滇池红鳍原鲌4种年龄鉴定材料的比较

采用耳石、鳞片、匙骨和鳃盖骨等4种年龄鉴定材料对云南滇池红鳍原鲌的年龄鉴定结果进行比较,以吻合率、可判读力和平均变异系数为依据确定最佳年龄鉴定材料。红鳍原鲌的微耳石轮纹清晰,在解剖镜入射光下呈现明暗相间的条纹,无明显杂纹,年轮标志清晰;而鳞片轮纹在4龄以上时年轮特征不清晰,读龄过程中易被忽略;此外,高龄个体匙骨和鳃盖骨分别出现中心部分透明、基部较厚等原因,造成年龄低估。判读结果表明,微耳石和鳞片的吻合率及平均变异系数均优于匙骨和鳃盖骨。因此,以微耳石年龄读数为基准,并与鳞片、匙骨和鳃盖骨进行对比。结果显示,鳞片与其吻合率最高,为92.7%,平均变异系数最小为1.9%,匙骨和鳃盖骨与其吻合率分别为77.2%和61.3%,平均变异系数分别为9.3%和12.6%。综合分析认为,耳石为滇池红鳍原鲌最佳年龄鉴定材料,鳞片因具有采集方便不伤鱼体的优点,也是很好的年龄鉴定材料,匙骨和鳃盖骨则不适于滇池红鳍原鲌的年龄鉴定。     

乌伦古湖欧鳊四种年龄鉴定材料的比较分析

对新疆乌伦古湖欧鳊(Abramis brama)耳石、鳞片、匙骨、鳃盖骨等四种年龄鉴定材料的形态和年龄特征进行了描述,并对其年龄读数的一致性进行了比较分析。结果显示:3龄以下个体鳞片年轮标志多为普通切割型,3龄以后年轮显示为碎裂切割和疏密切割,高龄个体鳞片外围有年轮缺失的现象;微耳石磨片在透射光下呈明暗相间的轮纹;匙骨中心区域透明,年轮不清晰,外侧年轮清晰,但高龄个体外侧有年轮缺失的现象;鳃盖骨中心部分较厚,年轮不易观察。同一观察者2次读龄年龄读数吻合率中,耳石横轴面磨片最高,为90.5%;耳石平面磨片、匙骨、鳃盖骨次之,分别为84.5%、83.7%、80.7%;鳞片最低,为74.2%。以耳石横轴面磨片年龄读数为基准,耳石平面磨片年龄读数与其吻合率较高,为83.6%,平均变异系数为1.5%;匙骨、鳞片次之,分别为71.2%、62.4%,平均变异系数分别为5.1%、4.3%;鳃盖骨最低,仅为30.0%,平均变异系数为13.8%。综合分析认为,耳石是乌伦古湖欧鳊年龄鉴定的最适宜材料,高龄个体采用其横轴面磨片观察更为精确。鳞片、匙骨和鳃盖骨在鉴定低龄个体年龄时可使用,但鉴定高龄个体年龄时,有低估年龄的可能。     

元江水系越鳠年龄鉴定材料的比较

分析比较了元江越鳠(Mystus pluriradiatus)不同年龄鉴定材料的鉴定结果。结果显示:微耳石磨片、星耳石和脊椎骨材料为鉴定元江越鳠年龄的可利用材料,矢耳石细小且脆不适合用于越鳠的年龄鉴定。微耳石磨片和星耳石的年龄判别能力最高,均达到96.0%,脊椎骨的年龄判别能力为93.3%;最大年龄读数出现在微耳石磨片和脊椎骨上,读数为5+龄;微耳石磨片的同一鉴定者两次独立年龄读数的吻合率最高为94.5%、脊椎骨次之为91.7%、星耳石最低为88.1%;两种年龄材料读数之间的吻合率比较中,微耳石磨片与星耳石的吻合率较高为90.9%,两者的年龄读数在低龄组时吻合较好,微耳石磨片与脊椎骨的吻合率为89.3%,3+龄以上时二者的年龄读数吻合率高。结果表明,鉴定低龄个体选择星耳石材料(n+龄≤3+龄),高龄个体用微耳石磨片进行辅助鉴定的年龄鉴定方法对元江越鳠进行年龄鉴定较为准确。     

新疆额尔齐斯河银鲫年龄鉴定比较与生长特征研究

以2013年4－10月从新疆额尔齐斯河采集的546尾银鲫（Carassius auratus gibelio）样本为材料,比较4种钙化组织（微耳石、鳞片、鳃盖骨和脊椎骨）年龄鉴定结果,选择最佳的年龄鉴定材料,研究其生长特征。结果表明,4种钙化组织中,微耳石磨片年龄读数的平均百分比误差（IAPE）最低（1.89%）,同一观察者2次读龄的吻合率最高（91.9%）,为4种材料中最为准确的年龄鉴定材料;采用微耳石进行年龄鉴定,银鲫样本由1～9龄组成,以3～4龄为主,占77.28%;银鲫体长与体重呈幂函数关系,雌雄群体间无显著性差异,体长与体重的关系为：W=2.661×10-5L3.085（R2=0.96,n=546）;生长规律用von Bertalanffy生长方程表示为：Lt=359.7 [1-e-0.172(t+1.066)], Wt=2042.3[1-e-0.172(t+1.066)]3.085;个体的生长拐点年龄为5.49龄,对应的体长及体重分别为243.2 mm和610.81 g。     

长湖短颌鲚耳石重量与年龄关系

利用2014年采自湖北长湖的378尾短颌鲚(Coilia brachygnathus)样本,去除包膜和黏液的矢耳石于55℃烘箱中烘烤24 h,电子天平称重(精确至0.001 g),成对t检验结果表明,短颌鲚左右矢耳石重量之间无显著差异(P0.05),数据分析以左右矢耳石重量的平均值计为矢耳石重量;采用直线、幂函数和多项式3种回归方程研究了其耳石重量与年龄的关系。结果显示,长湖短颌鲚的耳石和鳞片均可用于鉴定其年龄,且两者鉴定年龄的吻合度达到75.8%;根据222尾耳石与鳞片年龄一致的短颌鲚样本数据,发现耳石重量与个体的年龄呈显著相关(P0.05);按年龄组以耳石重量与相应的体长作图,可以初步判断所观测年龄的可靠性;利用建立的耳石重量-年龄关系函数估算得到的个体年龄,与直接读取耳石磨片获得的年龄结果无显著差异(P0.05),表明利用矢耳石重量直接推算其个体年龄,可以作为辅助短颌鲚年龄鉴定尤其快速鉴定的一种有效方法。     

伊犁裂腹鱼不同年龄鉴定材料的年轮特征比较

对伊犁河雅玛渡河段2010年1～4月采集的39尾伊犁裂腹鱼[Schizothorax (Racoma) pseudaksaiensis (Herzenstein)]样本进行了体表鳞片、臀鳞、脊椎骨、耳石和背鳍条共5种年龄鉴定材料的年轮特征研究。结果表明,体表鳞片没有明显的年轮特征,不能作为年龄鉴定材料,其他4种材料可作为伊犁裂腹鱼的年龄鉴定材料。样本为2+龄时,4种年龄材料鉴定结果的吻合率为100%;3+和4+龄鉴定结果吻合率较高,分别是87.3%和85.4%;5+～8+龄个体吻合率较低,为63.9%。伊犁裂腹鱼3+龄以上个体进行年龄鉴定时不能仅用1种鉴定材料,而应以耳石为主,其他年龄材料为辅。     

广东东江外来尼罗罗非鱼年轮特征及其影响因素

以养殖群体为对照,研究了广东东江外来尼罗罗非鱼(Oreochromis niloticus)鳞片、腹鳍棘、鳃盖骨、脊椎骨和矢耳石5种年龄材料的年轮结构特征。与养殖群体相比,整体上东江种群年轮的清晰度及对比度更高。结合周年水温数据,推测东江尼罗罗非鱼在1 3月份低温期形成1个年轮标志,而其副轮较多的特征可能与繁殖活动有关。在5种年龄材料中,以矢耳石的轮纹特征最为明显,且规律性强,而鳃盖骨和鳞片受副轮影响,可读性最低。5种年龄材料的可读性由大到小顺序为矢耳石、脊椎骨、腹鳍棘、鳃盖骨、鳞片。     

伊犁裂腹鱼不同年龄鉴定材料的年轮特征比较

对伊犁河雅玛渡河段2010年1～4月采集的39尾伊犁裂腹鱼[Schizothorax （Racoma） pseudaksaiensis （Herzenstein）]样本进行了体表鳞片、臀鳞、脊椎骨、耳石和背鳍条共5种年龄鉴定材料的年轮特征研究。结果表明,体表鳞片没有明显的年轮特征,不能作为年龄鉴定材料,其他4种材料可作...     

锦江河黄颡鱼耳石重量与年龄的关系及年龄鉴定

2017年1—12月逐月采集锦江河中野生黄颡鱼Pelteobagrus fulvidraco标本138尾,取微耳石,在60℃的烘箱中烘烤24h;取体前端5~7枚脊椎骨,煮沸3min,自然晾干。采用直线、幂函数、多项回归方程中最高相关系数的拟合公式和Kolmogrov-Smimow双样本验证估算年龄与计数年龄间的相同性,研究耳石重量与年龄的关系。结果表明:黄颡鱼的耳石重量与年龄成正相关,不同年龄组间耳石重量差异显著(P<0.05);耳石重量的频率分布能分离体长相近而年龄不相同的个体,与耳石磨片的年龄观察结果基本一致,即耳石重量和年龄之间的关系显著相关(P<0.05)。因此,耳石重量可直接确定锦江河黄颡鱼的年龄或作为验证根据耳石的钙化构造来判定年龄的精确性。     

条石鲷早期鳞被的形成和初生鳞的发育

采用茜素红染色法对条石鲷(Oplegnathus fasciatus)早期发育阶段鳞片的形成和发育过程进行了观察和测量。结果显示条石鲷鳞片的起始中心有3个,分别是鳃盖后缘、侧线上方和尾柄处。在水温为24~27℃的人工培育条件下,20日龄在这3个起始中心最早出现鳞片,鳃盖后缘至胸鳍基部的鳞被向上下前后扩展,胸鳍后缘的侧线上方鳞被向下和向前后扩展,尾柄处的鳞被前后扩展,头顶部的鳞被向四周扩展,到40日龄时鱼体全身被鳞进入幼鱼期。通过观察还发现,鳞片向下方发育的速度快于上方,上下方向的发育速度快于前后方向。向前扩展到鳃盖后暂停,向后发育到达尾柄末端,最后出现鳞片的部位是鳃盖。条石鲷鳞片为栉鳞,较细小。在鱼体的同一时期同一部位,鳞片的大小存在较大的差异。初生鳞鳞嵴(环片)数目与发育阶段的关系可用二次方程表示。     

基于microCT扫描技术的鲤骨骼和显微结构分析

了解活体鲤（Cyprinuscarpio）骨结构、形态、连接、空间分布以及骨骼矿物质组成对鲤的选育、行为学研究以及肉品加工有重要的意义。X射线显微CT技术（microCT）对样品没有破坏,可实现活体检测,并能获取活体任意形态的结构参数。因此,文章通过这项技术来研究活体鲤的骨骼状况。结果显示,脊椎骨与头、尾相连,胸鳍位于头骨后,背鳍、腹鳍和尾鳍与整个脊椎骨并不相连。骨体积分数和骨小梁厚度在腹鳍较高,头尾较低;骨表面积体积比、骨小梁数量和骨小梁间隔在头部较高,腹鳍较低;骨矿物质含量、骨矿物质密度和组织矿物质含量在背鳍最高;骨体积分数在腹鳍最高,胸鳍、背鳍和尾鳍次之,头尾较低。骨小梁厚度、矿物质含量等在背鳍、腹鳍部位较高,这可能与鲤的运动有关,而头骨表面积体积比、骨小梁数量和骨小梁间隔较高可能与头部的复杂结构密切相关。     

Distribution of the introduced cyprinid herpesvirus 3 in a wild population of common carp, Cyprinus carpio L.

Cyprinid herpesvirus 3 (CyHV-3), which causes a lethal disease in common carp, Cyprinus carpio L., and koi, C. carpio koi , first occurred in Lake Biwa, Japan in 2004. To elucidate distribution of CyHV-3 in a wild common carp population, we conducted a PCR survey of CyHV-3 among such fish in Lake Biwa in 2006. Only 6% (1/18) of the common carp smaller than 300 mm were positive with PCR, whereas 31% (18/58) of fish larger than 300 mm were positive. To evaluate their past exposure to CyHV-3 infection based on the presence of antibodies, we also measured the levels of serum anti-CyHV-3 antibodies in the carp, using an enzyme-linked immunosorbent assay. None (0/26) of the fish smaller than 300 mm was positive for the antibodies, whereas 54% (33/61) of fish larger than 300 mm were positive. Of the antibody-positive individuals, 44% (14/32) were also positive by PCR strongly suggesting that wild common carp that survived infection become CyHV-3 carriers. Five individuals were positive by PCR but negative for antibodies indicating that their infection with CyHV-3 had occurred recently. These results suggest that transmission of CyHV-3 from carriers to naïve common carp is still occurring in Lake Biwa.     

Fin erosion in a feral population of goldfish, Carassius auratus (L.), exposed to bleached kraft mill effluent

Abstract. The prevalence of acute and healed fin erosion in goldfish, Carassius auratus (L.), from the Waikato River, New Zealand, peaked in the vicinity of a pulp and paper mill which utilized a kraft pulping process in association with chlorine bleaching, and decreased down the effluent gradient. About 49% of goldfish sampled from the Kopakorahi Stream. which is part of the effluent treatment system (site 1), displayed pathological signs of fin erosion, whereas about 9% of control fish from a reference site located upstream of the official effluent discharge point were similarly affected. Fin erosion was less prevalent in male than in female goldfish, and occurred with different frequencies on different fins, the pectoral (56%) and caudal fins (33%) being most affected. Both the pectoral and caudal fins also had significantly higher proportions of healed erosion rather than acute erosion. The prevalence of acute and healed fin erosion increased significantly with increasing fish length (age). Physical deformities, predominantly in the form of eroded or otherwise malformed opercula, were found in nearly 5% of fish caught at site 1, but were not observed at the reference site. Changes in processing and bleaching technology at the pulp and paper mill in question have since been carried out, and long-term studies arc planned to monitor any subsequent improvements in fish health.     

Fluctuating asymmetry, abnormalities and parasitism as indicators of environmental stress in cultured stocks of goldfish and carp

Knowledge about the effects of captivity and environmental stress on fish populations is basic to culture them for ornamental, conservation or exploitation purposes. The aim of this study was to test how captivity affect morphological development of bilateral characters and whether levels of fluctuating asymmetry, morphological abnormalities and ectoparasites reflect developmental stress caused by adverse environmental conditions in two species of cyprinids, goldfish Carassius auratus and two varieties of carp Cyprinus carpio, scale and mirror carp. Samples from captivity were caught in an artificial pond (Madrid City, Spain), which presents poor environmental conditions; while samples from nature were captured in the Ebro River basin (NE Spain). Six meristic and four morphometric bilateral characters were measured and compared between the two samples. Additionally, the incidence of morphological abnormalities and ectoparasites was also recorded. Captive goldfish presented significant lower number of scales of the lateral line, scale rows above lateral line and length of pectoral and ventral fins. Captive carps showed significant shorter first barbels and longer ventral fins. Ornamental goldfish showed significant higher levels of fluctuating asymmetry than wild samples for number of branched rays of pectoral fin, lateral line, scale rows below lateral line and length of pectoral and ventral fins. Ornamental carps presented a similar trend for the same characters, except for branched rays and length of pectoral fins, together with the length of second barbels. In the artificial pond, the incidence of abnormalities was higher in carp, whereas goldfish showed a higher occurrence of ectoparasites. These facts support the hypothesis of a different species response to environmental stress. The overall results indicate that fish from the artificial pond are subjected to environmental stress caused by adverse conditions such as overcrowding and lower water quality. Moreover, estimated parameters in this study mean a useful tool to detect developmental instability in confined fish.     

鲤病毒病原的感染性测定

为查明养殖鲤（Cyprinus carpio）突然大批发病死亡的原因，对鲤病样品进行了细胞攻毒、空斑测定、电镜观察，以及鱼体感染等实验。先以患病鲤的组织匀浆液，经过滤后，分别接种到草鱼鳍条细胞（GCF）、鲤上皮瘤细胞（EPC）等14种培养细胞中。利用倒置显微镜观察显示，在1-2d内，该病鱼组织匀浆液可使其中9种细胞出现典型的细胞病变。收集出现病变的细胞液（即病毒悬液），进一步进行病毒滴度检测、空斑测定和鱼体感染实验。结果显示，在GCF细胞上的病毒滴度为10^7.3TCID50／mL；在FHM，TSB和GCO等细胞中可产生直径1～4mm的圆形空斑，空斑的大小与宿主细胞的种类和接种的病毒浓度有关。通过对感染细胞制备的超薄切片和病毒负染样品进行电镜观察，显示这是一类呈典型子弹头样的弹状病毒颗粒。感染了病毒悬液的鲫和鲤先后在第2天和第3天开始出现病症，间隔1～2d后发病的鱼开始死亡，至第14天，两种感染鱼的死亡率均达到83．3％。收集人工感染后濒死的鲫和鲤，分别制备组织匀浆液，回接感染鱼类培养细胞，24h内能使其出现与原发病鲤组织匀浆液所引起的类似的细胞病变。因此证实患病鲤是由病毒病原感染所致。[中国水产科学，2006，13（4）：617—623]     

Fin development in stream- and hatchery-reared Atlantic salmon

To determine the effect of development and environment on fin growth, we measured fin lengths of juvenile Atlantic salmon (Salmo salar) from two hatcheries (August, October and April–May), stream-reared fish (July and October) stocked as fry into two tributaries, and smolts from the main stem of the Connecticut River (May). For stream-reared parr, there was a linear relationship between the dorsal, caudal and anal fins with fork length, while the pectoral, pelvic and adipose fins exhibited a curvilinear relationship with fork length. Parr from a high gradient stream had larger caudal fins than fish from a low gradient stream, but other fins did not differ. Regression lines for the fins of stream-reared smolts were all linear when fin length was regressed against fork length. Stream-reared parr had larger pectoral, pelvic and anal fins than smolts of similar size while dorsal and caudal fin lengths did not differ. Regression equations formulated using the fins of stream-reared parr were used to calculate the percent difference (100×observed fin length/expected) in fin lengths between stream- and hatchery-reared parr. The pelvic, adipose, caudal and anal fins of hatchery-reared parr showed no signs of degeneration by the first sampling period 7 months after hatching, whereas degeneration in the pectoral (13–20%) and dorsal (15–18%) fins was evident at this time. By the end of the study, degeneration was present in every fin except the adipose, with the pectoral (35–65%) and dorsal (32–58%) fins exhibiting the greatest amount of fin loss. All fins of hatchery-reared parr became shorter with time. There were minor differences in fin degeneration among parr from the two hatcheries, but the overall pattern of decreasing fin size was similar, indicating a common cause of fin degeneration. Comparison of stream- and hatchery-reared fish is a valuable means of determining the impact of captive environments on fin growth.     

Plasma vitellogenin levels in male common carp Cyprinus carpio and crucian carp Carassius cuvieri of Lake Kasumigaura

In order to investigate the possible influence of estrogenic environmental endocrine disruptors on the reproductive activity of fish in Lake Kasumigaura, plasma levels of vitellogenin (VTG), a biomarker of estrogen exposure, were measured in wild and cultured male common carp Cyprinus carpio and wild crucian carp Carassius cuvieri . Testicular histology and plasma steroid hormone levels were also examined. Fish were collected from June 1998 to August 1999. Plasma VTG levels in most fish examined were below a detection limit (40 ng/mL) throughout the sampling period, and a small amount of VTG (43.5 ng/mL–1680 ng/mL) compared to that in females was detected in some fish. Active spermatogenesis in the testis and increased levels of plasma sex steroids were observed in most of the fish examined. Thus, no marked influence of estrogenic chemicals was detected in the reproductive activity of male common carp and crucian carp in Lake Kasumigaura collected from the sampling sites in the present investigation.     

低鱼粉日粮添加蛋氨酸对幼鲤生长的影响

以鱼粉10%的玉米大豆粕型幼鲤饲料为对照组(A),降低饲料鱼粉含量为5%后,分别添加不同水平的DL-蛋氨酸及其羟基类似物添加量分别为B:0.5%DL_蛋氨酸、C:0.514%蛋氨酸羟基类似物、D:0.564%蛋氨酸羟基类似物、E:0.614%蛋氮酸羟基类似物,比较研究用豆粕代替部分鱼粉,添加蛋氨酸及其羟基类似物对幼鲤的...     

三峡水库高、低水位下开县汉丰湖鱼类资源变化特征

2012年10-11月三峡水库高水位期以及2013年5-6月三峡水库低水位期调查了汉丰湖的鱼类资源,研究三峡水库高、低水位下汉丰湖鱼类种类组成、优势种类、生物多样性以及群落相似性,并对不同水位下汉丰湖鱼类群落结构的扰动特征和增殖放流情况进行了辨识和探讨。共采集到鱼类17 553尾,42种,隶属于4目7科31属。其中三峡水库低水位时采集到鱼类33种,高水位时采集到鱼类34种。汉丰湖优势种类在三峡水库低水位时为银鮈Squalidus argentatus、似鳊Pseudobrama simoni、歺又鱼Hemiculter leucisculus、蒙古鲌Culter mongolicus mongolicus和鲤Cyprinus(Cyprinus)carpio;在三峡水库高水位时为似鳊、鲤、鲫Carassius auratus、张氏歺又鱼Hemiculter tchangi和鲇Silurus asotus。汉丰湖鱼类Shannon-wiener多样性指数(H’)、Simpson优势度指数(D)、Pielous均匀度指数(E)和Margalef种类丰富度指数(R)在三峡水库低水位时分别为1.63、0.67、0.46和3.52;在三峡水库高水位时分别为2.15、0.80、0.61和4.34。三峡水库低、高水位时汉丰湖鱼类群落结构的Bray-Curtis相似性仅为26.52%,喜缓、静水生境的银鮈、张氏歺又鱼、鲤、歺又鱼、鲫、鲇、似鳊和蒙古鲌是群落结构差异的主要种类,累积差异贡献率为90.67%。汉丰湖鱼类群落在高水位时受到中等程度的干扰,而在低水位时受到严重干扰。建议每年均放流鲢、鳙、草鱼并进一步加大放流规模。     

一种保存鱼类鳍条的便捷方法

鳍条是研究鱼类分子生物学常用的组织样本,长期保存的鳍条为实验提供源源不断的基因组DNA。本研究介绍一种便捷保存鱼类鳍条用于DNA提取的方法---干燥法,并说明了用此方法保存鲤（Cyprinus carpio）、施氏鲟（Acipenser schrenckii）和虹鳟（Onchorynchus mykiss）鳍条效果。采集新鲜鳍条,贴在滤纸等吸水性强的纸张上,覆盖另一张滤纸,防止受潮、霉变,自然干燥后在室温保存3个月。剪取部分鳍条样本,用常规酚、氯仿抽提法提取基因组DNA,分别用紫外分光光度计、琼脂糖凝胶电泳、PCR扩增方法检测基因组DNA的质量。结果显示：用干燥法保存的3种鱼类的鳍条样品,提取获得的基因组DNA的OD260/OD280值在1.82-1.89之间, OD260/OD230值在2.29-2.70之间,琼脂糖凝胶电泳条带清晰明亮,可以用于后续的分子生物学研究。本研究证实用干燥法长期保存鱼类鳍条能够获得高质量的基因组DNA,为珍贵样品的长期保存提供了一种行之有效的方法,也为远距离、大样品的采集和保存提供了便捷的选择。