Impacts of sublethal lead exposure on the hemato-immunological parameters in tilapia (Oreochromis mossambicus)

The effects of exposure of tilapia (Oreochromis mossambicus) to sublethal concentrations of lead on hematological and immunological parameters were investigated. The fish were semistatically exposed to low (L) (0.5 mg L^?1), medium (M) (2.5 mg L^?1), and high (H) (5 mg L^?1) lead concentrations for 14 days. At the end of the trial, red blood cell (RBC) count, hematocrit (Hct) ratio and hemoglobin levels showed significant decreases in M and H groups, while RBC was significantly increased in L group compared to control group. Lysozyme activity showed a decrease in all groups on day 14 compared to control. A decrease in myeloperoxidase activity was seen in M and H groups on day 7, and in all treatment groups on day 14. In conclusion, it was found that exposure of O. mossambicus to lead concentrations affected hematological and immunogical parameters adversely.     

Observations on metal concentrations in commercial landings of two species of tilapia (Oreochromis mossambicus and Oreochromis niloticus) from reservoirs in six river basins in Sri Lanka

Samples of the muscle of two species of tilapia (Oreochromis mossambicus and O. niloticus; 17–20 cm length) were obtained from at least one reservoir in each of the six river basins (Aruvi Aru, Kala Oya, Kirindi Oya, Ma Oya, Mahaweli, and Walawe Ganga catchments) in Sri Lanka. The metals Ca, Cu, Fe, K, Mg, Mn, Na, and Zn were consistently detected in the muscle tissue. Overall, there were few differences in the concentration of metals between the two species of fish, although there were also some statistically significant differences (p < 0.05) in the concentrations of some metals in fish obtained from some of the reservoirs. Aruvi Aru stands out as a river basin in which the two fish species have significantly lower concentration of metals when compared to other river basins. The concentration of the metals studied were below WHO and FSANZ guideline values for fish, suggesting that the consumption of the metals found in tilapia from these reservoirs poses little risk to human health.     

A preliminary report on effect of pulsed magnetic fields on fresh water fish (Labeo rohita) chromosomes

Marine-life scientists around the world are already carrying out investigative trials to obtain higher yields under in-captive breeding conditions, on both edible varieties and ornamental fishes with optimal inputs. However, for such trials to succeed there is a need for genetic improvement. The idea that fish production can be enhanced by genetic manipulation is gaining acceptance, as there is a strong possibility that qualitative improvement of economically important traits can be achieved by identifying and utilizing more effective genotypes. In the present communication a tentative plan for genetic manipulation of fresh water fish using controlled, pulsed magnetic fields, is being discussed. Chromosome preparations of Labeo rohita were made using Colchicine-Methanol-Acetic acid air drying technique, using tissue from gills. The fish were exposed to Pulsed Magnetic Field (PMF)with intensity 0.2 Gauss, pulsing at 50 Hz frequency (sine wave) for 6 hours / day for a total period of 30 days inside specially designed magnetic field enclosures. The karyological investigations revealed no distinct difference between "test" and "control" groups.     

Effect of arsenite on certain aspects of protein metabolism in fresh water teleost, Tilapia mossambica (Peters)

The sublethal toxicity of sodium arsenite on protein metabolism was investigated in teleost fish, Tilalpia mossambica at the end of 24, 48, 72 and 96 h of exposure. Total protein content, free amino acid content and activities of the enzymes aspartate amino transferase (AAT) and alanine amino transferase (ALAT) in liver, gill, brain and muscle exhibited significant (P<0.05) alterations throughout the investigation in relation to that of control. It is suggested that the fish is able to respond to the stressful situations by gearing up the metabolic activity as revealed by the elevated protein, amino acid content and the activities of AAT and ALAT.     

Impact of industrial effluents on the biochemical composition of fresh water fish Labeo rohita

In acute toxicity (96 hr) experiment the fingerlings of freshwater fish Labeo rohita was exposed to tannery, electroplating and textile mill effluents. The LC0 and LC50 concentrations were 15% and 20% for tannery effluents, 3% and 6% for electroplating effluents and 18% and 22% for textile mill effluents respectively. It was found that, electroplating effluent was more toxic than tannery and textile mill wastes. After acute toxicity experiments for different industrial effluents, various tissues viz. gill, liver, muscle and kidney were obtained separately from control, LC0 and LC50 groups. These tissues were used for biochemical estimations. The glycogen content in all the tissues decreased considerably upon acute toxicity of three industrial effluents except muscle in LC50 group of tannery effluent and kidney in LC50 group of textile mill effluent, when compared to control group. The total protein content decreased in all tissues in three effluents except gills in LC50 group of tannery effluent, kidney in LC50 group of electroplating effluent and kidney in LC0 group of textile mill effluent. In general total lipid content decreased in all tissues after acute exposure when compared to control group. The results obtained in the present study showed that, the industrial effluents from tannery, electroplating and textile mills caused marked depletion in biochemical composition in various tissues of the fish Labeo rohita after acute exposure.     

Influence of season,ontogeny and tide on the diet of the temperate marine herbivorous fish Odax pullus (Odacidae)

The diet of the temperate marine herbivorous fish Odax pullus (Pisces: Odacidae) was examined using gut-content analysis followed by principal-component analysis and analysis of variance. Fish were collected near Leigh, on the northeast coast of New Zealand, from February 1983 to September 1984. The data were categorised by size of fish, season, and state of tide. A major ontogenetic shift in diet was observed. Juveniles fed on animal material (crustaceans and gastropods), epiphytic rhodophytes, and some phaeophyte material. Adults fed almost exclusively on two phaeophyte taxa, the laminarian Ecklonia radiata and the fucoid Carpophyllum spp. Dietary selection was evident at the level of particular plant components; the diet of larger fish in spring samples was dominated by fucoid reproductive receptacles. There was no direct evidence of a tidal influence on diet composition of O. pullus, although the relative proportions of E. radiata and Carpophyllum spp. ingested by adult fish appeared to vary with tidal state. The volume of gut contents varied seasonally for all size classes, although the timing of peak annual food intake varied among size classes. Tidal state did not influence the volume of the gut contents. The ontogenetic and seasonal trends evident in the diet of O. pullus appeared to be related to a number of factors including relative gut length, gonad development, ontogenetic changes in feeding anatomy and seasonal changes in algal composition.     

Uptake of 137Cs in cultured fresh water fish (Cyprinus carpio): Physiological and histological effects

An experiment was conducted in fresh‐water fish (Cyprinus carpio) cultured, in small water tanks, artificially contaminated with radioactive ¹³⁷Cs (3000 Bq/1) to determine the uptake of ¹³⁷Cs and its physiological and histological effects in different fish organs.

It was found that ¹³⁷Cs was located in muscular tissues, gills, head muscles, liver and kidneys. Moderate amounts were found in spleen, eyes, gonads, intestine and urinary bladder. It seems that sorption was of much less importance than ingestion in the uptake of ¹³⁷Cs. The histological examination in musculature tissue, revealed an acute hyperemia with focal hemorrages which may be due to allergic effects of ¹³⁷Cs. Hyperemia and focal fatty degeneration of hepatic cells was also noted in the liver which may be due to toxic effects of ¹³⁷Cs diffused hyperemia has also occurred in the brain and focal degeneration of epithelial cells of renal tubules.     

Toxicological effects on some biochemical parameters of fresh water fish Channa punctatus (Bloch.) under the stress of nickel

Toxicological effects of some biochemical parameters of freshwater fish Channa punctatus (Bloch), under the stress of Nickel (NiSO4. 6H2O), at various concentrations of 10, 20, 30 and 40 ppm for 30 days were observed. Gradual decrease in the levels of liver protein and liver ascorbic acid due to proteolysis and liver glucose breakdown respectively was observed. Contradictorily, high liver cholesterol level, may be due to hepatic disfunctioning and accumulation in brain. There was also gradual decrease in the brain protein level showing significant alterations but the brain ascorbic acid level showed no significant alterations. Decrease in the protein and ascorbic acid level and increase of cholesterol level thus indicates stressful condition of the fish.     

Effects of rogar and endosulfan on the metabolism of fresh water sponge (Spongilla lacustris)

Spongilla lacustris were exposed to sub lethal concentrations of pesticides, rogar and endosulfan for one month period. Metabolites like carbohydrates, protein and enzymes like those that peroxidase and carbonic anhydrase were estimated in the experimental and control animals. The results show, depletion of carbohydrates while protein elevated as the days progressed. Similarly an enzyme activity found to be decreased in exposed Spongilla lacustris.     

Reproduction of the estuarine mysid Taphromysis bowmani (Crustacea: Malacostraca) in fresh water

We have monitored the incorporation of ³H-glycine into, and the excretion of, soluble tissue and extrapallial fluid proteins in the hardshell clam Mercenaria mercenaria in an attempt to follow some of the metabolic events that occur antecedent to shell deposition. After incubating at 20°C for 48 h, clams were killed and the distribution of incorporated and unincorporated tritium in seawater, mantle fluid, hemocoelic-tissue fluid, extrapallial fluid and tissue was determined. Most of the incorporated tritium was in the insoluble tissue proteins. Much more incorporated tritium was found in the hemocoelic-tissue fluid fraction than in the extrapallial fluid. We assume that most of the radioactivity we followed was due to free or incorporated radioactive glycine. The ratio of ³H-protein to ³H-glycine was greater in the extrapallial fluid than in the hemocoelic-tissue fluid, suggesting either protein secretion into or glycine removal from the extrapallium. We also observed that both ³H-protein and ³H-glycine concentrations were higher in the mantle fluid than in the external sea water, although the ratios of ³H-glycine to ³H-protein in these two fluids were not different.     

Effect of water extract of the bark of Buchanania lanzan linn. on behaviour and chromatophores of a fresh water fish,Labeo rohita

Fish exposed to 150 ppm and 250 ppm doses saparately, showed eratic swimming with hyper-excitability, spiralling, convulsion and mortality. However at 350 ppm dose fish became lethargic and steady at the bottom of aquarium. This behaviour appears to be due to sedative effects of fish implicating the phychoactive nature of the plant B. Ianzan. At 150 ppm to 350 ppm doses, fish scale changed from reticulate to punctate chromatophores; and treated fish when transferred to fresh water, were slowly regained to normal behaviour after 96 h exposure. Hence doses regaining from 150 ppm to 350 ppm is considered to be psychoative in nature. In higher doses 450 ppm and 550 ppm fish could survive only 76 h and 4.30 h respectively and then died indicating toxicity of plant for the said doses. It is found that scale present on its body is most suitable test system for the study of psychoactivity and toxicity of plant extracts on fish, Labeo rohita.     

Biomarkers of oxidative stress as indicators of water pollution in Nile tilapia (Oreochromis niloticus) from a water reservoir in Riyadh,Saudi Arabia

Antioxidant enzyme activities of fish (Oreochromis niloticus) were determined in order to assess the status of pollution in the Wadi Namar (WN), near Riyadh, Saudi Arabia. Activities of four antioxidant enzymes as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and concentrations of glutathione (GSH) and oxidant malondialdehyde (MDA) were selected as bioindicators. Fish (n = 14) were sampled in the month of April 2013 from WN and a control site (CS). SOD activity was increased by 37.9%, 47%, and 29% in kidney, liver, and heart, respectively, while a significant decrease (36.4%) was observed in gills of O. niloticus from WN as compared to fish from CS. CAT activity was reduced by 51%, 55%, 47%, and 35% in kidney, liver, heart, and gills of O. niloticus from WN. The GST activities in kidney, liver, and heart of O. niloticus from WN were elevated by 34%, 48%, and 32%, respectively. However, significant fall (49%) in gills of fish was noted from WN compared to fish from CS. GSH levels were increased by 44%, 36%, and 38% in kidney, liver, and heart, respectively, but decreased by 30% in gills. MDA levels of O. niloticus were significantly increased in kidney, liver, and heart in fish from WN. Data indicated that WN is polluted mainly by industrial and urban discharge of liquid waste products.     

Pollutant effects on the mixed function oxygenase (MFO) and reproductive systems of the marine polychaeteNereis virens

The cytochrome P-450 dependent mixed-function oxygenase (MFO) system ofNereis virens, found in the endoplasmic reticulum of the intestinal epithelium, has similar components and cofactor requirements when compared to other invertebrates. Worms exposed to food containing benzo(a)pyrene or a mixture of polychlorinated biphenyls (Aroclor 1254) had significantly higher MFO activity and cytochrome P-450 content than unexposed ones.N. virens from a site in Porland, Maine, USA, which was heavily contaminated with oil, and nearby clean reference sites were studied. The weight, MFO activity and presence or absence of gametes were determined. The MFO activity in worms from the oil-contaminated site was approximately six times that of worms from the reference sites; worms from the reference areas were six times larger than oil-contaminated worms. Worms from the oil-contaminated area lacked or had undeveloped gametes in spring, summer and fall. In contrast, many of the worms collected from the reference sites at the same times had fully developed gametes.     

Effect of cadmium individually and in combination with other metals on the nutritive value of fresh water fish,Channa punctatus

Impact of metal cadmium on the nutritive value of Channa punctatus on exposure to a sublethal concentration (1.12 mg/l) of cadmium (Cd2+) for 15 and 60 days has been studied. Among the various parameters selected, the level of moisture in liver and muscle was increased, while decrease was noted in the level of ash, total proteins and inorganic constituents like iron, calcium, inorganic phosphate, sodium and potassium in both liver and muscle in the two types of exposure. The total lipid level of liver increased, while muscle lipid level was decreased. On the other hand, calcium, iron, inorganic phosphate, sodium and potassium levels showed increase in blood. Zinc and selenium decreased the percentage alterations in all the parameters selected for study. In the two types of exposure, zinc was most effective to counteract the cadmium toxicity to fish as in almost all the parameters insignificant alterations were recorded. In combination studies, protection against cadmium toxicity by the two chemicals became more marked with increase in the tenure of exposure.     

Density and distribution patterns of the temperate marine fish Cheilodactylus spectabilis (Cheilodactylidae) in a reef environment

Cheilodactylus spectabilis (Hutton) is common over shallow reefs in north-eastern New Zealand. Replicated transect between-area differences in density and in size frequency. C. spectabilis is not nocturnally active. The between-area differences in density and size frequency remained constant over daylight hours, demonstrating that C. spectabilis does not undergo any systematic feeding migrations. Topographic complexity was shown to have a significant positive influence on fish density. Mean size was related to water depth at 5 localities investigated, with small (<200 mm standard length, SL) individuals being restricted to shallow water. All sizes of C. spectabilis examined had fed on small invertebrates, with gammarid amphipods predominating. No evidence of size-related differentiation in feeding patterns was observed, although small individuals spent significantly more time feeding than large ones. Small (<200 mm SL) individuals occupied feeding areas and shelter sites from which they excluded other small C. spectabilis. Large individuals showed no site-associated aggression, covered a greater area during daily movements and overlapped with other large and small C. spectabilis while feeding. No evidence of dawn or dusk peaks of feeding activity or movement was collected.     

Influence of hydrostatic pressure on l-glutamate dehydrogenase from the Antarctic fish Chaenocephalus aceratus

The influence of hydrostatic pressure on the stability and activity of glutamate dehydrogenase (GDH) from the liver of the Antarctic fish Chaenocephalus aceratus (Notothenioidei: Channichthyidae) has been investigated using the homologous bovine enzyme for comparison. At gradually increasing pressure, the fish GDH retains all activity up to 140 MPa, whereas in the same pressure range the bovine enzyme is slightly inactivated. The kinetics of pressure-induced inactivation of Antarctic GDH displays an exponentially decreasing residual activity as a function of the incubation time, whereas the bovine enzyme shows a complex pattern of behaviour in the first 20 min of incubation, attributable to the transient formation of aggregates. The coenzyme NAD increases the stability of both enzymes. The activation volume calculated for the reaction catalysed under pressure by fish GDH is higher than that of the bovine enzyme. These results indicate that the molecular properties of fish and bovine GDH are affected differently by hydrostatic pressure. A common mode of inactivation under extreme conditions of pressure and temperature of the cold-adapted Antarctic fish and mesophilic bovine GDH is deduced and discussed. Received: 20 October 1998 / Accepted: 7 May 1999     

Studies on the family hemiuridae (Trematoda: Digenea), with a description of a new genus from marine fish of Indian waters

A new digenetic trematode, collected 1969–1970 at Ratnagiri (India) from the marine eel Leptocephalus conger, is described as Indostomachicola kinnei n. g., n. sp. The new genus differs from Stomachicola Yamaguti, 1934 and Allostomachicola Yamaguti, 1958 in many characteristics. The new species is characterized by an unlobed ovary, absence of receptaculum seminis, and presence of post-acetabular seminal vesicle and a ventral pit.     

Fecundity of the freshwater fish Channa punctatus (Bloch) from three aquatic bodies

The fecundity studies on Channa punctatus revealed that there is a relationship between length of the fish with fecundity, weight of the fish and ovary with fecundity. The length and fecundity exhibit curvilinear relationship and a straight line relationship is observed between fecundity and body weight. Fecundity and ovary weight also exhibited linear relationship. The comparative degree of fecundity of the fish is Jagat tank > Kadaganchi tank > Kagina river. Although fish collected from Jagat tank exhibits higher fecundity, all the other three aquatic bodies provide proper environmental conditions for the growth and reproductive activity of the fish.     

Fecundity of the freshwater fish, Notopterus notopterus (Pallas) in natural and heavy metal contaminated water

The knowledge of fecundity of fish from a specific aquatic body is extremely important in the successful management and exploitation of its fishery. In the present investigation the fecundity of the freshwater fish, Notopterus notopterus was studied in fish collected from a natural aquatic body (Sirnoor nala) near Gulbarga and also in fish exposed to some heavy metal contamination (HgCl2, CdCl2 and their combination) at sublethal concentration for 15 days in the laboratory. The mathematical relationship between fecundity and total length, body weight, ovary length and ovary weight were determined in both unexposed and exposed fish. The fish, N. notopterus has bigger oocytes and are few in number. Studies in the fish exposed to heavy metals indicate that significant reduction in these parameters after exposure to heavy metals at sublethal concentration was noticed. The fecundity has straight line relationship with total length, body weight, ovary length and ovary weight in control fish which did not alter after heavy metal exposure. This study provides the viability of species in only specific environment.     

Toxicity of neem pesticides on a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) of Darjeeling district in West Bengal

Static renewal bioassay tests were conducted to evaluate the acute toxicity of two neem based biopesticides, applied widely on tea plantation namely, Nimbecidine and Neem Gold either separately as well as, in combination to the fingerlings (mean body length- 4.46 +/- 0.15 cm; mean body weight- 0.49 +/- 0.15g) of a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) acclimatized to laboratory conditions prior to experiment. The 96 hours LC50 values for Nimbecidine and Neem Gold and the combination of the two were 0.0135 mgl(-1), 0.0525mgl(-1) and 0.0396 mgl(-1), respectively. The regular water quality analysis showed, that with increasing doses of biopesticides, dissolved oxygen level was lower and other parameters like pH, free carbon dioxide, total alkalinity total hardness, chloride ions of water increased. The fish under toxicity stress suffered several abnormalities such as erratic and rapid movement, body imbalance and surface floating responding proportionately to the increase in concentrations of the toxicant biopesticides. The 96 hours LC50 values proved Nimbecidine more toxic than Neem Gold and the combination of the two biopesticides.