Vol. 7 & Issue 4 ; Section D : Environmental Sciences

Date : Aug. to Oct.2017


Assessment of Physico- Chemical Parameters of Water of Ulsoor Lake in Bangalore


JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 801-804.

[DOI: 10.24214/jcbps.D.7.4.80104]

  • Abstract

    The Physico- Chemical parameters of Ulsoor Lake have been investigated. The water samples were collected from a point near the middle of the lake and analyzed for water quality parameters viz. Temperature, Dissolved oxygen, Biological oxygen demand (BOD), Chemical oxygen demand ( COD), Electrical conductivity (EC), Total Hardness, Total dissolved solids (TDS), chloride, sulphate and nitrate. The result were compared with values prescribed by WHO and other standards for drinking water quality. The pH exceeded the maximum limit of 9.0 recommended in the standards for treated wastewater. BOD exceeded permissible limit of 6 mg/l prescribed by WHO. EC exceeds the limit as per Europian standard. The nitrate levels were within the limits prescribed by all drinking water standards. All other parameters were all well within permissible limits. The water is safe based on most of the chemical parameters, the water may be unsafe due to poor microbial quality. This study was carried out from March 2011 to February 2012.

Hydrological study of Dhangarmola freshwater reservoir from Ajara tahsil of Kolhapur district, Maharashtra (India)

Sachinkumar R. Patil and S. S. Patil

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 805-818

[DOI: 10.24214/jcbps.D.7.4.80518]

  • Abstract

    The present study deals with the hydrological parameters from Dhangarmola freshwater reservoir of Ajara tahsil, Kolhapur district, Maharashtra (India). The investigation was carried out during July 2011 to June 2012 so as to detect physical parameters like air temperature, water temperature, transparency, electric conductivity and pH and chemical parameters like free CO2, alkalinity, total hardness, calcium, magnesium, chlorides, total dissolved solids, dissolved oxygen and biological oxygen demand. The present investigation revealed that all parameters were within the permissible limit for drinking, agricultural and domestic purposes. The study also concludes that reservoir water supports many biological entities as their feeding and breeding ground.

Evaluation of groundwater quality with special emphasis on heavy metal contamination in major areas of Joypurhat district, Bangladesh

Dipok Kumar, H. M. Zakir, M. A. Maleque and H. P. Seal,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 819-834.

[DOI: 10.24214/jcbps.D.7.4.81934.]

  • Abstract

    An attempt was made to assess the quality of groundwater collected from three Upazila’s of Joypurhat district, Bangladesh. Forty five (45) groundwater samples were collected to evaluate them on the basis of their suitability for drinking and irrigation usage. Major cation chemistry showed their dominance in order of Ca > Mg > Na > K and the study results inferred 29, 35 and 45 groundwater samples as problematic for irrigation due to higher concentration of Ca, Mg and K, respectively. Among the anions, Cl content in groundwater was the highest (4.80 to 29.60 meq L-1) followed by SO4 (1.50 to 18.90 mg L-1). The concentration of Fe, Mn, Cu, Pb and Cr varied from 0.32 to 0.84;trace to 0.14; 0.71 to 0.81; 1.71 to 10.55 and 2.33 to 3.68 mg L-1, respectively while the concentration of Zn was trace. EC and SAR reflected that all groundwater samples were low to high salinity (C1-C3) and low alkalinity (S1) hazards classes. As regards to hardness, 8 groundwater samples were classified as soft and the rest 37 samples were moderately hard in quality. The concentrations of Na, CO3, HCO3, Fe, Mn, Zn, SO4 and PO4 ions were detected below the toxic levels and might not pose threat to soil environment. But Cl content in all groundwater samples was above the recommended limit (4.0 meq L-1) for irrigation and 41 samples also exceeded the permissible limit (250 mg L-1) of drinking water quality. In context of heavy metals, all samples were found unsuitable for irrigation due to higher concentration of Cu, Cr and Pb. Concentrations of Fe, Cr, Pb, Ca and Mg in groundwater samples also exceeded the guideline value of drinking water. The study concluded that the substances which may cause pollution should be avoided through the use of good management practices

Metallic pollution in top soils of an urban industrialized city:a case study of Chittagong city, Bangladesh

H. M. Zakir, Md. Anwar Hossain and M. S. Alam,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 835-850.

[DOI: 10.24214/jcbps.D.7.4.83550.]

  • Abstract

    Top soils of Chittagong city is highly susceptible to environmental pollution due to over population, rapid industrialization, urbanization and disposal of different types of solid and liquid waste without any treatment. Total 22 top soil samples were collected from different locations of Chittagong city to assess metallic pollution level and concentrations of metals in samples were determined by an Atomic Absorption Spectrophotometer (AAS). The mean total concentrations of Cu, Zn, Cr, Fe and Pb in soil were 60.56, 108.05, 238.63, 37153.69 and 254.05 μg g-1, respectively, while the concentrations of Ni in most sampling sites were trace. The study revealed that the average Cu, Zn, Cr and Pb contents in soils were higher compared with several other industrial areas in home and abroad as well as geochemical background. The geoaccumulation index (Igeo) values for Pb ranged from 3.49-4.02, indicating Igeo class 4- 5, which means strongly to extremely polluted soil quality. But the calculated Igeo for Cr at all locations and Zn at 50% sites exhibited Igeo class: 1-2, indicating uncontaminated to moderately polluted soil quality. As regards to enrichment factors (EFc), all sampling sites had EFc values > 5.0 for Pb, which indicates anthropogenic load of the metal to the city. Estimated pollution load index (PLI) of all sites showed values >1.0, indicates significant pollution load at the study area. The comprehensive potential ecological risk index (RI) values ranged from 98.37-134.93 and the potential ecological risk index of single element ( Eir  ) values of Pb ranged from 85.61-123.46 means Pb was the most important metal leading to risk. The study results concluded that the top soil of the city is significantly polluted with Pb followed by Cr and Zn

Assessment of Microbial Degradation of Volatile Organic Compounds from Industrial effluents

Parulekar G.T.,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 851-862.

[DOI: 10.24214/jcbps.D.7.4.85162.]

  • Abstract

    Volatile organic compounds are carbon-based chemicals that easily evaporate into the air at room temperature it is an important outdoor air pollutant. In the present study VOC degrading microorganisms were isolated and identified from industrial effluents. Biodegradation of VOC was measured by weight loss in the polymer and GCMS. Thus, the duration of the microbial colonization is an important factor that effect period. It was observed that isolate V2 is potential isolate for the degradation of VOC, so it was selected for the further screening VOC degradation by V2 isolates by GCMS. The removal efficiencies of VOC of different microbes were compared. The major characteristics of fungi and bacteria that govern the biodegradation were discussed. The efficiency of fungi was found to be greater than that of bacteria. On the other hand, mixed culture was possibly found to have higher efficiency which was a result of the cumulative efficiency conferred by the fungal presence and the moisture content that obliges to attain higher efficiency. The efficiency of degradation is also influenced by the volatile compounds present in the sample.

Wintertime characterization of Carbonaceous and Inorganic constituents of PM2.5 and PM10 aerosols at an urban site of North Central India

Tripti Pachauri, Ram Kumar Saraswat, Anita Lakhani & K. Maharaj Kumari

  • Abstract

    Aerosol mass concentrations and chemical composition of PM2.5 and PM10 were studied during winter season at an urban site (Agra) of North Central India. Weekly samples were collected during winter season from October 2012 to February 2013. The average mass concentrations were found to be 116.4 ± 39 and 310.5 ± 42.9 μg/m3 for PM2.5 and PM10 indicating the combined impact of local anthropogenic emissions and meteorological conditions. On average, the concentrations of SO42-, NO-3 and NH+4 accounted for 46 and 48% of total WSIS in PM2.5 and PM10, respectively. The average ratio of ΣC/ΣA is > 1 suggesting the alkaline nature of aerosols. The average concentrations of OC and EC were found to be 35.8 ± 19.2 μg/m3 and 4.8 ± 1.3 μg/m3 in PM2.5 while 113 ± 23.5 μg/m3 and 16.3 ± 6.3 μg/m3 in PM10. A good OC – EC correlation for both PM2.5 and PM10 indicated the presence of common dominant sources for carbonaceous aerosols. The average concentration of TCA was found to be 62.6 ± 31.6 and 190 ± 35.8 μg/m3 in PM2.5 and PM10 indicating the dominance of carbon rich aerosols. On average, SOC accounted for 43.8 and 34.5% of total OC. High contribution of SOC to total OC may be probably due to the combined emissions of anthropogenically originated VOCs as well as naturally emitted terpenes.

Water quality analysis of amphibian habitats in Taluka Dokri, District Larkana Sindh

Kalsoom S., Ghulam S. Gachal, Saima Q. Memon, Muhammad Y. Shaikh,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 877-888,

[DOI: 10.24214/jcbps.D.7.4.87788.]

  • Abstract

    Present study is a sequential study of a wide research conducted in Sindh Province to record the status of amphibian habitats and hereby condition of amphibian habitats in Taluka Dokri is highlighted through deep study of numerous physico-chemical parameters (pH, CO2, EC, TDS, T-Hard, T-Alk, Cl, SO4, PO4, NO2, NO3 and K). Monthly field surveys were conducted for the collection of water samples from ponds where amphibians dwelled permanently and subsequently their Physico-chemical analysis was performed in the scientific Laboratory. It was confirmed that the concentration of various parameters was out of normal range except value of pH and CO2 which were recorded normal throughout the study period. Amphibians are highly vulnerable to environmental contamination and therefore strict conservation rules may be promulgated in the study area for the stable survival of amphibians.

Study of Physico-chemical parameters in amphibian habitats of District Jamshoro, Sindh-Pakistan

Kalsoom S., Muhammad Y. Shaikh, Ghulam S. Gachal, Saima Q. Memon,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 889-897,

[DOI: 10.24214/jcbps.D.7.4.88997.]

  • Abstract

    Present study was conducted in District Jamshoro (11,517 Km2) for the determination of water quality of amphibian habitations in agricultural ponds for an extensive period of three years (2011-2013). Investigation comprised of regular surveys of 18 permanent habitations for the collection of water samples and laboratory analytical study was also carried out for the evaluation of some main physico-chemical parameters (pH, EC, TDS, T-Hard, T-Alk, Cl, SO4, PO4, NO2, NO3, K and CO2). Specific scientific methodology and distinct analytical instrumentation was applied discretely for the study of each parameter. Results of this study showed that the values of pH and CO2 were normal; however concentration of all other parameters was very high making entire study sites highly contaminated and unfavorable for the delicate creatures in question. Tremendously inauspicious level of studied physico-chemical parameters persisted for the entire study period with seasonal variation

Chemical composition and antifungal activity of sugarcane bagasse and banana stem based wood vinegar

M. Ahasanur Rabbi, Ayesha Akhter, Mala Khan, H. Jahan Kadri, Bijoy Maitra and M. Hamida Khatun,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 898-904,

[DOI: 10.24214/jcbps.D.7.4.89804.]

  • Abstract

    Wood vinegar or pyroligneous liquid can be produced during the pyrolysis of biomass. Generally, the dark brown colored wood vinegar contains acetic acid, methanol, propanoic acid, phenolic and carbonyl compounds. The major components of biomass are cellulose, hemicellulose and lignin but during the thermochemical decomposition of different biomass produces wood vinegar with a different composition. Sugarcane bagasse and waste banana tree are two important agricultural wastes in Bangladesh. In this investigation, sugarcane bagasse and banana stem were pyrolysed under same pyrolytic conditions. Gas chromatography-mass spectroscopy (GC-MS) analysis was performed to identify the phenolic compounds and other ingredients present in sugarcane bagasse and banana stem based wood vinegar. Antifungal activities of the both samples were investigated. Among the four fungi, Trichoderma spp showed resistance against both wood vinegar samples. Significant activities were found against Aspergillus niger, Aspergillus flavus and Fusarium spp.

Rate Kinetics on Bioleaching of Realgar Mineral by Leptospirillum ferriphilum: Effects of Fe (II) Concentration

Venkatesa Prabhu.S, Uga Waktole. B, 1Gizachew Assefa and 2Sudhagar.P,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 905-512.

[DOI: 10.24214/jcbps.D.7.4.90512.]

  • Abstract

    The eco-friendly method of metal extraction, bacterial leaching is gaining more important in bio-hydrometallurgical industry. It is a proven method and can be applied for leaching process of several metals. This study was aimed to determine the efficiency of arsenic leaching from realgar mineral using the bacteria, Leptospirillum ferriphilum. The experiments were carried out in shaker flask, at fixed parameters 180 rpm, 0.2% pulp density (PD), 313 K at an initial pH of the media 1.5. The energy source, Fe2+ concentration was varied from 2−10 g/L. The effect of Fe2+ concentration on the kinetics of arsenic extraction was investigated. The experiment results showed that leaching of arsenic was highly influenced by concentration of Fe2+ used in the medium. The maximum of 74.42% As was leached after 30 days when using optimum of 6 g/L of Fe2+. Kinetic studies showed that the maximum rate constant value, 1.3633 d-1, was observed when optimum concentration of energy source was used.

A Study on Physical – Chemical Parameters to Assess the Industrial Effluent from Industrial Belt, KADAPA

B. Balaraju, S. Sumithra.

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 913-920,

[DOI: 10.24214/jcbps.D.7.4.91320.]

  • Abstract

    The present study was carried out in Kadapa to assess the extent of chemical contaminants by the industries. Effluent samples were collected from selected industries and the physical – chemical parameters were analyzed and compared with ISI standards. Results showed the pH value ranged from 2.1 – 12.5. The effluent samples collected showed extremely high Total Dissolved Solid (TDS) for many industries. Sodium was found to be higher than permissible limits. COD is within the recommended limits. These effluents are normally discharged into the surrounding water bodies. So there is urgent need to develop technology to reduce the pollution and make the area safe

Lithological reconstitution of offshore formations of the Ivorian Albian from logs

KOUAO Assiè François. A., ASSALE Fori Y. P., EBY Edna Y. A., MONDE Sylvain,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 921-934.,

[DOI: 10.24214/jcbps.D.7.4.92134.]

  • Abstract

    The lithological reconstruction of the offshore formations of the Ivorian Albian from the well logs is aimed at determining the different lithological limits in order to determine the deposit environments. This reconstruction reveals five (5) lithological facies (argillites, silty argillites, sandstones, limestone and marls).Relatively high Gamma Ray (GR) signatures distinguish argillites. Sandstones and Silty argillites are labeled with medium to low GR values. Carbonates are characterized by very low GR values. These different lithology are most often in the form of lenses and have very variable thicknesses (banks with lamellae). The correlative study reflects vertical and lateral facies variations. The Albian is dominated by alternations of sometimes silty argillites and sandstones.Carbonates are very rarely present, they usually occur at the end of the Albian in the southern part of the correlation profile. These carbonates could translate the beginning of the increase of the water slice (marine transgression). The northern part consists essentially of terrigenous (siliciclastic) inputs coming from the continent.

Reconstitution Lithologique Des Formations Offshores De L’Albien Ivoirien A Partir Des Diagraphies

KOUAO Assiè François. A., ASSALE Fori Y. P., EBY Edna Y. A., MONDE Sylvain,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 921-934.,

[DOI: 10.24214/jcbps.D.7.4.92134.]

  • Abstract

    La reconstitution lithologique des formations offshores de l’Albien ivoirien à partir des diagraphies a pour objectif de déterminer les différentes limites lithologiques en vue d’identifier les environnements de dépôts. Cette reconstitution révèle cinq (5) faciès lithologiques (argilites, argilites silteuses, grès, calcaires et marnes). Les argilites se distinguent par des signatures Gamma Ray (GR) relativement élevées. Les grès et les argilites silteuses sont marqués par des valeurs de GR moyennes à faibles. Les carbonates sont caractérisés par des valeurs de GR très faibles. Ces différentes lithologies se présentent le plus souvent sous forme de lentilles et possèdent des épaisseurs très variables (bancs à des lamelles). L’étude corrélative traduit des variations verticales et latérales de faciès. L’Albien est dominé par des alternances d’argilites parfois silteuses et des grès. Les carbonates sont très peu présents, ils se signalent généralement à la fin de l’Albien dans la partie Sud du profil de corrélation. Ces carbonates pourraient traduire le début de l’augmentation de la tranche d’eau (transgression marines). La partie Nord est essentiellement constituée d’apports terrigènes (silicoclastiques) qui proviendraient du continent.

Multicomponent and Competitive Sorption of Heavy Metals- Review on Significant Research and Studies

Dr. S.J. Kulkarni,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 935-943.,

[DOI: 10.24214/jcbps.D.7.4.93543.]

  • Abstract

    Heavy metals have acute and chronic effect on human beings and other living organisms also. It is very important to identify the risk and take steps for removal of heavy metals from the effluents. The industries such as paint, pigment, catalyst, fine chemicals, coating, automobile, electronics, battery etc. uses heavy metals in some or other form. They treat the wastewater by using conventional methods. Heavy metal removal from the wastewater by using adsorption is commonly investigated area of research. The wastewater generally contains more than heavy metals. It is envisaged to study the effect of presence of one heavy metal on removal of other heavy metal. It can help selective removal of specific heavy metal and selection proper adsorbent. Most of these investigations indicated that the presence of one metal has significant effect on sorption of other metal. This effect can be positive or negative. Competitive adsorption indicates competition for adsorbent sites. In cooperative mechanism, the presence of one metal has positive effect on sorption of other. The present review intends to study research and studies on the competitive adsorption of heavy metals on different materials.

Demonstration of the effective filtration and grazing of tilapias Sarotherodon galilaeus used for the biological control of microalgae and helminth eggs polluting the drinking water of the Ziga dam, Burkina Faso.

NEYA Bapiyan Augustin  KABRE Tinkoudgou Jean André and SAWADOGO Moumouni,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 944-963.

[DOI: 10.24214/jcbps.D.7.4.94463.]

  • Abstract

    This planktivorous mode, it arises that the near total of the preferential, secondary preys and some additional preys of the species consist of harmful kinds of alga to the quality of water (odors, taste, filling of the filters) and to human health (production of toxins).Indeed the examination of the mode of S. galilaeus made it possible to gather the preys according to the affected targets.The producing preys of tastes and odor in water consist of:Peridinium (preferential prey), Cosmarium (secondary prey) Synedra (secondary prey), Melosira (secondary prey), Anabeana (prey accessories), Microcystis (prey secondary), Scenedesmus (prey accessories) and Volvox (prey accessories).The preys colmatrices of filters are made up of:Peridinium (preferential prey), Cymbella (secondary prey) Synedra (secondary prey), Navicula (secondary prey), Melosira (secondary prey), Diatoma (additional prey), Tracholomonas (additional prey), Microcystis (secondary prey) and Anabeana (additional prey).The producing toxin preys include/understand kinds Ci afterwards: Nostoc (additional prey), Microcystis (secondary prey), Anabeana (additional prey) and Chroococcus sp (additional prey).Very harmful preys with human health as eggs of ascaris were also identified like prey preferential at the species.The analysis of the planktivorous mode of S. galilaeus from the MFI% cumulated, coupled with the multivariate regressions between the preys taken in dry season and rainy season and those introduced between the classes of size (88<ls<125 mm and 126<ls<242 mm) did not show any change of the mode of the species.The projection of the preys of the dry season on the preys of the rainy season and that of the class of size 88<ls<125 mm on that of the class 126<ls<242 mm, successively gave coefficients of correlation of 0,889and 0, 957. The intestinal coefficient (4, 96-11, 65) of the species made it possible to classify it among the trophic gilde microphage/macrophages and with the edge of the limivores. The coefficient of vacuity of the species is 2.817 for the rainy season;2.165 for the size ranging between 126 and 242mm;1.111 for the size from 88 to 125 mm;1.471 for the dry season and 1.703, all 411 captured subject.These low values of coefficients of vacuity in spite of the scarcity of the algae in rainy season, indicate the aptitude of fish to seek its preferential preys in order to satisfy its physiological functions.Taking into consideration what precedes, one can say that S. galilaeus has a broad spectrum of action on the harmful preys and could play a role of biological agent of fight in the data processing sequence of drinking water for the periods of efflorescences algales.

Mise En Evidence De L’efficace Filtration Et Broutage Des Tilapias Sarotherodon Galilaeus Utilisés Pour Le Contrôle Biologique Des Micro-Algues Et Des OEufs D’helminthes Polluant Les Eaux De Boisson Du Lac De Barrage De Ziga, Burkina Faso.

Neya Bapiyan Augustin  Kabre Tinkoudgou Jean André Et Sawadogo Moumouni,

JCBPS; Section D; August 2017 – October, 2017, Vol. 7, No. 4; 944-963.

[DOI: 10.24214/jcbps.D.7.4.94463.]

  • Abstract

    La lutte biologique constitue aujourd’hui un maillon important de la chaîne de traitement de l’eau potable au regard des problèmes que génère l’utilisation du chlore et autres produits chimiques pour traiter les toxines, les goûts et les odeurs produits par les algues dans l’eau potable. Pour participer à la résolution de cette problématique, le régime planctonophage de Sarotherodon galilaeus a été mis à contribution.En effet, de Janvier 2014 à février 2015, nous avons capturé 411 espèces de S. galilaeus.L’analyse des intestins et des estomacs des poissons a permis d’identifier 37 proies regroupées en 5 embranchements : les Chromophyta (51,932%) ; les Chlorophyta (26,327%) ; les Pyrrophyta (10,304%) ; les Cyanophyta (6,131%) ; les Euglenophyta (0,103%) et des oeufs d’helminthes nocifs à la santé humaine représentant 5,204%. De ce régime planctonophage, il ressort que la quasi-totalité des proies préférentielles, secondaires et quelques proies accessoires de l’espèce sont constituées de genres d’algue nuisibles à la qualité de l’eau (odeurs, goût, colmatage des filtres) et à la santé humaine (production de toxines). En effet l’examen du régime de S. galilaeus a permis de regrouper les proies en fonction des cibles affectées. Les proies productrices de goûts et d’odeur dans l’eau sont constituées de: Peridinium (proie préférentielle), Cosmarium (proie secondaire)Synedra (proie secondaire), Melosira (proie secondaire), Anabeana (proie accessoires), Microcystis (proie secondaires), Scenedesmus (proie accessoires) et Volvox (proie accessoires). Les proies colmatrices de filtres sont composées de: Peridinium (proie préférentielle),Cymbella (proie secondaire) Synedra (proie secondaire), Navicula (proie secondaire), Melosira (proie secondaire), Diatoma (proie accessoire), Tracholomonas (proie accessoire), Microcystis (proie secondaire) et Anabeana (proie accessoire). Les proies productrices de toxines comprennent les genres ci- après : Nostoc (proie accessoire), Microcystis (proie secondaire), Anabeana (proie accessoire) et Chroococcus sp (proie accessoire).Des proies très nocives à la santé humaine comme les oeufs d’ascaris ont été également identifiés comme proie préférentielles chez l’espèce. L’analyse du régime planctonophage de S. galilaeus à partir du MFI% cumulé, couplé aux régressions entre les proies prises en saison sèche et en saison pluvieuse et celles ingérées entre les classes de taille (88<ls<125 mm et 126<ls<242 mm) n’a montré aucun changement du régime de l’espèce. La projection des proies de la saison sèche sur les proies de la saison pluvieuse et celle de la classe de taille 88<ls<125 mm sur celle de la classe 126<ls<242 mm, ont donné successivement des coefficients de corrélation de 0,889 et 0, 957. Le coefficient intestinal (4,96-11,65) de l’espèce a permis de la classer parmi la gilde trophique des microphage/macrophages et à la lisière des limivores. Le coefficient de vacuité de l’espèce est de 2.817 pour la saison pluvieuse ; 2.165 pour la taille comprise entre 126 et 242mm ; 1.111 pour la taille de 88 à 125 mm ; 1.471 pour la saison sèche et 1.703, pour l’ensemble des 411 sujets capturés. Ces basses valeurs de coefficients de vacuité malgré la rareté des algues en saison pluvieuse, indiquent l’aptitude du poisson à rechercher ses proies préférentielles afin de satisfaire ses fonctions physiologiques et de croissance.Au regard de ce qui précède, on peut dire que S. galilaeus a un large spectre d’action sur les proies nuisibles et pourrait jouer un rôle d’agent de lutte biologique dans la chaîne de traitement de l’eau potable pendant les périodes d’efflorescences algales.