Halkieria is an Early Cambrian fossil genus with proposed phylogenetic affinities ranging from stem group lophotrochozoan to stem-group aculiferan. Skeletal similarities are often cited as evidence in support of a mol...Halkieria is an Early Cambrian fossil genus with proposed phylogenetic affinities ranging from stem group lophotrochozoan to stem-group aculiferan. Skeletal similarities are often cited as evidence in support of a mollusk interpretation for Halkieria and related Cambrian fossils. The skeletal microstructures of the polyplacophoran mollusk (chiton) Ischnochiton hakodadensis, which bears perinotum elements resembling sclerites of halkieriids and other coeloscleritophoran small shelly fossils (SSFs), were studied to evaluate the interpretations. There are both similarities and differences between chiton skeletal structures and halkieriid sclerites: 1) the head valve of L hakodadensis and the dorsal shell of Halkieria evangelista share a similar pattern of fine concentric growth lines, but halkieriid dorsal shells lack other polyplacophoran valve characteristics, including V-shaped indentation, radiate ribs; 2) the arrangement of I. hakodadensis perinotum elements in three zones is somewhat similar to the arrangement pattern of halkieriid sclerites; 3) the inner perinotum scales of L hakodadensis (-200 μm in diameter) have a base and a blade, remarkably similar in morphology to halkieriid palmate sclerites (-400 μm in diameter). However, I. hakodadensis perinotum scales are nearly solid whereas halkieriid sclerites are hollow. These observations add a microstructural dimension to the skeletal comparison between mollusks and halkeriids, and may prove to be useful in resolving the phylogenetic affinity of Halkieria and the Halwaxiidae.展开更多
This report based on the results of investigations conducted in June 2007 and July 2008, respectively, on the benthic community structure and characteristic diversity of the Huanghai Sea (Yellow Sea) Cold Water Mass...This report based on the results of investigations conducted in June 2007 and July 2008, respectively, on the benthic community structure and characteristic diversity of the Huanghai Sea (Yellow Sea) Cold Water Mass, as well as that in July 1959 during the national oceanic survey. The Naticidae specimens collected from Cold Water Mass in middle and northern Huanghai Sea were studied through morphological classification and the internal anatomy on radula. Three new species of Naticidae, i.e., Cryptonatica purpurfunda sp. nov., Cryptonatica sphaera sp. nov., and Cryptonatica striatica sp. nov. were identified. The morphological characteristics of the new species are described, and the similarties and differences between the new species and similar species are compared and discussed.展开更多
Adjacent intensive agriculture disturbs the natural condition of wetlands.However, to assess the effect of this agriculture on wetlands, few studies have used indices based on aquatic invertebrates.Multi-metric indice...Adjacent intensive agriculture disturbs the natural condition of wetlands.However, to assess the effect of this agriculture on wetlands, few studies have used indices based on aquatic invertebrates.Multi-metric indices(MMIs) have been successfully used to assess freshwater ecosystems worldwide and are an important management tool, but little is known about their applicability in the Sanjiang Plain, Northeast China.In this study, we developed a MMIs for aquatic invertebrates to assess freshwater wetlands in this region.The aquatic invertebrate assemblages were sampled in 27 wetlands in the Sanjiang Plain that included those in natural reserves and those affected by adjacent, intensive agriculture.Twenty-four candidate metrics were initially reviewed and screened before four core metrics were selected: total number of taxa, number of Hemiptera taxa, proportion of Gastropoda, and proportion of predators.Mann-Whitney U tests, Box and Whisker plots, correlation analyses, and redundant metric tests were used to assess the ability of metrics to distinguish among reference and impaired wetlands.Four ordinal rating categories for wetland were defined: poor, fair, good, and excellent.Of the impaired freshwater wetlands, 76.2% were in poor or fair categories.The MMIs was robust in discriminating reference wetlands from impaired wetlands and therefore have potential as a biomonitoring tool to assess the condition and to guide the restoration efforts of freshwater wetlands in Northeast China.展开更多
Two new species of Naticidae ( Mollusca, Gastropoda) collected from the coast of China are described: Cryptonaitca huanghaien- s/s sp. nov. and Sinum vittatum sp. nov. The morphological characteristics between the ...Two new species of Naticidae ( Mollusca, Gastropoda) collected from the coast of China are described: Cryptonaitca huanghaien- s/s sp. nov. and Sinum vittatum sp. nov. The morphological characteristics between the new species were described and the related information was provided. The similarities and differences between the new species and related species were also compared and discussed. The new species Cryptonaitca huanghaiensis differed from Cryptonaitca hirasei and Cryptonaitca andoi in outer shape, operculum and radula. The new species Sinum vittatum is similar to Sinumjaponicum (Lischke, 1869), but the shell of the former is flat-elliptical in shape, spire very small, slightly convex. While the latter is flat-globular in shape, apex light brown in color, without a brown band on the body whorl. The comparison results revealed that Cryptonaitca huanghaiensis and Sinum vittatum were two new species from the coast of China. Specimens studied were obtained from collections in the Marine Biological Museum, Chinese Academy of Sciences.展开更多
The marine environment provides a rich source of natural products with potential therapeutic application.This has resulted in an increased rate of pharmaceutical agents being discovered in marine animals,particularly ...The marine environment provides a rich source of natural products with potential therapeutic application.This has resulted in an increased rate of pharmaceutical agents being discovered in marine animals,particularly invertebrates.Our objective is to summarize the most promising compounds which have the best potential and may lead to use in clinical practice,show their biological activities and highlight the compounds currently being tested in clinical trials.In this paper,we focused on Bryozoa,Mollusca,Echinodermata and Urochordata.展开更多
Three new species of Family Mitridae (Mollusca: Gastropoda) from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI & S. ZHANG, Neocancilla daidaleosa sp. nov. B. LI & ...Three new species of Family Mitridae (Mollusca: Gastropoda) from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI & S. ZHANG, Neocancilla daidaleosa sp. nov. B. LI & X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.展开更多
Among small sized gastropods found in Aqaba (Jordan), Sansonia occurs relatively common with Sansoniacebuana which is recognized from the the fringing reef near the Marine Biological Stat...Among small sized gastropods found in Aqaba (Jordan), Sansonia occurs relatively common with Sansoniacebuana which is recognized from the the fringing reef near the Marine Biological Station at Aqaba, while Mecoliotia and Chrystella are rare. Mecoliotia aqabaensis n. sp and Chrystella shinaqi n. sp are described with the later resembling Chrystella finckhi. They are compared with other members of the Pick-worthiidae, of which a new species of Discrevina from Indonesia is described. A species of Aqabarella new genus resembles in shape of its teleoconch members of the Pickworthiidae but its protoconch is distinct in ornament of the larval shell and shape of the aperture and it is placed in it own family, Aqabarellidae. Aqabarella urdunensis is relatively more common than the rare Aqabarella pulchella. Similar larval shells are found in Vanikoridae, Planaxidae and Cerithiidae, those of Littorinidae and Rissoidae are more distinct and all of them differ from those of the Aqabarellidae, while some ancient small species from the Triassic tropical Tethys had a similar protoconch.展开更多
Trumpet shell(Charonia lampas sauliae)(Mollusca, Heterogastropoda, Cymatidae) has extensive economic value. Studies on the artificial larval development of C. lampas sauliae for aquaculture utilization have become esp...Trumpet shell(Charonia lampas sauliae)(Mollusca, Heterogastropoda, Cymatidae) has extensive economic value. Studies on the artificial larval development of C. lampas sauliae for aquaculture utilization have become especially important due to the finite natural resources. In the present study, the growth and survival rate of the larvae of C. lampas sauliae broodstocks fed three types of starfish diets, Asterina pectinifera Müller & Troschel 1842, A. amurensis Lütken 1871 and their mixture were compared. The larval size increased gradually between day 10 and day 20 after hatching at 15℃ and 20℃. No difference was found in body size and specific growth rate(SGR)(two-way ANOVA; P > 0.05). However, during transition from trochophore to veliger stage 20 days after hatching, significant increases in larval survival and growth rates were observed. The maximum survival rate was observed on day 10. The mean survival rate was 0.463, 0.730 and 0.515 at 15℃, and 0.369, 0.713 and 0.444 at 20 when ℃ A. pectinifera, A. amurensis and their mixture were fed, respectively. The SGR and survival rate of the larvae were definitely influenced by the diets(P < 0.05), and the effect of A. amurensis alone was higher than that of A. pectinifera alone and their mixture.展开更多
Mollusca is the second-largest animal phylum with over 100,000 extant species representing eight classes.Across 1000 extant species in the class Polyplacophora,chitons have a relatively constrained morphology but with...Mollusca is the second-largest animal phylum with over 100,000 extant species representing eight classes.Across 1000 extant species in the class Polyplacophora,chitons have a relatively constrained morphology but with some notable deviations.Several genera possess“shell eyes”,i.e.,true eyes with a lens and retina that are embedded within the dorsal shells.The phylogeny of the major chiton clades is mostly well established,in a set of superfamily-level and higher level taxa supported by various approaches,including morphological studies,multiple gene markers,mitogenome-phylogeny,and phylotranscriptomic approaches.However,one critical lineage has remained unclear,namely Schizochiton which was controversially suggested as being the potential independent origin of chiton shell eyes.Here,with the draft genome sequencing of Schizochiton incisus(superfamily Schizochitonoidea)plus assemblies of transcriptome data from other polyplacophorans,we present phylogenetic reconstructions using both mitochondrial genomes and phylogenomic approaches with multiple methods.We found that phylogenetic trees from mitogenomic data are inconsistent,reflecting larger scale confounding factors in molluscan mitogenomes.However,a consistent and robust topology was generated with protein-coding genes using different models and methods.Our results support Schizochitonoidea as the sister group to other Chitonoidea in Chitonina,in agreement with the established classification.Combined with evidence from fossils,our phylogenetic results suggest that the earliest origin of shell eyes is in Schizochitonoidea,and that these structures were also gained secondarily in other genera in Chitonoidea.Our results have generated a holistic review of the internal relationship within Polyplacophora,and a better understanding of the evolution of Polyplacophora.展开更多
Mollusc shell matrix proteins (SMPs) are important functional components embedded in the shell and play a role in shell formation. A SMP (Pif177) was identified previously from the nacreous layer of the Japanese p...Mollusc shell matrix proteins (SMPs) are important functional components embedded in the shell and play a role in shell formation. A SMP (Pif177) was identified previously from the nacreous layer of the Japanese pearl oyster Pinctadafucata, and its cleavage products (named pfPif97 and pfPif80 proteins) were found to bind to the chitin framework and induce aragonite crystal formation and orient the c axis. In this study, a homologue of pfPif177 was cloned from the mantle of the Pacific oyster Crassostrea gigas, containing the homologue of pfPif97 only and not pfPif80. This finding hints at the large divergence in gene structure between the two species. This homologue (cgPif97) shares characteristics with pfPif97, and suggests that the biological functions of these two proteins may be similar. The expression pattern of cgPif97 in different tissues and development stages in- dicates that it may play an important role in shell formation of the adult oyster. The morphology of the inner shell surface was af- fected by injected siRNA of cgPif97 and the calcite laths of the shell became thinner and narrower when the siRNA dose in- creased, suggesting that the cgPip7 gene plays an important role in calcite shell formation in C. gigas. In conclusion, we found evidence that the Pif177 gene evolved very fast but still retains a similar function among species [Current Zoology 59 (1): 109-115, 2013].展开更多
The study on trematode larvae found in Egyptian molluscs was initiated by the pioneering work of Sonsino in 1892 and Looss in 1896. Since then tens of cercariae and some digenean life cycles have been reported in the ...The study on trematode larvae found in Egyptian molluscs was initiated by the pioneering work of Sonsino in 1892 and Looss in 1896. Since then tens of cercariae and some digenean life cycles have been reported in the country. Unfortunately, only fragmentary publications are available for identification of cercariae present in the country. In addition, some of such publications may not be accessible to some researchers, as they are either theses or published in old volumes of non-international journals. The present work was carried out with the aim of preserving our heritage through reviewing the different types of cercariae known from the Egyptian inland water snails. We provide a survey based on literature. Major types of cercariae known to exist in the country are covered. They are presented as regards description, development, taxa, importance and snail hosts. This review can be used as a field guide for identification of cercariae colonising the Egyptian inland water snails.展开更多
基金Support from the National Natural Science Foundation of China(grant no.40602001)
文摘Halkieria is an Early Cambrian fossil genus with proposed phylogenetic affinities ranging from stem group lophotrochozoan to stem-group aculiferan. Skeletal similarities are often cited as evidence in support of a mollusk interpretation for Halkieria and related Cambrian fossils. The skeletal microstructures of the polyplacophoran mollusk (chiton) Ischnochiton hakodadensis, which bears perinotum elements resembling sclerites of halkieriids and other coeloscleritophoran small shelly fossils (SSFs), were studied to evaluate the interpretations. There are both similarities and differences between chiton skeletal structures and halkieriid sclerites: 1) the head valve of L hakodadensis and the dorsal shell of Halkieria evangelista share a similar pattern of fine concentric growth lines, but halkieriid dorsal shells lack other polyplacophoran valve characteristics, including V-shaped indentation, radiate ribs; 2) the arrangement of I. hakodadensis perinotum elements in three zones is somewhat similar to the arrangement pattern of halkieriid sclerites; 3) the inner perinotum scales of L hakodadensis (-200 μm in diameter) have a base and a blade, remarkably similar in morphology to halkieriid palmate sclerites (-400 μm in diameter). However, I. hakodadensis perinotum scales are nearly solid whereas halkieriid sclerites are hollow. These observations add a microstructural dimension to the skeletal comparison between mollusks and halkeriids, and may prove to be useful in resolving the phylogenetic affinity of Halkieria and the Halwaxiidae.
基金The Knowledge Innovation Program of Chinese Academy of Sciences under contract No. KZCX2-YW-417the Knowledge Innovation Program of Institute of Oceanology,CAS under contract No. 2007-12the National Marine Public Welfare Research Project under contract No.200805069
文摘This report based on the results of investigations conducted in June 2007 and July 2008, respectively, on the benthic community structure and characteristic diversity of the Huanghai Sea (Yellow Sea) Cold Water Mass, as well as that in July 1959 during the national oceanic survey. The Naticidae specimens collected from Cold Water Mass in middle and northern Huanghai Sea were studied through morphological classification and the internal anatomy on radula. Three new species of Naticidae, i.e., Cryptonatica purpurfunda sp. nov., Cryptonatica sphaera sp. nov., and Cryptonatica striatica sp. nov. were identified. The morphological characteristics of the new species are described, and the similarties and differences between the new species and similar species are compared and discussed.
基金Under the auspices of National Key Research and Development Project of China(No.2016YFC0500408)National Natural Science Foundation of China(No.41871099,41671260)Science and Technology Development Program of Jilin Province(No.20180101080JC)
文摘Adjacent intensive agriculture disturbs the natural condition of wetlands.However, to assess the effect of this agriculture on wetlands, few studies have used indices based on aquatic invertebrates.Multi-metric indices(MMIs) have been successfully used to assess freshwater ecosystems worldwide and are an important management tool, but little is known about their applicability in the Sanjiang Plain, Northeast China.In this study, we developed a MMIs for aquatic invertebrates to assess freshwater wetlands in this region.The aquatic invertebrate assemblages were sampled in 27 wetlands in the Sanjiang Plain that included those in natural reserves and those affected by adjacent, intensive agriculture.Twenty-four candidate metrics were initially reviewed and screened before four core metrics were selected: total number of taxa, number of Hemiptera taxa, proportion of Gastropoda, and proportion of predators.Mann-Whitney U tests, Box and Whisker plots, correlation analyses, and redundant metric tests were used to assess the ability of metrics to distinguish among reference and impaired wetlands.Four ordinal rating categories for wetland were defined: poor, fair, good, and excellent.Of the impaired freshwater wetlands, 76.2% were in poor or fair categories.The MMIs was robust in discriminating reference wetlands from impaired wetlands and therefore have potential as a biomonitoring tool to assess the condition and to guide the restoration efforts of freshwater wetlands in Northeast China.
基金The National Natural Science Foundation of China under contract Nos KZCX2-YW-417 and 30470217.
文摘Two new species of Naticidae ( Mollusca, Gastropoda) collected from the coast of China are described: Cryptonaitca huanghaien- s/s sp. nov. and Sinum vittatum sp. nov. The morphological characteristics between the new species were described and the related information was provided. The similarities and differences between the new species and related species were also compared and discussed. The new species Cryptonaitca huanghaiensis differed from Cryptonaitca hirasei and Cryptonaitca andoi in outer shape, operculum and radula. The new species Sinum vittatum is similar to Sinumjaponicum (Lischke, 1869), but the shell of the former is flat-elliptical in shape, spire very small, slightly convex. While the latter is flat-globular in shape, apex light brown in color, without a brown band on the body whorl. The comparison results revealed that Cryptonaitca huanghaiensis and Sinum vittatum were two new species from the coast of China. Specimens studied were obtained from collections in the Marine Biological Museum, Chinese Academy of Sciences.
文摘The marine environment provides a rich source of natural products with potential therapeutic application.This has resulted in an increased rate of pharmaceutical agents being discovered in marine animals,particularly invertebrates.Our objective is to summarize the most promising compounds which have the best potential and may lead to use in clinical practice,show their biological activities and highlight the compounds currently being tested in clinical trials.In this paper,we focused on Bryozoa,Mollusca,Echinodermata and Urochordata.
基金The study supported by the Natural Science Foundation of China (39899400 and 40276044), project of Chinese Academy of Sciences (KSCX2-SW-101B) and IOCAS for innovation (L57022807).
文摘Three new species of Family Mitridae (Mollusca: Gastropoda) from the South China Sea are described in the present paper. They are Ziba aglais sp. nov. B. LI & S. ZHANG, Neocancilla daidaleosa sp. nov. B. LI & X. LI, and Mitra holkosa sp. nov. B. LI. Their systematic positions are also discussed.
文摘Among small sized gastropods found in Aqaba (Jordan), Sansonia occurs relatively common with Sansoniacebuana which is recognized from the the fringing reef near the Marine Biological Station at Aqaba, while Mecoliotia and Chrystella are rare. Mecoliotia aqabaensis n. sp and Chrystella shinaqi n. sp are described with the later resembling Chrystella finckhi. They are compared with other members of the Pick-worthiidae, of which a new species of Discrevina from Indonesia is described. A species of Aqabarella new genus resembles in shape of its teleoconch members of the Pickworthiidae but its protoconch is distinct in ornament of the larval shell and shape of the aperture and it is placed in it own family, Aqabarellidae. Aqabarella urdunensis is relatively more common than the rare Aqabarella pulchella. Similar larval shells are found in Vanikoridae, Planaxidae and Cerithiidae, those of Littorinidae and Rissoidae are more distinct and all of them differ from those of the Aqabarellidae, while some ancient small species from the Triassic tropical Tethys had a similar protoconch.
基金financially supported by Chonnam National University in 2013
文摘Trumpet shell(Charonia lampas sauliae)(Mollusca, Heterogastropoda, Cymatidae) has extensive economic value. Studies on the artificial larval development of C. lampas sauliae for aquaculture utilization have become especially important due to the finite natural resources. In the present study, the growth and survival rate of the larvae of C. lampas sauliae broodstocks fed three types of starfish diets, Asterina pectinifera Müller & Troschel 1842, A. amurensis Lütken 1871 and their mixture were compared. The larval size increased gradually between day 10 and day 20 after hatching at 15℃ and 20℃. No difference was found in body size and specific growth rate(SGR)(two-way ANOVA; P > 0.05). However, during transition from trochophore to veliger stage 20 days after hatching, significant increases in larval survival and growth rates were observed. The maximum survival rate was observed on day 10. The mean survival rate was 0.463, 0.730 and 0.515 at 15℃, and 0.369, 0.713 and 0.444 at 20 when ℃ A. pectinifera, A. amurensis and their mixture were fed, respectively. The SGR and survival rate of the larvae were definitely influenced by the diets(P < 0.05), and the effect of A. amurensis alone was higher than that of A. pectinifera alone and their mixture.
基金supported by the Fundamental Research Funds for the Central Universities(202241002 and 202172002)Science and Technology Innovation Project of Laoshan Laboratory(No.LSKJ202203104)the Young Taishan Scholars Program of Shandong Province(tsqn202103036).
文摘Mollusca is the second-largest animal phylum with over 100,000 extant species representing eight classes.Across 1000 extant species in the class Polyplacophora,chitons have a relatively constrained morphology but with some notable deviations.Several genera possess“shell eyes”,i.e.,true eyes with a lens and retina that are embedded within the dorsal shells.The phylogeny of the major chiton clades is mostly well established,in a set of superfamily-level and higher level taxa supported by various approaches,including morphological studies,multiple gene markers,mitogenome-phylogeny,and phylotranscriptomic approaches.However,one critical lineage has remained unclear,namely Schizochiton which was controversially suggested as being the potential independent origin of chiton shell eyes.Here,with the draft genome sequencing of Schizochiton incisus(superfamily Schizochitonoidea)plus assemblies of transcriptome data from other polyplacophorans,we present phylogenetic reconstructions using both mitochondrial genomes and phylogenomic approaches with multiple methods.We found that phylogenetic trees from mitogenomic data are inconsistent,reflecting larger scale confounding factors in molluscan mitogenomes.However,a consistent and robust topology was generated with protein-coding genes using different models and methods.Our results support Schizochitonoidea as the sister group to other Chitonoidea in Chitonina,in agreement with the established classification.Combined with evidence from fossils,our phylogenetic results suggest that the earliest origin of shell eyes is in Schizochitonoidea,and that these structures were also gained secondarily in other genera in Chitonoidea.Our results have generated a holistic review of the internal relationship within Polyplacophora,and a better understanding of the evolution of Polyplacophora.
文摘Mollusc shell matrix proteins (SMPs) are important functional components embedded in the shell and play a role in shell formation. A SMP (Pif177) was identified previously from the nacreous layer of the Japanese pearl oyster Pinctadafucata, and its cleavage products (named pfPif97 and pfPif80 proteins) were found to bind to the chitin framework and induce aragonite crystal formation and orient the c axis. In this study, a homologue of pfPif177 was cloned from the mantle of the Pacific oyster Crassostrea gigas, containing the homologue of pfPif97 only and not pfPif80. This finding hints at the large divergence in gene structure between the two species. This homologue (cgPif97) shares characteristics with pfPif97, and suggests that the biological functions of these two proteins may be similar. The expression pattern of cgPif97 in different tissues and development stages in- dicates that it may play an important role in shell formation of the adult oyster. The morphology of the inner shell surface was af- fected by injected siRNA of cgPif97 and the calcite laths of the shell became thinner and narrower when the siRNA dose in- creased, suggesting that the cgPip7 gene plays an important role in calcite shell formation in C. gigas. In conclusion, we found evidence that the Pif177 gene evolved very fast but still retains a similar function among species [Current Zoology 59 (1): 109-115, 2013].
文摘The study on trematode larvae found in Egyptian molluscs was initiated by the pioneering work of Sonsino in 1892 and Looss in 1896. Since then tens of cercariae and some digenean life cycles have been reported in the country. Unfortunately, only fragmentary publications are available for identification of cercariae present in the country. In addition, some of such publications may not be accessible to some researchers, as they are either theses or published in old volumes of non-international journals. The present work was carried out with the aim of preserving our heritage through reviewing the different types of cercariae known from the Egyptian inland water snails. We provide a survey based on literature. Major types of cercariae known to exist in the country are covered. They are presented as regards description, development, taxa, importance and snail hosts. This review can be used as a field guide for identification of cercariae colonising the Egyptian inland water snails.