Determination of mercury by cold‐vapour technique in several tissues of treated American red crayfish (Procambarus clarkii)

Abstract Adult intermolt specimens of American red crayfish (Procambarus clarkii) collected from Lake Albufera (Valencia, Spain), were exposed to mercury during 96 h. The Hg‐concentrations used were 50, 100, and 250 μg Hg/1 as Cl2Hg. The content of mercury in muscle, midgut gland, antennal glands and gills was investigated. Determinations of mercury were made by cold‐vapour technique and AAS. The mercury levels in all examinated tissues increased significantly (ANOVA test, p < 0.01) with increasing Hg‐concentration in the water.

Effects of sublethal exposure to lead on levels of energetic compounds in Procambarus clarkii (Girard, 1852).

Lead is neither essential nor beneficial to living organisms; all existing data show that its metabolic effects are adverse. Lead is toxic to all phyla of aquatic biota. Most of the lead discharged into surface water is rapidly incorporated into suspended and bottom sediments. The American red crayfish, Procambarus clarkii, lives in a wide range of environmental conditions that include highly polluted waters. Lead present in take sediments can be available to aquatic animals such as P. clarkii because it is a detritivor and burrow into the sediment. In fact, we found remarkable levels of lead in tissues of P. clarkii caught in Albufera Lake and kept 15 days in clean water (e. g. 223 [mu]g/g…

Changes in biochemical composition of gills, hepatopancreas and muscle of the red crayfish Procambarus clarkii (Girard) after sublethal exposure to mercury.

Abstract 1. 1. The changes in the biochemical composition of gills, hepatopancreas and muscle after exposure to 0.25 mg Hg/l were studied in Procambarus clarkii . 2. 2. Sublethal exposure to mercury in P. clarkii resulted in significant decreases in protein concentration and caloric concentration in gills over the 96 hr period. Glycogen/lipid and glycogen/protein ratios increased after 48 and 96 hr of mercury exposure. 3. 3. Lipid and caloric concentration in the hepatopancreas were significantly lower in 96 hr mercury exposed group. 4. 4. Glycogen concentration in muscle was depleted as consequence of 96 hr mercury exposure.

Determination of lead in treated crayfish Procambarus clarkii: accumulation in different tissues.

The continual loading of trace metals into our environment represents a water pollution problem due to their toxic effects on aquatic biota. In addition, metal ions can be incorporated into food chains and concentrated by aquatic organisms to a level that affects their physiological state. There are several investigations on the toxic effects and bioaccumulation of lead in fishes, molluscs, and crustaceans. Lake Albufera (Valencia, Spain) and the surrounding rice-field waters are subjected to large loads of sewage and toxic industrial residues (including heavy metals) from many urban wastewaters in the area. In 1978, the American red crayfish Procambarus clarkii (Girard) appeared in Lake Al…

Nephrotoxic and hepatotoxic effects of chromium compounds in rats

The nephrotoxic, hepatotoxic and cardiotoxic actions of hexavalent chromium compounds, as well as their effects on lung, blood and circulation may contribute to the fatal outcome of chromium intoxication. Although trivalent chromium have been regarded as relatively biologically inert, there are a few salts of chromium III that have been found to be carcinogenic when inhaled, ingested or brought in contact with the tissues. Sensitive persons and industry workers have been subjects of dermatitis, respiratory tract injuries and digestive ulcers due to chromium compounds. In this work, the authors have studied the effect of trivalent and hexavalent chromium compounds on rats measuring the trans…

Effects of low mercury concentration exposure on hatching, growth and survival in the Artemia strain La Mata parthenogenetic diploid

The effects of exposure to low levels of mercury in the developmental events occurring from hatching to adult life in the Artemia strain La Mata parthenogenetic diploid were studied. Mercury (5, 25, 50, 250 and 500 nM) added at the beginning of incubation had no effect on hatching and emergence. We studied mercury effects on the growth of viviparous nauplii obtained from mothers that had been acclimatised to 25 nM of mercury for all their lives. Measurements of the length of Artemia individuals were carried out using video recordings in order to reduce the stress experienced by the test animals. The mean body length of the mercury-treated group (25 nM) was higher than that of the control an…

Effect of sublethal exposure to mercury in the biochemical composition of hepatopancreas in Procambarus clarkii during the recovery after starvation

Abstract Freshwater crayfish undergo seasonal periods of starvation. The hepatopancreas is the main energetic-storage organ in this animal. An adequate replenishment of energetic reserves after these periods of fasting is critical for the proper growth and reproduction in this species. Mercury compounds enter the biological environment from natural discharges and anthropogenic sources. Mercuric chloride is one of the most toxic metallic salts found in polluted waters. In these studies, we report the effect of mercuric chloride in the biochemical composition of crayfish hepatopancreas during the recovery period after prolonged starvation. Adult intermolt crayfish (P. clarkii) were kept starv…

Effects of cadmium on the biochemical composition of the freshwater crayfishProcambarus clarkii (Girard, 1852)

Lake Albufera of Valencia (Spain) and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic residues. Among these residues include heavy metals which have been deposited from the many urban and waste waters in this area. The American red crayfish, Procambarus clarkii from Albufera Lake has high resistance to heavy metals. The authors have also found that P. clarkii shows a high capacity for cadmium accumulation in experimental conditions and natural conditions since crayfish collected in this area contained considerable amounts of cadmium in several tissues even after 15 days of depuration in clean water. Since the physiological changes that take place when…

Effect of cadmium pre-exposure in cadmium accumulation by brine shrimp Artemia: Involvement of low-molecular-weight cadmium-binding ligands

Abstract Cadmium is a ubiquitous non-essential element that possesses high toxicity and is easily accumulated from the environment by aquatic organisms. It is known that pre-exposure to cadmium increases the resistance of animals to a subsequent exposure. In this work, we report studies of the effect of pre-exposure to cadmium on the accumulation of this metal from seawater by brine shrimp Artemia, as well as the involvement of low-molecular-weight cadmium-binding ligands in this process. During the pre-exposure experiments, animals were kept in seawater containing 20 mg/litre Cd for 24 h and then transferred to clean seawater for 48 h. Afterwards, pre-exposed and control animals were expos…

Cadmium-binding proteins in midgut gland of freshwater crayfishProcambarus clarkii

Metallothioneins, metal binding proteins, were originally isolated and characterized by Margoshes and Vallee. These proteins have a high affinity for various heavy metals, particularly cadmium and mercury and have extensively been studied in mammals. Metal binding proteins have been observed in a variety of marine invertebrates; however, there is very little information available on metal binding proteins in freshwater invertebrates, and particularly in freshwater crustaceans. Cadmium is an ubiquitous non essential element which possesses high toxicity to aquatic organisms. Cadmium binding proteins observed in invertebrates have similar characteristics to mammalian metallothioneins. In 1978…

Cadmium binding proteins induced in exposed freshwater crayfish Procambarus clarkii.

This work describes results on the characterization of cadmium binding proteins (Cd-BPs) obtained from cadmium exposed freshwater crayfish Procambarus clarkii. After acclimation to laboratory conditions, induction of Cd-BPs was achieved by water exposure at a concentration of 100 micrograms Cd/L during 2, 15, and 30 d. In accordance with the method followed by Engel and Brouwer, in each case two midgut glands were minced and homogenized in Tris-HC1 buffer with PMSF to prevent protease activity and DTT to maintain reducing conditions. The homogenate was centrifuged, heat treated, applied to a column of Sephadex G-75, and eluted with the same buffer (pH 8.6). Absorbances of the fractions coll…

Quantification of cadmium-induced metallothionein in crustaceans by the silver-saturation method

Metallothionein (MT) has been proposed as a specific biochemical probe for metal exposure of aquatic organisms. It is recognized that its usefulness as a monitoring tool depends on the full understanding of its function and on the possibility of measuring its concentration in tissues. Therefore the study of MT in crustaceans is interesting from two different points of view: the need to understand mechanisms associated with the toxicology of metals, and the potential use of this protein for monitoring metal-contamined environments. Several methods have been developed for quantitative measurements of MT in biological samples. Immunochemical and electrochemical procedures are reliable techniqu…

Effect of cadmium exposure on zinc levels in the brine shrimp Artemia parthenogenetica

Zinc and cadmium have been reported as metabolic antagonists, such that high zinc intake afford animals some protection against the potentially toxic effects of cadmium exposure. There is considerable evidence to support a role of metallothioneins (MTs) in regulating or controlling the intracellular availability of essential metals and the non-essential metal. The effect of 24-h cadmium pre-exposure (10 mg Cd/l) on zinc concentrations in the brine shrimp Artemia parthenogenetica exposed to zinc (5 mg Zn/l) was studied. The zinc content of shrimps was not altered by cadmium. The homeostatic mechanism for zinc regulation appears not to be disturbed by cadmium exposure in shrimps kept in natur…

Cadmium, mercury, and lead effects on gill tissue of freshwater crayfishProcambarus clarkii (girard)

Intermolt adult crayfish P. clarkii were used for this work. After acclimatization to laboratory conditions crayfish were exposed to sublethal concentrations of cadmium, mercury, and lead for 96 h. Gills of control and exposed crayfish were removed and ATPase activity and oxygen uptake rate were determined. Structural damage of gill filaments was also observed. Gill tissue respiration rates were measured for individual crayfish using a Gilson differential respirometer. Lead causes a decrease of gill oxygen uptake, but neither cadmium nor mercury seems to affect it at the concentrations employed. Although all metals studied alter gill filament structure, lead damage is the most apparent. In …

Gill ATPase activity in Procambarus clarkii as an indicator of heavy metal pollution.

Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues, including heavy metals, from the many urban and waste waters of this area. The American red crayfish, Procambarus clarkii have a high resistance to toxic effects of heavy metals. The sublethal effects of heavy metals on gills of fish and aquatic invertebrates have been extensively studied. Some metabolic disturbances and histologic damages have been reported, as well as osmoregulation alterations. However, little work has been done about the effect of heavy metals on Na,K and Mg-ATPases of freshwater invertebrate gills. Na,K-ATPase is the prime mediator of ion trans…

Oxygen uptake by excised gills ofProcambarus clarkii (Girard) from albufera lake of Valencia, Spain, under heavy metal treatments

The American red crayfish Procambarus clarkii, originally from Louisiana (USA) was introduced in Spain in the 70's in the Guadalquivir River swamps. It appeared first randomly and in a more regular basis afterwards since 1978 in the Albufera Lake south of Valencia and in the surrounding rice fields. Albufera lake and surrounding rice fields waters are being subject since the last three decades to very heavy load of sewage, toxic industrial residues including heavy metals and pesticides from the many urban and industrial settlements in the zone. In the present study, the authors have investigated the effect that heavy metals (Chromium, Cadmium and Mercury) have on the oxygen uptake by excise…

Developmental and Reproductive Effects of Low Cadmium Concentration onArtemiaparthenogenetica

Hatching, reproductive, and lifespan characteristics of an Artemia parthenogenetica population from La Mata (Alicante, Spain) exposed to cadmium were studied. No effects on percentage of cyst hatched nor time of hatching were observed on cysts exposed from 0.01 to 5 mg Cd/L. Cohorts of Artemia were chronically exposed to cadmium in life-table experiments to test whether ecologically relevant impacts may occur after several generations of exposure to a very low concentration of cadmium. Chronic toxicity tests were performed using neonates of a third generation of shrimps exposed to 0.08 mg Cd/L (1/1000 of the LOEC for 24 h acute toxicity test). No significant reduction in the intrinsic rate …

Cadmium induced metallothionein in hepatopancreas of Procambarus clarkii: Quantification by a silver-saturation method

Abstract 1. Cadmium induced metallothionein (MT) in crayfish hepatopancreas was measured by silver-saturation method. 2. An increase in MT content was recorded in crayfish hepatopancreas after 12 hr of exposure to 10 mg Cd/l. 3. There was found to be a linear relationship between MT concentrations in hepatopancreas and cadmium concentration in the water. 4. MT levels in hepatopancreas of 20 mg Cd/l exposed crayfish were 7-fold higher than those in control animals.

Cadmium accumulation in the crayfish,Procambarus clarkii, using graphite furnace atomic absorption spectroscopy

Lake Albufera and the surrounding rice-field waters are being subject to very heavy loads of sewage and toxic industrial residues (including heavy metals and pesticides) from the many urban and wastewaters in this area. The American red crayfish Procambarus clarkii is native to the Louisiana marshes (USA). In 1978, the crayfish appeared in Lake Albufera near Valencia (Spain), and presently, without adequate sanitary controls, the crayfish is being fished commercially for human consumption. In view of this interest, it is important to have accurate information on concentrations of cadmium in natural waters and cadmium levels of tissues of freshwaters animals used as human food, as well as th…

Comparing the acute response to cadmium toxicity of nauplii from different populations ofArtemia

The lethal responses to cadmium of instar II nauplii from eight populations of Artemia belonging to the species Artemia franciscana, Artemia salina, Artemia persimilis, and Artemia parthenogenetica have been compared. Generalized linear models were used to fit mortality. The model indicates that there is a relationship between species, type of population, and mortality rate. The two populations of A. franciscana were the most sensitive to cadmium toxicity (median lethal concentration, LC50, of 93.3-142 mg/L), while the population of A. persimilis was the most resistant (LC50 of 284 mg/L). Differences in the phenotypic variability in each population were assessed through the slope of the mor…

Effects of temperature on the acute toxicity of heavy metals (Cr, Cd, and Hg) to the freshwater crayfish, Procambarus clarkii (Girard).

Chromium, an essential trace element for humans and animals is involved in normal carbohydrate metabolism; however, it is toxic at high concentrations. There is no evidence that cadmium and mercury are biologically essential but their toxicity for organisms is well known. Both cause toxic effects at low concentrations to most organisms, especially in combination with other environmental variables such as temperature. Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues (including heavy metals) from the many urban and waste waters in this area. In 1978, the American red crayfish Procambarus clarkii appeared in lake Albu…

Sublethal zinc exposure has a detrimental effect on reproductive performance but not on the cyst hatching success of Artemia parthenogenetica

The sublethal zinc toxicity to Artemia parthenogenetica as regards the possibility of colonization of zinc polluted salterns by means of cysts has been assessed by a cyst hatching assay and a life table approach. Emergence and hatching at different times as well as the whole hatching profile were taken as end-points for evaluating success of development. Demographic and reproductive parameters calculated according to the Lotka equation were used as an indicator of the chronic toxicity of the population. No adverse effects of waterborne zinc were found on hatching and emergence of cysts of A. parthenogenetica at any of the concentrations tested (0.01 mg/l, 0.1 mg/l, 0.5 mg/l, 1 mg/l, 5 mg/l)…

Glutathione content, glutathione S-transferase and γ-glutamyltranspeptidase activities in mid-gut gland of Procambarus clarkii: time course in the presence of cadmium