Acorn barnacles are important model species in researches on intertidal ecology, larval development and biofouling. At present, with the development of mitochondrial genomics, it is helpful to understand the phylogene...Acorn barnacles are important model species in researches on intertidal ecology, larval development and biofouling. At present, with the development of mitochondrial genomics, it is helpful to understand the phylogenetic relationship from the mitogenomic level. The complete mitochondrial genome of Chthamalus challengeri was presented. The genome is a circular molecule of 15 358 bp. Compared with other species in Balanomorpha, the non-coding region is longer, while the length of the genes is similar to the other species. The overall A+T content of the mitochondrial genome of C. challengeri is 70.5%. There are variations of initiation and stop codons in the known Balanomorpha mitochondrial genomes. The C. challengeri and C. antennatus within the same genus share the identical gene arrangement. However, the gene arrangement of different genera in Chthamalidae is different, as there is a translocation between two tRNA genes and an inversion involving a large gene block. In particular, both srRNA and lrRNA of the two species in Chthamalus are encoded in the heavy strand, differing from the former Balanomorpha species. The topology and gene arrangement in Chthamalidae support each other. Phylogenetic analysis indicates that the Chthamalidae is monophyletic, while the Balanidae and Archaeobalanidae are polyphyletic.展开更多
With the increased use of copper （Cu）-based antifouling （AF） paints, copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barna...With the increased use of copper （Cu）-based antifouling （AF） paints, copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barnacle Chthamalus challengeri. These experiments attempted to identify a more sensitive index to monitor copper pollution in marine environments. The 24 h LC_50 ranged from 156.07 μg/L （nauplius Ⅱ） to 817.15μg/L （cypris） and the no observed effect concentration （NOEC） ranged from 81.75 μg/L （nauplius Ⅱ） to 571.04 μg/L （cypris）. The cypris settlement rate declined significantly when copper concentrations 〉135 μg/L. No cypris was found in the copper concentration of 60 and 75 μg/L treatment groups stressed for 22 d. Nauplius Ⅱ moulting was not affected by exposure to copper for 24 h; however, when extended to 48 h, the percent moulted in 75 μg/L treatment group was declined to 37.12%, which was significant lower （P〈0.05） than that in the control group. The phototaxis of nauplius II decreased significantly when copper concentrations _〉45 μg/L. Despite an initial significant increase at copper concentrations of 30 μg/L, ammonia excretion rate decreased when copper concentrations ≥60 μg/L. These results suggested that： （1） nauplius Ⅱ could not develop to the cypris when the copper concentration ≥60 μg/L; （2） cypris settlement is more susceptible to copper than cypris mortality rate; （3） nauplius II is the most sensitive larval stage; （4） nauplius II ammonia excretion rate is the most sensitive index to copper and might be as the indicator for copper pollution monitoring.展开更多
Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to es- tablish and spread in new habitats. Successful invaders must resist both physical and physiolog...Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to es- tablish and spread in new habitats. Successful invaders must resist both physical and physiological stresses associated with the changing environment. A common littoral barnacle, Chthamalus challengeri Hoek, 1883 （Crustacea, Cirripedia）, which is native to Japan, South Korea and northern China, has become established in the high-littoral zone adjacent to Yangshan Port, Shanghai, China. A comparison of the morphology of Chthamlus species from Zhoushan archipelago with previous description indicates the occur- rence of C. challengeri. The new immigrant becomes a dominant species in certain high-intertidal habitats of the adjacent area to of Yangshan Port. C. challengeri was found in part of sampling sites in Zhoushan in 2010; however, it dispersed to all the eleven sam- piing sites in 2012. Densities of C.challengeri had increased over 10 times in the last 2 years, with the highest mean value reaching 39533 ± 6243 ind. m-2 in the new habitat. The specific ratios of both operculum area （Sa） to base area （SA） and average height of pa- rietal plates （H） to length of base （L） revealed that C. challengeri displays morphological changes to resist stronger currents in the new habitats for invasion.展开更多
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.T...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.展开更多
基金The National Natural Science Foundation of China(NSFC)under contract No.41876147the Jiangsu Priority Academic Program Development(PAPD)+3 种基金the Graduate Research and Innovation Projects under contract Nos KYCX18_2570 and KYCX18_2566Jiangsu QinglanJiangsu 333Jiangsu Six Talent Peaks and Lianyungang 521 Talent Projects
文摘Acorn barnacles are important model species in researches on intertidal ecology, larval development and biofouling. At present, with the development of mitochondrial genomics, it is helpful to understand the phylogenetic relationship from the mitogenomic level. The complete mitochondrial genome of Chthamalus challengeri was presented. The genome is a circular molecule of 15 358 bp. Compared with other species in Balanomorpha, the non-coding region is longer, while the length of the genes is similar to the other species. The overall A+T content of the mitochondrial genome of C. challengeri is 70.5%. There are variations of initiation and stop codons in the known Balanomorpha mitochondrial genomes. The C. challengeri and C. antennatus within the same genus share the identical gene arrangement. However, the gene arrangement of different genera in Chthamalidae is different, as there is a translocation between two tRNA genes and an inversion involving a large gene block. In particular, both srRNA and lrRNA of the two species in Chthamalus are encoded in the heavy strand, differing from the former Balanomorpha species. The topology and gene arrangement in Chthamalidae support each other. Phylogenetic analysis indicates that the Chthamalidae is monophyletic, while the Balanidae and Archaeobalanidae are polyphyletic.
基金Supported by the National Natural Science Foundation of China(No.3107045820)the State Oceanic Administration Public Welfare Project(Nos.201305009,201305009-4,201005007)
文摘With the increased use of copper （Cu）-based antifouling （AF） paints, copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barnacle Chthamalus challengeri. These experiments attempted to identify a more sensitive index to monitor copper pollution in marine environments. The 24 h LC_50 ranged from 156.07 μg/L （nauplius Ⅱ） to 817.15μg/L （cypris） and the no observed effect concentration （NOEC） ranged from 81.75 μg/L （nauplius Ⅱ） to 571.04 μg/L （cypris）. The cypris settlement rate declined significantly when copper concentrations 〉135 μg/L. No cypris was found in the copper concentration of 60 and 75 μg/L treatment groups stressed for 22 d. Nauplius Ⅱ moulting was not affected by exposure to copper for 24 h; however, when extended to 48 h, the percent moulted in 75 μg/L treatment group was declined to 37.12%, which was significant lower （P〈0.05） than that in the control group. The phototaxis of nauplius II decreased significantly when copper concentrations _〉45 μg/L. Despite an initial significant increase at copper concentrations of 30 μg/L, ammonia excretion rate decreased when copper concentrations ≥60 μg/L. These results suggested that： （1） nauplius Ⅱ could not develop to the cypris when the copper concentration ≥60 μg/L; （2） cypris settlement is more susceptible to copper than cypris mortality rate; （3） nauplius II is the most sensitive larval stage; （4） nauplius II ammonia excretion rate is the most sensitive index to copper and might be as the indicator for copper pollution monitoring.
基金supported by China’s National Special Research Fund for Non-Profit Marine Sector (No. 2013418027)Marine Biology Program of Shanghai Leading Academic Disipline (No. J50701)+1 种基金Marine Special Fund of Shanghai Committee of Science and Technology (No. 11dz1205000)a Doctoral Research Fund from Shanghai Ocean University (No. A2-0302-14-300084)
文摘Invasive species generally possess unique characteristics that allow them to survive the invasion process in order to es- tablish and spread in new habitats. Successful invaders must resist both physical and physiological stresses associated with the changing environment. A common littoral barnacle, Chthamalus challengeri Hoek, 1883 （Crustacea, Cirripedia）, which is native to Japan, South Korea and northern China, has become established in the high-littoral zone adjacent to Yangshan Port, Shanghai, China. A comparison of the morphology of Chthamlus species from Zhoushan archipelago with previous description indicates the occur- rence of C. challengeri. The new immigrant becomes a dominant species in certain high-intertidal habitats of the adjacent area to of Yangshan Port. C. challengeri was found in part of sampling sites in Zhoushan in 2010; however, it dispersed to all the eleven sam- piing sites in 2012. Densities of C.challengeri had increased over 10 times in the last 2 years, with the highest mean value reaching 39533 ± 6243 ind. m-2 in the new habitat. The specific ratios of both operculum area （Sa） to base area （SA） and average height of pa- rietal plates （H） to length of base （L） revealed that C. challengeri displays morphological changes to resist stronger currents in the new habitats for invasion.
文摘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.
