The four palaemonoid(sub)families Anchistioididae,Gnathophyllidae,Hymenoceridae,and Pontoniinae are similar in morphology,and all live in marine habitats.Their systematic relationships are controversial.In this study,...The four palaemonoid(sub)families Anchistioididae,Gnathophyllidae,Hymenoceridae,and Pontoniinae are similar in morphology,and all live in marine habitats.Their systematic relationships are controversial.In this study,we used sequences from a mitochondrial ribosomal gene(16S rRNA) and three nuclear genes(H3,NaK,and enolase) to explore the phylogenetic relationships of these four taxa.Our tree based on 43 species belonging to 28 genera shows that Gnathophyllidae and Hymenoceridae are nested within Pontoniinae.This result is consistent with evidence from larval morphology.The defining characteristics of Gnathophyllidae and Hymenoceridae,a vestigial or missing mandibular incisor process and a broadened third maxilliped,can also be found in Pontoniinae;conversely,on the basis of published species descriptions,gnathophyllids and hymenocerids meet most of the defining characteristics of Pontoniinae.The peculiar form of the third maxilliped in gnathophyllids and hymenocerids might be the result of adaptive evolution,as these particular features are also present in pontoniines.According to our phylogenetic tree,Anchistioididae are more remote from Pontoniinae,which is consistent with the distinct morphological differences in the pleopods.The pontoniine genera analyzed(together with Gnathophyllidae and Hymenoceridae) are divided into two clades.The members of Clade I exhibit primordial characteristics similar to those of the Palaemoninae,and might be direct descendants of the ancestor of the Pontoniinae;members of Clade II are more specialized.展开更多
The morphologies of eumelanin, isolated from the six cephalopods species Sepia esculenta, Sepia lycidas, Sepia pharaonis, Sepiella japonica, Euprymna berryi, and Uroteuthis(Photololigo) edulis, were investigated using...The morphologies of eumelanin, isolated from the six cephalopods species Sepia esculenta, Sepia lycidas, Sepia pharaonis, Sepiella japonica, Euprymna berryi, and Uroteuthis(Photololigo) edulis, were investigated using atomic force microscopy(AFM). The results showed that the hierarchical aggregate structures of irregular spherical particles with different diameters are the common characteristics of these eumelanins. Furthermore, the diameters of these spherical particles present an uneven distribution in a wide range and mainly concentrate in the range of about 20-150 nm. In addition, the eumelanin from different cephalopods species show obvious differences in the morphologies, which is illustrated by different assembly forms of diverse aggregate units and the quantitative features of eumelanin particles derived from the images.展开更多
Boron isotope values in Paleozoic brachiopods and corals, collected from the Yunnan-Guizhou Plateau, China, can be used to constrain the boron isotope compositions of past oceans. All brachiopod shells and coral sampl...Boron isotope values in Paleozoic brachiopods and corals, collected from the Yunnan-Guizhou Plateau, China, can be used to constrain the boron isotope compositions of past oceans. All brachiopod shells and coral samples were screened for diagenetic recrystallization by cathodoluminescence microscopy, trace element geochemistry of B, Fe, Mn, Sr, and scanning electron microscopy. The boron isotope ratios for brachiopods in Silurian, Devonian, Carboniferous, and Triassic calcites are in the ranges 8.9‰-14.0‰, 8.8‰-13.8‰, 10.3‰-16.3‰, and 6.7‰-12.4‰, respectively. The boron isotope ratios of coral calcites in the Silurian, Devonian, and Permian are 9.1‰-12.2‰, 6.1‰-13.8‰, and 9.2‰-16.1‰, respectively. The δ11B values for both brachiopods and corals are significantly lower than those for modern biogenic carbonates, indicating that the Paleozoic oceans were depleted of δ11B by up to 10‰. Our results are consistent with previous published studies. The boron isotope compositions of corals and brachiopods show the consistent trends. The low δ11B values may be explained by an enhanced riverine flux of boron from the continents.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.41376163,30499340)the National Science Council,Taiwan to CHAN Tinyam
文摘The four palaemonoid(sub)families Anchistioididae,Gnathophyllidae,Hymenoceridae,and Pontoniinae are similar in morphology,and all live in marine habitats.Their systematic relationships are controversial.In this study,we used sequences from a mitochondrial ribosomal gene(16S rRNA) and three nuclear genes(H3,NaK,and enolase) to explore the phylogenetic relationships of these four taxa.Our tree based on 43 species belonging to 28 genera shows that Gnathophyllidae and Hymenoceridae are nested within Pontoniinae.This result is consistent with evidence from larval morphology.The defining characteristics of Gnathophyllidae and Hymenoceridae,a vestigial or missing mandibular incisor process and a broadened third maxilliped,can also be found in Pontoniinae;conversely,on the basis of published species descriptions,gnathophyllids and hymenocerids meet most of the defining characteristics of Pontoniinae.The peculiar form of the third maxilliped in gnathophyllids and hymenocerids might be the result of adaptive evolution,as these particular features are also present in pontoniines.According to our phylogenetic tree,Anchistioididae are more remote from Pontoniinae,which is consistent with the distinct morphological differences in the pleopods.The pontoniine genera analyzed(together with Gnathophyllidae and Hymenoceridae) are divided into two clades.The members of Clade I exhibit primordial characteristics similar to those of the Palaemoninae,and might be direct descendants of the ancestor of the Pontoniinae;members of Clade II are more specialized.
基金supported by the Special Fund Project of Industry, University and Research Institute Collaboration in Guangdong province (No.2013B090500036)the Project of Science & Technology in Guangdong Province (No.2014B040404071)+2 种基金the Project of Science & Technology in Zhanjiang City (No.2013A202-4)the Natural Science Foundation of Guangdong Province, China (No.2015A 030310406)the PhD. Programs Foundation of Lingnan Normal University (No.ZL1313)
文摘The morphologies of eumelanin, isolated from the six cephalopods species Sepia esculenta, Sepia lycidas, Sepia pharaonis, Sepiella japonica, Euprymna berryi, and Uroteuthis(Photololigo) edulis, were investigated using atomic force microscopy(AFM). The results showed that the hierarchical aggregate structures of irregular spherical particles with different diameters are the common characteristics of these eumelanins. Furthermore, the diameters of these spherical particles present an uneven distribution in a wide range and mainly concentrate in the range of about 20-150 nm. In addition, the eumelanin from different cephalopods species show obvious differences in the morphologies, which is illustrated by different assembly forms of diverse aggregate units and the quantitative features of eumelanin particles derived from the images.
基金supported by National Natural Science Foundation of China (Grant Nos. 407760071 and 40976074)
文摘Boron isotope values in Paleozoic brachiopods and corals, collected from the Yunnan-Guizhou Plateau, China, can be used to constrain the boron isotope compositions of past oceans. All brachiopod shells and coral samples were screened for diagenetic recrystallization by cathodoluminescence microscopy, trace element geochemistry of B, Fe, Mn, Sr, and scanning electron microscopy. The boron isotope ratios for brachiopods in Silurian, Devonian, Carboniferous, and Triassic calcites are in the ranges 8.9‰-14.0‰, 8.8‰-13.8‰, 10.3‰-16.3‰, and 6.7‰-12.4‰, respectively. The boron isotope ratios of coral calcites in the Silurian, Devonian, and Permian are 9.1‰-12.2‰, 6.1‰-13.8‰, and 9.2‰-16.1‰, respectively. The δ11B values for both brachiopods and corals are significantly lower than those for modern biogenic carbonates, indicating that the Paleozoic oceans were depleted of δ11B by up to 10‰. Our results are consistent with previous published studies. The boron isotope compositions of corals and brachiopods show the consistent trends. The low δ11B values may be explained by an enhanced riverine flux of boron from the continents.
