Component characteristics of organic matter in hydrothermal barnacle shells from Southwest Indian Ridge

In 2008-2009, hydrothermal barnacle and sediment samples were collected from the Southwest Indian Ridge during a survey of the China Ocean Mineral Resources R＆D Association （COMRA）. Samples were ana- lyzed by gas chromatography-mass spectrometer （GC-MS）, revealing the main organic constituents of hy- drothermal barnacle and sediment to be fatty acids and alkylbenzenes. N-alkanes which possessed obvious even carbon advantage were also detected in hydrothermal sediment. The high concentrations of aromatic compounds might be the result of macromolecular thermal alteration. Microorganism in the submarine hydrothermal ecosystem, especially those related to sulfur metabolism, might be the source of the high con- centrations of fatty acids detected in these samples. In high temperature and high pressure hydrothermal environments, n-alkanes which possessed obvious even carbon advantage might originate from thermal alteration of carboxylic acids and other lipid compounds.

Fouling acorn barnacles in China——a review

We review the species composition, distribution, and seasonal variation of fouling acorn barnacles in Chinese waters--from Bohai Sea and Yellow Sea to East and South China Seas. Thirty-two species of acorn barnacles were found, of which, the dominant species are Amphibalanus amphitrite, A. reticulatus, A. variegates, Balanus trigonus, Fistulobalanus kondakovi, Megabalanus tintinnabulum, Striatobalanus amaryllis, and Eurapha withersi in the fouling communities. A. amphitrite is the dominant species in the coastal waters of Bohai Sea and Yellow Sea and A. reticulatus is dominant in the East and South China Seas. The settlement period of fouling acorn barnacles is usually in summer and autumn. From north to south with the decrease of latitude, their settlement period obviously extends, even to the whole year, and the species number also increases. Other environmental factors, such as salinity and distance from shore, also play an important role in the distribution of fouling acorn barnacles.

Barnacle inspired strategy combined with solvent exchange for enhancing wet adhesion of hydrogels to promote seawater-immersed wound healing

Hydrogels are promising materials for wound protection,but in wet,or underwater environments,the hydration layer and swelling of hydrogels can seriously reduce adhesion and limit their application.In this study,inspired by the structural characteristics of strong barnacle wet adhesion and combined with solvent exchange,a robust wet adhesive hydrogel(CP-Gel)based on chitosan and 2-phenoxyethyl acrylate was obtained by breaking the hydration layer and resisting swelling.As a result,CP-Gel exhibited strong wet adhesion to various interfaces even underwater,adapted to joint movement and skin twisting,resisted sustained rushing water,and sealed damaged organs.More importantly,on-demand detachment and controllable adhesion were achieved by promoting swelling.In addition,CP-Gel with good biosafety significantly promotes seawater-immersed wound healing and is promising for use in water-contact wound care,organ sealing,and marine emergency rescue.

Trace metals in barnacles:the significance of trophic transfer

Barnacles have very high accumulated trace metal body concentrations that vary with local trace metal bioavailabilities and represent integrated measures of the supply of bioavailable metals. Pioneering work in Chinese waters in Hong Kong highlighted the potential value of barnacles (particularly Balanus amphitrite) as trace metal biomonitors in coastal waters,identifying differences in local trace metal bioavailabilities over space and time. Work in Hong Kong has also shown that although barnacles have very high rates of trace metal uptake from solution, they also have very high trace metal assimilation efficiencies from the diet. High assimilation efficiencies coupled with high ingestion rates ensure that trophic uptake is by far the dominant trace metal uptake route in barnacles, as verified for cadmium and zinc. Kinetic modelling has shown that low efflux rate constants and high uptake rates from the diet combine to bring about accumulated trace metal concentrations in barnacles that are amongst the highest known in marine invertebrates.

Some biological consequences of environmental change:A study using barnacles(Cirripedia:Balanomorpha)and gum trees(Angiospermae:Myrtaceae)

Uniformitarianism permits understanding of the past on the basis of the present,and modeling the future through consideration of the fossil record.The present paper addresses the impact environmental(climatic)change has had on acorn barnacles and eucalyptus trees.Acorn barnacles(Balanomorpha)are first recorded after the K/T massextinction event.In the Paleogene,rapid radiation resulted in their occupying most marine environments.That balanomorphs survived both the Paleocene–Eocene thermal maximum and the Pleistocene glaciation is testament to their ability to adapt to opportunities;they are known from the littoral(Chamaesipho)to depths of 3600 m(Tetrachaelasma)and within this from diverse substrates:rock,wood and miscellaneous flotsam,plus in symbiosis or commensalism with most larger marine organisms.Darwin’s(1854)view of the late Tertiary as the age of barnacles is reflected in their diversity,distribution and biomass.Barnacles are contrasted with the Australian Myrtaceae:plants ranging from woody shrubs to tall trees.The most significant is Eucalyptus sensu lato,which typifies Australia’s flora,and is characterized by aromatic leaves that produce eucalyptol.Eucalyptus has evolved strategies that result in its domination of Australian open woodlands:these include production of highly flammable eucalyptol oil(with a flashpoint of 49℃)and an unprecedented ability to regenerate following forest fires.Gum trees and barnacles first appear in the Paleogene,their earliest records are Australasian,and they both demonstrate extraordinary resilience when environmental conditions are optimal.

The“Tears of the Virgin”at Lakes Entrance,southeast Australia were made by the intertidal barnacle Chthamalus antennatus(Cirripedia:Thoracica)and cyanobacteria

Curious eroded depressions,most resembling an eye shedding an elongate tear,are found in gently sloping,intertidal,carbonate-rich arenite outcropping on the sea coast near Lakes Entrance,Victoria,southeast Australia.The depressions,known locally as“Tears of the Virgin,”are evidently formed by multiple generations of a barnacle,Chthamalus antennatus Darwin,1854 in association with cyanobacteria.While the round part of a depression offers the barnacle a modicum of protection from impacts during high tides,it is also partially inhabited by cyanobacteria,which extend into and tend to fill the elongate tear.As such,this appears to be the first case of mutualism between a higher invertebrate and cyanobacteria,with the cyanobacteria reducing the barnacle’s risk of desiccation while receiving metabolic wastes from it during low tides.It is also the first record of a balanomorph barnacle eroding calcareous arenite beneath its shell,the net effect of which would be expected to reduce its adhesion to the substrate.However,the siliceous residue,resulting from the barnacle’s dissolution of the more than 80%of the calcite-rich sedimentary rock,is sequestered in delicate folds on the inside of the shell wall as it grows.A brief review of cirripedes capable of excavation includes the first photographic documentation of excavation of a mollusc shell by a verrucomorph.

The barnacle and the building:a modern morality tale

A rare and almost complete barnacle fossil,previously described on the basis of two isolated shell fragments,wasrecently exposed in a limestone block on the outer wall of Melbourne’s Old Magistrates’Courts in Victoria,Australia.These courts comprise one of the oldest and grandest buildings in Melbourne and because of this they have aheritage listing.As heritage-listed buildings are protected from alteration by law,and as removal of the fossil wouldbe deemed“alteration”,official permission had to be obtained to extract the specimen.This paper discusses theprocesses involved with extraction of a unique specimen from a protected building and provides an overview of thepalaeontological significance of the fossil.Consideration is given to the likely fate of a fossil of this nature,situateda little below eye level on a busy city street,if it was left in situ;finally,the implications of designating a holotypefrom material removed from a building are assessed.

海洋污损生物藤壶生长过程及附着强度研究

研究海洋污损生物藤壶(Barnacle)不同生长阶段附着强度,可为科学制定藤壶清除规范及设计相关机械设备提供依据。本文采用浸泡法在湛江调顺岛(21°31′N,110°41′E)实海中挂板,结合形貌观察藤壶生长过程,利用自行设计的剪切强度测试装置,选取网纹藤壶测试不同生长阶段剪切强度。结果表明:试板浸泡10 d,幼体藤壶开始附着;30 d试板表面藤壶覆盖面积约占30%,基底直径1~6 mm,部分藤壶死亡形成空壳;60 d试板约50%面积被藤壶覆盖,试板表面有覆膜,空壳现象加剧,藤壶基底直径最大达10 mm;90 d试板约95%面积被藤壶覆盖,出现藤壶相叠现象,基底直径1~13 mm。藤壶附着生长过程中,剪切强度变化符合“快-慢”的特点,以藤壶基底直径为变量,构建藤壶剪切强度Logistic增长模型,决定系数R2=0.99,说明模型拟合良好。利用构建的Logistic增长模型将藤壶剪切强度划分为速增期(基底直径4.0~6.4 mm),缓增期(基底直径6.4~8.7 mm)及渐停期(基底直径>8.7 mm)3个阶段。结合藤壶附着生长过程,藤壶在附着后采用机械方式清除的最佳清除时期在速增期。

Seasonal Variability of Biofouling Community Structure in the Gulf of Mannar,Southeast Coast of India:A Multivariate Approach

In this research,an Underwater Biofouling Panel(UWBFP)system was erected for the qualitative and quantitative estimation of macro fouling organisms in the Gulf of Mannar.Forty-four biofoulers were identified from four types of selected test panels.Among these biofoulers,Amphibalanus amphitrite(Darwin,1854)was the dominant one.The concrete panel encouraged the highest barnacle density compared to the other panels.Three series of test panels were used to assess the seasonal density of biofouling communities.The overall variation in barnacle count in the seaward and shoreward sides of all these three series were tested.They were found to be significantly different from each other.The greater variations in the barnacle density observed in this study in A-series of test panels could be due to the lack of or absence of other foulers to compete within the fortnight.The Shannon-Wiener species diversity index showed the highest diversity in wood substratum among the three series with greater accumulation of different types of fouling organisms.Multivariate analyses were also performed to understand the seasonal variation as well as the settlement pattern on the different directions of test panels based on validated data.PCA showed a strong variability(PC1 between 70.8%and 98.6%variance)between the directions of the panels in connection with barnacle density.The shade plot and CAP analysis segregated the short-term A-series test panels from the long-term(B-and C-series)test panels.Hence,the output was helpful in understanding the recruitment status of various faunal resources involved in the biofouling processes.

Hierarchical Data Aggregation with Data Offloading Scheme for Fog Enabled IoT Environment

Fog computing is a promising technology that has been emerged to handle the growth of smart devices as well as the popularity of latency-sensitive and location-awareness Internet of Things(IoT)services.After the emergence of IoT-based services,the industry of internet-based devices has grown.The number of these devices has raised from millions to billions,and it is expected to increase further in the near future.Thus,additional challenges will be added to the traditional centralized cloud-based architecture as it will not be able to handle that growth and to support all connected devices in real-time without affecting the user experience.Conventional data aggregation models for Fog enabled IoT environ-ments possess high computational complexity and communication cost.There-fore,in order to resolve the issues and improve the lifetime of the network,this study develops an effective hierarchical data aggregation with chaotic barnacles mating optimizer(HDAG-CBMO)technique.The HDAG-CBMO technique derives afitness function from many relational matrices,like residual energy,average distance to neighbors,and centroid degree of target area.Besides,a chaotic theory based population initialization technique is derived for the optimal initial position of barnacles.Moreover,a learning based data offloading method has been developed for reducing the response time to IoT user requests.A wide range of simulation analyses demonstrated that the HDAG-CBMO technique has resulted in balanced energy utilization and prolonged lifetime of the Fog assisted IoT networks.

The first record of a Konservat-Lagerstätten in which early post-settlement stages of fossil archaeobalanids(Cirripedia:Balanomorpha)are preserved

A diverse sessile barnacle fauna from a Miocene shallow-water deposit at Dolnja Stara vas in Slovenia is described.It includes the first descriptions of early post settlement juveniles of Actinobalanus sloveniensis attached to mangrove leaves.These represent three distinct growth phases,the earliest being interpreted as being less than 24 h post settlement,the others being 1 to 2 days post settlement.An assessment of their taphonomy is provided.Associated adult balanomorphs are attached to a variety of organic substrates,including mangrove leaves and branches,fragments of the conifers?Taxodioxylon,Carapoxylon,pine cones,molluscs,and cetacean bones.The barnacles include A.sloveniensis,Amphibalanus venustus,and Perforatus perforatus—many with opercula retained within the shells.A.venustus retains some of the original shell color.This is the second record of barnacle–plant associations from the Central Paratethys from Kamnik and Trbovlje.The paleoecology and paleogeography of the site are discussed.

Of trees,geese and cirripedes:Man’s quest for understanding

At least zoologists know that barnacles are arthropods rather than mollusks.However,this knowledge is surprisingly new,for it was as recent as 1830 before J.Vaughan Thompson showed,through a careful study of barnacle larvae,that they were crustaceans.In the 1850s,Charles Darwin unraveled much of the taxonomy of barnacles,and,significantly,his observations and classification of them follow the structure that was to be published later as his evolutionary theory.Irrespective of these works,knowledge of the systematic placement of barnacles remains surprisingly poor in the wider population today,with most non-biologists viewing barnacles as shallow-water fouling organisms related to oysters and limpets.The present paper reviews the way humans have perceived barnacles for at least a millennium;it evaluates why they were thought to have grown from trees and to have been part of the life cycle of birds;it concludes by contemplating the manner in which we perceive our environment and by doing so try to make sense of our world.