果孢子体形成过程的影响,结果表明:龙须菜雌配子体藻枝的不同等级分枝表现出不同的生殖力,一级分枝最尖端新生细胞的成熟速度快于其它等级;温度对果孢子体形成有极显著影响(P<0.01),20℃为最适温度;硝酸盐浓度没有显著影响。 相似文献
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The reproductive ecology of the mudskipper Boleophthalmus pectinirostris was investigated during the spawning season in the Funing Bay, Fujian, China. The fish burrows were basically Y-shaped and had two openings onto the mudflats. Part of the intersection at the center of the burrow was dilated to form a "spawning chamber". The dissolved oxygen concentrations (0.40~0.65 mg/dm3)of water 15 cm deep inside the burrows were much lower than those (5.96~6.19 mg/dm3) of intertidal pool water. Water temperatures inside the burrows were much lower than those of intertidal pools. Field investigations indicated that eggs were laid on the inner wall and ceiling of the spawning chamber by means of filamentous attachments, and a male stayed inside the burrows to guard it. Field investigations also suggested that fish of both sexes constructed mud burrows by themselves but that the spawning chamber was made only in the male burrow. The male attracted a female to his burrow for mating and spawning. There was no water in the spawning chamber, and thus the eggs were exposed to the air in the chamber. Changes in spawning readiness and gonadosomatic index indicated that synchronization of spawning was related to the semi-lunar periodicity, and this is the first report of this relationship in the mudskippers. 相似文献
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Many animals are sexually dimorphic, but the underlying evolutionary causes and ecological consequences of sexual dimorphism are not fully understood. One predicted consequence for sexual dimorphism is that different sexes show niche differentiation. If sexual dimorphism is in feeding appendages, then differences may be manifested by different diets and thus contrasting behavioural responses to potential prey. Sexual dimorphisms in feeding appendages may also result in different handling times, which may then be correlated with differences in exposure, and, hence predation risk to the predator while feeding. In addition, the prey of the sexually dimorphic predator may respond differently to cues from each sex according to the predation risk each presents to the prey. We tested these predictions using a crab (Carcinus maenas) with sexual dimorphism in chelae dimensions, its predator the cuttlefish Sepia officinalis and prey with known differences in handling times; the gastropod molluscs Gibbula umbilicalis and Littorina littorea. We demonstrated that male C. maenas orientated more frequently to cues from L. littorea whereas females orientated more towards G. umbilicalis in contradiction of patterns predicted by handling times. Male crabs had a faster heart rate than females but this was not influenced by food‐based cues. We also showed no difference in foraging times with respect to changing levels of predator risk and also no differences in gastropod responses to odours from male or female crabs. Our results showed that predictions of handling time and sexual dimorphism are not associated. The experiments indicated the male and female crabs are probably ecological equivalents and thus niche differentiation is less likely. 相似文献