Ibeno, one of the major oil producing communities in South-South Nigeria is a coastal commercial fishery hub that houses Axon-Mobil operational base and pharmaceutical/plastic industries. Shrimp species (Macrobrachium...Ibeno, one of the major oil producing communities in South-South Nigeria is a coastal commercial fishery hub that houses Axon-Mobil operational base and pharmaceutical/plastic industries. Shrimp species (Macrobrachium vollenhovenii) is a major aquatic food frequently consumed by inhabitants of the coastal area and those living hinterland, thus, being a major route of human exposure to 2-methylnaphthalene, phenanthrene and didodecyl phthalate in the area. The purpose of the study was to evaluate factors that determine bioaccumulation and assess the potential cancer and non-cancer risk posed by these contaminants through human (adult and children) exposure via shrimp’s consumption using gas chromatography-mass spectroscopy. The associated sediment showed higher mean concentrations of 2-methylnaphthalene, phenanthrene and didodecylphthalate at the two sites relative to those in fresh shrimp samples and factors such as size, lipid content, physicochemical property and environmental condition influenced the uptake of these contaminants. Besides water loss, the traditional drying process enhanced the levels of phenanthrene and didodecylphthalate in dry shrimps most likely due to combustion process and relatively low volatility, respectively and lowered the level of 2-methylnapthalene linked to its relatively high volatility. The potential of cancer and non-cancer development in human were highest via dry large shrimp consumption and followed the sequence: dry small shrimp > fresh large shrimp > fresh small shrimp and were within the USEPA reference standards. Although children were more vulnerable, the exposed individuals may not exhibit notable health-associated adverse effects in the near future. Thus, adequate advocacy is needed to sensitize those living in the catchments who often prefer dry shrimp in their meals on the adverse health implications of these contaminants for their survival and the need to maintain the health of the ecosystem.展开更多
RATIONALE: Crustaceans, such as shrimp, crab, crayfish and lobster, play important role in human nutrition;they also can be important causes of severe acute hypersensitivity reactions. For patients diagnosed with a cr...RATIONALE: Crustaceans, such as shrimp, crab, crayfish and lobster, play important role in human nutrition;they also can be important causes of severe acute hypersensitivity reactions. For patients diagnosed with a crustacean allergy, strict avoidance is the only proven therapy, highlighting the need for more specific treatment. Our aim was to evaluate the efficacy and tolerance of sublingual shrimp immunotherapy in Egyptian patients allergic to shrimp. METHODS: This study was intended to help in diagnosis of shrimps allergen in 60 allergic patients (subdivided to 3 groups Urticaria (G1), rhinitis (G2) & asthma (G3)) and evaluate the sublingual immunotherapy by employing skin prick test, specific Immunoglobulin E, Total Immunoglobulin E, Immunoglobulin G, Eosinophilis and Peak Expiratory Flow Rate (PEFR), before and after therapy. Inclusion criteria were a history of shrimp allergy and positive skin prick test to crude shrimp extract from two species [Penaeus semisulcatus and Metapenaeus stebbingi] at allergy and clinical immunology unit, in-Shams Hospitals. They underwent immunotherapy with extract of shrimp species and administered sublingually (SLIT). The measurement of all latter investigations for shrimp allergen on the start and 6 months after immunotherapy, as compared to placebo control, were performed. Results: The clinical response and laboratory improvement of the patients was correlated with their decline in the eosinophils (p < 0.001), total Immunoglobulin E (p < 0.001) and specific Immunoglobulin E test (p < 0.001) and with their increased in PEFR (p < 0.001) and Immunoglobulin G (p < 0.001). This study suggests that the most desenstized responsed group was rhinitis group followed by Urticaria group. Also,The more effective season induce allergy in summer (48.3%) followed by springs (28.3%) and genatic predisposition of allergic diseases was highly accepted in patients had a family history (68%). In conclusion, sublingual immunotherapy for shrimp allergy was safe, simple, uncostly, well tolerated and efficacious, gave a good results especially in the treatment of patients with allergic rhinitis.展开更多
Clam shrimps are large bivalved branchiopod crustacean. They first occurred in the Devonian, and flourished during the Mesozoic in Asia. Fossil clam shrimps play an important role in the subdivision and correlation of...Clam shrimps are large bivalved branchiopod crustacean. They first occurred in the Devonian, and flourished during the Mesozoic in Asia. Fossil clam shrimps play an important role in the subdivision and correlation of non-marine fossil-bearing strata. The phosphatized carapaces or carapace external/internal moulds are the main objects for taxonomical studies. The delicate ornament and the ontogenetically developing morphological patterns on the growth bands of carapaces are the main fossil taxonomic criteria. While modern clam shrimp taxonomy is based on soft body morphological features and molecular data, which could not be found in the fossil records. This makes it difficult to discuss the fossil and modern clam shrimp phylogenetic relationship. Nowadays scanning electron microscopes are widely available, and can play an important role in investigating clam shrimp carapace morphology which could be common language to integrate fossil and modern taxonomy.展开更多
The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These t...The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These three species could not be identified during their naupliar stages. In the 1st protozoea,the antennule L1/L2 value is 1.7—2.0 in P.merguiensis,but lessthan 1.7 in P.chinensis and P.penicillatus;in the 2nd protozoea,the supra-orbital spine in P.chinensis isnot bifurcated,while those of P.merguiensis and P.penicillatus are bifurcated;in the 3rd protozoea,thereis a minute(or no)dorso-median spine on the posterior margin of the 1st and 2nd abdominal somite in P.chinensis,but they are prominent in P.merguiensis and P.penicillatus.In the mysis and 1st postlarvalstages,P.chinensis differs from P.merguiensis and P.penicillatus in having 9(8 in the other 2 species)longsetae on the exopod of pereopods 1—3;additionally,one dorsal tooth appears on the rostrum of P.chinensis in the 2nd mysis and that展开更多
Shrimp culture industry in China has been severely constrained by shrimp diseases,causing great economic losses.Controlling shrimp disease through immunological methods has become a research hotspot.This paper summari...Shrimp culture industry in China has been severely constrained by shrimp diseases,causing great economic losses.Controlling shrimp disease through immunological methods has become a research hotspot.This paper summarized the research results of Chinese herbal medicines on improvement of shrimp immunity in recent years,and put forward the research direction of fishery Chinese herbal preparations in the future,in order to provide technical reference for shrimp culture industry.展开更多
Plasmids pG DNA-RZ1 with a GFP (green fluorescent protein) reporter gene and a ribozyme gene incising penaeid white spot baculovirus (WSBV) were first introduced into the fertilized eggs of Chinese shrimps by gene gun...Plasmids pG DNA-RZ1 with a GFP (green fluorescent protein) reporter gene and a ribozyme gene incising penaeid white spot baculovirus (WSBV) were first introduced into the fertilized eggs of Chinese shrimps by gene gun. The treated and control samples of different development stages were observed with a fluorescent microscope. The transient expression of GFP gene was high in nauplius and zoea larvae. Results from RT-PCR and PCR for adults showed that the foreign genes had been transferred into the shrimps and had expressed the corresponding proteins. This work has established a transgenic method for penaeid shrimps, which will set base for the application of genetic engineering breeding into industry.展开更多
Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic value.However,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid ...Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic value.However,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid and massive mortality.etiological research often lags behind the emergence of new diseases,leaving the causal agents of some shrimp diseases unidentified and leading to nomenclature based on symptomatic presentations,especially in cases involving co-and polymicrobial pathogens.Comprehensive data on shrimp disease statuses remain limited.In this review,we summarize current knowledge on shrimp diseases and their effects on the gut microbiome.Furthermore,we also propose a workflow integrating primary colonizers,“driver”taxa in gut networks from healthy to diseased states,disease-discriminatory taxa,and virulence genes to identify potential polymicrobial pathogens.We examine both abiotic and biotic factors(e.g.,external and internal sources and specific-disease effects)that influence shrimp gut microbiota,with an emphasis on the“holobiome”concept and common features of gut microbiota response to diverse diseases.After excluding the effects of confounding factors,we provide a diagnosis model for quantitatively predicting shrimp disease incidence using disease common-discriminatory taxa,irrespective of the causal agents.Due to the conservation of functional genes used in designing specific primers,we propose a practical strategy applying qPCR-assayed abundances of disease common-discriminatory functional genes.This review updates the roles of the gut microbiota in exploring shrimp etiology,polymicrobial pathogens,and disease incidence,offering a refined perspective for advancing shrimp aquaculture health management.展开更多
The Rauer Group is located on the eastern margin of the early Paleozoic Prydz Belt in East Antarctica,and the typical ultrahigh-temperature(UHT,>900℃)granulites outcrop on Mather Peninsula.However,the timing of UH...The Rauer Group is located on the eastern margin of the early Paleozoic Prydz Belt in East Antarctica,and the typical ultrahigh-temperature(UHT,>900℃)granulites outcrop on Mather Peninsula.However,the timing of UHT metamorphism and P–T path of the UHT granulites have long been debated,which is critical to understanding the tectonic nature and evolution history of the Prydz Belt.Thus,both a sapphirine-bearing UHT metapelitic granulite and a garnet-bearing UHT mafic granulite are selected for zircon SHRIMP U-Pb age dating.The results show that metamorphic zircon mantles yield weighted mean^(206)Pb/^(238)U ages of 918±29 Ma and 901±29 Ma for the metapelitic and mafic granulites,respectively,while zircon rims and newly grown zircons yield weighted mean^(206)Pb/^(238)U ages of 523±9 Ma and 532±11 Ma,respectively.These new zircon age data suggest that the UHT granulites may have experienced polymetamorphism,in which pre-peak prograde stage occurred in the early Neoproterozoic Grenvillian orogenesis(1000–900 Ma),whereas the UHT metamorphism occurred in the late Neoproterozoic to early Paleozoic Pan-African orogenesis(580–460 Ma).This implies that P–T path of the UHT granulites should consist of two separate high-grade metamorphic events including the Grenvillian and Pan-African events,which are supposed to be related to assembly of Rodinia and Gondwana supercontinents respectively,and hence the overprinting UHT metamorphic event may actually reflect an important intracontinental reworking.展开更多
The sergestid shrimp Acetes vulgaris has long been an important fishery species in estuaries and coastal waters along the Pang-Rad River, Rayong province, Thailand. In nature, this shrimp feeds on a wide range of food...The sergestid shrimp Acetes vulgaris has long been an important fishery species in estuaries and coastal waters along the Pang-Rad River, Rayong province, Thailand. In nature, this shrimp feeds on a wide range of food items, such as phytoplankton, zooplankton, algae, plant matter, debris, sand, and mud. The objective of this study was to compare different feeds on growth and survival of A. vulgaris reared in fiberglass tanks containing 70 m<sup>3</sup> of seawater salinity 25 ppt over a period of 70 days. Individual shrimps were fed with four different types of feeds i.e., newly hatched Artemia (Ar), rotifer (Ro), newly hatched Artemia + rotifer (ArRo) and shrimp larvae commercial feed (SF). Results suggested that specific growth rates (both for body weight and body length) of shrimps reared with SF were not significantly different with treatment feed with Ar, ArRo and Ro (p ≥ 0.05). The survival rate of A. vulgaris did not vary significantly (p ≥ 0.05) among the Ar, Ro and ArRo treatments. However, the highest survival rate of shrimp (81.78% ± 3.08%) was observed in SF treatment and the percentage of survival rate was significantly different with treatment feed with Ar, Ro and ArRo (p ≤ 0.05). The findings reflected the ability of Acetes shrimps to consume diverse food types including both live feed and pelleted feed. Insights obtained from this research suggested that artificial feed can be as efficient as live feeds. This new knowledge is a needed addition to a currently lacking knowledge base for aquaculture of this Acetes species.展开更多
This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochl...This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochlorine, pyrethroid and organophosphorus families were investigated by gas chromatography, and heavy metals (Cd, Pb, As, Ni, Zn, Fe, Mg, Cr and Hg) by atomic absorption spectrophotometry. The metallic pollution indices, the contamination factor (CF) and the ecological risk index were calculated. The results revealed 8 active ingredients in the rainy season and 9 in the dry season. Glyphosate was the active ingredient with the highest concentration at all stations, 9.65 ± 0.84 mg/kg recorded in the dry season at the Aguigadji station. All glyphosate values were above the EQS. DDT, Atrazine and Endosulfan also showed high concentrations in the dry and rainy seasons. Emamectin, Abamectin and Lambda Cyhalothrin also showed high concentrations in the dry season at Aguigadji, Ahlan and Sele. Only glyphosate was recorded at the control station (Toho), but in very low concentrations. Lead showed the highest concentrations at all the stations, 265.96 ± 21.02 mg/Kg in the rainy season and 255.38 ± 79.09 mg/Kg in the dry season, all detected at the Aguigadji station and above the EQS. Zn, Ni, Fe, Cu and Cr were all representative in both the dry and rainy seasons at the contaminated stations. Manganese showed high concentrations in the rainy season. Pb showed very high contamination (FC ≥ 6) at the Aguigadji and Ahlan stations and significant contamination (3 ≤ FC 6) at the Sele station in both the rainy and dry seasons. Ni, Hg and Cd, showed either moderate or significant contamination at the contaminated stations. The risk values showed a considerable ecological Ri (190 ≤ Ri < 380) in the rainy season and a moderate ecological Ri (95 ≤ Ri < 190) in the dry season at these contaminated stations.展开更多
Objective:To determine growth and reproduction biology of Philocheras trispinosus(P.trispinosus)with abundance of other caridean shrimps caught by beam trawl in the Southern Black Sea.Methods:Samplings were carried ou...Objective:To determine growth and reproduction biology of Philocheras trispinosus(P.trispinosus)with abundance of other caridean shrimps caught by beam trawl in the Southern Black Sea.Methods:Samplings were carried out monthly with a beam trawl of 2 m length and 15 mm cod-end mesh size between December 2012 and November 2013.All individuals were sampled between 1 and 40+m water depth from 146 hauls.Results:A total of 550 P.trispinosus,618 Palaemon adspersus,12 Palaemon serratus,11 Philocheras fasciatus and 10 Crangon crangon were sampled during the study period.The crangonid shrimps started appearing during the winter and spring and the number of individuals increased to reach their highest value in mid-winter and mid-spring.The seasonal von Bertalanffy growth parameters for P.trispinosus were estimated as L_(∞)=29.3 mm total length,K=0.860/year,t_(0)=–0.900 year,C=0.180,and t_(s)=0.010.The start of the slow growth period was at the beginning of July(WP=0.510).Ovigerous females appeared in the sampling area between January and April.Size at sexual maturity was estimated as 25.69 mm total length.Conclusions:The results supported the distribution and abundance of caridean shrimp species from the study area and the population dynamics of the most abundant shrimp species,P.trispinosus.The current study can be answered as baseline data prior to management strategies to ensure sustainable conservation of the shrimp species.展开更多
The brine shrimp, Artemia salina, is affiliated with a lineage of Arthropoda-class Crustacea-subclass Branchiopodaorder Anostraca-family Arlemiidae. The individuals, 10 to 11 mm long for male but slightly longer for f...The brine shrimp, Artemia salina, is affiliated with a lineage of Arthropoda-class Crustacea-subclass Branchiopodaorder Anostraca-family Arlemiidae. The individuals, 10 to 11 mm long for male but slightly longer for female, show a striking adaptation to high-salinity waters and salt pans, for example, in Great Salt Lake of the U. S. A., a num-展开更多
文摘Ibeno, one of the major oil producing communities in South-South Nigeria is a coastal commercial fishery hub that houses Axon-Mobil operational base and pharmaceutical/plastic industries. Shrimp species (Macrobrachium vollenhovenii) is a major aquatic food frequently consumed by inhabitants of the coastal area and those living hinterland, thus, being a major route of human exposure to 2-methylnaphthalene, phenanthrene and didodecyl phthalate in the area. The purpose of the study was to evaluate factors that determine bioaccumulation and assess the potential cancer and non-cancer risk posed by these contaminants through human (adult and children) exposure via shrimp’s consumption using gas chromatography-mass spectroscopy. The associated sediment showed higher mean concentrations of 2-methylnaphthalene, phenanthrene and didodecylphthalate at the two sites relative to those in fresh shrimp samples and factors such as size, lipid content, physicochemical property and environmental condition influenced the uptake of these contaminants. Besides water loss, the traditional drying process enhanced the levels of phenanthrene and didodecylphthalate in dry shrimps most likely due to combustion process and relatively low volatility, respectively and lowered the level of 2-methylnapthalene linked to its relatively high volatility. The potential of cancer and non-cancer development in human were highest via dry large shrimp consumption and followed the sequence: dry small shrimp > fresh large shrimp > fresh small shrimp and were within the USEPA reference standards. Although children were more vulnerable, the exposed individuals may not exhibit notable health-associated adverse effects in the near future. Thus, adequate advocacy is needed to sensitize those living in the catchments who often prefer dry shrimp in their meals on the adverse health implications of these contaminants for their survival and the need to maintain the health of the ecosystem.
文摘RATIONALE: Crustaceans, such as shrimp, crab, crayfish and lobster, play important role in human nutrition;they also can be important causes of severe acute hypersensitivity reactions. For patients diagnosed with a crustacean allergy, strict avoidance is the only proven therapy, highlighting the need for more specific treatment. Our aim was to evaluate the efficacy and tolerance of sublingual shrimp immunotherapy in Egyptian patients allergic to shrimp. METHODS: This study was intended to help in diagnosis of shrimps allergen in 60 allergic patients (subdivided to 3 groups Urticaria (G1), rhinitis (G2) & asthma (G3)) and evaluate the sublingual immunotherapy by employing skin prick test, specific Immunoglobulin E, Total Immunoglobulin E, Immunoglobulin G, Eosinophilis and Peak Expiratory Flow Rate (PEFR), before and after therapy. Inclusion criteria were a history of shrimp allergy and positive skin prick test to crude shrimp extract from two species [Penaeus semisulcatus and Metapenaeus stebbingi] at allergy and clinical immunology unit, in-Shams Hospitals. They underwent immunotherapy with extract of shrimp species and administered sublingually (SLIT). The measurement of all latter investigations for shrimp allergen on the start and 6 months after immunotherapy, as compared to placebo control, were performed. Results: The clinical response and laboratory improvement of the patients was correlated with their decline in the eosinophils (p < 0.001), total Immunoglobulin E (p < 0.001) and specific Immunoglobulin E test (p < 0.001) and with their increased in PEFR (p < 0.001) and Immunoglobulin G (p < 0.001). This study suggests that the most desenstized responsed group was rhinitis group followed by Urticaria group. Also,The more effective season induce allergy in summer (48.3%) followed by springs (28.3%) and genatic predisposition of allergic diseases was highly accepted in patients had a family history (68%). In conclusion, sublingual immunotherapy for shrimp allergy was safe, simple, uncostly, well tolerated and efficacious, gave a good results especially in the treatment of patients with allergic rhinitis.
文摘Clam shrimps are large bivalved branchiopod crustacean. They first occurred in the Devonian, and flourished during the Mesozoic in Asia. Fossil clam shrimps play an important role in the subdivision and correlation of non-marine fossil-bearing strata. The phosphatized carapaces or carapace external/internal moulds are the main objects for taxonomical studies. The delicate ornament and the ontogenetically developing morphological patterns on the growth bands of carapaces are the main fossil taxonomic criteria. While modern clam shrimp taxonomy is based on soft body morphological features and molecular data, which could not be found in the fossil records. This makes it difficult to discuss the fossil and modern clam shrimp phylogenetic relationship. Nowadays scanning electron microscopes are widely available, and can play an important role in investigating clam shrimp carapace morphology which could be common language to integrate fossil and modern taxonomy.
文摘The morphology of larval and 1st postlarval stages of Penaeus penicillatus are described.Results from comparative studies on larval development of P.penicillatus,P.merguiensis and P.chinensis are as fol-lows: These three species could not be identified during their naupliar stages. In the 1st protozoea,the antennule L1/L2 value is 1.7—2.0 in P.merguiensis,but lessthan 1.7 in P.chinensis and P.penicillatus;in the 2nd protozoea,the supra-orbital spine in P.chinensis isnot bifurcated,while those of P.merguiensis and P.penicillatus are bifurcated;in the 3rd protozoea,thereis a minute(or no)dorso-median spine on the posterior margin of the 1st and 2nd abdominal somite in P.chinensis,but they are prominent in P.merguiensis and P.penicillatus.In the mysis and 1st postlarvalstages,P.chinensis differs from P.merguiensis and P.penicillatus in having 9(8 in the other 2 species)longsetae on the exopod of pereopods 1—3;additionally,one dorsal tooth appears on the rostrum of P.chinensis in the 2nd mysis and that
基金Supported by Open Fund of Jiangsu Key Laboratory of Marine Biotechnology(2014HS012)Qing Lan Project for Talent Training in Colleges and Universities in Jiangsu ProvinceUniversity-level Research Project of Jiangsu Agri-animal Husbandry Vocational College
文摘Shrimp culture industry in China has been severely constrained by shrimp diseases,causing great economic losses.Controlling shrimp disease through immunological methods has become a research hotspot.This paper summarized the research results of Chinese herbal medicines on improvement of shrimp immunity in recent years,and put forward the research direction of fishery Chinese herbal preparations in the future,in order to provide technical reference for shrimp culture industry.
基金This work was supported by the National Marine Hi-Tech "863" Project (Grant No. 819-04-08-98) and the "973" Project (Grant No. G1999012007).
文摘Plasmids pG DNA-RZ1 with a GFP (green fluorescent protein) reporter gene and a ribozyme gene incising penaeid white spot baculovirus (WSBV) were first introduced into the fertilized eggs of Chinese shrimps by gene gun. The treated and control samples of different development stages were observed with a fluorescent microscope. The transient expression of GFP gene was high in nauplius and zoea larvae. Results from RT-PCR and PCR for adults showed that the foreign genes had been transferred into the shrimps and had expressed the corresponding proteins. This work has established a transgenic method for penaeid shrimps, which will set base for the application of genetic engineering breeding into industry.
基金National Natural Science Foundation of China(32371596,32071549)Key Research and Development Project of Zhejiang Province(2021C02062)+2 种基金Key Scientific and Technological Grant of Zhejiang for Breeding New Agricultural Varieties(2021C02069-5-2)Key Project of Ningbo Science and Technology Bureau(2023S003)One Health Interdisciplinary Research Project of Ningbo University(HZ202404)。
文摘Litopenaeus vannamei is the most extensively cultured shrimp species globally,recognized for its scale,production,and economic value.However,its aquaculture is plagued by frequent disease outbreaks,resulting in rapid and massive mortality.etiological research often lags behind the emergence of new diseases,leaving the causal agents of some shrimp diseases unidentified and leading to nomenclature based on symptomatic presentations,especially in cases involving co-and polymicrobial pathogens.Comprehensive data on shrimp disease statuses remain limited.In this review,we summarize current knowledge on shrimp diseases and their effects on the gut microbiome.Furthermore,we also propose a workflow integrating primary colonizers,“driver”taxa in gut networks from healthy to diseased states,disease-discriminatory taxa,and virulence genes to identify potential polymicrobial pathogens.We examine both abiotic and biotic factors(e.g.,external and internal sources and specific-disease effects)that influence shrimp gut microbiota,with an emphasis on the“holobiome”concept and common features of gut microbiota response to diverse diseases.After excluding the effects of confounding factors,we provide a diagnosis model for quantitatively predicting shrimp disease incidence using disease common-discriminatory taxa,irrespective of the causal agents.Due to the conservation of functional genes used in designing specific primers,we propose a practical strategy applying qPCR-assayed abundances of disease common-discriminatory functional genes.This review updates the roles of the gut microbiota in exploring shrimp etiology,polymicrobial pathogens,and disease incidence,offering a refined perspective for advancing shrimp aquaculture health management.
基金supported by the National Nature Science Foundation of China(Grant no.41972050).
文摘The Rauer Group is located on the eastern margin of the early Paleozoic Prydz Belt in East Antarctica,and the typical ultrahigh-temperature(UHT,>900℃)granulites outcrop on Mather Peninsula.However,the timing of UHT metamorphism and P–T path of the UHT granulites have long been debated,which is critical to understanding the tectonic nature and evolution history of the Prydz Belt.Thus,both a sapphirine-bearing UHT metapelitic granulite and a garnet-bearing UHT mafic granulite are selected for zircon SHRIMP U-Pb age dating.The results show that metamorphic zircon mantles yield weighted mean^(206)Pb/^(238)U ages of 918±29 Ma and 901±29 Ma for the metapelitic and mafic granulites,respectively,while zircon rims and newly grown zircons yield weighted mean^(206)Pb/^(238)U ages of 523±9 Ma and 532±11 Ma,respectively.These new zircon age data suggest that the UHT granulites may have experienced polymetamorphism,in which pre-peak prograde stage occurred in the early Neoproterozoic Grenvillian orogenesis(1000–900 Ma),whereas the UHT metamorphism occurred in the late Neoproterozoic to early Paleozoic Pan-African orogenesis(580–460 Ma).This implies that P–T path of the UHT granulites should consist of two separate high-grade metamorphic events including the Grenvillian and Pan-African events,which are supposed to be related to assembly of Rodinia and Gondwana supercontinents respectively,and hence the overprinting UHT metamorphic event may actually reflect an important intracontinental reworking.
文摘The sergestid shrimp Acetes vulgaris has long been an important fishery species in estuaries and coastal waters along the Pang-Rad River, Rayong province, Thailand. In nature, this shrimp feeds on a wide range of food items, such as phytoplankton, zooplankton, algae, plant matter, debris, sand, and mud. The objective of this study was to compare different feeds on growth and survival of A. vulgaris reared in fiberglass tanks containing 70 m<sup>3</sup> of seawater salinity 25 ppt over a period of 70 days. Individual shrimps were fed with four different types of feeds i.e., newly hatched Artemia (Ar), rotifer (Ro), newly hatched Artemia + rotifer (ArRo) and shrimp larvae commercial feed (SF). Results suggested that specific growth rates (both for body weight and body length) of shrimps reared with SF were not significantly different with treatment feed with Ar, ArRo and Ro (p ≥ 0.05). The survival rate of A. vulgaris did not vary significantly (p ≥ 0.05) among the Ar, Ro and ArRo treatments. However, the highest survival rate of shrimp (81.78% ± 3.08%) was observed in SF treatment and the percentage of survival rate was significantly different with treatment feed with Ar, Ro and ArRo (p ≤ 0.05). The findings reflected the ability of Acetes shrimps to consume diverse food types including both live feed and pelleted feed. Insights obtained from this research suggested that artificial feed can be as efficient as live feeds. This new knowledge is a needed addition to a currently lacking knowledge base for aquaculture of this Acetes species.
文摘This study assessed sediment contamination by heavy metals and pesticide active ingredients linked to chemical inputs used in agricultural activities in the lower Ouémé. Pesticide residues from the organochlorine, pyrethroid and organophosphorus families were investigated by gas chromatography, and heavy metals (Cd, Pb, As, Ni, Zn, Fe, Mg, Cr and Hg) by atomic absorption spectrophotometry. The metallic pollution indices, the contamination factor (CF) and the ecological risk index were calculated. The results revealed 8 active ingredients in the rainy season and 9 in the dry season. Glyphosate was the active ingredient with the highest concentration at all stations, 9.65 ± 0.84 mg/kg recorded in the dry season at the Aguigadji station. All glyphosate values were above the EQS. DDT, Atrazine and Endosulfan also showed high concentrations in the dry and rainy seasons. Emamectin, Abamectin and Lambda Cyhalothrin also showed high concentrations in the dry season at Aguigadji, Ahlan and Sele. Only glyphosate was recorded at the control station (Toho), but in very low concentrations. Lead showed the highest concentrations at all the stations, 265.96 ± 21.02 mg/Kg in the rainy season and 255.38 ± 79.09 mg/Kg in the dry season, all detected at the Aguigadji station and above the EQS. Zn, Ni, Fe, Cu and Cr were all representative in both the dry and rainy seasons at the contaminated stations. Manganese showed high concentrations in the rainy season. Pb showed very high contamination (FC ≥ 6) at the Aguigadji and Ahlan stations and significant contamination (3 ≤ FC 6) at the Sele station in both the rainy and dry seasons. Ni, Hg and Cd, showed either moderate or significant contamination at the contaminated stations. The risk values showed a considerable ecological Ri (190 ≤ Ri < 380) in the rainy season and a moderate ecological Ri (95 ≤ Ri < 190) in the dry season at these contaminated stations.
基金Supported by Recep Tayyip Erdoğan University with project number 2013.103.03.01.
文摘Objective:To determine growth and reproduction biology of Philocheras trispinosus(P.trispinosus)with abundance of other caridean shrimps caught by beam trawl in the Southern Black Sea.Methods:Samplings were carried out monthly with a beam trawl of 2 m length and 15 mm cod-end mesh size between December 2012 and November 2013.All individuals were sampled between 1 and 40+m water depth from 146 hauls.Results:A total of 550 P.trispinosus,618 Palaemon adspersus,12 Palaemon serratus,11 Philocheras fasciatus and 10 Crangon crangon were sampled during the study period.The crangonid shrimps started appearing during the winter and spring and the number of individuals increased to reach their highest value in mid-winter and mid-spring.The seasonal von Bertalanffy growth parameters for P.trispinosus were estimated as L_(∞)=29.3 mm total length,K=0.860/year,t_(0)=–0.900 year,C=0.180,and t_(s)=0.010.The start of the slow growth period was at the beginning of July(WP=0.510).Ovigerous females appeared in the sampling area between January and April.Size at sexual maturity was estimated as 25.69 mm total length.Conclusions:The results supported the distribution and abundance of caridean shrimp species from the study area and the population dynamics of the most abundant shrimp species,P.trispinosus.The current study can be answered as baseline data prior to management strategies to ensure sustainable conservation of the shrimp species.
文摘The brine shrimp, Artemia salina, is affiliated with a lineage of Arthropoda-class Crustacea-subclass Branchiopodaorder Anostraca-family Arlemiidae. The individuals, 10 to 11 mm long for male but slightly longer for female, show a striking adaptation to high-salinity waters and salt pans, for example, in Great Salt Lake of the U. S. A., a num-
