Objective:To evaluate the antimicrobial activity of Turbinaria conoides(T.conoides).Padina gymnospora(P.gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.Methods:The antimicrobial activ...Objective:To evaluate the antimicrobial activity of Turbinaria conoides(T.conoides).Padina gymnospora(P.gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.Methods:The antimicrobial activities of the extracts against various organisms were tested by using disc diffusion method.Results:The methanol extract showed the better result than the other extracts.Whereas,the strong antibacterial inhibition was noted in methanol extracts of P.gymnospora against Bacillus subtilus(26.33±1.86) and the mild inhibition of ethanol extracts from T.conoides against Klebsiella pneumoniae(2.33±0.51).Acetone extraction of P. gymnospora had strong antifungal inhibition against Cryptococcus neoformans(23.00±1.78), and acetone extract of T.conoides had mild inhibition against Aspergillus niger(3.00±0.89). Conclusions:The seven different solvent extracts of seaweeds used in the present study have shown significant bacterial action.Further,a detailed study on the principle compound in the seaweeds which is responsible for antimicrobial activity is still needed and it can be achieved by using advanced separation techniques.展开更多
The present study revealed proliferation of macro-algae modifying coral reef ecosystems in a different manner due to diseases and sedimentations in the Mandapam group of islands in the Gulf of Mannar. Benthic surveys ...The present study revealed proliferation of macro-algae modifying coral reef ecosystems in a different manner due to diseases and sedimentations in the Mandapam group of islands in the Gulf of Mannar. Benthic surveys were conducted with major attack of seven coral reefs diseases with high sedimentation rate, nine species of fleshy macro-algae(Turbinaria ornata, Turbinaria conaides, Caulerpa scalpelliformis, Caulerpa racemosa, Kappaphycus alvarezii, Padina gymnosphora, Sargassum wightii, Ulva reticulata and Calurpa lentillifera) proliferation against major corals life forms(Acropora branching, Acropora digitate, Acropora tabulate, coral massive, coral submassive, coral foliose and coral encrusting). The results confirm that diseased corals most favor to macro-algae growth(15.27%) rather than the sedimentation covered corals(8.24 %). In the degradation of coral life forms, massive corals were more highly damaged(7.05%) than any other forms. Within a short period of time(May to September), coral coverage shrank to 17.4% from 21.9%, macro-algae increased 23.51% and the average sedimentation rate attained 77.52 mg cm^(-2) d^(-1) with persisting coral reef diseases of 17.59%. The Pearson correlation showed that the coral cover decreased with increasing macro-algae growth, which was statistically significant(r =-0.774, n = 100, P < 0.0005). The proliferation of the various macro-algae C. scalpellifrmis, T. ornata, C. racemosa, T. conaides, U. reticulata, S. wightii, K. alvarezii, P. gymnosphora and C. lentillifera increased with percentages of 6.0, 5.8, 5.7, 4.9, 4.2, 3.7, 2.7 and 1.9, respectively. If this trend continues, the next generation of new recruit corals will undoubtedly lead to a phase shift in Gulf of Mannar corals.展开更多
In this research,an Underwater Biofouling Panel(UWBFP)system was erected for the qualitative and quantitative estimation of macro fouling organisms in the Gulf of Mannar.Forty-four biofoulers were identified from four...In this research,an Underwater Biofouling Panel(UWBFP)system was erected for the qualitative and quantitative estimation of macro fouling organisms in the Gulf of Mannar.Forty-four biofoulers were identified from four types of selected test panels.Among these biofoulers,Amphibalanus amphitrite(Darwin,1854)was the dominant one.The concrete panel encouraged the highest barnacle density compared to the other panels.Three series of test panels were used to assess the seasonal density of biofouling communities.The overall variation in barnacle count in the seaward and shoreward sides of all these three series were tested.They were found to be significantly different from each other.The greater variations in the barnacle density observed in this study in A-series of test panels could be due to the lack of or absence of other foulers to compete within the fortnight.The Shannon-Wiener species diversity index showed the highest diversity in wood substratum among the three series with greater accumulation of different types of fouling organisms.Multivariate analyses were also performed to understand the seasonal variation as well as the settlement pattern on the different directions of test panels based on validated data.PCA showed a strong variability(PC1 between 70.8%and 98.6%variance)between the directions of the panels in connection with barnacle density.The shade plot and CAP analysis segregated the short-term A-series test panels from the long-term(B-and C-series)test panels.Hence,the output was helpful in understanding the recruitment status of various faunal resources involved in the biofouling processes.展开更多
Gulf of Mannar Marine Biosphere Reserve (GOMMBRE) is the first marine biosphere reserve in India and Southeast Asia. It has a rich marine biodiversity including coral reefs, but now facing threats from different envir...Gulf of Mannar Marine Biosphere Reserve (GOMMBRE) is the first marine biosphere reserve in India and Southeast Asia. It has a rich marine biodiversity including coral reefs, but now facing threats from different environmental factors and anthropogenic interferences. Particularly, coral reefs distributed in the 21 islands under the Gulf of Mannar (GoM) region are facing critical threats. Although several institutions and authors have studied various aspects on corals, direct and indirect influences of natural and anthropogenic catastrophes on corals have been poorly understood. Therefore, the main objective of this study was to identify the anthropogenic disturbances, biological stress factors and diseases on fringing reefs of GoM. The present study reveals that dead coral reefs are being replaced by assemblage of marine algae. Although several diseases were recorded during this study, pink line disease is wide spread in all the islands. Porites sp. and Acropora sp. were the more affected corals. This baseline data lays foundations to survey and to assess the rapid changes that occur over a period of time in coral reefs of GoM.展开更多
Coral reefs in the Gulf of Mannar(GoM)and Palk Bay regions are facing potential threats from climate change,sedimentation and anthropogenic activities.Considerably,coral reefs in these two regions are highly damaged d...Coral reefs in the Gulf of Mannar(GoM)and Palk Bay regions are facing potential threats from climate change,sedimentation and anthropogenic activities.Considerably,coral reefs in these two regions are highly damaged due to frequent bleaching events caused by increased sea surface temperature(SST)recorded over the past two decades.Recently,during February to May 2019,mass bleaching event of corals was documented again in GoM and Palk Bay regions due to increased sea surface temperatures ranged between 32°C to 36°C.Despite of completely bleached corals,some coral colonies of the same bleached coral species have displayed adaptive bleaching pattern(ABP)for survival.This incidence is displayed by the symbiotic zooxanthellae to protect coral polyps from environmental stress such as elevated temperatures.These observations infer that coral colonies with preferential bleaching pattern ability would serve as environmental stress resisting coral colonies which can be used for restoration activities and cryopreservation.Further studies are needed to explain the potential mechanisms or specific environmental drivers responsible for ABP.展开更多
Objective:To analyse the economically important gastropods for prospective antimicrobial,antioxidant and cytotoxic activities from the Gulf of Mannar region,southeast coast of India.Methods:The bioactive potential of ...Objective:To analyse the economically important gastropods for prospective antimicrobial,antioxidant and cytotoxic activities from the Gulf of Mannar region,southeast coast of India.Methods:The bioactive potential of some gastropods i.e.Babylonia spirata(B.spirata),Phalium glaucum,Tonna dolium,Hemifusus pugilinus,Xancus pyrum,Chicoreus ramosus(C.ramosus),Harpa articularis,Ficus ficus and Babylonia zeylanica were analysed.Antimicrobial activity was carried out against 8 human pathogenic bacteria and 3 fungal strains by well diffusion method.Antioxidant and cytotoxic activities were analyzed by standard methods.Results:In antibacterial and antifungal activities,methanolic extract of B.spirata significantly showed the highest inhibition zone against Aeromonas hydrophila and Fusarium spp.(P>0.05).In the total antioxidant activity,the maximum activity was observed in B.spirata(510μg/mg)and in the 1.1-diphenyl-2-picrylhydrazyl scavenging activity,B.spirata showed the highest percentage of inhibition(76.7%).In the case of cytotoxicity i.e.brine shrimp lethality tests the methanolic extract of C.ramosus showed the lowest percentage of mortality and the LC50 values were found to be 523.9μg/mL.Conclusions:The results revealed that all the gastropods in the present study possessed antimicrobial,antioxidant and cytotoxic effects.However,species like B.spirata and C.ramosus exhibited potent activity and can be used for further clinical studies.展开更多
Objective:To signify the economic importance of molluscan-gastropod food by estimating its biochemical composition.Methods:Samples were collected from the trawl net bycatch at the fish landing center of Mandapam coast...Objective:To signify the economic importance of molluscan-gastropod food by estimating its biochemical composition.Methods:Samples were collected from the trawl net bycatch at the fish landing center of Mandapam coast of the Gulf of Mannar region.The total protein,carbohydrate,lipid,ash and moisture contents were estimated from nine gastropods i.e.Phalium glaucum,Tonna dolium,Hemifusus pugilinus,Babylonia spirata,Xancus pyrum,Chicoreus ramosus,Harpa articularis,Ficus ficus and Babylonia zeylanica.Results:The percentages of protein(41.2%),carbohydrate(17.5%)and lipid(6.6%)contents were found highest in Babylonia spirata,followed by other gastropods.The maximum ash content was observed in Chicoreus ramosus(1.21%)and the maximum moisture content was observed in Phalium glaucum(83.71%).Conclusions:The results show that all the nine gastropods contain good sources of protein and other biochemical constituents and can be used for edible purposes to prevent starvation.展开更多
基金Supported by University Grants Commission,New Delhi.India
文摘Objective:To evaluate the antimicrobial activity of Turbinaria conoides(T.conoides).Padina gymnospora(P.gymnospora) and Sargassum tenerrimum against human bacterial and fungal pathogens.Methods:The antimicrobial activities of the extracts against various organisms were tested by using disc diffusion method.Results:The methanol extract showed the better result than the other extracts.Whereas,the strong antibacterial inhibition was noted in methanol extracts of P.gymnospora against Bacillus subtilus(26.33±1.86) and the mild inhibition of ethanol extracts from T.conoides against Klebsiella pneumoniae(2.33±0.51).Acetone extraction of P. gymnospora had strong antifungal inhibition against Cryptococcus neoformans(23.00±1.78), and acetone extract of T.conoides had mild inhibition against Aspergillus niger(3.00±0.89). Conclusions:The seven different solvent extracts of seaweeds used in the present study have shown significant bacterial action.Further,a detailed study on the principle compound in the seaweeds which is responsible for antimicrobial activity is still needed and it can be achieved by using advanced separation techniques.
基金the National Remote Sensing Center, ISRO-Hyderabad for providing financial supports
文摘The present study revealed proliferation of macro-algae modifying coral reef ecosystems in a different manner due to diseases and sedimentations in the Mandapam group of islands in the Gulf of Mannar. Benthic surveys were conducted with major attack of seven coral reefs diseases with high sedimentation rate, nine species of fleshy macro-algae(Turbinaria ornata, Turbinaria conaides, Caulerpa scalpelliformis, Caulerpa racemosa, Kappaphycus alvarezii, Padina gymnosphora, Sargassum wightii, Ulva reticulata and Calurpa lentillifera) proliferation against major corals life forms(Acropora branching, Acropora digitate, Acropora tabulate, coral massive, coral submassive, coral foliose and coral encrusting). The results confirm that diseased corals most favor to macro-algae growth(15.27%) rather than the sedimentation covered corals(8.24 %). In the degradation of coral life forms, massive corals were more highly damaged(7.05%) than any other forms. Within a short period of time(May to September), coral coverage shrank to 17.4% from 21.9%, macro-algae increased 23.51% and the average sedimentation rate attained 77.52 mg cm^(-2) d^(-1) with persisting coral reef diseases of 17.59%. The Pearson correlation showed that the coral cover decreased with increasing macro-algae growth, which was statistically significant(r =-0.774, n = 100, P < 0.0005). The proliferation of the various macro-algae C. scalpellifrmis, T. ornata, C. racemosa, T. conaides, U. reticulata, S. wightii, K. alvarezii, P. gymnosphora and C. lentillifera increased with percentages of 6.0, 5.8, 5.7, 4.9, 4.2, 3.7, 2.7 and 1.9, respectively. If this trend continues, the next generation of new recruit corals will undoubtedly lead to a phase shift in Gulf of Mannar corals.
基金supported by the government of India through DOD-OSTC program entitled‘Biofouling and Antifouling Organisms in the Gulf of Mannar,Southeast Coast of India’(No.DOD/11-MRDF/4/11/UNI/97/P-15)funding by the Department of Ocean Development(Ministry of Earth Sciences,Government of India)through project(No.DOD/11-MRDF/4/11/UNI/97/P-15)。
文摘In this research,an Underwater Biofouling Panel(UWBFP)system was erected for the qualitative and quantitative estimation of macro fouling organisms in the Gulf of Mannar.Forty-four biofoulers were identified from four types of selected test panels.Among these biofoulers,Amphibalanus amphitrite(Darwin,1854)was the dominant one.The concrete panel encouraged the highest barnacle density compared to the other panels.Three series of test panels were used to assess the seasonal density of biofouling communities.The overall variation in barnacle count in the seaward and shoreward sides of all these three series were tested.They were found to be significantly different from each other.The greater variations in the barnacle density observed in this study in A-series of test panels could be due to the lack of or absence of other foulers to compete within the fortnight.The Shannon-Wiener species diversity index showed the highest diversity in wood substratum among the three series with greater accumulation of different types of fouling organisms.Multivariate analyses were also performed to understand the seasonal variation as well as the settlement pattern on the different directions of test panels based on validated data.PCA showed a strong variability(PC1 between 70.8%and 98.6%variance)between the directions of the panels in connection with barnacle density.The shade plot and CAP analysis segregated the short-term A-series test panels from the long-term(B-and C-series)test panels.Hence,the output was helpful in understanding the recruitment status of various faunal resources involved in the biofouling processes.
文摘Gulf of Mannar Marine Biosphere Reserve (GOMMBRE) is the first marine biosphere reserve in India and Southeast Asia. It has a rich marine biodiversity including coral reefs, but now facing threats from different environmental factors and anthropogenic interferences. Particularly, coral reefs distributed in the 21 islands under the Gulf of Mannar (GoM) region are facing critical threats. Although several institutions and authors have studied various aspects on corals, direct and indirect influences of natural and anthropogenic catastrophes on corals have been poorly understood. Therefore, the main objective of this study was to identify the anthropogenic disturbances, biological stress factors and diseases on fringing reefs of GoM. The present study reveals that dead coral reefs are being replaced by assemblage of marine algae. Although several diseases were recorded during this study, pink line disease is wide spread in all the islands. Porites sp. and Acropora sp. were the more affected corals. This baseline data lays foundations to survey and to assess the rapid changes that occur over a period of time in coral reefs of GoM.
文摘Coral reefs in the Gulf of Mannar(GoM)and Palk Bay regions are facing potential threats from climate change,sedimentation and anthropogenic activities.Considerably,coral reefs in these two regions are highly damaged due to frequent bleaching events caused by increased sea surface temperature(SST)recorded over the past two decades.Recently,during February to May 2019,mass bleaching event of corals was documented again in GoM and Palk Bay regions due to increased sea surface temperatures ranged between 32°C to 36°C.Despite of completely bleached corals,some coral colonies of the same bleached coral species have displayed adaptive bleaching pattern(ABP)for survival.This incidence is displayed by the symbiotic zooxanthellae to protect coral polyps from environmental stress such as elevated temperatures.These observations infer that coral colonies with preferential bleaching pattern ability would serve as environmental stress resisting coral colonies which can be used for restoration activities and cryopreservation.Further studies are needed to explain the potential mechanisms or specific environmental drivers responsible for ABP.
基金Supported by UGC for BSR fellowship(Grant No.02.09.2013/4-1/2008(BSR)/Dt24.11.2009).
文摘Objective:To analyse the economically important gastropods for prospective antimicrobial,antioxidant and cytotoxic activities from the Gulf of Mannar region,southeast coast of India.Methods:The bioactive potential of some gastropods i.e.Babylonia spirata(B.spirata),Phalium glaucum,Tonna dolium,Hemifusus pugilinus,Xancus pyrum,Chicoreus ramosus(C.ramosus),Harpa articularis,Ficus ficus and Babylonia zeylanica were analysed.Antimicrobial activity was carried out against 8 human pathogenic bacteria and 3 fungal strains by well diffusion method.Antioxidant and cytotoxic activities were analyzed by standard methods.Results:In antibacterial and antifungal activities,methanolic extract of B.spirata significantly showed the highest inhibition zone against Aeromonas hydrophila and Fusarium spp.(P>0.05).In the total antioxidant activity,the maximum activity was observed in B.spirata(510μg/mg)and in the 1.1-diphenyl-2-picrylhydrazyl scavenging activity,B.spirata showed the highest percentage of inhibition(76.7%).In the case of cytotoxicity i.e.brine shrimp lethality tests the methanolic extract of C.ramosus showed the lowest percentage of mortality and the LC50 values were found to be 523.9μg/mL.Conclusions:The results revealed that all the gastropods in the present study possessed antimicrobial,antioxidant and cytotoxic effects.However,species like B.spirata and C.ramosus exhibited potent activity and can be used for further clinical studies.
基金Supported by UGC for BSR fellowship(Grant No.02.09.2013/4-1/2008(BSR)/Dt 24.11.2009).
文摘Objective:To signify the economic importance of molluscan-gastropod food by estimating its biochemical composition.Methods:Samples were collected from the trawl net bycatch at the fish landing center of Mandapam coast of the Gulf of Mannar region.The total protein,carbohydrate,lipid,ash and moisture contents were estimated from nine gastropods i.e.Phalium glaucum,Tonna dolium,Hemifusus pugilinus,Babylonia spirata,Xancus pyrum,Chicoreus ramosus,Harpa articularis,Ficus ficus and Babylonia zeylanica.Results:The percentages of protein(41.2%),carbohydrate(17.5%)and lipid(6.6%)contents were found highest in Babylonia spirata,followed by other gastropods.The maximum ash content was observed in Chicoreus ramosus(1.21%)and the maximum moisture content was observed in Phalium glaucum(83.71%).Conclusions:The results show that all the nine gastropods contain good sources of protein and other biochemical constituents and can be used for edible purposes to prevent starvation.
