A new species of genus Pseudogyrinocheilus (Teleostei: Cyprinidae) from Guangxi, China

A new species, Pseudogyrinocheilus longisulcus, was discovered from a tributary of Pearl River in Jingxi Co., Guangxi, China, The new species can be distinguished from other species of Pseudogyrinocheilus by the following combination of characteristics: prolonged post-labial grooves, and extended antero-medially close to anterior end of middle lower lip, but not meeting with its counterpart; posterior margin of lower lip free; scales of abdomen from thorax to pectoral-fin base embedded under skin; lateral-line scales 40-42; dark stripe longitudinal along lateral line on flank. The key to the species of Pseudogyrinocheilus is provided.

Opioid Withdrawal for 4 Days Prevents Synaptic Depression Induced by Low Dose of Morphine or Naloxone in Rat Hippocampal CA1 Area In Vivo

The formation of memory is believed to depend on experience- or activity-dependent synaptic plasticity, which is exquisitely sensitive to psychological stress since inescapable stress impairs long-term potentiation (LTP) but facilitates long-term depression (LTD). Our recent studies demonstrated that 4 days of opioid withdrawal enables maximal extents of both hippocampal LTP and drug-reinforced behavior; while elevated-platform stress enables these phenomena at 18 h of opioid withdrawal. Here, we examined the effects of low dose of morphine (0.5 mg kg(-1), i.p.) or the opioid receptor antagonist naloxone (1 mg kg(-1), i.p.) on synaptic efficacy in the hippocampal CA1 region of anesthetized rats. A form of synaptic depression was induced by low dose of morphine or naloxone in rats after 18 h but not 4 days of opioid withdrawal. This synaptic depression was dependent on both N-methyl-D-aspartate receptor and synaptic activity, similar to the hippocampal long-term depression induced by low frequency stimulation. Elevated-platform stress given 2 h before experiment prevented the synaptic depression at 18 h of opioid withdrawal; in contrast, the glucocorticoid receptor (GR) antagonist RU38486 treatment (20 mg kg(-1), s.c., twice per day for first 3 days of withdrawal), or a high dose of morphine reexposure (15 mg kg(-1), s.c., 12 h before experiment), enabled the synaptic depression on 4 days of opioid withdrawal. This temporal shift of synaptic depression by stress or GR blockade supplements our previous findings of potentially correlated temporal shifts of LTP induction and drug-reinforced behavior during opioid withdrawal. Our results therefore support the idea that stress experience during opioid withdrawal may modify hippocampal synaptic plasticity and play important roles in drug-associated memory. (C) 2009 Wiley-Liss, Inc.

泉水鱼的系统发育关系(英文)

泉水鱼（Pseudogyrinocheilus prochilus）是我国特有的一种鲤科鱼类,它广泛分布于宜昌以上长江上游干流、长江在四川境内的支流和乌江中,常栖息于山溪溪流及具流水的岩洞中;以舔刮底栖生物为食。它具有十分独特的口唇结构。不少学者对其分类作过研究,Sauvage et Dabry（1880）将泉水鱼认作一个种,置于Discognathus属中,名之为D.prochilus;Tchang;（张春霖,1929）将泉水鱼鉴定为两个种,归入Gyrinocheilus属中,命名为G.pellegri

鲤科野鲮亚科第二类群的系统分类及重要类群的系统发育检验

Zhang 等(2000)根据口唇部结构把鲤形目Cypriniformes 鲤科Cyprinidae 野鲮 亚科Labeoninae 鱼类分为三个类群。其中第二个类群鱼类的特征是吻皮发达向 腹面下包、上唇退化、下唇向复杂的形态演变，有的形成似吸盘状的雏形构造。 在整理广西鱼类标本时，发现来自广西桂林大埠的十余尾标本不能归到野鲮亚科 任何属中，在这里建立一个新属-狭吻鱼属(Stenorhinchus)。狭吻鱼属的口唇部结 构具有野鲮亚科第二类群鱼类的特征。本研究的目的是为了探讨狭吻鱼属的有效 性及其在野鲮亚科第二类群中的系统位置。传统的观点（张鹗，1998）认为异华 鲮属Parasinilabeo 与唇鱼属Semilabeo、泉水鱼属Pseudogyrinocheilus 的亲缘关 系较近，苏瑞凤（2001）认为异华鲮属与华缨鱼属、直口鲮属构成一个单系群， 本研究的另一目的是要探讨异华鲮属在野鲮亚科中的分类地位，同时描述了异华 鲮属一新种-长鳍异华鲮（Parasinilabeo longiventralis）。 基于外部形态和骨骼特征，利用分支系统学原理和方法对野鲮亚科第二类群 鱼类进行系统发育研究。选择野鲮亚科第二类群的直口鲮属（Rectoris）、穗唇鲃 属（Crossocheilus）、角鱼属（Akrokolioplax）、华缨鱼属（Sinocrossocheilus）、拟 缨鱼属（Pseudocrossocheilus）、异华鲮属（Parasinilabeo）、唇鱼属（Semilabeo）、 泉水鱼属（ Pseudogyrinocheilus ） 和第一类群的鲮(Cirrhinus) 、舌唇鱼 （Lobocheilus）、脂孟加拉鲮（Bangana）作为内群，以鲃亚科的刺鲃(Spinibarbus caldwelli)、大鳞高须鱼（Hypsibarbus vernayi）作为外群。利用外群比较法选取 性状，进行编码后建立一个性状状态矩阵。然后应用软件MacClade4.0 和Paup4.0 进行分析。本研究选取61 个性状来构建系统发育树。系统发育树结果表明：（1） 野鲮亚科第二类群的鱼类构成一个单系群，在这里把它们命名为穗唇鲃组；（2） 狭吻鱼属是个有效属，应置于野鲮亚科第二类群并与唇鱼属、泉水鱼属的亲缘关 系最近；（3）异华鲮属与狭吻鱼属、唇鱼属、泉水鱼属的亲缘关系较密切，在4 属之中，它是较早分化出来的类群； （4）宽唇华缨鱼和三齿华缨鱼不聚成姐妹 群，华缨鱼属不构成单系群；（5）直口鲮和宽唇华缨鱼的分类地位不稳定，需要 今后进一步的分子生物学研究确认。