侧条光唇鱼两邻近地理种群的繁殖生物学特征的差异

2007年7月至2009年6月间,分别于北江中上游及流溪河上游支流采集侧条光唇鱼样本358尾及522尾,对两种群的繁殖生物学特征的差异进行了研究。研究结果显示,两种群雌鱼及雄鱼的最小性成熟年龄均为1 龄,北江种群雌性由1 ~5 龄组成,雄性由1 ~4 组成,性比为雌性：雄性=1:1.73;而流溪河种群雌性由1 ~4 龄组成,雄性由1 ~3 组成,性比为雌性：雄性=1:1.40。北江种群繁殖群体的各年龄组体长及体重均较显著大于流溪河种群。北江种群的繁殖期约为2~10月份,高峰期为3~7月份;而流溪河种群繁殖期为2~8月份,高峰期约为每年的5~7月份;繁殖期内,北江种群雌性及雄性的成熟系数均高于流溪河种群。北江种群各年龄组或体长组的绝对生殖力、体长相对生殖力与体重相对生殖力均极显著地大于流溪河种群。本文结合北江和流溪河在营养状况、捕捞压力及溪流级别上的差异对研究结果进行了分析和讨论。     

Breeding strategy of Acrossocheilus fasciatus in the Puxi Stream of the Huangshan Mountain

Breeding strategies of Acrossocheilus fasciatus were studied from 592 specimens collected monthly during May 2007 and April 2008 in the Puxi Stream of the Huangshan Mountain.Sex ratio of the studied population was 0.90∶1(♀∶♂),not significantly different from 1∶1.Both sexes reached their first sexual maturity at age 2(the second calendar year of their birth).Fifty percent of females and males reached maturity at a total length of 69.75 mm and 69.36 mm respectively,and the minimum total length was 61.54 mm an...     

Acrossocheilus multistriatus,a new species of barbine fish(Teleostei: Cyprinidae) from the Zhujiang River basin,South China

A new barbine cyprinid fish, Acrossocheilus multistriatus sp. nov., is described from the Zhujiang River(Pearl River) basin in South China. It is separated from all other barred congeners except A. monticola by its unique coloration pattern of 8–12 vs. 5–7 vertical dark bars on the dorsum and flank. Although 8 vertical black bars are also present in specimens of A. monticola, the new species is distinct from it by having a well-developed(vs. poor-developed) lower lip, with or without a median interruption(vs. with a median interruption which wider than 1/2 mouth width) on lower jaw, the lower jaw entirely covered(vs. uncoverd) by the lower lip, body depth 22.57%–25.22% SL(vs. 25.64%–32.26% SL). Additional characteristices as follows: last simple dorsal-fin ray soft without serration; dark stripes on membranes between dorsal-fin rays; dark stripes absent on membranes between anal fin rays; maxillary barbels longer than eye diameter, extending to posterior edge of eyes.     

北江侧条光唇鱼的年龄与生长特征

于2007年7月至2009年6月间,在北江中上游地区采集了358尾侧条光唇鱼(Acrossocheilus parallens)样本,以鳞片作为年龄鉴定材料,对其年龄与生长特征进行了研究。侧条光唇鱼鳞片上年轮结构清晰,前区主要为疏密型,而侧区主要为切割型;鳞片的边缘生长率显示,其年轮的主要形成期为2~3月份。样本中的雌性由1+~5+龄5个龄组组成,优势龄组为1+~3+龄;而雄性由1+~4+龄4个龄组组成,优势龄组为1+~2+龄。雌鱼的体长(L,cm)范围为5.7~14.8 cm,集中于7.0~13.0 cm之间;体重(W,g)范围为4.75~108.40 g,集中于10.00~30.00 g之间。雄鱼的体长范围为5.7~12.6 cm,集中于7.0~11.0 cm之间;体重范围为4.40~61.50 g,主要集中于10.00~20.00 g之间。体长与体重的关系为W=0.017L3.167、W♀=0.017L3.198、W♂=0.023L3.025,协方差分析表明,雌、雄个体在体长与体重关系上,差异显著。体长(L,cm)与鳞径(R,mm)呈线性关系,L♀=3.126R+1.869、L♂=2.875R+2.152。拟合出Von Bertalanffy生长参数,雌性L∞=17.143 5 cm,k=0.270 5,W∞=150.347 4 g,t0=﹣0.614 6龄;雄性L∞=17.236 5 cm,k=0.226 9,W∞=126.468 6 g,t0=﹣0.921 5龄。雌鱼体重生长的拐点年龄为3.68龄,拐点体长约为11.8 cm,体重约为45.26 g;雄鱼的拐点年龄为3.96龄,拐点体长约为11.5 cm,体重约为37.60 g。作为渔业对策,建议起捕年龄3龄以上或体长10 cm以上的个体。     

珠江水系鱼类一新纪录——带刺光唇鱼(鲤形目：鲤科)

2008年5月及2010年8月在广东省增城市及河源市采得一批鱼类标本,其中20尾经鉴定为珠江水系鱼类新纪录——带刺光唇鱼(Acrossocheilus spinifer Yuan,WuZhang,2006)。该种主要鉴别特征包括:(1)体侧具有5~6条垂直的黑色条纹,每条约占2列鳞片宽,向下延伸至侧线以下2行鳞片,呈对称或不对称分布;(2)第2条垂直条纹位于背鳍末根不分枝鳍条的下方;(3)背鳍末根不分枝鳍条为粗壮的硬刺,后缘具细小的锯齿;(4)背鳍鳍间膜外缘2/3黑色。标本现保存于华南师范大学生命科学学院鱼类标本室。     

Mitochondrial DNA phylogeography of Acrossocheilus paradoxus (Cyprinidae) in Taiwan

Nucleotide sequences of 3' end of the cytochrome b gene, tRNA genes, D-loop control region, and the 5' end of the 12S rRNA of mitochondrial DNA (mtDNA) were used to assess the genetic and phylogeographic structure of Acrossocheilus paradoxus populations, a Cyprinidae fish of Taiwan. A hierarchical examination of populations in 12 major streams from three geographical regions using an analysis of molecular variance (AMOVA) indicates high genetic differentiation both among populations (PhiST = 0.511, P < 0.001) and among regions (PhiCT = 0.368, P < 0.001). Limited migration largely contributed to the genetic differentiation. High nucleotide diversity (1.13%) and haplotype diversity (0.80%) were detected among populations. The degree of genetic differentiation was correlated with geographical distance between populations, a result consistent with the one-dimensional stepping stone models. A neighbour-joining tree recovered by (DAMBE) supports the pattern of isolation by distance and reveals a closer relationship between populations of the central and southern regions. A minimum spanning network based on nucleotide substitutions reflected migration routes from populations of the central region to the northern and southern regions, respectively. Postglacial colonization and expansion can explain the phylogeographical pattern. Single and ancient migration events may have allowed the northern region to attain the monophyly of mtDNA alleles. In contrast, most populations within geographical regions are either paraphyletic or polyphyletic due to the relatively shorter time period for coalescence. Both low haplotype number and genetic variability suggest a bottleneck event in the Chingmei population of northern Taiwan. Based on coalescence theory, the monophyly of the Tungkang population of the southern region may be associated with a founder event.     

Acrossocheilus spinifer, a new species of barred cyprinid fish from south China (Pisces: Teleostei)

Acrossocheilus spinifer sp. nov. is described from the river basins in Fujian Province and the Han Jiang basin in Guangdong Province, south China. It is one of the barred Acrossocheilus species sharing five or six vertical bars on the flanks, with each bar being two scales in width. Acrossocheilus spinifer sp. nov. is morphologically most similar to Acrossocheilus wenchowensis , but distinguished from it by: a colour pattern of all vertical bars extending ventrally to the second scale row below the lateral line, and having the second bar placed posterior to the base of the last simple dorsal‐fin ray, a blunt snout; and a stout, last simple dorsal‐fin ray. Acrossocheilus spinifer sp. nov. resembles Acrossocheilus kreyenbergii and Acrossocheilus stenotaeniatus with which it shares a stout, last simple dorsal‐fin ray with a serrated posterior edge, but is separated from both species by having a narrow median interruption in the lower lip, a lower jaw fully covered by the lower lip when viewed ventrally and the second vertical bar placed posterior to the base of the last simple dorsal‐fin ray. The absence of a longitudinal stripe extending along the lateral line on the flanks in males readily distinguishes A. spinifer sp. nov. from four other species, namely Acrossocheilus fasciatus , Acrossocheilus paradoxus, Acrossocheilus parallens , and Acrossocheilus jishouensis .     

光唇鱼消化道的形态结构特征

采用解剖及石蜡切片显微技术,观察研究了光唇鱼消化道的形态结构特征。消化道由口咽腔、食道、肠构成。口下位、马蹄形,无颌齿,具咽齿,齿式为4/4。舌较小,前端游离,舌粘膜表层为复层鳞状上皮,有较多的杯状细胞和味蕾。食道及肠均由粘膜层、粘膜下层、肌层及外膜构成。食道内皱襞发达,粘膜层有大量杯状细胞。肠道盘曲,由前、中、后肠组成,肠长/体长为1.84±0.24;前肠管腔较大,中、后肠管腔渐变小;前、中肠皱襞及纹状缘比后肠发达;前肠及后肠杯状细胞较少,中肠杯状细胞较多。光唇鱼消化道的形态结构特征与其食性相适应。     

光唇鱼属鱼类一新种

本文记述采自湖南吉首的鲤科鱼类１新种,命名为吉首光唇鱼Ａｃｒｏｓｏｃｈｅｉｌｕｓｊｉｓｈｏｕｅｎｓｉｓｓｐ．ｎｏｖ．。新种有以下与同属其他种类相区别的特点：下唇两侧瓣间隙小,几相接触;背鳍末根不分支鳍条柔软不加粗,后缘光滑;背鳍及臀鳍鳍条间膜有黑色条纹;体侧具不规则的大块黑斑或具模糊不清的垂直或纵行条纹等。新种与半刺光唇鱼Ａ．ｈｅｍｉｓｐｉｎｕｓｈｅｍｉｓｐｉｎｕｓ和带半刺光唇鱼Ａ．ｈｅｍｉｓｐｉｎｕｓｃｉｎｃｔｕｓ较为相似。