首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Three new species of calanoid copepods are described: two in Heterorhabdus and one in Disseta. The males of H. pustulifer and H. caribbeanensis are described and the identities of H. proximus, H. norvegicus and H. austrinus are clarified. H. spinifer is recorded for the second time. A key to the subgenus Heterorhabdus is provided.  相似文献   

2.
From a trawling at 448–512 m in Palliser Bay, Cook Strait, New Zealand, molluscs associated with. Tertiary siltstone concretions and with a large colony of Goniocorella dumosa (Alcock) are listed. A juvenile Acesta, extremely tall and extremely broad forms of Emarginula striatula Quoy & Gaimard, and the animals of Stilifer neozelanica Dell and of Waipaoa marwicki Dell are described. Sculptifer, a new genus provisionally included in the Fossaridae, is proposed for Stilifer neozelanica. New species of Danilia and Pholadidea are described and their relationships discussed. Emarginula lophelia Beu, 1967 is synonymized with E. striatula Quoy & Gaimard, 1834, and the recent New Zealand forms of Emarginula are reviewed.  相似文献   

3.
Seven species of echinoids are added to the New Zealand fauna, two being described as new species of the genera Caenopedina and Spatangus Described species, new to the fauna, are Gracilechinus multidentatus (H. L. Clark), Pourtalesia laguncula A. Agassiz, Hemiaster expergitus gibbosus A. Agassiz, and Gymnopatagus magnus A. Agassiz and H. L. Clark. Fragments of Spatangus, possibly hybrid S. thor Fell, and fragments of Echinocardium, almost certainly not E. cordatum (Pennant), are also described.  相似文献   

4.
A brief account is given of the systematics and distribution of Heterozius rotundifrons A. Milne Edwards, Ozius truncatus H. Milne Edwards, and Heteropanope (Pilumnopeus) serratijrons (Kinahan). Keys are given for the separation of Zoea larvae of New Zealand xanthid Brachyura and to the Megalopa larvae of Heterozius rotundifrons and Ozius truncatus

Notes are given on the seasonal breeding cycle of Heterozius rotundifrons, and the pre‐Zoea larva, two Zoea larval stages, and Megalopa larva reared in the laboratory are described. Larval characters of H. rotundifrons are specialised and do not support its recently suggested classification in the family Atelecyclidae. The larvae show no relationships with those of the Cancridae or of the Corystidae, and affinities with described larvae of the Xanthidae or even the Brachyrhyncha are obscure. Larval development is incompletely abbreviated possibly to reduce dispersal in response to restricted intertidal habitat requirements of the adult crabs.

The pre‐Zoea larva, four Zoea larval stages, and the Megalopa larva of Ozius truncatus reared in the laboratory are described. A key to the Zoea larval stages is given. Larvae of this species are distinct both at the generic and specific levels, but are generally similar to those known of xanthid crabs. It is difficult to relate the genus Ozius to other xanthid genera on the basis of larval characters alone.

The pre‐Zoea larva and stage one Zoea larva of Heteropanope (Pilumnopeus) serratifrons are described. There are probably four Zoea larval stages in the development of this species. Zoea larval characters suggest that in the family Xanthidae, Heteropanope and Pilumnopeus should be separated from other genera in the subfamily Pilumninae with which they are currently classified.  相似文献   

5.
Abstract. Marine Ascomycetes, Basidiomycetes and Deuteromycetes were collected in tropical and subtropical regions (Australia, Belize, Fiji, Hawaii, Marshall Islands, Mexico, New Zealand, Palau, Thailand), and the known range of distribution for these fungi was extended. Exclusively tropical are 27 taxa, 9 are probably restricted to the tropics also, and 11 are cosmopolitan. Distribution maps are given for 5 taxa. New species (4), varieties (3), and combinations (2) of Ascomycetes are proposed, and keys to the taxa of Halosarpheia and Lulworthia are presented. Most of the species are decomposers of mangrove parts or of detritus in sandy beaches. Nine new host plants were found. Marine Ascomycetes were discovered for the first time living in shells of foraminifera.  相似文献   

6.
7.
东海、黄海底层鱼类数量分布季节变化的因子分析   总被引:1,自引:0,他引:1  
刘勇  程家骅 《海洋学报》2008,30(4):123-130
根据2000年春(4月)、夏(6月)、秋(9月)、冬(12月)四季东海、黄海底拖网鱼类资源调查资料,使用因子分析的方法分析了该海域鱼类数量分布的季节变化特征。R型分析发现,春季关系最密切的鱼种有4种:斑鳐、凤鲚、海鳗和黑鳃梅童鱼;夏季有5种:鳀、小黄鱼、黄鮟鱇、绿鳍鱼和长蛇鲻;秋季也有5种:带鱼、灰鲳、虻鲉、日本鲭和小黄鱼;冬季有3种:带鱼、鳄齿鱼和发光鲷。历史资源调查证实,夏季的这5个鱼种之间以摄食与被摄食关系为主。进一步分析发现,各季节关系密切的鱼种所聚集分布的水域,正是这些鱼种各季对应的生理周期洄游分布的主要水域。根据Q型分析可以得到各季的综合优势鱼种及其优势分布水域,发现带鱼和小黄鱼是东海、黄海渔业资源的绝对优势鱼种,除了带鱼、小黄鱼以外,其他的综合优势鱼种都是一些价值较低的、生长速度较快的小型鱼类。  相似文献   

8.
Vertical and horizontal distributions are described for megalopae of 11 brachyuran taxa common to the lower Chesapeake Bay and adjacent shelf. Three distribution patterns are apparent from horizontal distribution.
1. (1) More than 75% of the megalopae of estuarine adults, such as Hexapanopeus angustifrons, Neopanope sayi, Panopeus herbstii, Rhithropanopeus harrisii and Pinnotheres ostreum, are retained in estuarine waters.
2. (2) The megalopae of three estuarine taxa, Callinectes sapidus, Uca spp. and Pinnixa sp., are most abundant on the shelf.
3. (3) More than 90% of the megalopae of the shelf species, Portunus sp., Cancer irroratus and Libinia spp. remained in shelf waters.
Vertical distributions indicate the megalopae of a majority of estuarine crabs are epibenthic when waters are stratified. Exceptions include the megalopae of both Rhithropanopeus which are found slightly shallower in well mixed waters and Callinectes sapidus which are generally most abundant in the neuston. The megalopae of two shelf species, Portunus sp. and Cancer irroratus, reach highest densities in surface waters, while those of Libinia spp. are common in the epibenthos.Megalopal distributions analyzed with respect to water column stratification show megalopae never reached highest densities within the layer of the pycnocline. The megalopae of five species show significant shifts in vertical distributions between stratified and homogeneous water columns.  相似文献   

9.
Prionocidaris australis (Ramsay), Salenocidaris hastigera (A. Agassiz), Echinoneus cyclostomus Leske, Aphanophora echinobrissoides de Meijere (Echinoidea), and Ophiotholia multispina Koehler (Ophiuroidea) are recorded from off Norfolk Island; Peronella hinemoae Mortensen (Echinodea) and a new species of Amphiophiura (Ophiuroidea) are recorded from Wanganella Bank situated about midway between Norfolk Island and northern New Zealand.  相似文献   

10.
Pycnogonida collected at the Antipodes Islands (49° 45’ S, 178° 45’ E) by the University of Canterbury Antipodes Islands Expedition 1969 and during New Zealand Oceanographic Institute cruises are reported on here, and constitute all material known for this group of animals from these islands. To date eight species are known; two are endemic, (Pallenopsis antipoda n.sp. and Ammothea antipodensis n.sp.); two constitute a circum‐polar element (Tanystylum cayi‐dorsum Stock and Austrodecus breviceps Gordon); the remaining four species are known also from New Zealand mainland waters (Pallenopsis obliqua (Thomson), P. kupei n.sp., Achelia dohrni (Thomson) and Ammothea magniceps Thomson), as is T. cavidorsum. An attempt is made to indicate the range of variation in Achelia dohrni, and Pallenopsis mauii Clark, 1958 is redescribed although not a part of the Antipodes Islands fauna.  相似文献   

11.
The genus Euaetideus Sars, 1925 is here merged with Aetideus Brady, 1883 (Copepoda : Calanoida : Aetideidae). Three new species of the genus Aetideus are described from the Pacific as well as the males of three other known species. A key is given to the known males and females in the genus Aetideus. The closely related genera Paivella and Snelliaetideus are compared with Aetideus.  相似文献   

12.
13.
The systematics of the endemic New Zealand genus Paranephrops (Family Parastacidae) are re‐examined. Specific characters previously used to separate P. zealandicus and P. setosus are considered to be inadequate, and the two species are merged. The genus, as now proposed, contains only two species: P. planifrons, occupying the Whole of the North Island and northern and western areas of the South Island, and P. zealandicus, occupying eastern and southern parts of the South Island and Stewart Island.  相似文献   

14.
Two computations of the KCS model with motions are presented. Self-propulsion in model scale free to sink and trim are studied with the rotating discretized propeller from the Hamburg Model Basin (HSVA) at Fr = 0.26. This case is particularly complex to simulate due to the close proximity of the propeller to the rudder. The second case involves pitch and heave in regular head waves. Computations were performed with CFDShip-Iowa version 4.5, a RANS/DES CFD code designed for ship hydrodynamics. The self-propulsion computations were carried out following the procedure described in Carrica et al. [1], in which a speed controller is used to find the propeller rotational speed that results in the specified ship velocity. The rate of revolutions n, sinkage, trim, thrust and torque coefficients KT, KQ and resistance coefficient CT(SP) are thus obtained. Comparisons between CFD and EFD show that the rate of revolutions n, thrust and torque coefficients KT and KQ have higher prediction accuracies than sinkage and trim. For the simulation of pitch and heave in head waves, the geometry includes KCS hull and rudder under three conditions with two Froude numbers and three wave length and amplitude combinations. 0th and 1st harmonic amplitudes and 1st harmonic phase are computed for total resistance coefficient CT, heave motion z and pitch angle θ. Comparisons between CFD and EFD show that pitch and heave are much better predicted than the resistance. In both cases comparisons with simulations by other authors presented at the G2010 CFD Workshop [2] using different CFD methodologies are included.  相似文献   

15.
Phyllosomata and nistos of Scyllarus sp. Z taken from plankton around and offshore northern New Zealand and in the Tasman Sea are presumed to be those of S. aoteanus Powell, 1949, the most common Scyllarus species in this area. The full larval and postlarval development of this species are described. Three features are characteristic of Scyllarus sp. Z phyllosomata; a dorsal crest on the cephalic shield, dorsal thoracic spines, and a forked telson in middle stages persisting as two prominent spines outreaching the telson posterior margin in the final stage. Scyllarus sp. Z's closest affinities are with a group of Scyllarus species whose phyllosomata have forked telsons in middle stages and medium to strong posterolateral telson spines in the final stage. The nisto is low in profile but distinctive in its armature. Too few Scyllarus sp. nistos have been described to suggest any group to which that of Scyllarus sp. Z can be assigned. The spatial and temporal distribution of the larvae and postlarvae of Scyllarus sp. Z are also described. Although early larval stages and postlarvae are found close to New Zealand, mid‐ and late‐stage larvae are widely distributed, some well beyond the known latitudinal range of the adults. There is probably an extended egg‐bearing and hatching period as early stage larvae are caught in most months. Variable rates of development of the larvae and/or delayed metamorphosis, are also possible.  相似文献   

16.
In this study, CPT and FVT tests are carried out on young, normally consolidated clay (Busan clay, which is an unusually thick deposit) at several locations in the Nakdong River deltaic plane in Busan, Korea. Two correlation techniques are applied for estimating the cone factors for which the uncorrected and corrected field vane strengths are used as the reference strength. First, due to the scattered data over the entire depth, a direct correlation between the tested results (a method generally used in practice), is applied for each depositional environment (facies) that is detected from the CPT profiles and the geological analysis. Secondly, a special attempt is made to determine the cone factors based on the fact that the ratios of the field vane strength and the (q t  ? σ v0) and (u 2 ? u 0) values to the effective overburden pressure respectively, are approximately constant for each facies (the indirect correlation). It appears that the values obtained from the two techniques are almost identical. However, the direct correlation is sensitively affected by the fabric effects especially in some of the uppermost and lowermost layers of the clay and hence the arithmetic average values of each facies sometimes result in lower correlation coefficients. It is therefore inferred that the indirect correlation is more proficient for estimating the cone factors at each facies and can be used for practical applications. From the results of the indirect correlation, the cone factors of Busan clay are N kt  = 7.13–13.06, N kt,corr  = 9.45–17.07, N Δu  = 6.10–9.88 and N Δu,corr  = 8.41–12.24, the corrected values of which are considerably smaller or larger than the general ranges recommended by Lunne et al. (1997a). However, good correlations between N kt and I P , and between N Δu (or N kt ) and B q , are not found for the clay.  相似文献   

17.
Dependence of sea surface drag coefficient on wind-wave parameters   总被引:3,自引:2,他引:1  
The relationships between sea surface roughness z 0 and wind-wave parameters are analyzed,and spurious self-correlations are found in all of the parameterization schemes.Sea surface drag coefficient C D is fitted by four wind-wave parameters that are wave age,wave steepness,windsea Reynolds number R B and R H ,and the analyzed data are divided into laboratory,field and combined data sets respectively.Comparison and analysis of dependence of C D on wind-wave parameters show that R B can fit the C D most appropriately.Wave age and wave steepness are not suitable to fit C D with a narrow range data set.When the value of wave age has a board range,R H is not suitable to fit C D either.Three relationships between C D and R B are integrated into the bulk algorithm COARE to calculate the observational friction velocity,and the results show that the relationship between C D and R B which is fitted with field data set can describe the momentum transfer in the open ocean,under low-moderate wind speed condition,most appropriately.  相似文献   

18.
Abstract. Two new genera of Tantulocarida are described from the Ligurian deep sea (Western Mediterranean) off Corsica. Xenalytus scotophilia is referred to the Microdajidae and differs from Microdajus GREVE in thoracopodal segmentation as well as in the presence of coupling spines on thoracopod 6 and longitudinal lamellae on the cephalic shield. Aphotocentor styx is placed in the Deoterthridae and holds an intermediate position between Deoterthron BRADFORD & HEWITT and Boreotantulus HI/YS & BOXSHALL. Some aspects of cephalon internal structure are described for the first time and give a possible explanation for the mechanism of stylet protrusion. The external structures of the oral disc are described using SEM. The discovery of well-developed muscles in the trunk and thoracopods is discussed in the light of the benthic phase the tantulus passes through. The boundary between the thorax and abdomen in the tantulus is reinterpreted, corroborating the 5–7-5 bodyplan of the hypothetical urmaxillopodan as found in the Upper Cambrian Skaracarida and possibly also Dala peilertae MOLLER. Some aspects related to dispersal, infection, and feeding are reinterpreted or approached from a different perspective. SEM of Microdajus langi GREVE gives evidence that the tantuli hatch via a conspicuous slit located at the posterior end of the female trunk sac. A worldwide key to the tantulocaridan families and genera is given, and distributional records are compiled. It is suggested that Tantulocarida might be common representatives of the temporary meiobenthos and that their present species number represents only the tip of the iceberg.  相似文献   

19.
This paper reports the initial steps in the degradation of chlorophyll-a in a temperate, sandy intertidal sediment from a low-energy coastline at Corner Inlet, SE. Victoria. The chlorophyll-a is shown to be derived primarily from diatom input into the surface layers and it is possible to show that in this environment, relative stabilities are: chlorophyll-a > chlorophyllide-C2 > chlorophyllide-C1. Traces only of chlorophyll-b are present, and little or no degradation of this pigment with depth was observed. Bacteriochlorophyll-a, bacteriopheophytin-a concentrations are inversely proportional to one another in the upper sedimentary layers and the depth profile suggests a stabilised environment. A depth profile of a range of chlorophyll-a derivatives, including pheophytin-a, provides no basis for accepting that they are intermediates on the direct degradative pathway of chlorophyll-a in this environment. Rather, the evidence favours the view that chlorophyll-a degrades primarily to colourless compounds.  相似文献   

20.
我国近海鲚鱼生态习性及其产量变动状况   总被引:17,自引:1,他引:17  
一、概述 鲚鱼是鲚属(Coilia)鱼类的泛称,属鲱形目(Clupeiformes),鳀科(Engraulidae)。我国有记录的共8种,除去同物异名或错误记载,目前大家一致承认的共4种,即:刀鲚(长頜鲚,Coilia ectenes Jordan et Seale)、凤鲚[C.mystus(Linneaus)]、七絲鲚(C.grayii Richardson)和短頜鲚(C.brachygnathus Kreyenberg et Pappenheim)。刀鲚主要分布在我国黄渤海和东海一带。凡通海的江河如辽河、海河、黄河、长江、钱塘江等均能见到。凤鲚在我国海域分布十分广泛,北起  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号