饥饿和再投喂对短须裂腹鱼幼鱼体组分、消化酶活性及RNA/DNA的影响

通过探究饥饿和再投喂过程中短须裂腹鱼幼鱼的鱼体组分、消化酶活性及RNA/DNA的变化规律,为其人工养殖提供科学依据。以短须裂腹鱼幼鱼为研究对象,用凯氏定氮法测定粗蛋白,索氏抽提法测定粗脂肪,恒温干燥失重法测定水分,马弗炉灼烧法测定粗灰分,电感耦合等离子体发射光谱法测定矿质元素,分光光度法测定消化酶活性和DNA、RNA含量。饥饿后,幼鱼粗脂肪含量在饥饿5天时降至最低值5.01%,粗蛋白含量在饥饿2天时降至最低值13.61%;水分和灰分上升,鱼体的Ca和P含量上升;鱼体K、Na、Mg及Fe含量均先上升再下降,且在饥饿9天时上升至最大值;幼鱼肝胰脏蛋白酶和脂肪酶活性均呈先升高后下降再升高趋势;淀粉酶活性下降,肌肉中的DNA含量上升,RNA含量下降,RNA/DNA下降。恢复投喂后,S15、S25组Fe含量低于对照组水平,各组淀粉酶活性均恢复至正常水平,S15和S25组脂肪酶活性显著低于对照组水平(P<0.05),S15、S25组RNA含量及RNA/DNA极显著下降(P<0.01)。在饥饿9天时,短须裂腹鱼幼鱼的生化指标未受显著影响,恢复投喂后的生化指标与对照组均无显著差异。建议在其养殖中饥饿时间不超过9天。     

Hydrogeomorphic factors drive differences in otolith morphology in fish from the Nu‐Salween River

Understanding the relationship between intraspecific phenotypic variation and habitat is fundamentally important to ecology and evolution. However, it is largely unknown whether the environment drives the morphological variation in riverine fish otoliths, which are potential phenotypic markers. In this study, we investigated morphological variations in the otoliths of an endemic Chinese fish (Schizothorax nukiangensis Tsao) collected from seven sites with varying environmental gradients along the Nu‐Salween River. We compared morphological characters of S. nukiangensis otoliths among sampling sites and identified environmental sources of otolith morphological variation using multivariate regression trees and multiple factor analysis. Results showed that S. nukiangensis otoliths collected from different habitats were significantly different in morphology, mainly at the rostrum, excisura and posterior rim. Variations in otolith morphology (specifically the increase in otolith length) were predominantly governed by average river gradient; this might be a functional response to hydrogeomorphic conditions. Other environmental gradients (i.e., altitude, latitude and average annual temperature) played a minor role in otolith shape. This study highlighted the role of environmental factors in determining the otolith shape in riverine fish; thus, species and population discriminations based on otolith morphology should consider intraspecific variability.     

Hematological Parameters and Blood Cell Morphology of Male and Female Schizothorax (Racoma) davidi (Sauvage)

The aim of this study was to obtain a basic knowledge of the hematology of Schizothorax (Racoma) davidi (Sauvage). The results showed that red blood cell and white blood cell counts as well as mean cellular hemoglobin concentration were significantly higher in females than in males, while mean cell volumes were significantly lower in females than in males. No significant differences were seen in other hematological parameters in relation with gender. Under light microscope, erythrocytes (mature and immature), leukocytes (neutrophils, lymphocytes, and monocytes), and thrombocytes were distinguished. Mature erythrocytes were ellipsoidal cells with oval, central nucleus. Neutrophils contained banded or segmented nuclei. Small lymphocytes had a very thin rim of basophilic cytoplasm. Monocytes often possessed vacuoles in their cytoplasm. Thrombocytes existed in several forms with relatively large nucleus surrounded by a pink‐stained or hyaline cytoplasm. The percentage of the different leukocytes revealed predominance of neutrophils and small lymphocytes, followed by monocytes and large lymphocytes. The neutrophil percentages of each stage showed that metamyelocyte accounted for the most, followed by banded neutrophils. This investigation could be used for evaluation of the health status of cultured male and female S. davidi and will provide early detection of clinical pathology.     

伊犁裂腹鱼生物学特性

【目的】研究伊犁河水系特克斯河伊犁裂腹鱼系统生物学特性。【方法】2018~2020年通过采集伊犁河水系特克斯河伊犁裂腹鱼样本,运用经典鱼类生物学方法鉴定其形态特征,分析其年龄与生长等种群性状。【结果】特克斯河伊犁裂腹鱼,形态特征与其他水系裂腹鱼差异小,口下缘无硬质角质;体背细鳞,臀鳞较发达;体背部淡青色,微泛黄,体侧和腹部银白色,小个体体侧有斑点。体长均值为（21.56±10.48） cm,不符合正态分布。体重均值为（404.00±483.11） g,不符合正态分布。年龄均值（7.36±3.97）⁺,不符合正态分布,其中5⁺为优势年龄个体,占11.40％。体长和体重相关方程为：W=0.022 L³（R²=0.959 4）;渐进体长L∞=65.48 cm,生产系数k=0.06,W∞=4716.67 g,t₀= 0.09,t_i=18.40⁺;生长方程为：L_t = 65.48（1-e^{-0.06（t -0.09）}） 和W_t = 4 716.67（1-e^{-0.06（t -0.09）}）³。伊犁裂腹鱼成熟系数和丰满系数：GSI=（3.54±1.94）和K=（2.34±0.63）。【结论】伊犁河水系特克斯河伊犁裂腹鱼着细鳞,较大型土著鱼类,年龄结构差异较大,匀速生长,适应性较强,水域生态较优,生长周期较长,性状较稳定,拐点年龄大,性成熟周期长。     

齐口裂腹鱼鳃表面结构扫描电镜观察

用扫描电镜观察齐口裂腹鱼鳃表面结构 ,发现齐口裂腹鱼鳃的鳃弓、鳃丝、鳃小片上皮细胞表面均具有隆起的微脊 ;微脊形态特征随在鳃上分布部位不同而不同 ,与其他硬骨鱼比较有较大差异 ;鳃小片上皮细胞表面结构与其呼吸功能密切相关。     

齐口裂腹鱼幼鱼饲料中营养素适宜含量和最适能量蛋白比的研究

以增重率、饲料系数和蛋白质效率为评价指标,用正交试验法L9(34)对齐口裂腹鱼Spchizothoraxprenati摄食的9种配合饲料中蛋白质、脂肪、总能、无机盐需要量及最适能量蛋白比进行了研究。结果表明:各营养素对幼鱼的生长及蛋白质效率的影响大小依次为蛋白质>总能>脂肪>无机盐;适合幼鱼生长所需的蛋白质、脂肪、无机盐的质量分数分别为40.06%、6.02%、4%,总能为13.09 kJ/g,最适能量蛋白比(E/P)为32.68 kJ/g;各营养素中蛋白质为影响幼鱼生长和鱼体成分的主要因素,饲料蛋白质水平对鱼体水分和脂肪含量有显著影响(P<0.05),其它营养素水平变化则对鱼体成分没有显著影响(P>0.05)。     

塔里木裂腹鱼资源与分布的调查研究

于2003~2006年在新疆塔里木河水系调查了塔里木裂腹鱼(Schizothorax biddulphi Günther)的分布和资源现状。结果表明:塔里木裂腹鱼在流域内各主要河流均有分布;分布范围较广,但分布区域缩小;栖息环境条件恶劣,水温低,饵料少;主要种群分布在海拔1000~3300 m区域;个体低龄化,种群数量占土著鱼类的比例小。水利工程、过度捕捞、引入外来物种和生态环境恶化等因素已对该鱼资源造成严重破坏。     

抗浪鱼MC4R基因的PCR扩增及序列分析

[目的]对抗浪鱼MC4R基因进行PCR扩增。[方法]采用PCR方法,依据鲫鱼的黑素促黑素受体-4（MC4R）基因保守区的核苷酸序列,采用引物设计软件,对抗浪鱼的MC4R基因设计出一对引物进行PCR扩增和纯化测序,并利用phylip软件对抗浪鱼和其他已知MC4R基因序列的鱼类构建基因进化树。[结果]抗浪鱼MC4R基因的扩增长度为1001bp。9种鱼类的MC4R核苷酸序列聚为2大类。其中,比目鱼单独聚为一类;斑剑尾鱼、舌齿鲈、白斑角鲨、斑马鱼、抗浪鱼、黑青斑河豚、中华多纪豚和红旗东方豚聚为一类。[结论]抗浪鱼与斑马鱼的亲缘关系最近,与比目鱼的亲缘关系最远。     

重口裂腹鱼消化道黏液细胞类型及分布研究

应用AB-PAS染色法及JD-801形态学图像分析系统,对重口裂腹鱼(Schizothorax davidi Sauvage)消化道黏液细胞进行了分型研究。结果显示:重口裂腹鱼消化道黏液细胞可分为Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型。其中,口咽腔和食道黏液细胞以Ⅱ型为主;前肠以Ⅰ型为主;中肠以Ⅲ型、Ⅳ型为主;后肠以Ⅱ型为主。结果表明,黏液细胞分布密度与各段消化道功能密切相关。     

塔里木裂腹鱼胚胎和仔鱼的发育与生

2012年4月至6月,在新疆博湖苇业股份有限公司三苇场（新疆且末县）进行了塔里木裂腹鱼的人工繁殖和苗种培育研究。人工授精的受精率为83%,孵化率为89%。塔里木裂腹鱼受精卵在16~19 ℃下历时约93 h经过卵裂期、囊胚期、原肠期、神经胚期、孵化期等时期孵化出膜,初孵仔鱼平均体长（7.29±0.18） mm。1~25日龄的仔鱼可分为卵黄囊期、弯曲前期、弯曲期和弯曲后期4个发育阶段;对仔鱼阶段的全长（LT）、头长（LH）、躯干长（LQ）、尾部长（LC）、眼径（D）、体高（HB）、头高（HH）、湿重（W）8项生长指标的特定生长率进行了分析,结果表明仔鱼各个阶段的发育是异速的;仔鱼全长、尾部长、头长、头高、体高、眼径的生长方程都为二次多项式,体长与体质量之间呈指数相关。