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。     

小瓜虫在澳洲龙纹斑鳃器官上的分布及其影响

【目的】小瓜虫病是澳洲龙纹斑苗种阶段危害巨大的寄生虫病。探究小瓜虫在澳洲龙纹斑鳃器官上的分布及其影响可以丰富小瓜虫的致病性及病理学方面的研究内容,也可以为渔业生产中小瓜虫病的防治提供参考。【方法】采用光镜及扫描电镜技术确定病原,并观察小瓜虫在澳洲龙纹斑鳃丝、鳃小片及鳃盖上的分布情况及这些器官的变化情况。【结果】小瓜虫侵染澳洲龙纹斑的鳃器官后,分布在鳃丝、鳃小片及鳃盖的表面,上皮细胞之下及鳃小片之间,或是包裹在黏液细胞里,但侵染后期在鳃丝及鳃小片上的数量明显少于鳃盖。侵染后期,鳃丝、鳃小片及鳃盖出现一定程度的膨胀变形,黏液细胞分泌增多,鳃小片末端膨大变形甚至黏连融合,顶端充血呈球状或棒状。【结论】对于鳃部而言,侵染后期小瓜虫主要分布在澳洲龙纹斑的鳃盖上。小瓜虫主要通过侵染引发澳洲龙纹斑鳃部器官的变形膨大,使其丧失正常的功能,造成血液循环受阻、渗透压调节失衡,最终导致鱼体缺氧死亡。     

中国上二叠统济源四足动物群——2.地层、分类学评述及对比（英文）

重新研究了济源四足动物群的材料,表明其以锯齿龙类的复齿河南龙为主体,还包括至少三种迟滞鳄类和一种犬齿兽,可能还有一种凶脸兽。根据甲片特征推测,迟滞鳄类至少包括中国毕氏螈Bystrowiana sinica,扁平济源盖螈(新属新种)Jiyuanitectum fl atum gen.et sp.nov.以及大型脊廊盖螈(新种)Dromotectum largum sp.nov.。根据四足动物组合,济源动物群大致可以与俄罗斯Sokolki组合带的Ilinskoe亚带以及南非的小头兽组合带对比。     

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。     

河北昌黎乌鳢化石的发现

1955年冬,河北昌黎泥炭中发现了两块乌鳢(Ophicephalus argus Cantor)化石。在同一地层中还有四不象鹿和赤鹿等哺乳类化石。所发现的两块化石,代表两个不同个体的鳃盖骨。鳃盖骨略呈等边三角形。外侧的放射肋纹及生长线,因有原先复盖在上面的鳞片的印痕,故显示不清。内侧的关节窝较大,略呈椭圆形。鳃盖上的鳞片彼此复盖形成不规则的五边形。     

鱼类呼吸运动波形的微机分析系统

鱼类鳃呼吸运动均具有两种运动形式:鳃盖运动与洗涤运动(咳嗽反应),两者呈一定的比例关系。当环境因子(水温、P_(o2) P_(co2) pH等)改变和污染物(农药、石油产物和雨金属等)出现时,会引起鱼类呼吸运动发生明显的有规律的改变。因此,应用微机对鱼类呼吸运动的分析研究,对鱼类生理学和水环境的生物监测工作都有其理论与实践的意义。利用苹果Ⅱ微机,A/D转换器及国产LMS-2A二道生理记录仪组成鱼类呼吸信号的数据采集系统,并设计了分析处理鱼类鳃盖运动和洗涤运动频率关系的软件。     

威宁趾沟蛙早期胚胎发育的观察

用从野外采集受精卵室内观察的方法研究了威宁趾沟蛙的早期胚胎（8～25期）发育过程。结果表明：受精卵在水温为15±1℃的条件下从囊胚早期到鳃盖褶完成期需要519．23±1．57h,早期胚胎发育的特点是：大多数胚胎的孵化是在肌肉效应期;鳃盖褶完成中、后期胚体能到水面上活动;胚体纵轴伸长出现在神经褶后期;出水孔始于鳃盖褶完成期的胚体左侧靠前处;左侧鳃盖褶先发育完成。     

“鱼纲”的几个教学问题

在现行初中动物学课本中,有些教材内容,由于不是重点及照顾初中学生的接受能力,叙述较简单,如果教师忽视对教材深入细致的钻研和运用直观教学,必将影响学生对概念的正确理解。现提出几个容易发生的问题,供教师进行教学时参考: 鲫鱼的呼吸动作在鲫鱼的呼吸中,口、鳃盖、鳃孔如何配合活动?水在什么情况下由口流入?在什么情况下由鳃孔流出? 鲫鱼的呼吸动作主要靠口、鳃盖和下颌的的活动来完成。当鲫鱼的口张开时,鳃盖向外移动,略往前缩,鳃盖膜紧贴头部两侧,鳃孔关闭,同时下颌降低,口腔内容积增加,产生负压,水由外界进入口腔(图1,A)。口闭,鳃盖内收,略往后伸,下颌升高,口腔容积减少,产生正     

中三叠世脊椎动物生物地层的高精度时间校准:铀-铅锆石法测定的中国肯氏兽动物群和永和鳄年代（英文）

四足动物组合带是全球陆相三叠系对比的有力手段,但是迄今为止中三叠世的四足动物组合尚没有可靠的时间框架。报道了5个采自二马营组和铜川组,与四足动物化石共同产出的火山凝灰岩样品的锆石化学剥蚀-热电离质谱法年龄。结果表明中国肯氏兽动物群时代为安尼期晚期,而永和鳄的时代为拉丁期早期。通过生物地层对比,这一结果还为其他中三叠世的四足动物组合,如南非的犬颌兽带上部、俄罗斯的引鳄动物群以及新疆的克拉玛依组提供了准确的年龄。鄂尔多斯盆地下中三叠统界线应低于二马营组底界。     

颅骨过度气化1例影像表现并文献复习

目的:颅骨过度气化(Craniocervical bone pneumatisation)比较少见,近年来对其报道和认识逐渐增多。本文介绍一例偶然发现的颅骨过度气化的影像表现并对相关文献进行复习。方法:分析我院1例颅骨过度气化的影像学图像。并从国外pubmed数据库(www.pubmed.gov)及国内中国知网数据库(www.cnki.net)查找发表的文献进行文献复习。结果:颅骨过度气化表现为颅骨的气腔形成并局部膨出,多为偶然发现或因并发症就诊,可涉及颅盖骨、颅底骨及颈椎等,近年来对其认识逐渐增多。结论:颅骨过度气化尽管少见,对征象的认知有助于相关科室医师正确识别此征象,从而有利于临床一些相关疑难病例的诊断和操作并对防止漏、误诊具有一定的意义。     

Which way to turn? Effect of direction of body asymmetry on turning and prey strike orientation in starry flounder Platichthys stellatus (Pallas) (Pleuronectidae)

Starry flounder Platichthys stellatus , a rare polymorphic flatfish exhibiting a large-scale geographic cline in the frequency of right-eyed (dextral) and left-eyed (sinistral) morphs, was studied to investigate whether foraging behaviour (turning angle and prey strike orientation) differed between dextral and sinistral laboratory-raised juveniles. Platichthys stellatus foraging on brine shrimp Artemia sp. nauplii tended to strike dorsally at prey ('left' to an observer for dextral flounder and 'right' to an observer for sinistral flounder), although this effect was stronger for sinistral fish. This dorsal tendency also increased with body size. Non-strike behaviours (movements between strikes) were ventrally biased for both morphs. Maximum turn angles were larger for both morphs towards the dorsal side than the ventral side during prey strikes but were the same during non-strike behaviours. The positioning of the eyes of the juvenile starry flounder was skewed towards the dorsal midline rather than being symmetrically placed between dorsal and ventral margins on the eyed side of each fish. The migrating eyes of dextral fish, however, were significantly closer to the dorsal midline than in sinistral fish. This, in addition to the more dorsally oriented prey strikes in sinistral fish, suggests that the morphs are not simple behavioural mirror images of one another and therefore may differ ecologically.     

On the lens pad of Benthalbella infans, a scopelarchid deep-sea teleost

The tubular eye of scopelarchids contains a lens pad, derived from cornea, lateral to the lens and opposite a gap in the iris. The pad, transparent in life, is formed of optically dense lamellae arranged at ca. 45 degrees to the sagittal plane of the fish. The lamellae are ca. 155 nm thick, separated by ca. 185 nm. The pad does not deviate light passing normally through the lamellae, but does deviate light at an acute angle to the lamellae unequally through ca. 40 degrees, converting a spot to a streak. Light from ca. 20 degrees to the vertical below the fish will be projected onto the accessory retina of the dorsally pointing tubular eyes. The pad also disperses white light, blue light ca. 34 degrees and red light ca. 44 degrees. The deviation of light from below may enable the fish to detect predators below, and the dispersion may play a role in breaking camouflage by spreading photophore light over an area of retina.     

Use of the lateral line and tactile senses in feeding in four antarctic nototheniid fishes

Synopsis Fishes of the family Nototheniidae (Pisces: Perciformes) dominate antarctic fish communities and have radiated to fill diverse niches. The most southern species must operate under an extended austral night and under thick sea ice, yet have eyes more typical of shallow coastal fishes. In winter, the eyes are probably useless, except for detecting bioluminescence. I compared the responses of four species to hydromechanical and tactile signals: two benthivores,Trematomus bernacchii andT. pennellii, a benthic planktivore,T. nicolai, andPagothenia borchgrevinki, which feeds near the ice undersurface and within ice cracks. The planktivores have dorsal mouths, with eyes oriented dorsally or laterally (Pagothenia); their lateral line canals and receptor organs are larger dorsally. The benthivores have more ventrally oriented mouths and eyes. All species responded to hydromechanical cues to the head, but only the two benthivores responded to trunk hydromechanical stimuli or tactile stimuli to the ventral trunk or pelvic fins. Possibly responses to plankton along the trunk are of little use if a reorientation washes pelagic prey away. In responding to trunk stimuli,T. bernacchii reorients its head to the target in two stages by slowly pivoting on its pelvic fins. In contrast,T. pennellii reorients in a single quick flip. It is argued that, becauseT. bernacchii has wider canals thanT. pennellii, it must move more slowly to reduce self-generated noise. It is likely that further studies of winter diet and prey behavior may reveal the relative advantages of the two repositioning styles.     

A new species of Malmiana (Oligochaeta: Hirudinida: Piscicolidae) from tidepool fishes in northern California

Malmiana buthi n. sp. is described from the body and fins of the fluffy sculpin, Oligocottus snyderi, the tidepool sculpin, Oligocottus maculosus, and the woolly sculpin, Clinocottus analis, collected from tidepools at Horseshoe Cove on the Bodega Marine Reserve in Sonoma County, California. Prevalence of the leech was 32.6% on live-caught O. snyderi; mean intensity on O. snyderi was 3.3 leeches per fish, with a range from 1 to 7. The leech is not known to exceed 8 mm total length. The body is smooth, lacking papillae, tubercles, or pulsatile vesicles. Two pairs of crescentiform eyes are present on the oral sucker, and 1 pair of punctiform eyes occurs on the second annulus of the trachelosome. The caudal sucker has 14 small punctiform ocelli spaced evenly around the margin. The last 9 segments of the urosome have pairs of large punctiform ocelli both dorsally and ventrally. Body and caudal sucker pigmentation is uniformly reddish brown dorsally and ventrally with segental, lateral, unpigmented areas on both the urosome and trachelosome; pigmentation on the oral sucker is in the form of a cross. There are 5 pairs of testisacs; accessory gland cells on the atrial cornua and vector tissue are absent.     

A new species of marine leech (Hirudinida: Piscicolidae) from giant kelpfish, Heterostichus rostratus Girard, in southern California

Collections of giant kelpfish at inner Cabrillo Beach, San Pedro, California revealed the presence of an undescribed species of Heptacyclus, described here as Heptacyclus cabrilloi n. sp. The leech is small, only up to 14 mm total length including suckers; it has 2 pair of slightly crescentiform eyes on the oral sucker, 1 pair of punctiform ocelli on the second annulus of the trachelosome, 13 pairs of punctiform ocelli dorsally and ventrally on the urosome, and 14 marginal punctiform ocelli on the caudal sucker. Pigmentation is yellowish-tan with an unpigmented mid-dorsal stripe on both trachelosome and urosome, and with unpigmented halos around eyespots and urosome ocelli. Male reproductive system with 5 pairs of large, spherical testisacs. Mycetomes present, accessory gland cells on atrial cornu absent. Prevalence was 24.1% in June, 2011 with a range of 1-2 leeches per fish and 25.8% in October, 2011 with a range of 1-6 leeches per fish.     

Pelagic juvenile of <Emphasis Type="Italic">Halargyreus johnsonii</Emphasis> (Gadiformes: Moridae) from Suruga Bay,Japan

 A pelagic juvenile (43.0 mm standard length) of the deep-sea gadiform fish Halargyreus johnsonii was collected by a larva net towed at depths from 200 m to 90 m at Suruga Bay, Japan. The specimen had an elongate body, eyes located dorsally on the head, a depressed anal fin, small bony tubercles on the lower jaw symphysis, elongate pelvic fin rays, and a pointed caudal fin. The body was silver with numerous small black spots. The gut was filled with a copepod, Pareuchaeta russelli, that is characterized by a surface to mesopelagic distribution. Received: May 30, 2002 / Revised: December 16, 2002 / Accepted: December 24, 2002     

Ericandersonia sagamia, a new genus and species of deep-water eelpouts (Perciformes: Zoarcidae) from Japan

A new genus and species of deep-water zoarcid fish, Ericandersonia sagamia, is described on the basis of four specimens collected from Sagami Bay, Japan, at depths of 880–930 m. This species is placed in the subfamily Gymnelinae and is distinguished from all genera of gymnelines by the following characters: pseudosubmental crest present; frontals partially fused dorsally; parietals meeting in midline; pelvic fins absent; ventral ramus of posttemporal weak; postorbital head pores 5; pectoral-fin rays 14. The phylogenetic analysis (based on 42 morphological characters) indicates that its position is outside the highly modified (= advanced) genera Seleniolycus, Melanostigma, Puzanovia, Nalbantichthys, Opaeophacus, and Andriashevia.     

Observations on the "dorsal eyes" of fishes

The positioning of the eyes in 14 species of flat fishes and 8 species of non-flat fishes were studied by morphometrical means. All of these had dorsally located eyes and the eye positioning of the flatfish was related to the positioning of the mouth and significant shifting in the position was evident in this group during growth.     

Transplantation of eyes to the adult rat brain: Histological findings and light-evoked potential response

Entire eyes were transplanted from fetal rats into the brains of blind adults. In most cases, grafts placed deep within the brain grew and differentiated, and were found to contain retinal cells when examined histologically. Grafts placed within the cerebral cortex infrequently survived. The grafts were found to be sensitive to light, in that electrical potentials similar to electroretinograms (ERGs) or partial ERGs were evoked by flashes of light. It is concluded that fetal eyes can develop a form of light sensitivity when transplanted to the adult rat brain.