In December 2016 to July 2017 the selected bivales were collected from Abu Hummus, River Nile, El Beheira Egypt (Figure 1). The shell sizes of the detected samples were ranging from (10-15 cm) in length, from (6-9 cm) in width and from (2.6 to 4.5 cm) in height. The sediment and water samples were collected in corresponding to the clam settlements to determine the initial level of heavy metals.

Samples of Spathopsis rubens were collected from Abu Hummus El Beheira, Egypt. Abu hummus lies between the Cairo-Alexandria Agricultural road and the El Mahmodea stream at; 31.10063^oN-30.310063^oE. The water samples, sediment and flesh of Spathopsis rubens were collected from the river water side. Water samples were collected in plastic bottles, pre-rinsed with distilled water. The bivalves were chosen by harvesting only large but with similar sizes and healthy. A total of 151617181920 samples were collected/location/season then were kept in plastic containers filled with water.

The biochemical analysis includes the determination of metal analysis, organic pollutants, protein, lipids, carbohydrates and antioxidant enzymes (CAT, SOD, GPx and MDA). The analysis of heavy metals (Cu, Fe, Mg, Zn, Pb and Hg) of fresh water was done according to Ayodele and Abubakar 5. The heavy metals in sediment and in soft tissues were measured according to 37. The results are presented as mean ± S.D. values. One-way analysis of variance (ANOVA) was used to test the significance of depuration in each metal concentration and TPHs. Post hoc test was used to analyse the multiple comparisons among water, sediment and soft parts. All statistical analyses were performed using the SPSS 15.0 software 38. Determination of carbohydrate and lipids were according to 39. Determination of protein was estimated by Lowry s method 40. Determination of Catalase activity (CAT) was measured according to Aebigh 41. Superoxide dismutase (SOD, EC 1.15.1.1) activity was measured using the procedure of Beauchamp and Fridovich 4243. Glutathione peroxidase activity levels were determined by the method of Pagtia and Valentine 44. Lipid peroxidation (Malondialdehyde) was determined by the method of OhKawa 45.

Bivalve samples were collected from their natural beds from Abu Hummus, El Behirea, Egypt.The survey in the present study was reported as the following: Spathopsis wahlbergi hartmanni (Martens, 1866), Spathopsis rubens arcuata (Cailliaud, 1823), Caelatura (Horusia) parreyssi (Philippi, 1847), Lanistes carinates (Olivier, 1804) and Melanoides tuberculata (Müller, 1774), Melanoides tuberculata (Müller, 1774), Lanistes carinates (Olivier, 1804), Mutela singularis (Pallary, 1924), Caelatura (Caelatura) prasidens (Cailliaud, 1827). The Spathopsis rubens had been choosen (Figure 2) in the present study. (Table 1, Table 2, Table 3, Table 4)

The mean concentration level of Hg was hiher in winter in sediment as 2.3µg/g than in water and in tissue.

The mean concentration level of Zn was higher in summer in sediment as 8.1 than in water and tissue. The mean concentration level of Pb was higher in winter in water as 3.3µg/g than in sediment and tissue. The mean concentration level of Fe was higher in summer as 492µg/g than in winter and tissue. The Mg concentrations were higher in sediment as 408µg/g than in water and tissue. The Cu concentrations were higher in summer in sediment as 301µg/g than in water and tissue. (Table 5, Table 6, Table 7, Table 8, Table 9, Table 10, Table 11)

A Histogram of the mean activity level of different enzymes in the bivalve (2016-2017) (Figure 3, Figure 4, Figure 5, Figure 6)

A histogram representing the selected biochemical parameters in the bivalve (2016-2017)(Figure 7, Figure 8, Figure 9)

A histogram of the mean concentration levels of the selected heavy metals in water (µg/g) in different seasons during the year (2016-2017) (Table 12, Table 13, Table 14, Table 15, Table 16) (Figure 10, Figure 11, Figure 12, Figure 13, Figure 14, Figure 15)

In Autumn the activity of GPx and of MDA were positively correlated with the carbohydrate contents in the bivalve as r=0.956* an r=0.865*; respectively. The activity level of SOD is negatively correlated with MDA, Hg, Fe as r=-0.873*, r=-0.998*, r=-0.925*; respectively. The activity of CAT is negatively correlated with the lipid content, Pb as r=-0.922*, r=-0.87*; respectively.

The total protein content is negatively correlated with Fe concentration level in tissues as r=-0.908*. The lipid contents is positively correlated with the carbohydrate contents as r=0.877* and r=0.910*; respectively. Both Hg and Pb are positively correlated with Fe concentration level in tissues of the bivalve as r=0.932* and r=0.856*; respectively.

The correlation coefficient in winter was only between SOD mean activity inhibition level and CAT mean activity level as r=0.838*. Negative correlation was found between CAT and Hg as r=0.88*. The mean concentration level of Fe and Mg in tissues showed a negative correlation as r=-0.835*.

In spring only the mean concentration level of Pb and Cu in tissue showed a high significant correlation as r=0.978*.

In summer there were positive correlation between the mean activity level of GPx and lipid content and Hg in tissues as r=0.837* and r=0.865*; respectively. The mean activity level of MDA was positively correlated with the mean concentration level of Fe in tissues as r=0.821*. The mean level of the total protein content was positively correlated with Pb mean concentration level as r=0.893* and negatively correlated with Cu mean concentration level as r=-0.912*. Whereas the mean concentration level of the lipid content was negatively correlated with the mean concentration level of the carbohydrate contents as r=-0.828* and Pb in tissue was also negatively correlated with Cu in tissues as r=-0.985.

In the present study Spathopsis rubens was collected from El Beheira, Egypt, Abu Hummus. These species was already detected in previous reports 46. In the present study the heavy metals (Hg, Zn, Pb, Fe, Cu and Mg) were detected in the four seasons from autumn (2016) to summer (2017). In fresh water, in sediment and in the soft tissues of Spathopsis rubens. Some enzyme activities were detected as; CAT, SOD, GPx and MDA. The total protein, Lipid and carbohydrates in the soft tissues of Spathposis rubens were detected. There is a general acceptance that fresh water ecosystems undergo little ecological stress when subjected to salinities up to 1000 mgL-1. Much of the knowledge of the impacts of salinity on aquatic ecosystems comes from field sampling a long a gradient of salinity from which it is difficult attribute cause of ecological change 47.

Bivalves have been used as bioindicators of pollution because they have the ability to concentrate heavy metals to several other magnitudes 48. The mean concentrations of Fe in the present study are within the permissible limits of law 48/1982 (<1 mg/l) and the guideline of 49 which is <1 mg/l. The mean concentration level of copper is within the permissible limits of law 48/1982 (<1.0 mg/l), the values of the measured metal. The mean levels of the heavy metals in water are less than that of the permissible limits recommended by 50. The changes in metabolic rates of bivalves within the seasons and the variation in bioavailability of metals in the surrounding environment with time might be responsible for the health status of the molluscs 51. The present study is in agreement with Cossa and Rondeau 51 in that the higher metal burden and concentration in the wet season (such as for Fe and Zn). Lower levels for Cd and Hg could be attributed to wash out of the lagoons during the rainy period. Biological variables such as changes in the tissue composition as well as the season of sampling and the hydrodynamics of the lagoons have to be considered. Seasonal variations are related to a great extent to seasonal changes in flesh weight during development of gonadic tissues 52.

The present observation showed that the mean concentration levels of Cu, Hg and Fe in tissues are higher in winter than the other seasons as; the mean concentration level of Hg in winter 1.46 µg/g ˃ spring 1.26µg/g ˃ summer 1.1 µg/g˃ autumn 0.93µg/g. The mean concentration level of Cu in winter 1.6 µg/g˃ spring 1.4µg/g ˃ summer 1.14µg/g˃ Autumn 1.35µg/g and the mean concentration level of Fe in winter 322.33 µg/g˃ Autumn 299.67µg/g ˃ summer 274.17 µg/g˃ spring 252.33µg/g. The mean concentration levels of Pb and Mg are higher in autumn than the other seasons as Pb in Autumn 1.73 µg/g˃ winter 1.65µg/g ˃ spring 1.32µg/g˃ summer 0.89µg/g, Mg in autumn 2.6 µg/g˃ spring 2.38µg/g ˃ summer 2.4µg/g˃ Autumn 1.73µg/g. The mean concentration level of Zn is higher in summer than the other seasons as, Zn in summer 4.23 µg/g˃ spring 2.83µg/g ˃ winter 2.17µg/g˃ autumn 2.08µg/g.

The present observation showed that the mean concentrations level of heavy metal in the sediment were high when compared with standard values 48. The mean concentration level of Hg in sediment is higher in winter than the other seasons as, winter 2.3 µg/g ˃ summer 2.2 µg/g ˃Autumn 2.1 µg/g ˃ spring 1.9 µg/g.The mean concentration level of Zn, Cu, Pb, Fe and Mg were higher in summer than the other seasons as; Zn in summer 8.1 µg/g ˃ spring 5.2 µg/g winter 4.5 µg/g ˃ Autumn 4.2 µg/g, Cu in summer 3.1 µg/g ˃ spring 2.3 µg/g ˃ Autumn 2.2 µg/g ˃ winter 2 µg/g, Pb in summer 2.9 µg/g ˃ spring 2.6 µg/g ˃ winter 2.5 µg/g˃Autumn 2.2 µg/g. Fe in summer 492 µg/g ˃ Autumn 417 µg/gram ˃ spring 400 µg/gram ˃ winter 395 µg/g, Mg in summer 4.8 µg/gram ˃ spring 4.1 µg/gram ˃ Autumn 3.7 µg/gram ˃ winter 3.5 µg/g.The variations in metal concentration of the shellfish tissues in the present study could be related to the concentration of heavy metals in the fresh water.

Abdulah 53 reported that the high level of heavy metals in the lake may be related to their concentration in the stream and rivers discharging into the lake. The high level of Zn, Cu and Pb in the river indicates the quality of the water prevailing at the period of sampling. Trace metal concentrations in clams depend on numerous environmental and biological factors 54. Earlier studies by Chouba et al. 55 in Tunisia demonstrated higher concentrations of heavy metals in clams during high rainfall periods. These findings are in agreement with that of the present study. Studies have shown that during the spawning period, proteins and carbohydrate contents, which have a high affinity for heavy metals, are accumulated for gonad tissue production, energetic storage and consumption 56.There is no access waste water treatment in Abo Hummus rural areas as 20% of Egyptian villages have inadequate potable water 5758.

Pollution of the aquatic environment by inorganic and organic chemicals is a major factor posing a serious threat to the survival of aquatic organisms 59. The aquatic environment is subjected to various types of pollutants which enter water bodies 60. It is estimated that the total amount of reused treated wastewater in Egypt was about 1.4 billion m3 in 2000 61. Industrial waste water is considered the second of the main sources of Nile water pollution. Effluent wastewater is often partially treated 62. Major pollutants in agricultural drains are salts, nutrients, pesticide residues, pathogens and toxic organic and inorganic pollutants 6364. At high pollution stress however, protein synthesis can be suppressed indicating disturbance of normal metabolic processes 656667. The fall in protein level during pollutant exposure may be due to increased catabolism and decrease in protein synthesis 68. The digestive gland is the main site of degradation and detoxification of toxicants and hence resulting into increasing utilization of protein to meet energy demand. The higher degradation of protein is the tool to access the extent of toxicity 69.

In the present study there is a significance between all seasons in the protein content in the soft tissue of Spathopsis rubens as the mean concentration level in Spring was reported as 102.83mg/g which is higher then that of autumn 100.5 mg/g, summer 93.33 mg/g and winter 80.50 mg/g. Kharat et al. 70 studied depletion in protein content in the tissues of Macrobrachium kistnensis exposed to different concentrations of tributyltin chloride stress on protein metabolism similar results were obtained by Sole and Porte 71. Inhibition in the protein synthesis was reported to be due to non-selective blocking of phosphorylation process in the central nervous system 72. Bivalves generally store carbohydrates in large amounts during their growing seasons and use them over the rest of the year although proteins may be an energy reserve in some bivalve species. Lipids have been reported to function most importantly as energy storage substances and physical properties of biological membranes. In the present study the higher concentration of lipid in autumn 12.78 mg/g than in winter 10.60 mg/g, spring 10.25 mg/g and in summer 9.38mg/g. Fall in carbohydrates level may be due to the prolonged exposure of the metabolism to the heavy metals and this may be the reason for inactivation of the enzyme, involved in the carbohydrate metabolism 73. In the present study the higher concentration of carbohydrates was found in spring 13.40 mg/gm than in autumn 12.05 mg/gm, summer 11.78 mg/gm and in winter 10.62mg/gm.

Free radicals are able to react with biological macromolecules and produce enzyme activation, lipid peroxidation 74. Antioxidant enzymes activity levels of marine bivalve Perna viridis during heavy metals exposure were significantly higher in tissues. The mantle was observed to significantly contribute to the organismal response to lipid peroxidation as indicated by high activity levels of antioxidant enzymes 75. Cu strongly stimulates the lipid peroxidation damage of the gill plasma membranes 7677. Pannunzio and Storey 78 observed a suppression of GPx activity during anoxia exposure in the hepatopancreas of the marine gastropods Littorina littorea. Main enzymes involved in detoxification from reactive oxygen species. SOD and GPx have been shown to contribute to antioxidant defense in the mussels 79. Glutathione is considered a scavenger able to protect cells from oxidative damage 8081. Aerobic organisms are protected against oxidative stress by antioxidant systems which mobilis enzymes such as the (Cu-Zn superoxide dismutase) which transfers O₂ to H₂O₂82.

Oxidative stress induced by copper exposure, evidenced by increased lipid peroxidation products such as malondi aldehyde has also been demonstrated for the mussels Mytilus galloprovincialis 83, Perna perna 84, Ruditapes decussatus 85, and for the oyster Crassostrea virginica 86. Antioxidant defenses may be increased or inhibited by chemical stressors. The occurrence of one kind of response or the other depends on the intensity and duration of the applied stress and the susceptibility of the species that are exposed 87. There are several reports on increased SOD and CAT activities in bivalves in the presence of excess free radicals 88. Dietary copper appears to be innocuous to the digestive system at low concentrations as copper is a cofactor of enzymes such as cytosolic SOD (Cu-SODiso-enzyme) 89 and is also part of the hemocyanin molecule. The excess of this metal could be sequestered into vacuoles or immobilized by biological compounds for a possible excretion 9091. Metals can induce oxyradical production leading to lipid peroxidation 92. In the present study the mean activity level of GPx in Spring was higher than the other seasons such as spring 31.33U/g ˃ summer 28.33 U/g ˃autumn 26.67 U/g ˃ winter 20.50U/g. The mean activity level of SOD in summer was higher than the other seasons such as summer 38.83 U/g ˃ spring 33.33 U/g ˃autumn 28.83U/g ˃ winter 22.83U/g. The mean activity level of CAT in spring was higher than the other seasons such as spring 25.67U/g ˃ summer and autumn19.83U/g ˃ winter 15.17U/g. The mean activity level of MDA in winter was 30.50 U/g ˃ summer 22.50U/g ˃ autumn 18.0 U/g ˃spring 16.83U/g. In the present study it was found that the mean activity level of MDA increased in winter at the same time the mean activity level of CAT, SOD and GPx were decreased in winter.