中国近海猿头蛤科的研究

猿头蛤科(Chamidae)的种类生活在热带和亚热带海洋中，利用左壳或右壳固着在潮间带下部的岩石或珊瑚的表面和缝隙中生活，分布深度可达250米。在有强击岸浪的开阔性岩石海岸或珊瑚礁区，猿头蛤的固着基很坚实，贝壳的固着面也大，壳面的棘和鳞片发达，但较钝，其表面常附着海藻和其它生物。在平静的内湾，猿头蛤固着或不固着，壳面披着一层极厚的海藻、苔藓虫或其它生物，原来壳面上的棘或鳞片变得很不规则，甚至被外来物完全披覆。 Lamarck(1818)根据猿头蛤壳顶部的旋转方向，把利用左壳固着、壳顶右旋的称为正规型，而把右壳固着、壳顶左旋的称为反转型。在有些种，同一种中的个体既有用左壳也有用右壳固着者，所以这一分类法没有受到重视。Odhner(1919)研究了猿头蛤的形态和分类的关系，对正规型和反转型的标本进行了比较解剖，他把反转型的种类归并为一个属——拟猿头蛤属(Pseudochama)。Reeve(1847)在猿头蛤的专论中记载55种，其中有75%的种类是左壳固着、壳顶右旋的。Lischke(1870) 发表4个日本海的猿头蛤新种。Clessin(1889)在猿头蛤的系统研究中发表78种。Lamy(1927)在“巴黎自然史博物馆猿头蛤的订正”一文中发表40种和8个变种。Habe(1964)报道日本产的猿头蛤3属16种。 我国沿海猿头蛤的记载较少，Reeve(1847)认为Chama lobata应分布于中国外海；Angas记载过产于香港的Chama fragum; Kuroda报道Chama lazarus，Chama lobata，Chama ostoma, Chama brassica, Chama divaricata, Chama reflexa, Chama jukesi和Chama (Pseuidochama) retroversa等8种分布于我国台湾省；张玺等发表了Chama lobata, Chama lazaru和Chama dunkeri等3种。 中国科学院海洋研究所于1954-1963年在浙江、福建、广东和广西沿海采到不少猿头蛤标本，1958年全国近海综合调查又补充了许多南海的拖网标本，共150号。经鉴定共10种，分隶于二个属。     

Deformation of a sandstone–mudstone particle mixture induced by periodic saturation

This study focuses on the evaluation on deformation induced by periodic saturation of a sandstone–mudstone particle mixture. Two types of triaxial tests, without and with periodic saturation, were performed. The strain–stress relationships from the two types of tests indicate that the periodic saturation may induce an increment of axial strain (Δε), and the Δε values are related to the ratio of confining to atmospheric pressure (σ₃/p_a), stress level for periodic saturation (L), and number of periodic saturation or cycles (N). The values of Δε are increasing along logarithmic curves with increment of N value from 1 to 20, and increase along straight lines with increasing L value from 0.18 to 0.82 or σ₃/p_a value from 1 to 4. Based on the analyses of experimental data, a logarithmic fitting equation, which is a function of N, L, and σ₃/p_a, is suggested to predict the Δε value. And based on the fitting equation and simple analyses on stress state, another equation, which may be used to estimate the settlement induced by periodic saturation of a large-area foundation filled using the sandstone–mudstone particle mixture, is also suggested.     

The virtual mass of a rectangular flat plate of finite aspect ratio

The skin friction of a two-dimensional planing flat plate is made up of two opposing components; a drag force from the flow aft of the stagnation line and an opposing thrust force from the jet flow. This paper is concerned only with the drag term and the wake velocity defect which it causes in the water behind the transom.It is concluded that the skin friction is less than would be expected from a flat plate at ambient static pressure (D_fo say) and is approximately equal to D_fo (1 − C_R), where C_R is the normal force coefficient based on wetted area. The wake velocity decrement due to this drag is found to be significant, particularly for surface piercing propellers.     

New and little‐known arietellidae (Copepoda: Calanoida) mainly from the south‐west pacific

Three species of Arietellidae are described from the south‐west Pacific: a new species of Paraugaptilus, a species which can not be separated from P. buchani, and Arietellus aculeatus. The identity of A. aculeatus is clarified by comparison of type material and material from the U.S. National Museum of Natural History, and an unidentified Atlantic species of Arietellus, evident from the comparison, is described.     

桃花水母的核糖体RNA基因ITS区序列分析及物种鉴定

利用PCR扩增和DNA测序技术,获得了青岛野外采集到的桃花水母(Craspedacusta)核糖体RNA基因ITS区序列。序列比对以及系统进化分析显示,在青岛采集到的桃花水母与索氏桃花水母(Craspedacusta sowerbyi)的ITS区序列相似度最高,同源性在93%以上;同时,在系统发育树中也与索氏桃花水母聚为一支。研究结果表明,青岛采集到的桃花水母为索氏桃花水母,这也是青岛地区桃花水母的新记录。     

Estimation of Residual Undrained Shear Strength from Gravity Corer Penetration Data

Residual undrained shear strength, s _{u_res} , is an important parameter for analyzing the response of structures buried within potentially unstable soil mass. A framework for estimating s _{u_res} of fine grained sediments from gravity corer penetration has been developed considering viscous drag during free fall of the corer through seawater and cohesive energy loss during sediment penetration. The procedure was used to estimate s _{u_res} using data from a submarine geotechnical investigation in western Canada. Comparison of the results with alternative estimates of s _{u_res} from miniature torvane tests on the gravity core samples and CPTs performed nearby reveals a reasonable agreement.     

Pumping rates of the mud shrimpCallianassa japonica

Pumping rate of a mud shrimp,Callianassa japonica, in its burrow was measured by continuous monitoring of dye concentration in the burrow water. Measurement of dilution in two directions from stained overlying seawater to normal burrow water andvice versa, gave no significant difference in results. The rate of exchange (v) of burrow water was estimated from,v=(u _t−u ₀)V/(m−u _t−1)t, whereV is volume of burrow water,u ₀,u _t−1 andu _tis dye concentration of burrow water at time 0,t−1 andt, respectively, andm is dye concentration of overlying water. The pumping rate ranged from 0.63 to 5.46 ml min⁻¹, which corresponded to a turnover time for the burrow water of 7–51 min. Short term changes in the pumping rate were correlated to intermittent behaviour of the shrimp in the burrow.     

Macroparasites of angelfish Brama brama (Bonnaterre, 1788) in the southern Benguela Current ecosystem

The angelfish Brama brama is a mesopelagic species distributed circumglobally in temperate to warm-temperate waters, including continental-shelf-edge and upper-slope waters of the Benguela Current ecosystem. Little is known about the parasite assemblage of Benguela B. brama, with only three parasite taxa having previously been documented from this species in the southern Benguela. This study describes the macroparasites recorded from 35 B. brama collected during research surveys off the west coast of South Africa in 2015 and 2016. A total of six macroparasite taxa were documented, including the nematode Anisakis pegreffii, the copepod Hatschekia conifera, the cestode Hepatoxylon trichiuri, an acanthocephalan from the genus Rhadinorhynchus, a monogenean from the family Diclidophoridae, and an unidentified species. Three of these (He. trichiuri, Rhadinorhynchus sp. and the unidentified species) had not previously been found to infect B. brama. The most prevalent macroparasite taxa were A. pegreffii (94%), the unidentified species (71%) and Ha. conifera (60%). Two of the parasites, Ha. conifera and He. trichiuri, showed seasonal variation in infection, and infection with the latter was positively correlated with host length. These findings increase our knowledge of B. brama biology and contribute to our understanding of the biodiversity of the southern Benguela ecosystem.     

Report of Prionospio complex (Annelida: Polychaeta: Spionidae) from China's waters, with description of a new species

Nine species of Prionospio complex are recorded from China’s waters, including one new species and six newly recorded species. Prionospio (Prionospio) pacifica sp. nov., is characterized by having first and forth pairs of branchiae pinnate, second and third pairs of apinnate, ventral crest on Setiger 9 and dorsal crests on Setigers 10—25. Apoprionospio kirrae (Wilson, 1990), Prionospio (Aquilaspio) convexa Imajima, 1990, Prionospio (Minuspio) multibranchiata Berkeley, 1927, Prionospio (Prionospio) bocki Sderstrm, 1920, Prionospio (Prionospio) dubia Maciolek, 1985 and Prionospio (Prionospio) paradisea Imajima, 1990 are recorded for the first time from China’s waters.     

Genetic and morphological evidence for a single species of pink ling (Genypterus blacodes) in New Zealand waters

Two species of ling, Genypterus blacodes (Forster in Bloch & Schneider, 1801) and G. microstomus (Regan, 1903) have been recorded from New Zealand and Australian waters; a third species, G. tigerinus (Klunzinger, 1872) has been recorded from Australia. Specimens of ling collected from northern, central, and southern localities in the New Zealand Exclusive Economic Zone (EEZ), and specimens of G. blacodes from Australia were shown to be similar with respect to partial sequences of mitochondrial (mt)DNA, and morphometric and meristic characters. DNA sequences of part of the cytochrome b and control region showed that G. blacodes from Tasmania and New Zealand differed by 1/291 and 4/284 nucleotides respectively, but there was much greater genetic differentiation between G. blacodes and G. tigerinus (14/291 and 14/284 nucleotides), and between G. blacodes and G. capensis (23/291 and 8/284 nucleotides). MtDNA haplotypes within New Zealand show that G. blacodes is subdivided into northern and southern stocks. It is concluded that ling in New Zealand represent a single species referable to G. blacodes, and that G. microstomus Regan is a junior synonym.     

多鳞(Sillago sihama)鱚4个野生地理群体的微卫星标记分析

采用微卫星DNA分子标记方法对中国南部沿海多鳞鱚(Sillago sihama)广西北海、广东湛江、汕尾及海南三亚4个野生地理群体进行了遗传多样性及遗传分化等研究。结果表明:(1)用于研究的34对微卫星引物在4个群体中具有丰富的多态性,有效等位基因数介于1.71—20.46之间,多态信息含量PIC介于0.40—0.95之间。4个群体总的平均期望杂合度(He)为0.598,观测杂合度(Ho)为0.572,SY群体的杂合度最大(He=0.606,Ho=0.623),SW群体的最小(He=0.586,Ho=0.508)。(2)群体间F-统计量分析表明,群体遗传分化处于高度分化水平(Fst平均值为0.306);基于奈氏遗传距离(DA)构建的NJ和UPGMA聚类树均显示地理位置相邻的群体聚在一起。     

新疆一种琥珀螺线粒体基因组测序分析

本研究利用高通量测序技术获得采自新疆昭苏琥珀螺科一未知种的线粒体全基因组序列。该种琥珀螺线粒体基因组全长14219bp,由13个蛋白质编码基因,22个tRNA基因,2个rRNA基因及1个控制区组成。基因组中AT含量为76.43%,GC含量为23.57%,表现出明显的AT偏好性。13个PCGs多使用ATG为起始密码子,TAA为终止密码子。tRNA基因中tRNA-Ser1和tRNA-Ser2缺少DHU臂,其中tRNA-Ser1在缺失的DHU臂处有一个小的茎环结构。非编码区位于COX3与tRNA-Ile之间,长度为58bp。琥珀螺科中现有腐败琥珀螺Succineaputris、五家渠尖缘螺Oxylomawujiaquensis和Omalonyxunguis的线粒体基因组被报道。三者的基因排列顺序和结构基本相似。昭苏琥珀螺未知种的基因排列顺序与它们有所不同。昭苏琥珀螺未知种的tRNA-Tyr和tRNA-Trp基因位于COX2和tRNA-Gly之间,上述三种tRNA-Tyr和tRNA-Trp基因位于tRNA-Ser2和tRNA-Ser1之间。系统发育树结果显示,琥珀螺科的四种聚为一支,为单系群,其中腐败琥珀螺和Omalonyxunguis亲缘关系更近。本研究结果支持昭苏琥珀螺未知种为中国一未报道的属种,但要确定其是否为一新属新种尚需更多的分子和形态数据。     

Mooring forces in horizontal interlaced moored floating pipe breakwater with three layers

The paper presents the results from model scale experiments on the study of forces in the moorings of horizontally interlaced, multi-layered, moored floating pipe breakwaters. The studies are conducted with breakwater models having three layers subjected to waves of steepness H_i/L (H_i is the incident wave height and L the wavelength) varying from 0.0066 to 0.0464, relative width W/L (W is the width of breakwater) varying from 0.4 to 2.65, and relative spacing S/D (S is the spacing of pipes and D the diameter of pipe) of 2 and 4. The variation of measured normalized mooring forces on the seaward side and leeward side are analyzed by plotting non-dimensional graphs depicting f/γW² (f is the force in the mooring per unit length of the breakwater, γ the weight density of sea water) as a function W/L for various values of H_i/d (d is the depth of water). It is found that the force in the seaward side mooring increases with an increase in H_i/L for d/W values ranging between 0.081 and 0.276. The experimental results also reveal that the forces in the seaward side mooring decrease as W/L increases, up to a value of W/L=1.3, and then increases with an increase in W/L. It is also observed that the wave attenuation characteristics of breakwater model with relative spacing of 4 is better than that of the model with relative spacing of 2. The maximum force in the seaward side mooring for model with S/D=4 is lower compared to that for the breakwater model with S/D=2. A multivariate non-linear regression analysis has been carried out for the data on mooring forces for the seaside and leeside.     

Developing empirical formulas for assessing the scour of vertical and inclined piers

Abstract

Because scour is one of the main reasons for bridge failure, this study focuses on accurately predicting the maximum scour depth around different vertical and inclined piers. Scouring is an issue of concern in the bridge design process, as most existing equations for predicting local scour near bridge piers suffer from over- or underprediction issues, resulting in higher foundation costs or bridge failure and inaccurate predictions of the scour around piers. The dimensionless maximum scour depths (y_s/D) of vertical and inclined piers were investigated for seven pier shapes with different L/D ratios and four inclination angles (θ) under shallow flow conditions. The inclined pier configuration reduced the y_s/D of the piers. The maximum y_s/D was observed for a rectangular pier with an L/D of 4.5 in both vertical and inclined configurations (θ of 10, 15 and 21°, respectively). The y_s/D was significantly decreased by increasing the angle of the pier from 10 to 30°. The y_s/D of the inclined rectangular piers decreased as θ decreased from 30 to 10° and the L/D ratio increased from 1 to 4.5. The best y_s/D results were obtained for inclined rectangular piers at a θ value of 30° and an L/D ratio of 7.5 compared to other shapes and inclination angles. New equations were developed to predict the local scour depth for circular, square and rectangular bridge piers. The equations yielded excellent results for predicting the maximum clear water scour depth around vertical and inclined piers with inclination angles of 10, 15, 21 and 30°, respectively.     

Wave forces on, and water-surface fluctuations around a vertical cylinder encircled by a perforated square caisson

The wave forces and moments on and the water surface fluctuations around a vertical circular cylinder encircled by a perforated square caisson were experimentally investigated. The porosity of the outer square caisson was varied from 4.24 to 14.58%. The in-line wave forces on the inner vertical cylinder are influenced by changing the porosity of the outer caisson, whereas the variations in the water surface fluctuations are less influenced in this porosity range. The in-line moment on the vertical cylinder is relatively less sensitive when the porosity is increased from 4.24 to 8.75%, but varies substantially when it is increased from 8.75 to 14.58%. The force and moment ratio (i.e. the ratio of the force or moment on the vertical cylinder, when it is encircled by the perforated caisson to the force or moment on the cylinder without any protection around it) reduces with increased wave height, H, and wave length, L, whereas the wave height ratio (ratio of the wave height at a point in the vicinity of the structure to the incident wave height) is less sensitive for the varying H and L. A new non-dimensional parameter, p^1.5 (D/L)/(H/d), is introduced to predict the in-line force and moment on the inner vertical cylinder, where d is local water depth, D is the diameter of the inner cylinder and p is the porosity of the outer caisson in percentage. Simple predictive equations for forces, moments and water surface fluctuations are provided.     

Seagrasses from the Nansei Islands, Southern Japanese Archipelago: species composition, distribution and biogeography

The Nansei Islands in the southern Japanese Archipelago have 15 taxa of seagrasses from seven genera within three families. Seagrasses in this region grow on coral sands or coral debris in shallow reefs and on sandy or muddy substrata in the shallow areas of bays and inlets. Certain Halophila species grow in deep water off some islands. Enhalus acoroides only reaches to Ishigaki I. with winter sea water temperature (WST) at 23 °C, while Okinawa I. (WST at 21.6 °C) is the northern biogeographic limit for Halophila decipiens, H. okinawensis, H. major and H. gaudichaudii. Amami‐oshima I. (WST at 20.7 °C) is the northern border for Thalassia hemprichii, H. minor, H. ovalis, Cymodocea serrulata, Cymodocea rotundata, Syringodium isoetifolium, Halodule uninervis and Halodule pinifolia. Halophila mikii the sole seagrass collected from Yakushima I. (WST at 19.3 °C), is of volcanic origin. The distribution of tropical seagrasses in the Nansei Islands is clearly associated with the warm Kuroshio Current, WST and habitat availability. Zostera japonica is the only temperate species occurring in the region. Meadows of Z. japonica, H. ovalis and Halodule pinifolia have disappeared from certain localities in the Archipelago, due probably to human activities and natural siltation.     

Myctophid fish recorded from New Zealand as Lampanyctus Guentheri reidentified as L. austraus (note)

The myctophid fish Lampanyctus guentheri ( = Lcpidophanes guenlheri) recently recorded from New Zealand is reindentified as Lampanyctus australis. The genus Lepidophanes is known only from the Atlantic Ocean.     

Rhinochimaera africana,a new longnose chimaera from southern Africa,with comments on the systematics and distribution of the genus Rhinochimaera Garman, 1901 (Chondrichthyes,Chimaeriformes, Rhinochimaeridae)

Rhinochimaera africana, a new species (Chondrichthyes, Chimaeriformes, Rhinochimaeridae), is described from five specimens from the Western Cape and KwaZulu coasts of southern Africa and from the Moçambique Channel between South-Western Madagascar and Europa Island. Two more specimens are known from off the Agulhas Bank, South Africa. It differs from the partially sympatric R. atlantica Holt and Byrne, 1909, and the Pacific R. pacifica (Mitsukuri, 1895) in its darker coloration, longer, broader, paddle-shaped snout, tooth plates of different shape, a more elongate-oval clasper glans, a shorter caudal fin with very short filament, and possibly a smaller dorsal fin and longer interdorsal space. R. africana males are mature at 568 mm body length (BDL), females adolescent at 476 mm BDL. A large, probably adult female of 650 mm BDL is larger than any recorded R. atlantica or R. africana. Wounds on two specimens indicate possible "cookie-cutter" bites by squaloid sharks, and one has a possible bite by another Rhinochimaera. Data on R. pacifica and R. atlantica, including 45 specimens from off Namibia and South Africa, are presented for comparison with R. africana. Caudal tubercle counts of R. africana (40–46) are intermediate between those of R. atlantica (most with 19–33, rarely up to 43) and of R. pacifica (41–68, rarely as low as 25–34). Southern African R. atlantica agree with North Atlantic R. atlantica in having few caudal tubercles, but there is slight overlap with R. pacifica in the case of higher counts recorded for R. africana. The systematics and distribution of the genus Rhinochimaera are reviewed, a terminology and abbreviation system for morphometries presented, and a key to species provided. The separation of R. atlantica and R. pacifica on caudal tubercle counts is provisionally accepted but considered problematical until adequate samples of both species can be critically compared. Proportional measurements and counts of caudal tubercles were highly variable in Rhinochimaera, with much allometry in proportions with growth and much individual variation. Selected morphometrics are plotted to show allometric trends in proportions that separate R. africana from other species.     

Experimental study on interaction between compressibility and permeability of a crushed sandstone–mudstone particle mixture

The present study focuses on the compressibility and permeability characteristics of a crushed sandstone–mudstone particle mixture (SMPM). Two type of laboratory tests, which are compressibility–permeability test (CPT) and compressibility test only (CTO), are performed. Based on the test data, the effects of the seepage action on the compressibility and ones of the void ratio (e) on the permeability are analyzed. The rate of consolidation of the crushed SMPM is also discussed. The values of compressibility index (C_c) obtained from the CPT are greater about 1.32–4.81% than ones obtained from the CTO, but the values of preconsolidation stress (σ_p) obtained from the CPT are smaller about 2.34–9.83% than ones obtained from the CTO. The slope of fitting line of e～logK (where K is the coefficient of permeability, and log is the logarithm to base 10), defined as the permeability index (K_c), ranges from 0.146 to 0.337 with an average of 0.226. The value of C_c/K_c, used to evaluate the rate of consolidation, ranges from 0.905 to 1.250 with an average of 1.031. The rate of consolidation of the crushed SMPM may be analyzed by Terzaghi’s theory due to the average value of C_c/K_c very close to 1.0.     

Growth of red gurnard (Teleostei: Triglidae) from Pegasus bay,Canterbury, New Zealand

Growth of the red gurnard, Chelidonichthys kumu (Lesson and Garnot), from Pegasus Bay, Canterbury, was measured during 1966–67. Otoliths were used as an indicator of fish growth; mean length‐at‐age data were obtained from back‐calculated fish lengths at the time of formation of successive annual rings in the otoliths. Growth in length was found to be adequately expressed by the von Bertalanffy growth equation :

l_t = 52.0 [1 ‐ e‐^{0.406 (t‐o.291)}]

(where l_t is the fork length in cm at age t). The length: weight relationship was:

w = 78.56 × 10^‐4 l ^3.072

(where w is the weight in grams). From this relationship, growth in weight was described by the equation:

w_t = 1469 [1 ‐ e‐0.406 (t‐0.291)]³.