Plankton of lake Ototoa,a sand‐dune lake in Northern New Zealand     

J. D. Green 《新西兰海洋与淡水研究杂志》2013,47(1):43-59

The seasonal cycles of abundance of the phytoplankton and zooplankton in Lake Ototoa, Northland, at 36° 31 S, 174° 14 E, are described. Concentrations of chlorophyll a were low (range 0.04–4.61 mg.m^‐3; mean 0.97 mg.m^‐3), and highest values were in winter. Phytoplankton densities were also low; an oligo‐trophic diatom‐desmid assemblage associated with Botryococcus, Dinobryon, and Svhaerocyslis was found.

The zooplankton was dominated by the calanoid copepod Calamoecia lucasi whose numbers remained fairly constant throughout the year, and the only other copepod found was the cyclopoid Mesocyclops leuckarti which was present in very low numbers. Bosmina meridionalis was the only limnetic cladoceran and was most abundant during autumn and spring. A number of rotifer species were also common.  相似文献   

Fecundity in the marine spiny lobster Jasus verreauxi (H. Milne Edwards) (Crustacea: Decapoda: Palinuridae)     

Craig B. Kensler 《新西兰海洋与淡水研究杂志》2013,47(2):143-155

Fecundity in Jasus verreauxi (H. Milne Edwards, 1851) has been studied by a detailed investigation of (a) the total weight of eggs carried by female specimens, (b) the average number of eggs per 1 g sample, and (c) the total number of eggs carried by females. In mid October 1966, 217 females “in berry” (that is, carrying external eggs) were examined and measured at Spirits Bay, New Zealand. The fecundity study is based on the results obtained from 21 selected specimens, with carapace lengths from 15.5 cm to 23.5 cm.

A direct relation was found between the total weight of eggs carried and increase in carapace length. The total weight of eggs carried varied from about 51 g to 238 g for carapace lengths of 15.5 cm to 23.5 cm. No correlation was shown between the average number of eggs per 1 g sample and increase in carapace length. Considerable variation was noted in the number of eggs per 1 g sample, which ranged from a low count of 6,453 eggs to a high count of 8,341 eggs. The total number of eggs carried by female J. verreauxi was found to be related to an increase in carapace length. Furthermore, increase in fecundity per relative carapace length increase was noted to be greater in smaller specimens than in larger specimens. The total number of eggs carried ranged from about 385,000 for a carapace length of 15.5 cm to 1,940,000 for a carapace length of 23.5 cm.

Fecundity, as measured by the total weight of eggs carried and the total number of eggs produced, was found to be much higher in J. verreauxi than in several Jasus species previously studied by other workers.  相似文献   

Mass stranding of molluscs at Te Waewae bay,southland, New Zealand (note)     

D. Eggleston  R. W. Hickman 《新西兰海洋与淡水研究杂志》2013,47(3):379-382

A stranding of shellfish on the beach at Te Waewae Bay, Southland, occurred during a period of very cold, stormy weather in September 1970. More than 20 million shellfish were stranded, the majority being Mactra discors Gray. It is suggested that the cause was a combination of Strong inshore winds and low air temperatures, coupled with an increased flow of fresh, cold water across the beach.  相似文献   

New aposematic and presumably repellent bark cockroach from Lebanese amber     

《Cretaceous Research》2017

Balatronis cretacea Šmídová et Lei, 2017 – ancestor of the repellent harlequin cockroach (Insecta: Blattaria) is reported in this issue as the earliest representative of the type cockroach family Blattidae in the Cenomanian Myanmar amber (98 Ma). Balatronis libanensis sp.n. from the Lebanese amber (130 Ma) extends the palaeogeographic (to Gondwana) and chronostratigraphic (to Early Cretaceous) range of this advanced Mesozoic bark cockroach and shifts the expected origin of the Blattidae to the J/K boundary. In relation also to the living harlequin Neostylopyga rhombidifolia, B. libanensis is primitive in being extremely small, less coloured and with well-developed wings. It has the standard cockroach head and rudimentary, but clearly visible plesiomorphic macula-like central ocellus (as the only representative of the modern Mesoblattinidae–Blattidae–Ectobiidae–Blaberidae lineage) and represents the earliest significant record of an aposematic and thus very probably also a repellent and/or poisonous insect.  相似文献   

Effects of a multi-year experimental flood regime on macroinvertebrates downstream of a reservoir   总被引：3，自引：0，他引：3  

Christopher?T.?RobinsonEmail author  Urs?Uehlinger  Michael?T.?Monaghan 《Aquatic Sciences - Research Across Boundaries》2003,65(3):210-222

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滇中妥甸组中首次发现昆虫化石   总被引：3，自引：1，他引：3  

张志军卢立伍  靳悦高方晓思 洪友崇 《地质通报》2003,22(6):452-455

首次在云南滇中地区晚侏罗世妥甸组滥泥阱剖面和级山坡一带发现昆虫化石2新种：Mesobluttula tuodianensis sp.nov.和Neorthophlebia yunnanensis sp．nov．，未定种3种。其中长翅目新直脉蝎蛉新直脉蝎蛉属(Neorthophlebia)在国内为首次发现。  相似文献   

Palaeoenvironmental reconstruction of the Younger Dryas in Jersey, UK Channel Islands, based on plant and insect fossils     

R.L. Jones 《Proceedings of the Geologists' Association. Geologists' Association》2004,115(1):43-53

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Can ecological and evolutionary arguments solve the riddle of the missing marine insects?     

Graeme D. Ruxton  & Stuart Humphries 《Marine Ecology》2008,29(1):72-75

We critically appraise the recent literature on the paucity of marine insects and conclude that this near‐absence does demand explanation; but this explanation is unlikely to be found in the suggested problems of depth for insect respiratory systems. We tentatively suggest some areas where further consideration may yield fruitful answers to this long‐standing evolutionary riddle.  相似文献   

西藏那曲地区孔玛盆地第四纪昆虫化石的发现及意义     

邵兆刚  孟宪刚  朱大岗  杨朝斌  雷伟志  王津  韩建恩  余佳  孟庆伟  钱程 《地质通报》2010,29(2)

首次在西藏那曲地区孔玛盆地第四系湖相沉积地层中发现了昆虫化石,对昆虫化石的特征和产出层位进行了描述,昆虫化石经初步鉴定分别属于膜翅目、双翅目和异翅目.采集了该套地层的ESR年代学样品,测试结果表明该套地层的时代为早中更新世.昆虫的分布演化与环境关系密切.这一发现为研究青藏高原第四纪以来的生物进化,湖泊、河流演化,气候变化,古地理、古环境变迁.第四系地层划分等提供了新资料.  相似文献   

Sub‐fossil Chironomidae as indicators of palaeoflow regimes: integration into the PalaeoLIFE flow index     

Lynda C. Howard  Paul J. Wood  Malcolm T. Greenwood  Helen M. Rendell  Stephen J. Brooks  Patrick D. Armitage  Chris A. Extence 《第四纪科学杂志》2010,25(8):1270-1283

The sub‐fossil head capsules of larval Chironomidae have been widely exploited as palaeoecological indicators of lentic ecosystems but their value in the interpretation of the evolution of lotic systems has been underutilised by comparison. Recent research has demonstrated that the remains of Chironomidae are abundant within fluvial sequences and that they offer a valuable record of channel change and floodplain evolution that may complement that derived from existing biological and sedimentological techniques. This paper demonstrates the use of Chironomidae in characterising the palaeoflow regime of a large mid–late Holocene floodplain palaeochannel (5470–4960 to 1530–1350 cal. a BP) of the River Trent (Derbyshire, UK). Using expert knowledge and published information regarding flow preferences, larval Chironomidae were incorporated into the PalaeoLIFE (Lotic‐invertebrate Index for Flow Evaluation) methodology. The results clearly demonstrate that the sub‐fossil record provided by Chironomidae can be used to characterise changes in the flow regime within palaeochannel sections. At the scale of the channel section, species‐ and generic‐level ecological associations can provide useful information regarding habitat characteristics, including the presence of instream vegetation, mineral substrates and woody debris. The ability to undertake environmental reconstruction and channel evolution history was significantly enhanced through the application of a multi‐proxy approach, by incorporating other aquatic insect groups (Trichoptera and Coleoptera) into the PalaeoLIFE metric, together with sedimentological data. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献