乐山棒花鱼形态特征的两性异形和雌性个体生育力

测定了乐山棒花鱼(Abbottina kiatingensis)繁殖期形态特征包括体长、头长、头宽、头高、吻长、眼后头长、眼径、眼间距、体高、尾柄长、尾柄高、尾鳍长、背鳍基前距、背鳍基长、腹鳍基前距、腹臀间距、体重和去内脏体重的两性异形和雌性个体生育力。繁殖期雄性个体的数量显著多于雌性个体,雌雄两性个体的体长差异不显著。特定体长的雌性个体的头长、头宽、头高、吻长、眼后头长、尾柄高、背鳍基前距、背鳍基长和去内脏体重显著小于雄性个体,其余指标不存在明显的差异。回归分析表明,乐山棒花鱼的怀卵数量与体长和体重回归关系显著,雌性通过个体大小(体长和体重)的增加来提高个体生育力。     

黄颡鱼的两性异形和雌性繁殖特征

测定了黄颡鱼成体的体长、头长、头宽、头高、吻长、眼径、眼间距、眼后头长、体高、尾柄高、背鳍基前距、背鳍基长、尾柄长、腹鳍基前距、背鳍脂鳍间距、腹鳍臀鳍间距、尾鳍长、体重、去内脏体重等形态指标以及雌体的怀卵数量。雌性成体的体长显著小于雄性成体。其它局部特征皆与体长呈正相关,回归剩余值的t—检验表明,雌性成体的眼径、头高、体高、腹鳍基前距、体重显著大于雄性成体,其它局部形态特征不存在显著的两性差异。黄颡鱼雌体通过个体大小的增加和腹部形态的改变增加腹腔容量,增加繁殖输出。     

棒花鱼形态特征的两性异形和雌性个体生育力

测定了棒花鱼(Abbottina rivularis)繁殖期形态特征包括体长、头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、胸鳍腹鳍间距、尾柄长、尾鳍长和体重的两性异形和雌性个体生育力。结果表明,雄性个体的数量显著多于雌性个体,雄性个体的体长显著大于雌性个体。特定体长的雌性个体的胸鳍腹鳍间距显著大于雄性个体,头长、头宽、头高、眼间距、鼻间距、背鳍基长、胸鳍长、尾柄长和尾鳍长显著小于雄性个体,雌雄两性体重不存在显著差异。棒花鱼的怀卵数量与体长和体重回归关系显著。偏相关分析显示,当控制第三者恒定时,怀卵数量与体长和体重呈正相关但不显著。棒花鱼存在个体大小和其他局部特征显著的两性异形,雌性个体主要通过腹腔容积的增加提高个体生育力。棒花鱼形态特征的两性异形是性选择和生育力选择共同作用的结果。     

A new miniature species of the genus Triplophysa (Balitoridae: Nemacheilinae) from Yunnan, China

During a re-examination of museum specimens of Triplophysa species, some specimens that had been collected from the Jialonghe River in Yunnan Province, China, in April 1975, were identified as a new species. Triplophysa parvus n. sp. can be distinguished by the following combination of characters: dorsal fin rays 3, ; anal fin rays 3, ; pectoral fin rays 1, 11; scales absent; two saddle-like blotches with fuzzy borders cranial to the dorsal fin and four saddle-like blotches caudal to the dorsal fin; distal margin of the dorsal fin emarginate; pelvic fin reaching caudally almost to the anus; anus located immediately cranial to the origin of the anal fin; caudal fin forked; caudal chamber of air bladder reduced to a small free protuberance; head slightly laterally compressed, head deeper than wide at nape; length of caudal peduncle being 18.0–20.0% of standard length; depth of caudal peduncle being 7.8–8.4% of standard length; eye diameter 17.6–21.4% of head length; body depth being 60.7–70.2% of head length; caudal peduncle depth being 39.1–45.0% of caudal peduncle length; and body width at the base of caudal peduncle 59.0–68.0% of the body depth at the base of caudal peduncle. These characters allow a distinction from the similar species of T. nasobarbatula, T. nandanensis, and T. macromaculata.     

中国平鳍鳅科鱼类一新纪录种

20 0 2年 6月于云南省河口瑶族自治县采集到鱼类标本 3尾 ,经鉴定为我国华吸鳅属鱼类之新纪录种———红河华吸鳅 (Sinogastromyzonchapaensis)。测量标本 3尾均保存在台湾清华大学。体长 35～ 5 0mm。背鳍iii,8;臀鳍ii,5 ;胸鳍xiv～xv ,14～ 16 ;腹鳍x～xi,11～ 12。侧线鳞 6 0～ 6 4。体长为体高的 7 0～ 7 2倍 ,为体宽的 4 3～ 4 6倍 ,为头长的 4 9～ 5 1倍 ,为尾柄长的 5 4～ 6 0倍 ,为尾柄高的 12 7～ 14 0倍 ,为背鳍前距的 2 2倍 ,为腹鳍前距的 2 4～ 2 7倍。头长为头高的 1 8～ 1 9倍 ,为头宽的 0 9～ 1 1倍 ,为吻长的 2 0～2 1倍 ,为眼径的 4 7～ 5 0倍 ,为眼间距的 2 0～ 2 3倍。尾柄长为尾柄高的 2 2～ 2 6倍。头宽为口宽的 3 7～4 6倍。     

中国广西金线鲃属一新种(鲤形目,鲤科,鲃亚科)

2001年5月作者于广西环江县驯乐乡顺宁村采集到金线鲃属盲鱼5尾,经鉴定为一新种.新种眼睛完全退化,头后急剧隆起但尚未形成额骨突等体型特征与无眼金线鲃Sinocyclocheilus anophthalmus Chen et Chu,1988相似,而明显有别于属内其他物种.但两者在以下性状上又存在明显区别:1)新种背鳍硬刺纤弱;而无眼金线鲃的背鳍硬刺比较粗壮;2)新种背部自额骨后隆起,但是额骨顶部并不隆起;无眼金线鲃则自眼眶上方的额骨顶部开始显著隆起,直至肩部;3)新种侧线平直;无眼金线鲃的侧线在腹鳍和臀鳍之间的上方有一比较明显的向上弯曲;4)新种胸鳍长,超过腹鳍起点;无眼金线鲃胸鳍不超过腹鳍起点;5)分布区亦有所不同,新种分布于柳江水系;无眼金线鲃则分布于南盘江水系.此外,在一些可测性状上二者亦有区别,在标准长与体高和头长的比例、尾柄长与尾柄高的比例、侧线鳞的数目等性状上都有所差异.     

眼斑双锯鱼仔稚鱼发育异速生长

运用生态学和传统理论生物学的研究方法, 对孵化后眼斑双锯(Amphiprion ocellaris)仔、稚鱼在早期生存和环境适应上的异速生长及器官优先发育生态学意义进行了研究, 以期为眼斑双锯鱼人工繁殖和育苗提供参考资料。以11日龄为眼斑双锯鱼仔、稚鱼的区分时期, 结果表明, 眼斑双锯鱼仔、稚鱼的感觉、摄食和游泳等器官快速分化, 均存在异速生长现象。在头部器官中, 吻长、眼间距、口宽和头高在仔鱼期均为正异速生长, 吻至鳃裂前缘长和眼径为负异速生长。在身体各部位中, 仔鱼期体高、躯干长、尾长、尾柄长、尾柄高和体厚均为正异速生长, 仅头长为负异速生长; 在游泳器官中, 仔鱼期眼斑双锯鱼尾鳍、背鳍、胸鳍、腹鳍和臀鳍均为正异速生长。稚鱼期眼斑双锯鱼头部、躯干及游泳等各器官均为负异速生长。眼斑双锯鱼这些关键器官的异速发育, 对适应环境因子变化具有重要的生态学意义。     

大别山区黑沟绿太阳鱼种群的形态特征研究

绿太阳鱼是2015年4月在大别山区淠河流域支流中新发现的入侵鱼类。利用2015年7月从黑沟中采集的78尾绿太阳鱼标本,对该物种的形态特征进行了详细测量和分析。结果发现绿太阳鱼种群内的形态相似性较高,但还存在一定的形态差异。相比性别,年龄是造成这种形态差异的主要原因。雄性从Ⅰ龄开始出现显著的形态分化,而雌性差异并不显著。这种形态学的差异完全符合雄鱼筑巢护卵的习性,具体表现在雄鱼头部指标（D1-2、D2-3、眼间距、眼后头长、头长）、臀鳍附近指标（D5-7、D5-8）、背鳍基部指标（D6-8）和尾柄处指标（D9-10）增大。同时相比Ⅰ龄以上的雄鱼,雌鱼和0龄雄鱼的尾柄指标（D8-10、D8-9）较长,身体更适于流水环境。这种雌雄体型上的变化,将有助于雄鱼占领溪流环境中的静水区（深潭）,而雌鱼和0龄鱼占领流水区（急滩、湍流）,这为该种群适应山区溪流的水文环境,合理分配生态位提供了便利条件,同时也使其对大别山区其他鱼类具有较大的生态危害潜力。     

中国NFDA2亚科金线NFDA2属鱼类一新种及其生态和适应(鲤形目：鲤科)

1999年11月在广西都安县下坳乡一岩洞地下水中采到1尾鱼类标本,经鉴定为金线NFDA2属一新种。新种与大鳞金线NFDA2S. macrolepis和陆良金线NFDA2S. macroscalus相近。但新种在背腹鳍相对位置以及背鳍末根不分枝鳍条后缘具锯齿等方面与上述两种存在明显差异;特别是该新种仅局限分布于洞穴中,就其生境来说也与上述两种更为不同。此外,新种头长与吻长和头长与眼径的比例是目前该属内已知最小的,眼明显偏大,反映出其对弱光生境条件的适应。     

<Emphasis Type="Italic">Amblyceps improcerum</Emphasis>, a new sisoroid catfish from Kachin State,Myanmar (Teleostei: Siluriformes: Amblycipitidae)

A new species of amblycipitid catfish is here described from the Indawgyi Lake basin of the Irrawaddy River drainage in Kachin State, Myanmar as Amblyceps improcerum, new species. It can be distinguished from congeners in having a unique combination of the following characters: lower jaw longer than upper; head length 17.4–22.3% SL; head width 13.7–15.2% SL; head depth 9.0–11.7% SL; interorbital distance 31–39% HL; eye diameter 7–10% HL; 37–38 vertebrae; lateral line incomplete; predorsal length 25.5–30.7% SL; smooth posterior margin of pectoral spine; pectoral-fin length 13.5–16.8% SL; pelvic-fin length 9.6–13.4% SL; dorsal-to-adipose distance 25.2–28.7% SL; length of adipose-fin base 19.4–23.3% SL; adipose fin separate from dorsal procurrent caudal-fin rays; preanal length 62.1–66.9% SL; body depth at anus 9.8–12.8% SL; depth of caudal peduncle 10.1–12.6% SL; length of caudal peduncle 21.4–24.0% SL, post-adipose distance 15.8–17.8% SL; weakly-forked caudal fin with short broadly, rounded lobes (length of longest ray 1.3–1.5 times length of median rays); centrally projecting hooks on proximal lepidotrichia of median caudal-fin rays absent.     

四种杂交组合奥尼罗非鱼及其亲本的生长对比研究

通过RFID电子标记注射、跟踪和生长性状测量,对2个奥利亚罗非鱼品系(ZZ、AA)、2个尼罗罗非鱼品系(XX、EE)自交群体及其杂交奥尼罗非鱼4个群体(XZ、XA、EZ、EA)进行生长对比研究,罗非鱼亲本来自国家罗非鱼产业技术体系研发中心。结果表明:XZ、XA、EZ、EA四个奥尼罗非鱼群体雄性率均达94%以上,全长、体长、头长、体高等性状特征值显著高于亲本品系(P<0.05),奥尼罗非鱼的生长速率相对其亲本品系具有一定的优势,同时4个奥尼群体间生长性状特征值也存在显著差异(P<0.05);生长性状相关分析显示罗非鱼各配组群体的体质量与尾柄长相关性较低(0.690—0.846),与全长、体长、体高、体厚相关性较高;对罗非鱼各配组群体的比例性状进行主成分分析,第1主成分主要代表BS、HS、CDS、BWS性状特征,第2主成分主要代表TS、HS、CLS性状特征,通过第1、第2主成分作图可将AA与其他6个罗非鱼配组群体有效区分。     

河南省淮河流域鳑鲏亚科5种鱼形态差异分析

为进一步从可量性状比较中华鳑鲏(Rhodeus sinensis)、越南鱊(Acheilongnathus tonkinensis)、大鳍鱊(A. macropterus)、兴凯鱊(A. chankaensis)和斑条鱊(A. taenianalis)的种间形态差异, 丰富鳑鲏亚科鱼类的形态分类特征, 研究采用多变量形态度量学方法对河南省淮河流域这5种鱼的形态进行比较分析。结果表明: 这5种鱼在体宽/体长、头长/体长、吻长/体长、尾柄长/体长、背鳍基底长/体长、腹鳍长/体长、臀鳍长/体长和头长/吻长8个比值性状上存在极显著性差异(P< 0.01), 在全长/体长、体高/体长2个比值性状上存在显著性差异(P<0.05), 这些差异主要集中在鱼体的头部、尾部和鳍等部位。主成分分析、聚类分析和判别分析显示5种鱼存在显著性形态差异, 斑条鱊与越南鱊的差异程度最大, 与大鳍鱊差异程度最小。判别分析获得的判别准确率在82.35%—100.00%变化, 可以从一定的角度区分这5种鱼。     

四川省条鳅亚科鱼类的研究——Ⅰ.副鳅、条鳅和山鳅属鱼类的整理(鲤形目:鳅科)

本文为四川省条鳅亚科鱼类分类研究的第一部分,对分布于四川省的副鳅属(Paracobitis)、条鳅属(Nemacheilus)和山鳅属(Oreias)鱼类进行了比较系统的整理,这3个属分布在四川共有5种和亚种,其中乌江副鳅(Paracobitis wujiangensis sp.nov.)为新种。     

Morphological differences between an artificial lentic and adjacent lotic environments in a characid species

Dam constructions cause fundamental changes in the natural landscape, creating new ecological and evolutionary challenges for aquatic organisms. In some cases, such water impoundments have been related with morphological changes in organisms. Understanding how populations respond to rapid environmental changes imposed by dams is the first step to elucidate the consequences that disturbed habitats may have on species evolution. In this work, we analyzed shape and size variation in Bryconamericus iheringii Boulenger 1887 from the Chasqueiro stream basin, south of Brazil, which was recently dammed. We used linear measurements and geometric morphometrics to identify morphological differences among specimens from the reservoir (lentic habitat) compared to the habitat upstream and downstream of the dam (lotic habitats). We also tested for size- and shape-related sexual dimorphism to determine whether variations observed were the same for both sexes. We found that B. iheringii from the artificial reservoir were distinct in shape and size to those from their natural habitat in the stream. The size variation between environments was the same for both sexes, but the shape variation differed between males and females. Regarding the linear measurements, lotic populations were larger (greater body length, width, pectoral fin base length and caudal peduncle length), probably in response to increased swimming activity. Regarding body shape, we found that both sexes have a more fusiform body in lotic habitats than in the reservoir. In addition, females showed an altered mouth position that was distinct between these environments. This work indicates that the water reservoir seems to be an important factor influencing morphological variation in B. iheringii, a species with sexual shape dimorphism.

     

蛇鮈属一新亚种记述

蛇(鱼句)属为一群小型鲤科鱼类.蛇(鱼句)广泛分布于东亚大陆.通过对采自云南程海和珠江、闽江、长江、辽河、松花江等水系蛇标本的形态、度量特征进行仔细分析和比较,认为蛇程海种群是蛇的1个新亚种,命名为程海蛇(Saurogobio dabryi chenghaiensis).程海蛇(鱼句)的特征为:吻皮发达,盖过上唇;上下唇布满发达的乳突;体及尾柄极细长,体高为体长的12.7%～15.0%,尾柄高为体长的5.5%～6.1%、为尾柄长的31.8%～39.1%;沿体侧中轴自鳃孔上方至尾鳍基具一浅色暗纹,其上布有6～11个大型棒状黑斑(黑斑长为宽的2～4倍);肛门位于腹鳍长度的中点之后;尾鳍最长鳍条为其最短鳍条的2倍以上;仅分布于云南程海.     

云南星云湖长臀云南鳅两性异形及其生境适应性

云南鳅属鱼类是云贵高原及邻近区域特有鱼类,其独特两性异形现象可能是对喀斯特高原特定生境的一种重要适应。本文对云南星云湖特有鱼类长臀云南鳅两性异形、个体繁殖力及与之关联的雌雄摄食分化问题进行了研究,以揭示其两性异形特征并探讨其与生境的关系。结果表明: 长臀云南鳅两性异形指数为0.23,表明它是偏向于雌性体型较大的两性异形类型。同时,雌雄外部形态存在明显的色斑差异,雌鱼体侧密布横向色斑,而雄鱼体侧则有一明显的纵向条纹,横向色斑稀少或缺乏。单因素方差分析、主成分分析、判别分析及单因素相似性分析(ANOSIM)等进一步证实长臀云南鳅雌雄形态性状明显分离,全长、叉长、体长、头宽/头长、腹鳍起点-胸鳍起点(JK)/体长等对两性形态差异起主导作用。雌鱼繁殖力为(1364.5±489.3)粒,变化幅度为470~2430粒,其繁殖力随体长的增长而增大。食物分析显示,长臀云南鳅以摇蚊幼虫、蜉蝣稚虫为主要食物,食性较为狭窄。雌雄长臀云南鳅食物组成较为相似,但两者具有统计学意义上的显著差异。繁殖力选择压力、食物分化等可能对星云湖长臀云南鳅两性异形的形成起重要驱动作用,而两性异形的出现是长臀云南鳅对喀斯特贫营养龙潭生境的一种重要适应。     

广西洞穴鱼类一新种（鲤形目：鳅科）

本文记述了采自广西河池地区的洞穴鱼类一新种,并讨论了其分类地位。透明间条鳅,新种Ｈｅｍｉｎｏｅｍａｃｈｅｉｌｕｓ ｈｙａｌｉｍｕｓ ｓｐ．ｎｏｖ．与同属种的区别主要表现在尾鳍分枝鳍条数目较少、须较短、眼睛完全退化、头较大和尾柄较细长等方面。     

Sexual Dimorphisms in the Dermal Denticles of the Lesser-Spotted Catshark,Scyliorhinus canicula (Linnaeus, 1758)

The dermal layers of several elasmobranch species have been shown to be sexually dimorphic. Generally, when this occurs the females have thicker dermal layers compared to those of males. This sexual dimorphism has been suggested to occur as a response to male biting during mating. Although male biting as a copulatory behaviour in Scyliorhinus canicula has been widely speculated to occur, only relatively recently has this behaviour been observed. Male S. canicula use their mouths to bite the female’s pectoral and caudal fins as part of their pre-copulatory behaviour and to grasp females during copulation. Previous work has shown that female S. canicula have a thicker epidermis compared to that of males. The structure of the dermal denticles in females may also differ from that of males in order to protect against male biting or to provide a greater degree of friction in order to allow the male more purchase. This study reveals that the length, width and density of the dermal denticles of mature male and female S. canicula are sexually dimorphic across the integument in areas where males have been observed to bite and wrap themselves around females (pectoral fin, area posterior to the pectoral fin, caudal fin, and pelvic girdle). No significant differences in the dermal denticle dimensions were found in other body areas examined (head, dorsal skin and caudal peduncle). Sexually dimorphic dermal denticles in mature S. canicula could be a response to male biting/wrapping as part of the copulatory process.     

Ecomorphology and habitat utilization of Cottus species

We investigated relationships between morphological attributes and mesohabitat use in populations of Cottus carolinae. Field studies revealed significant differences between Ozark and prairie stream mesohabitats where populations of C. carolinae occurred. Features of the mesohabitat that were characteristic of each stream type correlated with intra- and inter-specific differences in morphological attributes of Cottus. The morphology of Cottus occurring in the deeper, slower, and siltier prairie stream exhibited larger head width and depth, body width and depth, and caudal peduncle width while those occurring in a shallower, faster flowing Ozark stream had longer pelvic fins, larger eyes, and deeper caudal peduncles. Each population had a morphology tailored to optimize its performance in a specific habitat. Results of laboratory based performance studies using a variable flow chamber revealed that critical current velocities (CCV) of live and preserved specimens were weakly associated with distinct combinations of morphological traits. Specimens with higher CCV measurements typically had longer pelvic fins, larger eyes, and deeper caudal fins (Ozark morphology). Those with lower CCVs had larger head width and depth, body width and depth, and caudal peduncle width (prairie morphology) in studies using cobble as the substrate. Differences in flow regimes between prairie and Ozark streams may generate specific niches for specific morphotypes, and current velocity may exert selective pressure on morphology.     

Morphological divergence within and between the Mexican sailfin mollies, Poecilia velifera and Poecilia petenensis

This study examined the patterns of morphological variation both between species, and between sexes and among populations within each species of the Mexican sailfin mollies, Poecilia velifera and Poecilia petenensis , using geometric morphometrics and linear measurements of morphological traits. While sexes within each species differed in characteristics that may be important in sexual selection, such as length of the dorsal fin, species differed in traits, such as body depth, that may also be influenced by natural selection due to differences in habitats. Within each species, many morphological traits were similar among populations, but important differences, including caudal peduncle depth in P. petenensis (but not in P. velifera ), suggested that habitat differences may also be important in shaping population divergence independently within each species. Indeed, the evolutionary vectors of male morphological population divergence for each species differed by an angle of 98·5°, representing nearly orthogonal vectors and suggesting independent shape divergence between these two molly species. Finally, geographic isolation did not explain the morphological differentiation seen among populations, suggesting that natural and sexual selection were strong forces promoting morphological diversification within these two species, despite the potential for a high degree of population connectivity and gene flow.