The present study deals with the infestation study of Livoneca redmanii (Isopoda, Cymothoidae) on Mugil cephalus in Lake Qarun, Egypt. Out of 576 examined fish collected monthly from the different localities of Lake Qarun during the period (January - December, 2016) there are 269 (46.7 %) fish were infested by crustacean parasite. Results showed that the highest infestation percentage in Mugil cephalus was 76.20 % recorded in February and the lowest one occurred in January (19.40 %). Generally, the infestation percentage in male fishes is lower than those in females being, 34.6 % and 65.4 % respectively. In case of males the highest infestation percentage occurred in July being, 65.5 %, while in case of females the highest percentage was 72.1 % in March. The isopod parasite, Livoneca redmanii, preferred medium size fish (14-17 cm) with infestation percentage 70.64 % and fishes that had weight ranged between 12 g and 14 g with infestation percentage being, 78.82 %. Also, this parasitic isopodinfected gill bilateral and/or unilateral infection per hosted fish with percentage being 98.1 %. The main clinical signs in infected fishes appeared in slow swimming at the water surface, extensive mucus secretion, increased opercula movement and some fishes aggregated on the surface and accumulated at the fresh water inlet. Examination of post mortem lesions revealed that presence of ulcer and erosion blew the gills at the site of parasite and skin abnormalities such as skin ulcers, scale-less and discoloration. Histopathological examination of infected gills showed hyperplasia of epithelial cells in gill filament. Hyperplasia of lamellar epithelium and mucous secreting cells tend to be confusion between secondary gill lamellae, lifting of secondary lamellaeand congested blood vessels were also noticed. It is now clear that cymothoid isopod, Livoneca redmanii was causes economic loss associated with reduced fish growth, high mortality and marked drop in fish production from Lake Qarun.

A total of 693 specimens of the freshwater crayfish, Procambarus clarkii were collected from four sites chosen along the River Nile, at Helwan (Site #1), El Warraq (site #2), El Rahawy (Site #3) and El Rayah El Mounofy (Site#4) during the period from summer 2014 to the following spring 2015. Most individuals of the collected specimens were characterized by hard-rigid outer exoskeleton, with dark-red, or deep brownish color carapace. But some specimens had old green or grey color carapace with scars and epibiotes. The collected specimens showed spatial and temporal variations, recorded 242 specimens (34.92% of all) from El Rayah El Mounofy, declined gradually into 173 (24.96%), 163 (23.52% ) and 115 (16.59%) at El Warraq, El Rahawy and Helwan, respectively. Seasonally, the highest number of individuals was 266 (29.4%), collected in spring, of them 115 were obtained from El Warraq, but declined gradually into 193 (28.9%) in summer, and 183 (24.3%) in autumn and reached the minimum number (51 individuals, 17.3%) in winter. The present results also showed that, no specimens were collected from Helwan during winter, and only 3 individuals were obtained from El Warraq, compared with 17 and 31 specimens collected from El Rahawy and El Rayah El Mounofy, respectively. In contrast, during summer, only 11 specimens were collected from El Rayah El Mounofy. The fluctuations in number of collected individuals of this species were greatly correlated with increasing in water temperature and water level after winter enclosure. The general sex ratio was 1:0.47 males: females and showed significant statistical variations between sites and seasons, recorded 1:0.40, 1:49, 1:0.63 and 1:0.40, males to females at Helwan, El Warraq, El Rayah El Mounofy and El Rahaway, respectively. The present data showed that, the whole populations of this species were varied from 6.6 to 14.3 cm in total length, from 26.84 ±14.42 at Helwan to 34.48±22.5g at El Rahawy.

Tathleeth governorate in Aseer region of southwestern Saudi Arabia has been surveyed for 22 lizard species belonging to 6 families throughout three years started from 2015. A total of 412 specimens of these lizards were encountered and identified. Gekkonidae represented the major family inhabiting the region comprising more than 50% of the collected lizards. Agamidae was represented by 5 species comprising more than 23% of the recorded lizards. The other four families (Lacertidae, Scincidae, Chamaeleonidae and Varanidae) comprised approximately 20% of all the collected lizards. The current survey could be used as conservational clue for the herpetofauna of Tathleeth.

This study was conducted to investigate the potential effects of mannan-oligosaccharide (MOS) and ß-glucan (BG) prebiotic (AGRIMOS®) on the redox homeostasis, histopathology, and microglia count in the brain of heat-stressed broiler chickens. One hundred sixty eight (168) Ross one-day-old broiler chicks were obtained from local hatchery. The experiment was started at 28-day old; where birds were exposed to heat stress and were randomly allotted to four dietary treatments containing 0 (control), 0.5, 2, and 4 g/kg MOS and BG probiotic, respectively, for 14 days. Each treatment consisted of three replicates of 14 birds each (i.e., total birds/treatment count is 42 birds). The results indicated a significant decrease in catalase and superoxide dismutase activities in all MOS and ß-glucan prebiotic treated groups. Supplementation with 0.5 g of prebiotic/kg diet resulted in a significant increase in glutathione levels; however, a significant decrease in superoxide radicals was found at dose of 4 g of prebiotic/kg diet. The levels of lipid peroxidation in supplemented groups exhibited a significant decrease at doses of 2 and 4 g of prebiotic/kg diet. Although there were no obvious changes in the histoarchitecture of cerebellar tissues, a significant increase in the number of microglia was evident following administration with 4 g of prebiotic/kg diet. In conclusion, supplementation of MOS and BG may be regarded as promising candidate for alleviating the undesirable effects of heat challenge on the brain of broiler chickens, nevertheless; further studies are warranted to look for other nutritional approaches.

The reproductive biology of the ascidian Herdmania momus (Savigny, 1816) was studied at anthropogenic impacted sites along Hurghada coasts, Red Sea, Egypt, during January - December 2013. The specimens of this species were collected monthly from the shallow subtidal zones, and varied from 1.20 to 7.0 cm in total length and from 1.28 to 50 g in total body weight. The results showed that, H. momus is hermaphrodite, carries ovaries and testes at the same individuals, but ovaries are larger in size and shapes than testes. The smallest immature individual has 1.2 cm in length; while the smallest mature individual measured 1.46 cm in length and 1.18 g in weight, with ovaries of 0.041g in weight. The sexually mature individuals of this species have ovaries containing oocytes varied in shapes and sizes, passing through four main stages of maturation reaching stage IV or late vitellogenic stage (ripe ova), with oocytes varied from 100 to 140 µm in diameter, characterized with deep orange color and dense accumulation of yolk granules. It was followed by stage V or spent stage of irregular resorbed eggs. The appearance of ripe ova at stage IV showed spatial and temporal variations. The monthly averages of gonadosomatic indices (GSI) exhibited that, the whole populations of this species at all sites have lengthy breeding season extends nearly all the year around and characterizes with high peaks in gonadal activity during January (6.21), April (6.15), June (6.47), July (6.28), declined slightly in May (5.86), and September (5.15), with remarkably spatial variations at the studied sites. The number of mature eggs or fecundity varied from 1481 to 3724 and averaged of 3082.96±769.96 eggs for all populations. These values exhibited greatly individual variations denoting to partially spawning for each individual. The relationship between total body length (cm) and mean the number of eggs (fecundity) showed an increase in egg number with an increase in animal length

This study was carried out on 694 Clarias gariepinusand 846Oreochromis niloticus fish specimens. The fish were randomly collected seasonally, from different fish farms of El-Abbassa, Abu-Hammad, Sharkia Governorate, Egypt. They were used to investigate the prevalence of cestode parasites in C. gariepinus and O. niloticus. Parasitological examination of these fishes revealed that the, highest prevalence rates of Cestodain the fish were recorded in small fishes during summer and the lowest values were observed in the samples of the large size during winter. The study concluded that, the C. gariepinus are more attacked by internal cestode parasites compared O. niloticus. Parasites included Proteocephalus glanduligerus, Polyonchobothrium clarias and Monobothrium sp. The morphology of each species was compared with earlier descriptions, and a diagnostic character of intestinal Cestode species in this geographic region was developed.

In vivo acute and chronic toxicity effects of pendimethalin were carried out on the haematology and biochemical parameters of juvenile Clarias gariepinus subjected to different acute (0.00, 0.25, 0.50, 0.75, 1.00 mg/l) and chronic (0.00, 0.05, 0.10, 0.15, 0.20 mg/l) concentrations of pendimethalin for 4 and 28 days, respectively. As concentration of the toxicant increased in both assays, there were significant (P < 0.05) increase in red blood cells (RBCs), haemoglobin (HB) and mean corpuscular haemoglobin concentration (MCHC), while the white blood cells (WBCs), packed cell volume (PCV), mean cell volume (MCV) and mean cell haemoglobin (MCH) significantly decreased compared to the control. Alterations in biochemical parameters in C. gariepinus tissues during both acute and chronic exposures exhibited similar trend of either increase or decrease in activities as the concentration of toxicant increases. In both exposures, the activities of aspartate amino transferase (AST), alanine amino transferase (ALT) and malondialdehyde (MDA) significantly increased (P < 0.05) in the blood, gill and liver, whereas the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD), acetylcholinesterase (AChE), glucose and protein in these tissues were significantly inhibited (P < 0.05) compared to the control groups, though the magnitude of induction or inhibition in each tissue differs. The study shows that exposure of C. gariepinus to pendimethalin toxicity could cause oxidative stress and alterations in the haemato-biochemical profile of the fish. Therefore, the use of pendimethalin should be minimized and discouraged especially around aquatic bodies so as to prevent adverse effects on the fauna inhabiting them.

The effect of electromagnetic radiation at frequencies (50, 100, 200 & 250 Hz) and intensity of 2 mT on the mortality of Rattus norvegicus norvegicus rat by oral administration of water exposed to this radiation for four hours was investigated. Effect of the sublethal frequency on the physicochemical parameters of water, count of bacteria in water and liver tissues of the rat were also studied. After one month of the experiment, the highest frequency 250 Hz recorded 80% mortality of rats. While, the lowest frequency 50 Hz not exhibited any mortality till the end of experiment. This sublethal frequency caused an increase in temperature, a decrease in total dissolved solids and no change in pH value, salinity, chlorinity and alkalinity of water. It showed also observed bactericidal effect against the water bacteria. It is significantly reduced the number of Escherichia coli and Serratia marcescens colonies and completely prevent the growth of Klebsiella pneumoniae, Pseudomonas fluorescens, Staphylococcus aureus and Staphylococcus epidermidis bacteria in comparing to the unexposed water (control). Destroying in the liver tissue cells was also recorded by this frequency.

The effect of chitosan and nano-chitosan on the land snails Eobania vermiculata and Monacha obstructa was investigated. Under laboratory conditions, the LC50 values recorded, 8.6%. and 6.9 % for E. vermiculata and M. obstructa treated with chitosan, respectively. On the other hand, snails treated with different concentrations of nano-chitosan, resulted in LC50 values of 1.4% and 0.16% for E. vermiculata and M. obstructa, respectively. The effects of both compounds on certain biochemical parameters were recognized. When chitosan and nano-chitosan were applied at the LC50 level, the total protein activities showed significant increase compared to control for E. vermiculata. The same compounds showed a significant decrease in the level of total protein for M. obstructa . Natural chitosan increased the level of total lipid from 32.5 to 52.5 g/dL after the treatment. While nano-chitosan increased it up to 78.33 g/dL for E. vermiculata. Also, natural chitosan increased the total lipid from 25.0 to 37.5 g/dL for M. obstructa compared to an increase of 52.5g/dL attained by the effect of nano-chitosan particles.

The amplified PCR products from mitochondrial 16S rRNA gene were sequenced for seven River Nile teleost species. The obtained sequences ranged in size from 557 (Clarias gariepinus) to 602 (Bagrus bajad) nucleotides. Nucleic acid base composition of the 16S rRNA gene sequences were found to be comparable to other vertebrates having higher AT content relative to GC content. The 16S rRNA sequences have variable regions flanked by six conserved stretches, which could be useful for phylogenetic studies. Results indicated the close genetic relations among the studied actinopterygian River Nile fish species, which are likely to share a common ancestor. These new sequence data could be beneficial for effective fish management, conservation and aquaculture purposes. The value in generating sequence data from other family representatives of River Nile telesot species using the 16S rRNA gene primers developed here could provide a useful contribution to future fish phylogenetic and evolutionary studies of fish in this region

There was a relationship between hyperglycemia and pharmakinetic of toxicity of doxorubicin that leads to increasing oxidative stress on cells. This study was aimed to detect the curative effect of some antioxidants drugs (fullerene C60 and mesocarp fruit extract of Balanites aegyptaica) on the hematological and biochemical of kidney function parameters after induced by diabetes and toxicity with doxorubicin on the rats. nine groups of adult male albino rats were established (n= 8). The first group (Gp. 1) was served as a normal group. Gp. 2 was injected intraperitoneal (i.p.) with by streptozotocin at a single dose (45 mg/kg body weight). Diabetic rats (Gp. 3)were injected intraperitoneal (i.p.) with doxorubicin at the dose (5mg/kg body weight)for three days.Diabetic rats (Gp. 4) was given orally fullerene C60 daily at the dose (4 mg/kg body weight).Diabetic rats (Gp. 5) treated orally bymesocarp fruit extract of Balanites aegyptaicaat dose (1.5ml/kg. body weight). Diabetic rats(Gp. 6) treated orally with fullerene C60 plus mesocarp fruit extract of Balanites aegyptaica. Diabetic rats (Gp. 7) intoxicated DOX treated orally with fullerene C60. Diabetic rats (Gp. 8) intoxicated DOX treated orally with mesocarp fruit extract of Balanites aegyptaica. Diabetic rats (Gp. 9) treated orally with fullerene C60 plus mesocarp fruit extract of Balanites aegyptaica. Whole blood and serum were collected for hematological and biochemical of kidney functions examinations, respectively. Diabetes induces, hematotoxicity was determined by a highly significant decrease in red blood cells (RBCs), white blood cells (WBCs), blood Platelets (PLTs), haemoglobin (Hb) and PCV value, as well as nephropathy was determined by a highly significant increase in creatinne, urea and uric acid. diabetic rats intoxicated DOX showed the reduction in hematological parameters, also, there were a highly significant increase in kidney function parameters. Fullerene C60 and mesocarp fruit extract of Balanites aegyptaica meliorated hematological and kidney functions indices. It could be concluded that Fullerene C60 and Balanites aegyptiaca, clarified a modulatory role against the cellular damage produced by oxidative stress.

This work highlighted the embryo-toxic and teratogenic effects of D. discolor leaves extract to the embryo of D. rerio, a model. Apparently, 100% mortality of embryos was observed in 5% and 10% treatment concentration at 12 hpta. Meanwhile, mortality in lower concentrations increases as time of exposure is prolonged and as the amount of treatment concentration increases. Coagulation was the toxic effect of the plant water extract. On the other hand, heartbeat and hatchability rate decreases as the amount of treatment concentration increases. In terms of teratogenicity, tail malformation was the most marked teratogenic effect of the plant extract. Moreover, growth retardation, head malformation, yolk deformities and abdominal edema were observed. Altogether, D. discolor leaves water extract exhibit toxic and teratogenic effects against D. rerio embryo. Thus, this plant contains active phytochemical components that can be developed as anticancer drugs.

A total of 161 specimens of C. sapidus were collected during the fishing season from November 2016 to July 2017, of the 100 specimens were males (62.1%) and 61 were females (37.9%). The number of obtained specimens has seasonally fluctuated. The highest number of individuals was 67 (41.6%) obtained during spring, compared with the minimum number of 28 individuals (17.4%) collected in summer. The present results showed that 87.3% of the population fell within 75 and 124.9 mm CW and was represented by two modes comprising the sub adults and adults. There were seasonal changes in the size frequency distribution of pooled samples of this species. Males over-dominated females and were represented by the general sex ratio of 1:0.61 males: females. This ratio was tested using the Chi-square (X2) Test for Goodness (P<0.05, df=1) and recorded significant differences in autumn and winter (X2 = 20.82 and 9.32, respectively),where males outnumbered females, but not significant in spring and summer. These results showed also that five maturity stages of females were determined based on morphological shapes called immature, maturing, mature, ripe and spent,but no ovigerous females were detected among the seasonally obtained specimens. The estimated size for 50% sexually mature females was 96 mm CW. There were seasonal changes in the percentage of females with regard to the different maturation stages. Gonad index indicated that males had the highest average in spring and exceeded females which had the highest in summer.

The diversity and dynamics of phytoplankton at a tropical tidal creek in Lagos, in relation to water chemistry changes, were investigated for twenty-four months. Water samples were collected with a 75cl plastic bottle whereas phytoplankton samples were collected by a 55 µm mesh size standard plankton net towed horizontally for 5 mins at <4 Km/h. Water samples were processed to the laboratory for analysis and the phytoplankton samples were preserved by the addition of 4% unbuffered formalin. Water chemistry characteristics were measured using standard methods. The drop count microscopic analysis method was used to study the phytoplankton. Notable parameters that showed marked variations with season include salinity (0.17 – 30.4‰), rainfall (6 – 330mm), transparency (26 – 191cm), total suspended solids (30 - 360 mg/L), total hardness (18 - 3760 mg/L), chloride (60 - 11165 mg/L), conductivity (263 - 32900 µS/cm), total dissolved solids (197 - 21230 mg/L), sulphate (18.9 - 1140 mg/L), nitrate (4.1 - 42 mg/L), calcium (4.9 – 400.2 mg/L), Magnesium (1.4 - 648 mg/L) and iron (0.08 – 0.99 mg/L). A total of sixty-four phytoplankton species (dominated by diatoms) from five (5) algal classes namely Bacillariophyceae (43 species), Cyanophyceae (11 species), Chlorophyceae (7 species), Euglenophyceae (2 species) and Chrysophyceae (1 species) were observed. The green algae, euglenoids and golden brown algae were more frequently occurring during the wet season. The species with the highest biomass (in terms of numbers) was Aulacoseira granulata var. augustissima. The preponderance of very few species primarily Aulocoseira and Microcystis species in the wet season and Coscinodiscus, Actinoptycus, Odontella and Parabelius species in the dry season is a reflection of the changing water conditions within the tidal creek system from season to season and from fresh to high brackish water conditions. Freshwater taxa in the lagoon were primarily recruited from the freshwater areas especially upstream and including the Ologe lagoon from where they existed in higher concentration and usually brought in with floodwater inflow during the rains. Species of Surirella where likely scoured from the creek substratum whereas Parabelius (tube diatoms) were detached from attached submerged hard substrates

A total of 161 specimens of C. sapidus were collected during the fishing season from November 2016 to July 2017, of the 100 specimens were males (62.1%) and 61 were females (37.9%). The number of obtained specimens has seasonally fluctuated. The highest number of individuals was 67 (41.6%) obtained during spring, compared with the minimum number of 28 individuals (17.4%) collected in summer. The present results showed that 87.3% of the population fell within 75 and 124.9 mm CW and was represented by two modes comprising the sub adults and adults. There were seasonal changes in the size frequency distribution of pooled samples of this species. Males over-dominated females and were represented by the general sex ratio of 1:0.61 males: females. This ratio was tested using the Chi-square (X2) Test for Goodness (P<0.05, df=1) and recorded significant differences in autumn and winter (X2 = 20.82 and 9.32, respectively),where males outnumbered females, but not significant in spring and summer. These results showed also that five maturity stages of females were determined based on morphological shapes called immature, maturing, mature, ripe and spent,but no ovigerous females were detected among the seasonally obtained specimens. The estimated size for 50% sexually mature females was 96 mm CW. There were seasonal changes in the percentage of females with regard to the different maturation stages. Gonad index indicated that males had the highest average in spring and exceeded females which had the highest in summer.

The effect of electromagnetic radiation at frequencies (50, 100, 200 & 250 Hz) and intensity of 2 mT on the mortality of Rattus norvegicus norvegicus rat by oral administration of water exposed to this radiation for four hours was investigated. Effect of the sublethal frequency on the physicochemical parameters of water, count of bacteria in water and liver tissues of the rat were also studied. After one month of the experiment, the highest frequency 250 Hz recorded 80% mortality of rats. While, the lowest frequency 50 Hz not exhibited any mortality till the end of experiment. This sublethal frequency caused an increase in temperature, a decrease in total dissolved solids and no change in pH value, salinity, chlorinity and alkalinity of water. It showed also observed bactericidal effect against the water bacteria. It is significantly reduced the number of Escherichia coli and Serratia marcescens colonies and completely prevent the growth of Klebsiella pneumoniae, Pseudomonas fluorescens, Staphylococcus aureus and Staphylococcus epidermidis bacteria in comparing to the unexposed water (control). Destroying in the liver tissue cells was also recorded by this frequency.

The amplified PCR products from mitochondrial 16S rRNA gene were sequenced for seven River Nile teleost species. The obtained sequences ranged in size from 557 (Clarias gariepinus) to 602 (Bagrus bajad) nucleotides. Nucleic acid base composition of the 16S rRNA gene sequences were found to be comparable to other vertebrates having higher AT content relative to GC content. The 16S rRNA sequences have variable regions flanked by six conserved stretches, which could be useful for phylogenetic studies. Results indicated the close genetic relations among the studied actinopterygian River Nile fish species, which are likely to share a common ancestor. These new sequence data could be beneficial for effective fish management, conservation and aquaculture purposes. The value in generating sequence data from other family representatives of River Nile telesot species using the 16S rRNA gene primers developed here could provide a useful contribution to future fish phylogenetic and evolutionary studies of fish in this region

The effect of chitosan and nano-chitosan on the land snails Eobania vermiculata and Monacha obstructa was investigated. Under laboratory conditions, the LC50 values recorded, 8.6%. and 6.9 % for E. vermiculata and M. obstructa treated with chitosan, respectively. On the other hand, snails treated with different concentrations of nano-chitosan, resulted in LC50 values of 1.4% and 0.16% for E. vermiculata and M. obstructa, respectively. The effects of both compounds on certain biochemical parameters were recognized. When chitosan and nano-chitosan were applied at the LC50 level, the total protein activities showed significant increase compared to control for E. vermiculata. The same compounds showed a significant decrease in the level of total protein for M. obstructa . Natural chitosan increased the level of total lipid from 32.5 to 52.5 g/dL after the treatment. While nano-chitosan increased it up to 78.33 g/dL for E. vermiculata. Also, natural chitosan increased the total lipid from 25.0 to 37.5 g/dL for M. obstructa compared to an increase of 52.5g/dL attained by the effect of nano-chitosan particles.

There was a relationship between hyperglycemia and pharmakinetic of toxicity of doxorubicin that leads to increasing oxidative stress on cells. This study was aimed to detect the curative effect of some antioxidants drugs (fullerene C60 and mesocarp fruit extract of Balanites aegyptaica) on the hematological and biochemical of kidney function parameters after induced by diabetes and toxicity with doxorubicin on the rats. nine groups of adult male albino rats were established (n= 8). The first group (Gp. 1) was served as a normal group. Gp. 2 was injected intraperitoneal (i.p.) with by streptozotocin at a single dose (45 mg/kg body weight). Diabetic rats (Gp. 3)were injected intraperitoneal (i.p.) with doxorubicin at the dose (5mg/kg body weight)for three days.Diabetic rats (Gp. 4) was given orally fullerene C60 daily at the dose (4 mg/kg body weight).Diabetic rats (Gp. 5) treated orally bymesocarp fruit extract of Balanites aegyptaicaat dose (1.5ml/kg. body weight). Diabetic rats(Gp. 6) treated orally with fullerene C60 plus mesocarp fruit extract of Balanites aegyptaica. Diabetic rats (Gp. 7) intoxicated DOX treated orally with fullerene C60. Diabetic rats (Gp. 8) intoxicated DOX treated orally with mesocarp fruit extract of Balanites aegyptaica. Diabetic rats (Gp. 9) treated orally with fullerene C60 plus mesocarp fruit extract of Balanites aegyptaica. Whole blood and serum were collected for hematological and biochemical of kidney functions examinations, respectively. Diabetes induces, hematotoxicity was determined by a highly significant decrease in red blood cells (RBCs), white blood cells (WBCs), blood Platelets (PLTs), haemoglobin (Hb) and PCV value, as well as nephropathy was determined by a highly significant increase in creatinne, urea and uric acid. diabetic rats intoxicated DOX showed the reduction in hematological parameters, also, there were a highly significant increase in kidney function parameters. Fullerene C60 and mesocarp fruit extract of Balanites aegyptaica meliorated hematological and kidney functions indices. It could be concluded that Fullerene C60 and Balanites aegyptiaca, clarified a modulatory role against the cellular damage produced by oxidative stress.

This work highlighted the embryo-toxic and teratogenic effects of D. discolor leaves extract to the embryo of D. rerio, a model. Apparently, 100% mortality of embryos was observed in 5% and 10% treatment concentration at 12 hpta. Meanwhile, mortality in lower concentrations increases as time of exposure is prolonged and as the amount of treatment concentration increases. Coagulation was the toxic effect of the plant water extract. On the other hand, heartbeat and hatchability rate decreases as the amount of treatment concentration increases. In terms of teratogenicity, tail malformation was the most marked teratogenic effect of the plant extract. Moreover, growth retardation, head malformation, yolk deformities and abdominal edema were observed. Altogether, D. discolor leaves water extract exhibit toxic and teratogenic effects against D. rerio embryo. Thus, this plant contains active phytochemical components that can be developed as anticancer drugs.

The diversity and dynamics of phytoplankton at a tropical tidal creek in Lagos, in relation to water chemistry changes, were investigated for twenty-four months. Water samples were collected with a 75cl plastic bottle whereas phytoplankton samples were collected by a 55 µm mesh size standard plankton net towed horizontally for 5 mins at <4 Km/h. Water samples were processed to the laboratory for analysis and the phytoplankton samples were preserved by the addition of 4% unbuffered formalin. Water chemistry characteristics were measured using standard methods. The drop count microscopic analysis method was used to study the phytoplankton. Notable parameters that showed marked variations with season include salinity (0.17 – 30.4‰), rainfall (6 – 330mm), transparency (26 – 191cm), total suspended solids (30 - 360 mg/L), total hardness (18 - 3760 mg/L), chloride (60 - 11165 mg/L), conductivity (263 - 32900 µS/cm), total dissolved solids (197 - 21230 mg/L), sulphate (18.9 - 1140 mg/L), nitrate (4.1 - 42 mg/L), calcium (4.9 – 400.2 mg/L), Magnesium (1.4 - 648 mg/L) and iron (0.08 – 0.99 mg/L). A total of sixty-four phytoplankton species (dominated by diatoms) from five (5) algal classes namely Bacillariophyceae (43 species), Cyanophyceae (11 species), Chlorophyceae (7 species), Euglenophyceae (2 species) and Chrysophyceae (1 species) were observed. The green algae, euglenoids and golden brown algae were more frequently occurring during the wet season. The species with the highest biomass (in terms of numbers) was Aulacoseira granulata var. augustissima. The preponderance of very few species primarily Aulocoseira and Microcystis species in the wet season and Coscinodiscus, Actinoptycus, Odontella and Parabelius species in the dry season is a reflection of the changing water conditions within the tidal creek system from season to season and from fresh to high brackish water conditions. Freshwater taxa in the lagoon were primarily recruited from the freshwater areas especially upstream and including the Ologe lagoon from where they existed in higher concentration and usually brought in with floodwater inflow during the rains. Species of Surirella where likely scoured from the creek substratum whereas Parabelius (tube diatoms) were detached from attached submerged hard substrates