桑沟湾栉孔扇贝生物沉积的现场测定

运用沉积物捕集器于桑沟湾对栉孔扇贝 (Chlamysfarreri)的生物沉积进行了现场测定 ,以评价贝类养殖对近岸生态环境的影响。结果表明 :桑沟湾栉孔扇贝具有相当高的生物沉积速率。壳高 68 1～77 9mm、软体干重 2 75～ 3 91g的栉孔扇贝 ,其生物沉积速率为 0 93～ 6 97g ind·d,平均 3 99g ind·d ;而壳高 40 8～ 67 4mm、软体干重 0 5 9～ 1 85g的栉孔扇贝生物沉积速率的变化范围为 0 5 2～ 6 42g ind·d,平均为 2 3 8g ind·d ;另外 ,壳高为 2 5 8～ 2 8 3mm、软体干重 0 1 2～ 0 1 7g的栉孔扇贝 ,其生物沉积速率在2 0 0 2年的 1 1和 1 2月以及 2 0 0 3年的 1月分别为 0 74、1 1 1和 0 1 5g ind·d。在桑沟湾 ,影响栉孔扇贝生物沉积的主要因素包括水温、悬浮颗粒物、扇贝个体大小和年龄。高密度、大规模的近岸浅海贝类养殖所产生的大量生物沉积物可能会对海区的物理、化学和生物环境产生影响。     

几何形态测量学在古生物学研究中的应用概况北大核心CSCD

几何形态测量学(Geometric morphometrics)是一种研究生物形状变异的测量学研究方法。形态测量学中较早出现了传统形态测量学,而后革命性演变出只针对形状差异的几何形态测量学。几何形态测量学因定量化和描述客观准确,在生物学上得到广泛应用,后被引入到了古生物学研究中,同样发挥了极其重要的作用并被不断发展。本文从几何形态测量学方法以及传统测量学方法在古生物中应用历史和应用方向两个角度对其在古生物学研究中的应用概况进行介绍,并对应用前景做展望。     

一株形态特殊的细菌对栉孔扇贝致病性的初步研究

为研究分离到的一株形态特殊的细菌对栉孔扇贝(Chlamys farreri)致病性,采用测定病原液蛋白含量的方法,对病原相对定量。用含200～300μg／ml蛋白的病原液进行了不同浓度梯度、同一温度和相同浓度梯度、不同温度对栉孔扇贝的致病作用的测试,结果表明：扇贝人工感染后潜伏期3～7d,死亡高峰期为5～10d,符合一般病原感染的规律。病死贝的一般病理变化与养殖海区自然发病扇贝的病理变化一致。23、26℃下该病原体对栉孔扇贝具有强致病作用。可以确定该细菌为造成栉孔扇贝大规模发病死亡的主要病原之一。     

轮廓形态测量法在生物分类应用中的研究进展

本文阐述了形态测量学中一类重要的研究方法——轮廓形态测量法的基本概念和发展,总结了轮廓形态测量法在生物分类学研究中的应用,将轮廓形态测量法与另一类重要的形态测量学方法——标点法进行了比较,分析了这两类方法各自的优势和局限性,展望了轮廓形态测量法在昆虫分类学研究中的应用前景。     

栉孔扇贝生理生态学特征的实验研究

基于近年发展起来的生物沉积法,在烟台四十里湾养殖海区采用室内大型流水系统对栉孔扇贝的滤水率、吸收率和生态效率等生理生态学参数进行了测定,并探讨了它们与养殖密度与食物可获得性的关系．栉孔扇贝滤水率(平均3．65L·ind^-1·h^-1)与扇贝放养密度和饵料浓度无显著关系,而栉孔扇贝摄食率随放养密度的升高而降低,与POM呈正相关．扇贝对食物的吸收效率较高(平均75．9％),这与低饵料浓度行关．扇贝氨基酸泄漏所损失的能量高于排氨的能量损失．扇贝的生长余力(SFG)、总生长效率(尺：)和净生长效率(尺z)均与饵料浓度呈正相关．扇贝对氮的总生态效率(平均9．9％)高于对碳(平均5．9％)和磷(平均4．1％)．在氟的预算中,如果仅考虑NH4^ —N的排泄,而忽视其它形态氟的排泄,将会产生较大偏差(平均约20％)．贝壳不管在能量预算还是在元素预算中部不应该被忽视．在沿岸养殖海域,栉孔扇贝通过大量的滤水摄食、生长、排泄、生物沉积等对生态系统的能量流动和物质循环产生影响．     

栉孔扇贝×虾夷扇贝杂交子一代与双亲染色体核型的分析

连续几年栉孔扇贝大面积死亡现象严重制约了北方贝类养殖业的发展 ,造成了巨大的经济损失。栉孔扇贝和虾夷扇贝生物学性状差异较大 ,可望通过杂交途径培育出抗逆性强、生长快的扇贝养殖新品种。杨爱国等[1] 和周丽青等[2 ] 的研究结果表明 ,栉孔扇贝与虾夷扇贝正反交杂交子一代     

黔北志留系石牛栏组松坎段上部近岸——远岸的相分异

华南板块上扬子区滇黔桂古陆以北的陆表海缓坡带,因海水深度变化导致志留纪兰多维列世埃隆晚期石牛栏组的岩相—生物相差异,这种差异始于松坎段上部沉积期。本文选择2个剖面,分别代表近岸和远岸带的古地理位置,作松坎段上部灰岩岩相学和沉积环境指标分析。余庆大庄村剖面位于近岸带,可频繁出现薄层泥粒状灰岩和颗粒灰岩,属浅水高能带常见的壳相生屑滩堆积;而桐梓水坝塘剖面位于远岸带,偏深水低能环境中的瘤状灰岩和含泥灰岩透镜体多含灰泥和粉砂屑。这些证据从细节上揭示松坎段上部沉积时,靠近黔中古陆近岸带存在壳相动物大量繁衍的生态位,还伴随有钙质微生物形成的叠层石和核形石,但空间展布上可能是狭窄的,大部分陆表海区的海水深度处于最大风浪暴浪基面以下。     

四十里湾栉孔扇贝清滤率、摄食率和吸收效率的现场研究

运用生物沉积法在四十里湾不同海区对栉孔扇贝的生理生态学特征进行了研究。 1龄栉孔扇贝 (4 1 .1± 4.1 mm,软体干重 0 .48± 0 .1 0 g/ ind)清滤率变化范围为 0 .72～ 2 .5 4(平均 1 .2 7) L/ (ind· h)或 1 .65～ 5 .97(平均 2 .61 ) L/ (g· h)。清滤率受 TPM的变化影响不大 ,而摄食率却随 TPM的升高而升高。 2龄扇贝 (软体干重 1 .91± 0 .3 2 g/ ind)清滤率为2 .0 9～ 3 .99(平均 3 .1 0 ) L/ (ind· h)。栉孔扇贝吸收速率与 POM呈正相关关系 ,而与饵料质量 (POM/ TPM)无明显的相关性。1龄扇贝和 2龄扇贝吸收效率没有显著差别 ;扇贝对 POM的吸收效率与 TPM (或 POM)关系不大 ,却与饵料质量呈明显的正相关关系 ;扇贝对 POC、PON和 PP的吸收效率平均分别为 68.9%、64.0 %和 63 .6%。在沿岸养殖海域 ,栉孔扇贝通过大量的滤水摄食以及较高的吸收效率对生态系统的能量流动和物质循环产生影响。     

基于几何形态测量学的黄蜻翅的雌雄二态性研究

【目的】本研究运用几何形态测量学方法对黄蜻Pantala flavescens Fabricius前翅和后翅的雌雄二态性进行分析,探讨黄蜻雌雄性在翅上的形态差异。【方法】通过对黄蜻的前翅和后翅做数字化标点,获得翅的形态信息。经主成分分析(PCA)和薄片样条法(TPS)获得雌雄性在翅型和翅脉上的差异性。【结果】PCA结果表明,黄蜻雌雄性的前翅和后翅在翅型、翅脉结构上存在着明显差异,而且后翅间的差异更大。经TPS分析可知,雌雄性黄蜻前翅上的差异部位主要发生在亚翅结和三角室,后翅的差异部位主要发生在亚翅结、肘脉域和臀角区域。对黄蜻前后翅的大小分析(CS)可知,雌性黄蜻前后翅较大,雄性黄蜻前后翅较小。【结论】黄蜻雌雄性间的翅型结构差异性表明雌雄性在其各自生活史中履行不同的职责,特定的飞行模式逐渐形成特定的翅型、翅脉结构。     

形态测量学(Morphometrics)常用方法及其在微体古生物学中的应用

形态测量学用定量化的方法和手段描述、研究对象形态特征。几何形态测量学是形态测量学的分支,用界标点或轮廓线等标识研究对象的形态,并运用多变量运算进行量化分析和判别。形态测量学方法在生物学与古生物学领域的应用日益广泛,在生物的个体发育、系统演化、类群判别等方面均可发挥重要作用。本文重点介绍了目前在形态测量学中常用的数据类型、分析方法与步骤,即线性距离、界标点、轮廓线等数据类型的获取,普鲁克迭加、傅里叶转换、特征形状分析与增强特征形状分析等数据转换方法,以及主变量分析、典型变量分析等常用多变量线性回归方法的原理与分析过程。选择以类有孔虫个体发育与类群鉴定中几何形态测量学的应用为例,解释最常用的多变量线性回归方法——主成分分析与典型变量分析的应用与结果剖析。     

The Halomonhystera disjuncta population is homogeneous across the Håkon Mosby mud volcano (Barents Sea) but is genetically differentiated from its shallow‐water relatives

The deep sea has a high biodiversity and a characteristic bathyal fauna. Earlier evidence suggested that at least some shallow‐water species invaded the ecosystem followed by radiation leading to endemic deep‐sea lineages with a genetic and/or morphological similarity to their shallow‐water counterparts. The nematode Halomonhystera disjuncta has been reported from shallow‐water habitats and the deep sea [Håkon Mosby mud volcano (HMMV)], but the morphological features and the phylogenetic relationships between deep‐sea and shallow‐water representatives remain largely unknown. Furthermore, nothing is known about the genetic structure of the H. disjuncta population within the HMMV. This study is the first integrative approach in which the morphological and phylogenetic relationships between a deep‐sea and shallow‐water free‐living nematode species are investigated. To elucidate the phylogenetic relationships, we analysed the mitochondrial gene Cytochrome oxidase c subunit I (COI) and three nuclear ribosomal genes (Internal Transcribed Spacer region, 18S and the D2D3 region of 28S). Our results show that deep‐sea nematodes comprise an endemic lineage compared to the shallow‐water representatives with different morphometric features. COI genetic divergence between the deep‐sea and shallow‐water specimens ranges between 19.1% and 25.2%. Taking these findings into account, we conclude that the deep‐sea form is a new species. amova revealed no genetic structure across the HMMV, suggesting that nematodes are able to disperse efficiently in the mud volcano.     

Shape differentiation and characterization in the two morphotypes of the Antarctic limpet Nacella concinna using Elliptic Fourier analysis of shells

The Antarctic limpet Nacella concinna (Strebel 1908) presents two ecotypes (littoral and sublittoral) differing in morphological and behavioral characteristics and more recently discovered, in physiological traits and genetic population structure. Previous works, based on traditional morphometry, used only three measurements (length, width and height of the shell) and their relationships. However, this methodology could not describe in detail the shape of the morphotypes. In the present work, Elliptic Fourier analysis (EFA) of shells was used to study the shape of the two morphotypes in six localities along the Antarctic Peninsula. The use of EFA confirmed the morphometric differences. The littoral morphotype has higher and globose shells with the apex displaced to the anterior part; the sublittoral individuals are more flat and pointed, and have the apex very well defined. Low allometric effect was detected in SL individuals, whereas L specimens did not show an allometric relationship within the examined size range. Differences in shell shape among localities were recorded. EFA analysis reflected the overall shell shape and allowed to characterize the main differences in shell shape between ecotypes that were difficult to quantify using the standard morphometric approach.     

Patch-reef morphology as a proxy for Holocene sea-level variability,Northern Florida Keys,USA

A portion of the northern Florida Keys reef tract was mapped with the NASA Experimental Advanced Airborne Research Lidar (EAARL) and the morphology of patch reefs was related to variations in Holocene sea level. Following creation of a lidar digital elevation model (DEM), geospatial analyses delineated morphologic attributes of 1,034 patch reefs (reef depth, basal area, height, volume, and topographic complexity). Morphometric analysis revealed two morphologically different populations of patch reefs associated with two distinct depth intervals above and below a water depth of 7.7 m. Compared to shallow reefs, the deep reefs were smaller in area and volume and showed no trend in topographic complexity relative to water depth. Shallow reefs were more variable in area and volume and became flatter and less topographically complex with decreasing water depth. The knoll-like morphology of deep reefs was interpreted as consistent with steady and relatively rapidly rising early Holocene sea level that restricted the lateral growth of reefs. The morphology of shallow “pancake-shaped” reefs at the highest platform elevations was interpreted as consistent with fluctuating sea level during the late Holocene. Although the ultimate cause for the morphometric depth trends remains open to interpretation, these interpretations are compatible with a recent eustatic sea-level curve that hindcasts fluctuating late Holocene sea level. Thus it is suggested that the morphologic differences represent two stages of reef accretion that occurred during different sea-level conditions.     

Swimming behavior and morphometry of the file shell Limaria fragilis

Swimming has evolved in only a few orders of Bivalves. In this study, the behavior, morphometry, and mechanics of swimming in the file shell Limaria fragilis were characterized and compared to the better understood scallops. Absolute swimming speed (cm sec^-1) increased with increasing shell height, although relative swimming speed (body lengths sec^-1) did not covary with shell height. The increase in absolute swimming speed was due to an increase in the distance covered during each valve clap as clap distance (cm clap^-1) also increased with shell height while clapping frequency (claps sec^-1) did not covary with animal size. Limaria fragilis displayed a variety of morphological changes related to size. Shell length was negatively allometric with shell height indicating the shell became proportionately slimmer in larger animals. Dry shell mass was negatively allometric with shell height, while both dry adductor muscle mass and dry mantle + tentacle mass were positively allometric. Autotomy of mantle tentacles significantly decreased clap distance by 13% without affecting clapping frequency or swimming speed.     

From offshore to onshore: multiple origins of shallow-water corals from deep-sea ancestors

Shallow-water tropical reefs and the deep sea represent the two most diverse marine environments. Understanding the origin and diversification of this biodiversity is a major quest in ecology and evolution. The most prominent and well-supported explanation, articulated since the first explorations of the deep sea, holds that benthic marine fauna originated in shallow, onshore environments, and diversified into deeper waters. In contrast, evidence that groups of marine organisms originated in the deep sea is limited, and the possibility that deep-water taxa have contributed to the formation of shallow-water communities remains untested with phylogenetic methods. Here we show that stylasterid corals (Cnidaria: Hydrozoa: Stylasteridae)--the second most diverse group of hard corals--originated and diversified extensively in the deep sea, and subsequently invaded shallow waters. Our phylogenetic results show that deep-water stylasterid corals have invaded the shallow-water tropics three times, with one additional invasion of the shallow-water temperate zone. Our results also show that anti-predatory innovations arose in the deep sea, but were not involved in the shallow-water invasions. These findings are the first robust evidence that an important group of tropical shallow-water marine animals evolved from deep-water ancestors.     

Swimming behavior and morphometry of the file shell Limaria fragilis

Swimming has evolved in only a few orders of Bivalves. In this study, the behavior, morphometry, and mechanics of swimming in the file shell Limaria fragilis were characterized and compared to the better understood scallops. Absolute swimming speed (cm?sec^?1) increased with increasing shell height, although relative swimming speed (body lengths?sec^?1) did not covary with shell height. The increase in absolute swimming speed was due to an increase in the distance covered during each valve clap as clap distance (cm?clap^?1) also increased with shell height while clapping frequency (claps?sec^?1) did not covary with animal size. Limaria fragilis displayed a variety of morphological changes related to size. Shell length was negatively allometric with shell height indicating the shell became proportionately slimmer in larger animals. Dry shell mass was negatively allometric with shell height, while both dry adductor muscle mass and dry mantle + tentacle mass were positively allometric. Autotomy of mantle tentacles significantly decreased clap distance by 13% without affecting clapping frequency or swimming speed.     

Effects of substrate on interactions between juvenile sea scallops (Placopecten magellanicus Gmelin) and predatory sea stars (Asterias vulgaris Verrill) and rock crabs (Cancer irroratus Say)

We investigated the effect of substrate (glass bottom, sand, granule, pebble) on predation of juvenile sea scallops (Placopecten magellanicus) by sea stars (Asterias vulgaris) and rock crabs (Cancer irroratus) at two prey sizes (11-15 mm and 24-28 mm shell height), and two prey densities (10 and 30 scallops per aquarium) in laboratory experiments. Specifically, we quantified predation rate and underlying behaviours (proportion of time a predator spent searching for and handling prey, encounter rate between predators and prey, and various outcomes of encounters). We detected a significant gradual effect of particle size of natural substrates on sea star predation: specifically, predation rate on and encounter rate with small scallops tended to decrease with increasing particle size (being highest for sand, intermediate for granule, and lowest for pebble). Substrate type did not significantly affect predation rates or behaviours of sea stars preying on large scallops or of rock crabs preying on either scallop size classes. Other factors, such as prey size and density, were important in the scallop-sea star and scallop-rock crab systems. For example, predation rate by sea stars and crabs and certain sea star behaviours (e.g. probability of consuming scallops upon capture) were significantly higher with small scallops than with large scallops. As well, in interactions between small scallops and sea stars, predation rate and encounter rate increased with prey density, and the proportion of time sea stars spent searching was higher at low prey density than high prey density. Thus, substrate type may be a minor factor determining predation risk of seeded scallops during enhancement operations; prey size and prey density may play a more important role. However, substrate type still needs to be considered when choosing a site for scallop enhancement, as it may affect other scallop behaviours (such as movement).     

贵州寒武纪始海百合类萼部形态定量评价及其意义

始海百合类是贵州寒武纪杷榔动物群和凯里生物群代表性化石类群。产出杷榔动物群和凯里生物群的杷榔组和凯里组主要由灰绿色、灰色的泥、页岩组成,始海百合类化石保存在2个组中上部的泥、页岩中,化石保存好,丰度高,是陆棚斜坡较深水环境生态类群的典型代表。本文基于来自杷榔组的36块Guizhoueocrinus yui,29块Protogloboeocrinus yini标本,和凯里组的20块Sinoeocrinus lui,20块Globoeocrinus globulus标本,采用几何形态测量方法和传统形态测量方法,对每块标本萼部选定了4个界标点(landmark),进行数理统计和几何形态的定量分析。发现寒武纪始海百合类的萼部尺寸上差异较小,在形态上,杷榔组的Protogloboeocrinus yini和Guizhoueocrinus yui萼形相似,均偏细长形,而凯里组的Sinoeocrinus lui和Globoeocrinus globulus萼形差异较大,口部区域宽度均出现增大,萼茎连接处宽度则出现变大和变小两种趋势。结果说明:同一生态环境下寒武纪早期的Guizhoueocrinus yui,和中期的Sinoeocrinus lui的萼在演化上具连续性,细长的萼与长茎能够让始海百合个体更有效捕食上部水域的食物,而寒武纪早期的Protogloboeocrinus yini和中期的Globoeocrinus globulus的萼在形态上具有演化上的连续性。球状的萼配合粗短的茎,可以增强始海百合个体的稳定性,以适应更强的水动力环境,表明出现了生态位的扩张。     

Relationships between morphometry,geographic location and water quality parameters of European lakes

I addressed the question how lake and catchment morphometry influences water chemistry and water quality over a large scale of European lakes, and developed the regression equations between most closely related morphometric and water quality indices. I analysed the data of 1,337 lakes included in the European Environment Agency (EEA) database, carrying out separate analyses for three basic lake types: large lakes (area ≥100 km², 138 lakes), shallow lakes (mean depth ≤3 m, 153 lakes) and large and shallow lakes (area ≥100 km² and mean depth ≤8 m, 35 lakes). The study revealed that in Europe, the lakes towards North are larger but shallower and have smaller catchment areas than the southern lakes; lakes at higher altitudes are deeper and smaller and have smaller catchment areas than the lowland lakes. Larger lakes have generally larger catchment areas and bigger volumes, and they are deeper than smaller lakes, but the relative depth decreases with increasing surface area. The lakes at higher latitudes have lower alkalinity, pH and conductivity, and also lower concentrations of nitrogen and phosphorus while the concentration of organic matter is higher. In the lakes at higher altitudes, the concentration of organic matter and nutrient contents are lower and water is more transparent than in lowland lakes. In larger lakes with larger catchment area, the alkalinity, pH, conductivity and the concentrations of nutrients and organic matter are generally higher than in smaller lakes with smaller catchments. If the lake is deep and/or its residence time is long, the water is more transparent and the concentrations of chlorophyll a, organic matter and nutrients are lower than in shallower lakes with shorter residence times. The larger the catchment area is with respect to lake depth, area and volume, the lower is the water transparency and the higher are the concentrations of the nutrients, organic matter and chlorophyll as well as pH, alkalinity and conductivity. The links between lake water quality and morphometry become stronger towards large and shallow lakes. Along the decreasing gradients of latitude, altitude and relative depth, the present phosphorus concentration and its deviation from the reference concentration increases.     

The impact of the Mid-Pleistocene Transition on the composition of submerged reefs of the Maui Nui Complex,Hawaii

The submarine reef terraces (L1–L12) of the Maui Nui Complex (MNC—the islands of Lanai, Molokai, Maui and Kahoolawe) in Hawaii provide a unique opportunity to investigate the impact of climate and sea level change on coral reef growth by examining changes in reef development through the Mid-Pleistocene Transition (900–800 ka). We present an analysis of the biological and sedimentary composition of the reefs that builds directly on recently published chronological and morphological data. We define nine distinct limestone facies and place them in a spatial and stratigraphic context within 12 reef terraces using ROV and submersible observations. These include oolitic, two coral reef, two coralline algal nodule, algal crust, hemi-pelagic mud, bioclastic and peloidal mud facies. These facies characterise environments from high energy shallow water coral reef crests to low energy non-reefal deep-water settings. Combining the bottom observations and sedimentary facies data, we report a shift in the observed sedimentary facies across the submerged reefs of the MNC from dominant shallow coral reef facies on the deep reefs to coralline algae dominated exposed outcrop morphology on the shallower reefs. We argue that this shift is a reflection of the change in period and amplitude of glacioeustatic sea level cycles (41 kyr and 60–70 m to 100 kyr and 120 m) during the Mid-Pleistocene Transition (MPT, ~ 800 ka), coupled with a slowing in the subsidence rate of the complex. The growth of stratigraphically thick coral reef units on the deep Pre-MPT reefs was due to the rapid subsidence of the substrate and the shorter, smaller amplitude sea level cycles allowing re-occupation and coral growth on successive cycle low-stands. Longer, larger amplitude sea level cycles after the MPT combined with greater vertical stability at this time produced conditions conducive to deep-water coralline algae growth which veneered the shallower terraces. Additionally, we compare reef development both within the MNC, and between the MNC and Hawaii. Finally we suggest that climatic forcings such as sea-surface temperature and oceanographic currents may also have influenced the distribution of coral species within the sample suite, e.g., the disappearance of the Acropora genus from the Maui Nui Complex in the Middle Pleistocene.