广西南宁渐新世基于咽齿的鲤亚科一新属（英文）

记述了产自广西南宁盆地渐新世早—中期的鲤科鲤亚科一新属种——伍氏南宁鲤(?Nanningocyprinus wui gen.et sp.nov)。化石材料包括一些咽喉骨和咽齿。这些咽喉骨和咽齿的以下特征组合明显不同于其他鲤科鱼类:齿式—3·2·1,主行第一枚咽齿大小是第二枚的3~4倍,第二枚咽齿及第二行第一枚咽齿咀嚼面上各仅有一条沟纹,咽骨前角很发育。该属种的发现进一步证明鲤亚科是鲤科中较早的分支,中国南方很有可能是鲤亚科的起源和分化中心。     

鲤咽齿个体发生及其与近缘种间关系的比较研究

鲤具鲤科咽齿个体发生的共同性征,又呈现其种的独特性状.主要特性;(1)主列齿相连3齿胚几乎同时出现、同时脱落,形成3个相连齿种同时置换的特殊模式;(2)主列齿发生中曾出现4枚齿,替换3代后A_4齿退化消失,最终齿式1.1.3-3.1.1,成为迄今3列咽齿的鱼类中齿数最少的种类.鲤与其近缘种间系统关系比较结果;依最近缘属顺次排列为中鲤、原鲤、肥鲤;而最近缘的亚科为肥亚科.       

锦鲤咽齿替换及齿胚的解剖学观察,前插1

从鱼类解剖学和口腔医学的角度,观察和讨论了锦鲤咽齿、齿胚的形态结构和咽齿的替换,并对咽齿和咬合板做了扫描电镜观察.发现锦鲤咽齿替换与齿胚有密切关系;咽齿替换分为两侧不同名齿同时替换、同侧两枚不同名齿同时替换和单侧一枚齿自主替换3种类型;咽齿替换是终生发生的,遵循着"被替换咽齿的骨性支持从基骨骨孔开始吸收-同名齿胚的移行与就位-旧齿脱落与新齿支持组织改建为骨性"的过程.认为齿胚的发育是启动咽齿替换的起始因素;锦鲤与野生鲤有近缘关系.     

雅罗鱼亚科咽骨及咽齿的研究

本文根据对雅罗鱼亚科咽骨及咽齿的研究,将其咽骨分为三种类型。研究结果表明,本亚科咽骨形态及咽齿结构表现有与食性高度适应的现象。本亚科的咽齿有圆锥型,斜齿面型及特化型,这是对三种不同食性适应的结果。依据咽骨、咽齿的结构特点,试拟了雅罗鱼亚科属的检索。     

柴达木盆地渐新世的鲤科鱼类化石

记述了首次发现于柴达木盆地早渐新世晚期至晚渐新世早期(距今27～29 Ma)的鲤科鱼类化石。材料包括咽骨、咽齿、匙骨、腹鳍骨及一些零散的鳍条。咽骨及咽齿化石与原始鲃亚科鱼类及裂腹鱼亚科裂腹鱼属鱼类的相似;腹鳍骨化石与原始鲃亚科鱼类的更相似。鲃亚科鱼类现今分布于北纬35°以南的亚洲、欧洲南部及非洲北部;裂腹鱼属鱼类分布局限于青藏高原东、南、西面的边缘区域,在柴达木盆地没有分布。柴达木盆地水系现生鱼类仅见适于高寒环境的高度特化等级的裂腹鱼亚科鱼类及鳅科高原鳅属鱼类,鱼类组成与早渐新世晚期至晚渐新世早期的不尽相同。     

鲤科鱼类咽喉齿的剥取与计数

鲤科鱼类是鱼类中最大的科,因而也最为常见.在我国淡水鱼类中,鲤科分为9亚科119属700余种,占淡水鱼类的半数以上(56％左右).由于鲤科鱼口腔诸骨上不生牙齿,而在喉部的咽骨(第五对鳃弓演变而成)上长有牙齿,因而称为咽喉齿或下咽齿.咽喉齿的排列行数和各行齿数(齿式)以及齿的大小、形状,为鲤科鱼分类的重要依据之一,因而剥取咽喉齿及其计数,是研究鲤科鱼的一项重要基本功. 根据大小不同类型的鱼体,采用眼科镊子、普通镊子甚至骨钳,先微微挑起鳃盖的后缘,合拢镊子插人鳃孔,以鱼头宽度的一半为插入深度,自背方向腹方沿鳃     

鲤形目鱼类咽齿形态及发育的比较研究

对鲤形目所属６科类的咽龄形态及个体发育模型进行了较详细的比较研究。结果得出除双孔鱼科鱼类未形成咽齿外,其它５科鱼类在咽齿发生的过程中具有齿着生方向完全相反的两种发育模式。以亚口鱼科,鳅科和平鳍鳅为一类的齿后向增长的类型和以鲤科另一类的齿同增长的类型。     

稀有ju鲫咽齿个体发生的研究

稀有Ｊｕ鲫是一种２,４－４船２齿式的小型鲤科鱼类,通过对其胚后发育连续材料的观察,作者认为：１,成体中咽齿的行齿是遗留的早期替换齿;２,成体中排成一行的主行齿实际分属两代齿,其替换过程与幼体中齿的替换无本质上的差别;３,整个咽齿的替换过程可用Ｅｄｍｕｎｄ的齿序理论和Ｏｓｂｏｒｎ的假设共同解释。     

稀有鮈鲫咽齿个体发生的研究

稀有鲫是一种２,４－４,２齿式的小型鲤科鱼类,通过对其胚后发育连续材料的观察,作者认为：１．成体中咽齿的副行齿是遗留的早期替换齿;２．成体中排成一行的主行齿实际分属两代齿,其替换过程与幼体中齿的替换无本质上的差别;３．整个咽齿的替换过程可用Ｅｄｍｕｎｄ的齿序理论和Ｏｓｂｏｒｎ的假设共同解释。     

似鮈属鱼类遗传多样性的RAPD分析及种的划分问题

似属PseudogobioBleeker隶属鲤形目Cypriniformes、鲤科Cyprinidae的鲤亚科Gobioninae。       

Bimodal oxygen uptake in a freshwater air-breathing fish,Notopterus chitala

Measurements of bimodal oxygen uptake have been made in a freshwater air-breathing fish,Notopterus chitala at 29.0±1(S.D.)°C. xhe mean oxygen uptake from continuously flowing water without any access to air, was found to be 3.58±0.37 (S.E.) ml O₂ · h^?1 and 56.84+4.29 (S.E.) ml O₂ · kg^?1 · h^?1 for a fish weighing 66.92 + 11.27 (S.E.) g body weight. In still water with access to air, the mean oxygen uptake through the gills were recorded to be 2.49 ± 0.31 (S.E.) ml O₂ · h^?1 and 38.78 ± 1.92 (S.E.) ml O₂ · kg^?1 · h^?1 and through the accessory respiratory organs (swim-bladder) 6.04±0.87 (S.E.) ml O₂ · h^?1 and 92.32±2.91 (S.E.) ml O₂ · kg^?1 · h^?1 for a fish averaging 66.92±11.27 (S.E.) g. Out of the total oxygen uptake (131.10 ml O₂ · kg^?1 · h^?1), about 70% was obtained through the aerial route and the remainder 30% through the gills.     

The first record of the genus <Emphasis Type="Italic">Isurichthys</Emphasis> (Perciformes,Ariommatidae) in the Lower Oligocene of the Northern Caucasus

An ariommatid fish, Isurichthys breviusculus sp. nov. (Perciformes), from the Lower Maikopian (Lower Oligocene) of the northern Caucasus (Apsheronsk District) is described based on an almost complete skeleton. This is the first record of the Oligocene genus Isurichthys in the Caucasus. Direct evidence of the presence of a toothed pharyngeal sac in the oesophagus of Isurichthys is obtained for the first time. Of two known species of Isurichthys, the new species is closer to I. roumanus Baciu et Bannikov, 2004 from the Oligocene of Romania. The fossil record of Stromateoidei sensu stricto is reviewed.     

The impact of intra- and interspecific interactions on young-of-the-year brook charr, in temperate lakes

The abundance, growth, spatial distribution, and feeding habits of five allopatric brook charr, Salvelinus fontinalis, populations (young-of-the-year, 0+ juveniles; YOY) were compared with five other populations living sympatrically with white sucker, Catostomus commersoni. The study was made in oligotrophic lakes of the Laurentian Shield (Québec, Canada) during three sampling periods in 1989 (July, August and September). The abundance of YOY charr was significantly higher in allopatric than in sympatric populations (45·3 ± 3·8 vs 3·4 ± 3·8 fish/lake caught in 1773 m² of gillnets; P<0·005). The mean length of YOY charr did not differ among allopatric and sympatric populations at each sampling period; July: 60·2 ± 3·0 vs 60·0 ± 4·5 mm; August: 61·9 ± 4·5 vs 63·2 ± 4·1 mm; September: 77·9 ± 8·7 vs 77·3 ± 7·8 mm respectively. Horizontal distribution of allopatric YOY charr did not differ from that of sympatric charr, 65% of the fish being captured within the first 2 m depth and the rest between 2 and 7 m depth. In contrast, the vertical distribution of allopatric YOY charr from both communities was significantly different; 81% of allopatric charr were captured within 0·5 m from the substrate compared to 64% for sympatric charr (P<0·001). Differences in vertical distribution of the fish were related to differences in diet; allopatric charr fed mainly on benthic and large planktonic organisms whereas sympatric charr fed less on these organisms and more on terrestrial organisms. In the lake where YOY charr were most abundant, individuals were spatially segregated into two groups; one ‘littoral’, found in 0–2m depth, and one ‘profundal’, found in 3–6 m depth. Growth, condition, and feeding habits of charr from the two groups were different, especially during the last sampling period.     

An energy budget for juvenile thick-lipped mullet, Crenimugil labrosus (Risso)

A series of experiments were carried out to construct an energy budget for juvenile thick lipped mullet, Crenimugil labrosus Risso. A partial factorial experimental design was used to examine the effects of temperature, fish size and meal size on growth. The maximum ration that the fish were able to ingest completely per day was found to be 0·8, 1·4 and 2·3% wet body weight (b.w.) at 13,18 and 23°C, respectively. Ingested maintenance requirements (M.R.) were estimated to be 137, 205 and 288 cal fish^-1 day^-1 at 13, 18 and 23°C, respectively. At 18deg; C, M.R. varied as 25 W^1.04 cal day^-1, where W= fish weight (g). Growth rate increased with increasing temperature. Maximal conversion efficiency was 21–24% and was achieved closer to the maximum ingested ration with increasing temperature. The relationship between respiration rate and W at 18deg; C for 3-20 g fish is described by: respiration rate (ml O₂ h^-1) = 0·128 W^0.976 The energy cost of apparent specific dynamic action at 18deg; C was found to vary between 5·1% and 23·6% of the calorific value of the ingested meal (1% wet b.w.) , mean (± S.E.)=10·2 ± 2·0%. Post mortem analyses of groups of fish fed 0·2, 0·8 and 1·5% wet b.w. meals showed a significant increase in total lipid and a significant decrease in water content with increasing ratio size. A negative correlation was found between body water content and total lipid (and calories). The mean assimilation efficiency (±s.e.) for 5–10 g mullet at 18deg; C was 73·9 ± 3·6%. The observations reported in this study were brought together to construct an energy budget for juvenile C. labrosus which was found to give a reliable prediction (within 10%) of energy demand and growth under the prevailing experimental conditions. Both gross (K₁) and net (K₂) growth efficiencies, based on energy values, increased with increasing ratio size up to satiation and were independent of temperature. The maximum values of K₁ and K₂ observed were 0·33 and 0·46, respectively. The third order efficiency (K₃) appeared to be independent of temperature and ration size; mean values ranged between 0·66 and 0·84.     

Heart rate as an indicator of metabolic rate and activity in adult Atlantic salmon, Salmo salar

Telemetered heart rate (f_H) was examined as an indicator of activity and oxygen consumption rate (VO₂) in adult, cultivated, Atlantic salmon, Salmo salar L. Heart rate was measured during sustained swimming in a flume for six fish at 10° C [mean weight, 1114 g; mean fork length (f. l.), 50·6 cm] and seven fish at 15° C (mean weight, 1119 g; mean f. l., 50·7 cm) at speeds of up to 2·2 body lengths/s. Semi–logarithmic relationships between heart rate and swimming speed were obtained at both temperatures. Spontaneously swimming fish in still water exhibited characteristic heart rate increases associated with activity. Heart rate and Vo₂ were monitored simultaneously in a 575–1 circular respirometer for six fish (three male, three female) at 4° C (mean weight, 1804 g; mean F. L., 62· cm) and six fish (three male, three female) at 10° C (mean weight, 2045 g; mean f. l., 63·2 cm) during spontaneous but unquantified activity. Linear regressions were obtained by transforming data for both f_H and Vo₂ to log values. At each temperature, slopes of the regressions between f_H and Vo₂ for individual fishes were not significantly different, but in some cases elevations were. All differences in elevation were between male and female fish. There were no significant differences in regression slope or elevation for fish of the same sex at the two temperatures and so regressions were calculated for the sexes, pooling data from 4 and 10° C. There was no significant difference in the mean ± S. D. Vo₂ between the sexes at 4° C (male, 66·0 ± 59·6 mgO₂ kg^?1 h^?1; female, 88·0 ± 60·1 mgO₂ kg^?1 h^?1) or 10° C (male, 166·2 ± 115·4 mgO₂ kg^?1 h^?1; female, 169·2 ± 111–1 mgO₂ kg^?1h^?1). Resting Vo₂ (x?± s. d.) at 4°C was 36·7 ± 8.4 mgO₂ kg^?1 h^?1, and 10° C was 72·8 ± 11·9 mgO₂ kg^?1 h^?1. Maximum Vo₂ (x?± S. D.) at 4° C was 250·6 ± 40·2 mgO₂ kg^?1 h^?1, and at 10° C was 423·6 ± 25·2 mgO₂ kg^?1 h^?1. Heart rate appears to be a useful indicator of metabolic rate over the temperature range examined, for the cultivated fish studied, but it is possible that the relationship for wild fish may differ.     

How many daddies: microsatellite genotyping reveals polyandry in a live‐bearing clinid fish Muraenoclinus dorsalis

Fishes belonging to the family Clinidae in South Africa display super‐embryonation, a rare reproductive mode were females gestate broods at different gestational stages, but little is known regarding the mating systems of this family. Here we tested the hypothesis that multiple males would contribute not only to the offspring of each female, but that several males would contribute to each brood, by sampling Muraenoclinus dorsalis from three sampling locations along the west and south‐west coast of South Africa. Larval (n = 97) and maternal (n = 14) genotpyes, generated with newly developed microsatellites, were used to estimate the number of potential mates per female. Our results show that up to 78% of females displayed multiple mating with an average of 2·1–2·2 males. In addition, 39–42% of females displayed polyandry with an average of 1·5–1·6 sires per brood. This study provides the evidence for multiple mating and polyandry within a clinid fish characterized by super‐embryonation that offers important baseline information regarding rare reproductive strategies, highlighting several gaps in our knowledge concerning clinid reproduction and mating systems.     

Effects of two parasites, Schistocephalus solidus (Cestoda) and Bunodera spp. (Trematoda), on the escape fast-start performance of three-spined sticklebacks

The fast‐start performance of three‐spined sticklebacks Gasterosteus aculeatus infected with Schistocephalus solidus and Bunodera spp. was determined and two distinct fast‐start responses (A and B) were observed. ‘A’ starts were of higher flexibility than B and three‐way ANOVA showed significant effects of A and B starts (P < 0·05), time (P < 0·05) and per cent standard body length, L_S (P < 0·05) on the orientation angle (angle of an individual segment of the fish with respect to the direction of travel). Schistocephalus solidus infection reduced maximum velocity (P < 0·05) and maximum acceleration (P < 0·05) of infected fish. Uninfected fish and fish infected with S. solidus up to a parasite index (parasite mass divided by the sum of fish and parasite mass) of 0·1 executed both types. Infected fish exclusively executed B starts for parasite index between 0·1 and 0·2. This was not due to a reduction in body flexibility associated with mechanical obstruction caused by S. solidus as no significant difference in the ratios of body width (P > 0·05) or depth (P > 0·05) to L_S were found between uninfected and infected fish. At a parasite index >0·2, infected fish were unable to perform escape fast‐starts increasing the likelihood of predation by their definitive hosts such as loons or belted kingfishers. Three‐spined sticklebacks infected with S. solidus with a parasite index of c. 0·2–0·3, however, were compromised by a suite of behavioural (e.g. increased foraging activity and amount of food consumed, increased risk associated with feeding and increased response latency to predatory stimuli), physiological (e.g. increased rate of oxygen consumption, slower growth, delayed sexual maturation and breeding success) and biomechanical (e.g. decreased fast‐start performance) factors. Bunodera spp. did not affect the escape fast‐start performance of three‐spined sticklebacks and no significant difference for maximum velocity (P > 0·05) and maximum acceleration (P > 0·05) was found.     

北部湾盆地海中凹陷古近纪古气候研究

古气候对烃源岩的发育具有重要的控制作用,温暖湿润的气候成为优质湖相烃源岩发育的有利气候条件。本次根据X1井及X2井的孢粉资料及粘土矿物数据,采用孢粉定量统计分析与粘土矿物分析相结合的方法,对海中凹陷中始新世—晚渐新世的古气候进行了研究。研究显示海中凹陷流沙港组二段沉积时期(中—晚始新世)气候相对温暖湿润,为南亚热带湿润—半湿润气候;流沙港组一段沉积时期(晚始新世—早渐新世早期)气候开始转凉,为中亚热带湿润—半湿润气候;涠洲组沉积时期(早渐新世晚期—晚渐新世晚期)气候逐渐变得干燥,为中亚热带半湿润—半干旱气候,同时明确了流沙港组二段沉积时期为海中凹陷优质湖相烃源岩发育的最佳时期。     

Development and ossification of the feeding apparatus in the larvae of two co‐occurring species of kob (Sciaenidae), Argyrosomus japonicus and Argyrosomus inodorus,in South Africa

The teeth of the oral jaws of two sympatric species of Argyrosomus, Argyrosomus japonicus and Argyrosomus inodorus, found along the South African coast developed first on the premaxilla and then on the dentary of the lower jaw. Teeth were observed on the premaxilla of A. inodorus [head length (L_H) = 1·0 mm; notochord length (L_N) = 2·7 mm] at a smaller size than in A. japonicus (L_H = 1·2 mm; L_N = 4·7 mm). The ventral elements of the gill arches (hypo‐ and basibranchials) were not ossified by the end of preflexion. The fifth ceratobranchial began ossifying and possessed pharyngeal teeth by 1·2 mm L_H (L_N = 4·7 mm) in A. japonicus and 1·1 mm L_H (L_N = 3·2 mm) in A. inodorus. To complement the osteological data, stomach contents were also analysed as a proxy for feeding apparatus functionality. Prey were first present in the stomach of A. japonicus at 1·2 mm L_H (L_N = 4·7 mm) and only 22% of the stomachs contained no prey suggesting that A. japonicus is already actively foraging by preflexion. In comparison, 83% of the stomachs of A. inodorus contained no prey and a single prey item was present in the largest examined specimen (L_H = 1·6 mm; L_N = 5·4 mm). Elements of the feeding apparatus begin to ossify early during ontogeny. While the overall pattern of ossification is similar between the two species, A. japonicus may be able to begin feeding at smaller head lengths relative to A. inodorus in their nursery habitats.