[Objective] The aim is to identify the composition of female sex pheromones of Orthaga achatina and to understand the differential attractiveness of these components to Orthaga achatina moths. [Method] The pheromone g...[Objective] The aim is to identify the composition of female sex pheromones of Orthaga achatina and to understand the differential attractiveness of these components to Orthaga achatina moths. [Method] The pheromone glands of female moths were extracted and analyzed using gas chromatography coupled with mass spectroscopy（GC-MS）; the chemical analysis was confirmed by electroantennogram（EAG） bioassays; a field trial was conducted to confirm the optimized blends. [Result] Z11-16：Ac could elicit the largest EAG responses in male moths at all the doses tested. EAG responses to plant volatiles and to the pheromone isomers of Z11-16：Ac were at a similar level and lower than the responses to Z11-16：Ac. In the field tests, it was demonstrated that synthetic Z11-16：Ac was significantly more attractive to male O. achatina moths, that its pheromone isomers, whether these were presented alone or in mixtures with Z11-16：Ac. [Conclusion]（Z）-11-hexadecenyl acetate（Z11-16：Ac） was identified as the main component of the sex pheromone and it was demonstrated that synthetic Z11-16：Ac was significantly more attractive to male O. achatina moths.展开更多
</span><i><span style="font-family:Verdana;">Achatina</span></i> <i><span style="font-family:Verdana;">togoensis</span></i><span style="...</span><i><span style="font-family:Verdana;">Achatina</span></i> <i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:""><span style="font-family:Verdana;"> is a giant land snail taxa endemic to the northern sectors of the Monts Togo, which has been regarded as full species or subspecies of the highly variable, widespread </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> (L.). To address this issue, samples of snails were taken throughout the distribution range of the two taxa in the Dahomey Gap (West Africa) and separated into 112 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> and 141 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> according to color of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">columella and parietal wall. Radulae were compared and shell characters of these 2 species were evaluated through </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">traditional morphometric method. The results indicate that the species cannot be distinguished by overall shell size and radular morphology, but they exhibit significant differences in shell shape and meristic traits. The typical </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">with vinaceous-red columella</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">has a low-spired shell and an expanded aperture (globose shape) whereas </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> has a higher-spired and smaller aperture (a fusiform shape). We suggest that local environmental effects are probably the causes of morphological divergence between the two taxa. It is likely that peripheral populations of the typical form of </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> would have isolated and developed in the drier facies of the humid forest that individualized in the northern sector of the mountains after the arid or interpluvial period of Holocene. In addition, we find that </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> meets the criteria B2ab</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">(ii, iii) to categorize as “Endangered”. However, whether this latter should be considered as separate species cannot be decided at the current state of knowledge.展开更多
Tropical land snail (Achatina achatina) were collected from three areas viz.Nsit Ibom Local Government Area (NTB), Nsit Ubium Local Government Area (NTU) and Uyo Municipality (UYM), all in Akwa Ibom State to deter...Tropical land snail (Achatina achatina) were collected from three areas viz.Nsit Ibom Local Government Area (NTB), Nsit Ubium Local Government Area (NTU) and Uyo Municipality (UYM), all in Akwa Ibom State to determine the levels of Ni, Pb, Zn and Cr in their shells and muscles. Generally, the levels of all the metals in the muscles were comparatively higher than that in the shells. Correspondingly, the metals appear to have been more stable in the muscles with comparatively lower coefficients of variation than in the shells. Moreover while there was no significant correlation between the levels of all the metals in shells and muscles of NTU samples, Pb and Zn in NTB correlated very significantly. The correlation between levels of Cr in NTB samples and of Zn in UYM samples in shells and muscles were equally significant. On the whole, the levels of these metals were found to be much lower in both shells and muscles of NTU samples obtained from the “enclosed and restricted” environment than in NTB and UYM samples collected randomly from “open and unrestricted” environments.展开更多
This study aimed at exploring for new natural peptides with strong inhibitory capabilities on α-amylase, the main metabolic enzyme that regulates mellitus diabetes, in order to contribute in controlling this global p...This study aimed at exploring for new natural peptides with strong inhibitory capabilities on α-amylase, the main metabolic enzyme that regulates mellitus diabetes, in order to contribute in controlling this global pandemic. It has consisted in heat shock (to 60°C, 70°C, 80°C, 90°C and 100°C for 10, 20 and 30 minutes) of crude proteins extracted from biomass and extracellular parts of Saccharomyces cerevisiae under cultivation, and from the digestive fluid of the giant snail Achatina achatina, and in-vitro assays of the resulting solutions, as effectors, in human α-amylase catalyzing reactions. The results showed that whatever the temperature and time of treatment, an increase (from 2.65 to 3.98-fold) in proteins concentration was noticed. When blended up to 75 microliters in reaction mixtures, the three peptide extracts showed beyond 11% of inhibition of initial α-amylase activity. By reducing samples volume, only 5 microliters of the studied peptide extracts representing 4.70 μg of S. cerevisiae biomass peptides, 0.55 μg of S. cerevisiae extracellular peptides or 1.05 μg of peptides from the digestive fluid A. achatina were quite sufficient to induce complete (100%) inhibition of the human α-amylase activity. Compared to the inhibitory effect obtained from 2.50 μg of acarbose, a renowned antidiabetic, the studied peptide effectors showed more pronounced inhibitory activities. So, we can positively state that S. cerevisiae as well as A. achatina are both capable of synthesizing proteins made up of small inhibitory peptides which deserve purification and structural analysis for potential exploitation as healthy antidiabetic drugs.展开更多
Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African...Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.展开更多
2,4-Dichlorophenoxyacetic (2,4-D), glyphosate, and nicosulfuron, because of their modes of action and selectivity, are the most widely used herbicides in Ivorian horticulture. Fuels toxicity was the reason of many deb...2,4-Dichlorophenoxyacetic (2,4-D), glyphosate, and nicosulfuron, because of their modes of action and selectivity, are the most widely used herbicides in Ivorian horticulture. Fuels toxicity was the reason of many debates in the world because of their massive and uncontrolled use. They are frequently blamed for the reduction of soil fertility and terrestrial biodiversity observed in agricultural areas. In view of the debates raised by their toxicities, the use of these herbicides requires the greatest caution and clear information on the real risk incurred by the edaphic fauna by conducting ecotoxicity studies. The present study aims to evaluate the effect of 2,4-D, glyphosate and nicosulfuron herbicides on the growth and reproduction of Achatina fulica snails in microcosm. To do this, we treated each plot on which snail microcosms were placed with 2,4-D, glyphosate or nicosulfuron herbicides according to the manufacturer’s recommendations. The results showed for all the herbicides used, that after 28 days of exposure, the growth of juvenile snails was slowed down. The number of eggs laid per pair was reduced in adult snails. The egg hatchability test revealed a reduction in egg hatchability. In addition, each effect was dependent on the herbicide used. Thus, toxicity was found to be greater according to the following order: nicosulfuron ? glyphosate ? 2,4-D. From the results obtained, we concluded that 2,4-D, glyphosate, and nicosulfuron treatments under field conditions are a potential threat to the sustainability of snail species and therefore to soil life. The intensity of the effect depends on the toxicity of the herbicides used.展开更多
基金Ningbo Natural Science Foundation(Grant No.201201A6104001)Zhejiang Province Department of Education Research Projects(Grant No.ZWT14048)~~
文摘[Objective] The aim is to identify the composition of female sex pheromones of Orthaga achatina and to understand the differential attractiveness of these components to Orthaga achatina moths. [Method] The pheromone glands of female moths were extracted and analyzed using gas chromatography coupled with mass spectroscopy（GC-MS）; the chemical analysis was confirmed by electroantennogram（EAG） bioassays; a field trial was conducted to confirm the optimized blends. [Result] Z11-16：Ac could elicit the largest EAG responses in male moths at all the doses tested. EAG responses to plant volatiles and to the pheromone isomers of Z11-16：Ac were at a similar level and lower than the responses to Z11-16：Ac. In the field tests, it was demonstrated that synthetic Z11-16：Ac was significantly more attractive to male O. achatina moths, that its pheromone isomers, whether these were presented alone or in mixtures with Z11-16：Ac. [Conclusion]（Z）-11-hexadecenyl acetate（Z11-16：Ac） was identified as the main component of the sex pheromone and it was demonstrated that synthetic Z11-16：Ac was significantly more attractive to male O. achatina moths.
文摘</span><i><span style="font-family:Verdana;">Achatina</span></i> <i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:""><span style="font-family:Verdana;"> is a giant land snail taxa endemic to the northern sectors of the Monts Togo, which has been regarded as full species or subspecies of the highly variable, widespread </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> (L.). To address this issue, samples of snails were taken throughout the distribution range of the two taxa in the Dahomey Gap (West Africa) and separated into 112 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> and 141 </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> according to color of </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">columella and parietal wall. Radulae were compared and shell characters of these 2 species were evaluated through </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">traditional morphometric method. The results indicate that the species cannot be distinguished by overall shell size and radular morphology, but they exhibit significant differences in shell shape and meristic traits. The typical </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">with vinaceous-red columella</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">has a low-spired shell and an expanded aperture (globose shape) whereas </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> has a higher-spired and smaller aperture (a fusiform shape). We suggest that local environmental effects are probably the causes of morphological divergence between the two taxa. It is likely that peripheral populations of the typical form of </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">achatina</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> would have isolated and developed in the drier facies of the humid forest that individualized in the northern sector of the mountains after the arid or interpluvial period of Holocene. In addition, we find that </span><span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">A</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">togoensis</span></i><span style="font-family:Verdana;"></i></span></span><span style="font-family:Verdana;"> meets the criteria B2ab</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">(ii, iii) to categorize as “Endangered”. However, whether this latter should be considered as separate species cannot be decided at the current state of knowledge.
文摘Tropical land snail (Achatina achatina) were collected from three areas viz.Nsit Ibom Local Government Area (NTB), Nsit Ubium Local Government Area (NTU) and Uyo Municipality (UYM), all in Akwa Ibom State to determine the levels of Ni, Pb, Zn and Cr in their shells and muscles. Generally, the levels of all the metals in the muscles were comparatively higher than that in the shells. Correspondingly, the metals appear to have been more stable in the muscles with comparatively lower coefficients of variation than in the shells. Moreover while there was no significant correlation between the levels of all the metals in shells and muscles of NTU samples, Pb and Zn in NTB correlated very significantly. The correlation between levels of Cr in NTB samples and of Zn in UYM samples in shells and muscles were equally significant. On the whole, the levels of these metals were found to be much lower in both shells and muscles of NTU samples obtained from the “enclosed and restricted” environment than in NTB and UYM samples collected randomly from “open and unrestricted” environments.
文摘This study aimed at exploring for new natural peptides with strong inhibitory capabilities on α-amylase, the main metabolic enzyme that regulates mellitus diabetes, in order to contribute in controlling this global pandemic. It has consisted in heat shock (to 60°C, 70°C, 80°C, 90°C and 100°C for 10, 20 and 30 minutes) of crude proteins extracted from biomass and extracellular parts of Saccharomyces cerevisiae under cultivation, and from the digestive fluid of the giant snail Achatina achatina, and in-vitro assays of the resulting solutions, as effectors, in human α-amylase catalyzing reactions. The results showed that whatever the temperature and time of treatment, an increase (from 2.65 to 3.98-fold) in proteins concentration was noticed. When blended up to 75 microliters in reaction mixtures, the three peptide extracts showed beyond 11% of inhibition of initial α-amylase activity. By reducing samples volume, only 5 microliters of the studied peptide extracts representing 4.70 μg of S. cerevisiae biomass peptides, 0.55 μg of S. cerevisiae extracellular peptides or 1.05 μg of peptides from the digestive fluid A. achatina were quite sufficient to induce complete (100%) inhibition of the human α-amylase activity. Compared to the inhibitory effect obtained from 2.50 μg of acarbose, a renowned antidiabetic, the studied peptide effectors showed more pronounced inhibitory activities. So, we can positively state that S. cerevisiae as well as A. achatina are both capable of synthesizing proteins made up of small inhibitory peptides which deserve purification and structural analysis for potential exploitation as healthy antidiabetic drugs.
文摘Fishmeal is the most preferred source of protein in aquafeeds, but it is expensive and scarce. Hence, Achatina fulica meat meal (AFM), which is much less preferred for human consumption out of three species of African giant land snails, was tested as a fishmeal substitute for Clarias gariepinus growth. Five iso-nitrogenous and iso-calorific diets were formulated, in which AFM substituted fish meal at 0% (control or Diet A), 25% (Diet B), 50% (Diet C), 75% (Diet D) and 100% (Diet E). These dietary treatments were each replicated thrice in a completely randomized design experiment, using 36-L plastic tanks in which the fish were fed daily rations corresponding to 5% of their body weight, for 8 weeks. Water quality parameters in the tanks were monitored. Proximate analyses were conducted on the fish meal, snail meal and experimental diets before the feeding trials. Cost-benefit analysis of the different diets was performed. The crude protein content of AFM (69.18%) was significantly higher than that of fish meal (55.81%). There was no significant difference (P > 0.05) in the mean weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio and survival rate in fish fed Diet A and Diet B. The best protein efficiency ratio (0.77) was recorded in fish fed Diet B. Furthermore, the survival rate of fish increased with increased levels of AFM substitution. Water quality parameters were within a suitable range for tropical fish culture, indicating that the AFM did not pollute the water. The fish fed 25% AFM diet significantly (P Clarias gariepinus diets at a 25% substitution level. The aquaculture industry can thus exploit the availability of this feed resource.
文摘2,4-Dichlorophenoxyacetic (2,4-D), glyphosate, and nicosulfuron, because of their modes of action and selectivity, are the most widely used herbicides in Ivorian horticulture. Fuels toxicity was the reason of many debates in the world because of their massive and uncontrolled use. They are frequently blamed for the reduction of soil fertility and terrestrial biodiversity observed in agricultural areas. In view of the debates raised by their toxicities, the use of these herbicides requires the greatest caution and clear information on the real risk incurred by the edaphic fauna by conducting ecotoxicity studies. The present study aims to evaluate the effect of 2,4-D, glyphosate and nicosulfuron herbicides on the growth and reproduction of Achatina fulica snails in microcosm. To do this, we treated each plot on which snail microcosms were placed with 2,4-D, glyphosate or nicosulfuron herbicides according to the manufacturer’s recommendations. The results showed for all the herbicides used, that after 28 days of exposure, the growth of juvenile snails was slowed down. The number of eggs laid per pair was reduced in adult snails. The egg hatchability test revealed a reduction in egg hatchability. In addition, each effect was dependent on the herbicide used. Thus, toxicity was found to be greater according to the following order: nicosulfuron ? glyphosate ? 2,4-D. From the results obtained, we concluded that 2,4-D, glyphosate, and nicosulfuron treatments under field conditions are a potential threat to the sustainability of snail species and therefore to soil life. The intensity of the effect depends on the toxicity of the herbicides used.
