记宁夏石炭纪扁体鱼类化石一新属*

本文记述的标本采自宁夏中卫晚石炭世土坡组下部,属于个体较小的扁体鱼类,身长与身高近相等,约3cm。眼眶大,眶下感觉管明显。鳃盖骨大致呈长条形,下鳃盖骨大小与鳃盖骨相近,前鳃盖骨呈椭圆状,匙骨强壮。锁骨保存于匙骨前上部。背、腹棘鳞发育。胸鳍小,腹鳍没有保存。背鳍中等长,臀鳍与背鳍等长,均起点位于身体最高点后。尾鳍呈外形对称的歪型尾。全身覆盖长条形鳞,胸鳍下方具有一枚异常大型的鳞片。经过与北美、澳洲以及中国浙江的扁体鱼类标本对比,发现其间有明显差异,应为一新属新种——小型宁夏扁体鱼(Ningxiaplatysomus parvus gen.et sp.nov.),归于扁体鱼亚目,科不定。     

中国金线鱼科鱼类一新纪录

2008年10月在广西北海市侨港镇渔港码头采获金线鱼科Nemipteridae、金线鱼属Nemipterus鱼类标本2尾,经鉴定为红棘金线鱼Nemipterus nemurus(Bleeker,1857),系我国鱼类1新纪录.其主要特征为:体延长,侧扁,体背缘前部陡高;眼较大;上颌前端具大犬牙3～4对;第1鳃弓上鳃耙钝而短,鳃耙数12～13枚;体被中等大薄弱栉鳞,侧线鳞50～53枚;背鳍X-9,臀鳍Ⅲ-7;胸鳍和腹鳍长,末端可达肛门;尾鳍叉形,上叶末端呈丝状延长.新鲜标本全身桃红色,具银白色金属光泽;体侧有2条较宽的黄色纵带;背鳍鳍膜浅黄色,背鳍前2枚鳍棘间的鳍膜上半部鲜红色;尾鳍浅红色,尾鳍上叶丝状延长呈金黄色.     

黄山九龙峰尖头鱥的年龄鉴定

鱼类的年龄鉴定及其最佳骨质材料的选择,是鱼类年龄研究的必要前提,也是鱼类基础生物学和生态学研究的基础。利用2012年4月于黄山九龙峰采集的132尾尖头鱥标本,研究了其鳞片、鳃盖骨、脊椎骨和耳石等骨质材料的年轮特征,并以根据全长分布频率确定的"真实年龄"为参照,比较了鳃盖骨、脊椎骨和微耳石在年龄判读中的精确度和准确度。尖头鱥体侧部和尾柄部的鳞片均无任何年轮标志,星耳石磨片上暗带和明带排列无明显规律,但鳃盖骨、脊椎骨和微耳石上存在明显年轮。鳃盖骨、脊椎骨和微耳石3种骨质材料的年龄判读精确度或准确度差异视不同年龄组有所不同。总体上,脊椎骨年龄判读的精确度最高,鳃盖骨次之,微耳石最低;但年龄判读的准确度正好相反,即微耳石最高、脊椎骨最低。因此,微耳石是尖头鱥年龄鉴定的最佳骨质材料,而其较低的年龄鉴定精确度及其对准确度的潜在影响可通过提高磨片质量和优化判读方法来改善。     

中国鱼类新纪录科——法老鱼科及其一新纪录种记述(仙女鱼目)

法老鱼科(Anotopteridae)物种是一类凶猛的肉食性鱼类,主要分布在北太平洋、北大西洋和南冰洋中高纬度的寒冷海区,共有1属3种,以往在中国海域没有记录。我们在整理20世纪80年代初采自中国南海的馆藏鱼类标本时,发现了该科1种,即尼氏法老鱼(Anotopterus nikparini Kukuev)。其主要特征为,体甚柔软而细长,近圆筒形。口裂大,上下颌延长,上颌具1行短齿;腭骨有1行镰刀状的大型齿;下颌有1行扁薄的大齿。鳃裂甚宽,鳃膜不与颊部相连;鳃耙退化。鳃盖骨扁薄而柔软。体表无鳞。背鳍缺失,脂鳍发达。各鳍无棘,臀鳍15,胸鳍14,腹鳍11。侧线完全,有侧线孔85。脊椎骨80。法老鱼科、法老鱼属(Anotopterus)和尼氏法老鱼是中国鱼类的新纪录科、新纪录属和新纪录种。标本保存于上海海洋大学鱼类标本馆。     

中国隆头鱼科一新纪录种——雀尖嘴鱼

尖嘴鱼属(Gomphosus)是一群分布于印度洋和太平洋热带珊瑚礁海域鱼类,共有2种,以往在中国海域记录有1种杂色尖嘴鱼(G.varius)。我们在分析20世纪90年代采自中国南海大陆坡的鱼类标本时,发现了该属的另一种雀尖嘴鱼(Gomphosus caeruleus Lacepède,1801),为中国新纪录种。本种的主要鉴别特征为:体呈浅黄褐色(雌)或深黑色(雄);吻部特别延长呈管状;体长为体高的4.2倍,为头长的2.6倍;背鳍Ⅷ-13,臀鳍Ⅲ-11,胸鳍i(不分支)+14(分支);脊椎骨25;鳃盖条7;体被中大圆鳞;侧线完全,在背鳍条的后部下方急剧向下弯折,侧线有孔鳞片27;头部仅鳃盖上部有9枚呈三角状排列的小鳞;背鳍起点前方有鳞8行;背鳍第一至第三鳍棘间的鳍膜具1黑斑;尾鳍截形。     

中国棘茄鱼属(Halieutaea)的研究(Oncocephalidae)

棘茄鱼属种类虽不多,但分布较广,一般栖息于较深海域。我国经过几年来的鱼类区系调查,现已发现有三种,经比较研究后,其中一种Halieutaea fumosa Alcock为国内新纪录,一种被认为是新种,命名为中华棘茄鱼Halieutaea sinica sp.nov.,分述如下。 棘茄鱼属Halieutaea Cuvier et Valendennes Halieutaea Cuvier et Valenciennes, 1837, Hist. Nat. Poiss. 12:455 (Lophius stellata Vahl). 体平扁而宽,头部近呈圆形。口大,前位,近呈水平。颌部及咽部具牙,犁骨与腭骨部无牙。前额部隆起形成吻触手(illicium)隐伏的凹窝。鳃孔较小,位于体背方。鳃弓五对。鳃2(1/2)个,第一对鳃弓无鳃丝。鳃盖条5,最外一条分为二支。体上无鳞,被以棘     

鳜类系统发育的线粒体Cytb基因全序列分析

测定了鳜、大眼鳜、斑鳜、暗鳜、波纹鳜、长体鳜、中国少鳞鳜等7种鳜类12个个体的线粒体细胞色素b基因全序列。结合GenBank中的同源序列,共分析了9种鳜类的系统发育关系。序列分析表明,鳜属鱼类属内种间的遗传距离(0.015～0.093)明显小于少鳞鳜属鱼类属内种间的遗传距离(0.152～0.178)。在分子系统发育树上,长体鳜与鳜属的鳜、大眼鳜、斑鳜、波纹鳜、暗鳜聚合成一分支,少鳞鳜属的种类聚成另一分支;支持将长体鳜归入鳜属,鳜类分为鳜属和少鳞鳜属等二个属的分类处理。在鳜属鱼类中,鳜和大眼鳜亲缘关系十分密切;斑鳜与波纹鳜亲缘较近;长体鳜与鳜属其它5个种的亲缘关系较远。在少鳞鳜属鱼类中,中国少鳞鳜和日本少鳞鳜的亲缘关系较远,韩国少鳞鳜的系统位置较不明确。鳜类的单系性及其鳜类的系统位置仍有待进一步研究。     

斑鳜种内遗传多态性以及与翘嘴鳜的分子鉴别

鳜鱼属鲈形目、酯科、酯亚科,种类繁多。有长体鳜、波纹鳜、斑鳜、无斑鳜、暗鳜、大眼鳜、翘嘴鳜等,是淡水鱼类中的名贵鱼类[1],肉质纯白细嫩,味道鲜美可口。对其报道多集中在水产养殖方面,而从遗传学和DNA角度进行分析的报道较少,本文用RAPD技术对斑鳜(Siniperca scherzeriSte     

宁夏中卫纳缪尔期古鳕类化石一新属

记述了产于宁夏中卫县石炭纪纳缪尔期地层的古鳕类化石一新属新种——潘氏黄河鳕(huanghelepis pani gen.et sp.nov.)。新属种的个体中等大小,体形狭长,头长约为体长的1/6左右。颌悬挂很倾斜,具有长而窄的梯形鳃盖骨、相对较大的下鳃盖骨。全身覆鳞,体侧各有一列高度远大于宽度的长方形侧线鳞。这是在中国石炭纪地层中古鳕类化石的首次描述。     

鳜类鱼类的线粒体DNA控制区结构及其系统发育分析

鳜类为低等鲈形目鱼类,是东亚特有类群。然而,关于其系统位置、分类以及一些物种的有效性等尚有争议。采用PCR扩增直接测序的方法,获得了鳜、大眼鳜、斑鳜、暗鳜、波纹鳜、长体鳜、中国少鳞鳜线粒体DNA控制区基因的序列。对比其他已报道鱼类控制区的结构识别序列,对鳜类鱼类控制区的结构进行了分析,识别了终止序列区、中央保守区和保守序列区,并找到了DNA复制终止相关的序列ETAS和中央保守区的保守序列CSB-F、CSB-E、CSB-D以及保守序列区的保守序列CSB1、CSB2、CSB3。几种鳜鱼间共有191个变异位点,其中,终止序列区的变异最高,占总变异的61．3％,中央保守区和保守序列区占总变异的38．7％。这一结果可为全面了解鱼类线粒体DNA控制区的结构特征提供资料。同时,利用高度变异的控制区序列,以鲈科和错科作为外群,使用邻接法和最大简约法构建了这几种鳜鱼的系统发育树。结果表明：鳜类为一单系类群,鳜、大眼鳜、斑鳜、暗鳜、波纹鳜、长体鳜构成一支鳜鱼群,其中,鳜与大眼鳜为姐妹种;中国少鳞鳜为另一支少鳞鳜群;长体鳜未单独成一支,而是聚入鳜鱼群内,应更名为Siniperca roulei。研究结果支持将现生鳜类分为两个类群的观点。     

Ciliary elongation in blastulae of Arbacia punctulata induced by trypsin

Hatched sea urchin blastulae, which have primarily short 25-μm cilia except for some long 40-to 70-μm cilia at the apical tuft, were induced to form long (40- to 70-μm) cilia around most of their circumference when treated with trypsin (0.008–0.1%) or concanavalin A. Other animalizing agents did not induce the formation of long cilia when applied to the normal blastulae. The formation of long cilia by trypsin was both time and concentration dependent. The long cilia first appeared around the apical tuft after 6–8 hr in trypsin (21°C), and by 18–22 hr most of the blastula was covered with the long cilia. Length distribution studies on cilia isolated at various times showed that the percentage of long cilia increased from approximately 10% in the normal blastula to over 66% in the 22-hr trypsin-treated embryo, and indicated that the long cilia formed by the elongation of the original short cilia. Only the blastulae and gastrulae could be induced to form long cilia; the prisms and plutei could not. Once development was inhibited by the trypsin and the first long cilia appeared, the trypsin effect could not be reversed. When blastulae with long cilia were removed from the trypsin for 10 hr, the cilia remained long; when the long cilia were detached, the blastulae regenerated long cilia in the absence of trypsin. The induced long cilia moved poorly, similar to the long, apical tuft cilia of normal embryos. The formation of long cilia by trypsin treatment of sea urchin blastulae provides a model system for studying the mechanisms of ciliary length control.     

Costs and benefits of giant sperm and sperm storage organs in Drosophila melanogaster

In Drosophila, long sperm are favoured in sperm competition based on the length of the female's primary sperm storage organ, the seminal receptacle (SR). This sperm–SR interaction, together with a genetic correlation between the traits, suggests that the coevolution of exaggerated sperm and SR lengths may be driven by Fisherian runaway selection. Here, we explore the costs and benefits of long sperm and SR genotypes, both in the sex that carries them and in the sex that does not. We measured male and female fitness in inbred lines of Drosophila melanogaster derived from four populations previously selected for long sperm, short sperm, long SRs or short SRs. We specifically asked: What are the costs and benefits of long sperm in males and long SRs in females? Furthermore, do genotypes that generate long sperm in males or long SRs in females impose a fitness cost on the opposite sex? Answers to these questions will address whether long sperm are an honest indicator of male fitness, male post‐copulatory success is associated with male precopulatory success, female choice benefits females or is costly, and intragenomic conflict could influence evolution of these traits. We found that both sexes have increased longevity in long sperm and long SR genotypes. Males, but not females, from long SR lines had higher fecundity. Our results suggest that sperm–SR coevolution is facilitated by both increased viability and indirect benefits of long sperm and SRs in both sexes.     

Assessing Costs of Reproduction in Mountain Birch: The Importance of Considering the Modular Level

We studied the effects of production of male catkins on growthand the subsequent year's male catkin production in mountainbirch, Betula pubescens subsp. czerepanovii at both the shootand branch level. (Shoot is defined here as the product of asingle growing season while branch refers to a structure consistingof several shoots.) Like heterophyllous trees in general, mountainbirch canopy expansion takes place via the production of longshoots. We found phenotypic trade-offs between long shoot growthand male reproduction at the shoot level in the year of catkinproduction. Generative parental long shoots (long shoots withmale catkins) were significantly shorter than the vegetativeones (long shoots without a male catkin). In contrast, we foundno effects of male reproduction on the subsequent year's malecatkin production at the shoot level. Although the mean lengthof secondary long shoots (long shoots growing from the lateralbuds of parental long shoots) did not differ between vegetativeand generative parental long shoots, there was considerablebetween-individual variation in the response of individual trees.In addition, production of male catkins diminishes canopy expansionin mountain birch because the number of secondary long shootsproduced by generative parental long shoots was smaller thanthat of vegetative parental long shoots. At the branch level,the association between total long shoot growth and male catkinproduction was positive, i.e. no trade-off was found. This maybe because the strong sink strength (the ability of a branchto import assimilates from elsewhere in the tree) of branchesbearing reproductive long shoots masks possible trade-offs.We emphasize the importance of considering several levels ofthe modular hierarchy when analysing costs of reproduction inmodular organisms. Copyright 2000 Annals of Botany Company Hierarchical structure, modularity, mountain birch, short and long shoots, trade-off, Betula pubescens subsp.czerepanovii (Orlova) Hämet-Ahti     

Gibberellins in Relation to Flowering and Stem Elongation in the Long Day Plant Silene armeria

Two long days induced some flowering and 4 or more long days caused 100% flowering in Silene armeria. On long days microscopically detectable flower primordia were first seen after 6 days, which is at least 1 day before the start of stem elongation. Both gibberellin A₃ and A₇ caused flowering on short days, but the results were variable and flowering was never 100%. Three different gibberellins were detected in Silene extracts. The pattern of gibberellins extracted from plants on short and long days was qualitatively the same, but on long days gibberellin content was up to 100% higher than on short days. Only small amounts of diffusible gibberellins were obtained from Silene shoot tips (including very young leaves) on short days. However, on long days the diffusible gibberellins increased by as much as 10-fold after 4 to 6 long days but then declined somewhat after 10 long days. The gibberellins extracted from the shoot tips at the completion of the diffusion period also increased under long days, although the increase was not as large as for the diffusible gibberellins. An A₅-like gibberellin present in extracts was not detected in diffusates.     

Long Tongues and Loose Niches: Evolution of Euglossine Bees and Their Nectar Flowers1

I examined relationships between tongue length of orchid bees (Apidae: Euglossini) and nectar spur length of their flowers in the genera Calathea, Costus, and Dimerocostus using phylogenetically independent contrasts. Long‐tubed flowers have specialized on one or several species of long‐tongued euglossine bees, but long‐tongued bees have not specialized on long‐tubed flowers. Whereas long tongues may have evolved to provide access to a wider variety of nectar resources, long nectar spurs may be a mechanism for flowers to conserve nectar resources while remaining attractive to traplining bee visitors.     

Carry-over effects of long and short photoperiods on body fattening and gonadal weight of blackheaded bunting (Emberiza melanocephala)

A study was made of the carry-over effect of long photoperiods followed by short photoperiods ou the fattening and gonadal response in a photoperiodic migratory species, the Blackheaded Bunting (Emberiza melanocephala). The effect was studied in photosensitive and then in photostimulated birds. Two experiments were performed: experiment I with photosensitive males and experiment II with photosensitive males exposed to 30 long photoperiods. In both of them, five groups were submitted to the following treatments for 30 days: Group S, a short daily photoperiod; Group L, a long daily photoperiod; Group LS, alternating long and short daily photoperiods; Group L 2S, one long with two short daily photoperiods; Group L 3S, one long with three short daily photoperiods. The results showed that the inductive effect of long days or the inhibitory effect of short days was affected by intervening reversed daylengths.     

Functions of the two particles of tobacco rattle virus

Functions of long and short particles of five different tobacco rattle virus (TRV) systems were studied by complementation experiments with the corresponding long and short species of ribonucleic acid (RNA). The progeny of long RNA species alone was proteinless or “free” infectious long RNA, whereas short RNA species alone did not replicate by themselves but appeared to be dependent on long RNA for replication. When both types of RNA derived from the same isolate were inoculated together, particulate virus with long and short particles was produced in more than 50% of the resulting primary infections. These virus systems obtained by homologous complementation resembled the parent isolates in all their characteristics. In addition, heterologous complementation tests were performed with long and short RNA, each derived from another isolate. Heterologous interaction could be observed in only 2 out of 20 possible combinations. As a result, two “mixed” TRV systems with respect to their particle length distributions were obtained, since their long and short particles resembled the ones from the other isolate. The symptoms produced by these mixed viruses were determined by the corresponding long RNA and appeared not to be influenced by the heterologous short one. However, the protein coat of both particles of the “mixed” viruses was specified by the corresponding noninfectious short RNA. Therefore, TRV is a system of at least two functionally defective and mutually complementing components which appear to be specialized in early and late functions.     

Postnatal long bone growth in terrestrial placental mammals: Allometry,life history,and organismal traits

The ontogenetic allometry of long bone proportions is poorly understood in Mammalia. It has previously been suggested that during mammalian ontogeny long bone proportions grow more slender (positive allometry; length ∝ circumference^>1.0), although this conclusion was based upon data from a few small‐bodied taxa. It remains unknown how ontogenetic long bone allometry varies across Mammalia in terms of both taxonomy and body size. We collected long bone length and circumference data for ontogenetic samples of 22 species of mammals spanning six major clades and three orders of magnitude in body mass. Using reduced major axis bivariate regressions to compare bone length to circumference, we found that isometry and positive allometry are the most widespread patterns of growth across mammals. Negative allometry (i.e., bones growing more robust during ontogeny) occurs in mammals but is largely restricted to cetartiodactyls. Using regression slope as a proxy for long bone allometry, we compared long bone allometry to life history and organismal traits. Neonatal body mass, adult body mass, and growth rate have a negative relationship with long bone allometry. At an adult mass of roughly 15–20 kg, long bone growth shifts from positive allometry to mainly isometry and negative allometry. There were no significant relationships between ontogenetic long bone allometry and either cursoriality or basal metabolic rate. J. Morphol. © 2012 Wiley Periodicals, Inc.     

Division of labor of anthers in heterantherous plants: flexibility of bee pollen collection behavior may serve to keep plants honest

Heteranthery is thought to reflect a division of labor, with some anthers serving a pollinator-feeding function and others serving a pollinating function. Mutualism theory predicts that each participant should try to maximize the benefit it receives from its partner: plants should allocate more pollen to pollination, and pollinators should collect more pollen. Accordingly, plant and pollinator may engage in a ‘tug of war’ with respect to pollen from each anther type, resulting in incomplete division of labor. Here, we explored this idea by conducting a fully factorial manipulation of the availability of pollen in long and short anthers of staminate flowers of Solanum houstonii. We found the following: (1) Bumble bees (Bombus impatiens) preferred to sonicate (collect pollen from) short anthers over long anthers, consistent with a role as feeding and pollinating anthers, respectively; (2) Blocking short anther pores alone increased sonication of long anthers and resulted in collection of pollen from long anthers; (3) Blocking long anther pores alone did not influence sonication of short anthers; (4) The increase in sonication of long anthers, when short anther pores are blocked, was greater when pollen was available in long anthers; (5) Despite shifting sonication effort to long anthers, bees do not move their bodies closer to long anther pores where pollen could be collected more effectively; and (6) analysis of the growth of corbicular loads over time spent buzzing indicates that significant amounts of pollen are collected from long anthers as well as short anthers. We conclude that bees can flexibly increase pollen collection from pollinating anthers, but are constrained from fully exploiting this pollen. This results in checks and balances between plant and bee that may help maintain heteranthery.