De Gustibus Non Est Disputandem: A Spiral Center for Taste in the Brain of the Teleost Fish, Heterotis niloticus

The teleost fish, Heterotis niloticus, has elaborate paired, spiraled pharyngeal structures that aid in concentrating and swallowing food. These epibranchial organs are lined by an epithelium rich in taste buds. Both the taste buds and the muscles of the epibranchial organs are innervated by components of the vagal nerve. Horseradish peroxidase neuronal tracing experiments show that these nerve fibers are connected centrally to an enormous epibranchial portion of the vagal lobes-a special visceral sensory and motor region of the medulla. The epibranchial portion of the vagal lobe is among the most remarkable structures found in the brains of vertebrates, for it is itself a spiral.     

Control of crystal size and lattice formation by starmaker in otolith biomineralization

The stone-like otoliths from the ears of teleost fishes are involved in balance and hearing and consist of calcium carbonate crystallites embedded in a protein framework. We report that a previously unknown gene, starmaker, is required in zebrafish for otolith morphogenesis. Reduction of starmaker activity by injection of modified antisense oligonucleotides causes a change in the crystal lattice structure and thus a change in otolith morphology. The expression pattern of starmaker, along with the presence of the protein on the growing otolith, suggest that the expression levels of starmaker control the shape of the otoliths.     

NompC TRP channel required for vertebrate sensory hair cell mechanotransduction

The senses of hearing and balance in vertebrates rely on the sensory hair cells (HCs) of the inner ear. The central element of the HC's transduction apparatus is a mechanically gated ion channel of unknown identity. Here we report that the zebrafish ortholog of Drosophila no mechanoreceptor potential C (nompC), which encodes a transient receptor potential (TRP) channel, is critical for HC mechanotransduction. In zebrafish larvae, nompC is selectively expressed in sensory HCs. Morpholino-mediated removal of nompC function eliminated transduction-dependent endocytosis and electrical responses in HCs, resulting in larval deafness and imbalance. These observations indicate that nompC encodes a vertebrate HC mechanotransduction channel.     

东南太平洋公海智利竹筴鱼年龄与生长研究

智利竹筴鱼是一种重要的中上层经济鱼类,对其生活史关键过程的认识还相当有限。根据2006年5-8月在智利公海采集的智利竹筴鱼样本,利用其中963尾智利竹筴鱼耳石对其年龄进行了鉴定,估算了智利竹筴鱼叉长体重关系以及von Bertalanffy生长方程参数,并分析了智利竹筴鱼耳石重量(OW)与年龄的关系。研究结果表明,样本最大年龄9龄,最小年龄2龄,样本年龄组成以4龄为主(71.5%)。智利竹筴鱼叉长体重方程参数a、b分别为0.000 03和2.801 9,von Bertalanffy生长方程参数L∞为738.4 mm,k为0.107,t0为-1.08。耳石重量与年龄呈显著线性关系(r=0.74,P<0.001),表明耳石重量可用于智利竹筴鱼年龄鉴定。     

东南太平洋公海智利竹(荚)鱼年龄与生长研究

智利竹筴鱼是一种重要的中上层经济鱼类,对其生活史关键过程的认识还相当有限。根据2006年5-8月在智利公海采集的智利竹筴鱼样本,利用其中963尾智利竹筴鱼耳石对其年龄进行了鉴定,估算了智利竹筴鱼叉长体重关系以及von Bertalanffy生长方程参数,并分析了智利竹筴鱼耳石重量(OW)与年龄的关系。研究结果表明,样本最大年龄9龄,最小年龄2龄,样本年龄组成以4龄为主(71.5%)。智利竹筴鱼叉长体重方程参数a、b分别为0.000 03和2.801 9,von Bertalanffy生长方程参数L∞为738.4 mm,k为0.107,t0为-1.08。耳石重量与年龄呈显著线性关系(r=0.74,P<0.001),表明耳石重量可用于智利竹筴鱼年龄鉴定。     

Steroid-dependent auditory plasticity leads to adaptive coupling of sender and receiver

For seasonally breeding vertebrates, reproductive cycling is often coupled with changes in vocalizations that function in courtship and territoriality. Less is known about changes in auditory sensitivity to those vocalizations. Here, we show that nonreproductive female midshipman fish treated with either testosterone or 17beta-estradiol exhibit an increase in the degree of temporal encoding of the frequency content of male vocalizations by the inner ear that mimics the reproductive female's auditory phenotype. This sensory plasticity provides an adaptable mechanism that enhances coupling between sender and receiver in vocal communication.     

鲶鱼内脏鱼油的提取工艺研究

本文探讨了鲶鱼内脏中提取鱼油的工艺条件。以鱼油的感官质量和提取率为观察指标,以几种常用有机溶剂为提取剂,以中性蛋白酶为水解酶,通过单因素和正交试验确定提取溶剂的种类和酶解工艺参数。结果表明:提取剂以正己烷-异丙醇(3︰2)最好;提取的工艺条件为:先以中性蛋白酶进行酶解,设定料液比为1︰6,加酶量为1 400 u/g,酶解温度为45℃,酶解时间为2 h;经过滤后,按料液比1︰5加入正己烷-异丙醇(3︰2),振荡萃取25 min。在此条件下,鱼油的提取率为25.3%,产品为淡黄色、澄清透亮的液体;经测定,鱼油的酸价(mg KOH/g)、过氧化值(g/100 g)、碘价(g I2/100 g)分别为3.88、0.067 1、127.4。所以,采用有机溶剂和中性蛋白酶处理相结合对鱼油进行提取,鱼油的感官质量好,提取率高。     

国外对鱼类耳石日轮生长的研究

鱼类耳石日轮生长的研究是国际上70年代初开展起来的新领域,它的研究为我们开辟了一条更精确研究鱼类生长、鱼类生长与环境关系的新途径. 本文概述了1980年以来国际上在耳石日轮生长研究方面的进展,比较详细地介绍了日轮的观察方法、日轮的鉴定、日轮的形成与环境的关系、日轮研究的野外应用、存在的问题和展望.     

鱼类尾部神经分泌系统研究进展

尾部神经分泌系统是鱼类特有的神经分泌系统,位于脊髓末端,是鱼类适应环境的关键。该系统作为应激系统的一部分,在鱼类生理和行为方式等多方面具有综合调节作用。综述了自19世纪末尾部神经分泌系统被发现以来,尤其是近年来生物学家在该系统形态结构及组成、主要内分泌细胞(Dahlgren细胞)及其分泌物的功能和生理调节、神经支配等方面的研究成果,以及一些环境变化引起的应激反应与尾部神经分泌系统的相关性的研究。为研究该系统相关分泌肽及其功能提供更为广泛的参考,同时为进一步了解相关分泌肽在高等脊椎动物甚至人类中的功能提供借鉴。     

草鱼的低盐-高水分冷冻半干制品耐藏性研究

[目的]探讨草鱼加工成低盐-高水分冷冻半干制品的可适性及其耐藏性。[方法]通过腌制、干燥、包装、速冻和冻藏将市售新鲜的草鱼加工成低盐-高水分冷冻半干制品,研究冻藏过程中鱼体水分含量、盐分含量、系水力和其感官品质的变化。[结果]相对于擦干鱼体对照组,腌制、干燥后的试验组鱼体失水更慢,系水力下降较慢。随着冻藏时间的延长,2组鱼体的感官品质均下降,但试验组鱼体的下降速度更慢。冻藏过程中,2组鱼体的盐分含量变化较小,但对照组鱼体的盐分含量有缓慢上升趋势。[结论]草鱼较适合制成低盐-高水分冷冻半干制品,耐藏性较好,且在盐渍和干燥过程中增加了制品的风味,具有较好的口感。     

草鱼脆化过程中血液学指标及组织氧化还原的动态变化

以常规配合饲料和蚕豆饲喂平均体质量为(936.7±6.1)g的草鱼,测定了草鱼在脆化过程中血液学指标及肌肉、肝胰脏、鳃组织氧化还原的动态变化。结果表明,白细胞数、淋巴细胞数、血红蛋白含量、平均红细胞体积及平均红细胞血红蛋白含量均受饲料种类和饲喂时间的双重影响,蚕豆组草鱼12 w时的白细胞数、淋巴细胞数、红细胞数、血红蛋白含量均较对照组显著下降(P0.05);蚕豆组草鱼4 w时肝胰脏过氧化氢酶(CAT)活性,8 w时鳃超氧化物岐化酶(SOD)活性、肌肉丙二醛(MDA)含量,12 w时肝胰脏、肌肉及鳃SOD活性,肌肉及鳃CAT活性,肝胰脏、肌肉MDA含量均较对照组显著升高(P0.05);而蚕豆组草鱼在4 w时的肌肉、鳃,8 w时的肝胰脏、鳃,及12 w时的鳃内还原型谷胱甘肽(GSH)含量均显著低于对照组(P0.05);4 w时的肌肉、鳃,8 w时的肝胰脏、鳃、肌肉,及12 w时鳃中的GSH/GSSG系数均较对照组显著降低(P0.05)。上述结果表明,摄食蚕豆会对草鱼带来血液学指标及组织抗氧化机能的时间累积性损伤,提示在养殖过程中需采取措施以提高机体抗氧化能力。     

海洋养殖鱼类体内汞污染及其在不同器官中的生物富集特征

以浙江省宁波市象山港和舟山市六横岛海洋渔业养殖区典型养殖鱼体为研究对象,选取三种人工海洋网箱养殖鱼类(黑鲷、鲈鱼和红鮋),通过测定其不同组织和器官中总汞和甲基汞的含量,探讨了不同形态汞在海洋养殖鱼体不同组织和器官中的分布及富集特征。结果显示:象山港和六横岛渔业养殖区鱼体肌肉组织中总汞平均含量分别为106、43.4 ng·g~(-1),甲基汞含量分别为81.0、33.6 ng·g~(-1);鱼体不同器官组织的功能不同导致其对汞的富集程度也不同,各器官组织总汞和甲基汞含量分布规律基本表现为肌肉肝脏其他器官。肌肉组织中总汞和甲基汞在两地均表现为黑鲷显著高于鲈鱼和红鮋,主要是由于黑鲷以杂鱼为主要食物,而鲈鱼和红鮋以颗粒鱼粮为主要食物,杂鱼汞含量显著高于颗粒鱼粮;但是鱼鳃、鱼鳞等组织中的汞在不同鱼种之间无显著差异,说明这些组织中的汞主要来源于水体。象山港和六横岛两地鱼体肌肉组织中甲基汞的生物富集系数高于总汞的生物富集系数,说明甲基汞更易在鱼体中富集。     

新疆乌伦古湖湖拟鲤的生长特征

根据2007年1月至2008年5月采集的1 033尾标本,以微耳石磨片为年龄鉴定和生长退算材料,对乌伦古湖湖拟鲤种群的生长特征进行了研究.结果显示:乌伦古湖湖拟鲤种群雌、雄个体均由7个年龄组(0+～6+龄)组成,相同年龄组雌鱼个体显著大于雄鱼.雌、雄鱼体重与全长表现为异速生长:W♀＝0.9×10<-6TL3.4606,W♂＝1.0×10-6TL3.964.用退算全长拟合的von Bertalanffy生长参数为:雌性TL∞＝300.9 mm,k=0.181 9/y,t0=-0.843 2y;雄性TL∞＝271.8 mm,k＝0.197 4/y,t0＝-0.636 6 y.体重生长参数为:雌性W∞＝=339.5 g,k＝0.181 9/y,t0＝-0.823 9 y;雄性W∞＝-186.0 g,k＝0.196 6/y,t0＝-0.645 0y.生长特征指数为:雌性 =9.708 9;雄性 =9.587 5.雌、雄鱼的生长拐点年龄分别为6.0龄和5.6龄,拐点时全长和体重分别为214.2 mm,104.3 g和192.5 mm,55.5 g.与20世纪90年代种群相比,乌伦古湖湖拟鲤生长速度明显下降,呈现出个体小型化和低龄化趋势.引起这种变化的主要原因可能是过度捕捞、水体盐度上升、SO42-和CL-含量升高以及种间饵料生物竞争加强.     

稀土元素镧在草鱼体中的分布与积累

采用同位素示踪技术，研究了稀土元素镧在草鱼（Ｃｔｅｎｏｐｈａｒｙｎｇｏｄｏｎｉｄｅｌｌｕｓ）体各组织器官中的分布及积累状况。结果表明，草鱼对稀土元素吸收积累能力较弱，但各组器官中镧分布差异较大，积累量依次为鳃＞内脏＞鳞＞头＞骨骼＞肌肉；高浓度（１０ｍｇ／Ｌ）处理组鱼体中镧的积累量明显高于低浓度（２ｍｇ／Ｌ）处理组，但两组的积累能力（ＣＦ值）差异不大。     

Expression of myelin-associated glycoprotein by small neurons of the dorsal root ganglion in chickens

Biochemical and immunocytochemical investigations have shown that myelin-associated glycoprotein (MAG) is exclusively related to myelin and myelin-forming cells in mammals. In the present study it was found that dorsal root ganglia in young chickens display MAG-immunoreactive material in most small sensory neurons. The presence of MAG at the surface of small sensory neurons raises the question of whether this glycoprotein acts as a cell adhesion molecule in lower vertebrates.     

鲤鱼、黄鱼和大眼鰤鲈消化酶活性的比较研究

对鲤鱼 (Cyprinuscarpio)、黄 鱼桑鱼 (Pseudobaqrusfulvidraco)、大眼 鱼师鲈 (Stizostedionvitreum)各消化器官消化酶进行了测定分析。结果表明 :鲤鱼肝胰脏蛋白酶活性最强 ,黄鱼桑鱼和大眼鱼师鲈胃中蛋白酶活性最强 ,3种鱼蛋白酶活性顺序为 :大眼鱼师鲈 >黄鱼桑鱼 >鲤鱼 ,表明食性不同 ,摄食能力不同 ,蛋白酶活性也不同 ;3种鱼淀粉酶的活性顺序为 :鲤鱼 >黄鱼桑鱼 >大眼鱼师鲈 ,其酶活性与鱼类的食性有关 ;消化酶在肠道分布 ,无固定规律 ,而是因鱼而异     

鲫耳石年轮的观察及其确证

对耳石边缘年轮形成周期进行了分析。结果表明，鲫耳石上1a形成1个年轮，年轮形成时期洪湖种群主要在4－6月，洞庭湖种群主要在3－5月。星耳石和微耳石一样，可用于鲫年龄测定，而且不经磨片即可直接读取年轮，完整星耳石和微耳石与微耳石磨片上的年轮读数的吻合率均在80％以上，误差不超过1龄。但相对而言，微耳石上年轮更易观察。文中对耳石形态和年轮特征进行了描述。     

鱼类性别决定及其基因的研究进展

综述鱼类性别决定类型及其机制的研究动态和进展,旨在为系统研究鱼类性别决定机制提供参考。     

Natal homing in a marine fish metapopulation

Identifying natal origins of marine fishes is challenging because of difficulties in conducting mark-recapture studies in marine systems. We used natural geochemical signatures in otoliths (ear bones) to determine natal sources in weakfish (Cynoscion regalis), an estuarine-spawning marine fish, in eastern North America. Spawning site fidelity ranged from 60 to 81%, comparable to estimates of natal homing in birds and anadromous fishes. These data were in contrast to genetic analyses of population structure in weakfish. Our findings highlight the need for consideration of spatial processes in fisheries models and have implications for the design of marine reserves in coastal regions.     

Descending efferents from the superior colliculus relay integrated multisensory information

By means of their efferent projections to motor and premotor structures, the cells in the deep superior colliculus are intimately involved in behaviors that control the orientation of the eyes, pinnae, and head. These same efferent cells receive multiple sensory inputs, thereby apparently enabling an animal to orient its receptor organs in response to a wide variety of cues. This sensory convergence also provides a system in which motor responses need not be immutably linked to individual stimuli but can vary in reaction to the multitude of stimuli present in the environment at any given moment.