Effects of toxicants on developing oocytes and embryos of the blue crab, Callinectes sapidus

Oocytes (90 μm in diameter) were isolated from ovaries of 14-day post-molt adult female crabs and maintained in culture media. The addition of cadmium (20 μg/ liter) or tributyltin (2 μg/liter) to developing oocytes resulted in decreases in the growth of oocytes as measured by protein and lipovitellin accumulation relative to controls. Crab embryos isolated from yellow ‘sponge’ of female blue crabs were maintained in seawater until hatching (6–8 days). Toxicants tested included cadmium, copper, tributyltin and endosulfan. Some of the processes or events which were followed included water uptake, lipovitellin utilization rate, formation of appendages, formation of a heart, formation of eyespots and hatching to zoea stage. The primary effects from addition of toxicants were deformed eyespots and reduced hatching success. The hatching EC₅₀ (concentration at which 50% of embryos failed to hatch) for copper, cadmium, tributyltin and endosulfan were 3.1, 0.25, 0.047 and 450 μg/liter, respectively. Crab embryos appear to be suitable for testing of the effects of a variety of toxicants with advantages including low cost, reproducibility, low variability and sensitivity.     

Effect of zinc on regeneration in the fiddler crab Uca pugilator and its interactions with methylmercury and cadmium

After multiple autotomy (one chela and six walking legs) fiddler crabs (Uca pugilator) were exposed to zinc chloride, cadmium chloride, methylmercuric chloride or combinations of these metals. Zinc at 1, 3 and 5 ppm had a retarding effect on limb regeneration, which was amplified in water of reduced salinity. Methylmercury at 0·5 ppm and cadmium at 1·0 ppm have previously been found to retard regeneration. When crabs were exposed to meHg and Zn the effects were additive, both in sea water (30% salinity) and in water of reduced salinity (7–8%). However, when crabs were exposed to combinations of Zn and Cd the effects were antagonistic and the rate of regeneration was almost that of controls. In water of 7–8% salinity the Cd effect was greatly intensified and growth was almost totally prevented. The presence of Zn counteracted this and allowed growth and ecdysis to occur.     

Plasma steroid levels in female flounder (Platichthys flesus) after chronic dietary exposure to single polycyclic aromatic hydrocarbons

The chronic effects of polycyclic aromatic hydrocarbons (PAHs) on ovary development, total hepatic lipids and plasma sex- and corticosteroid levels in female flounder (Platichthys flesus) were examined. Sexually mature feral female flounder were exposed via the diet to phenanthrene (0.5, 2.5 or 12.5 nmol/g food) or chrysene (0.4 nmol/g food) for 12 weeks, during the previtellogenic phase of the annual reproductive cycle. PAH exposure did not directly affect germ cell development since no structural and/or developmental differences were observed between control and exposed fish. On the contrary, all treatments resulted in altered plasma steroid levels. The most pronounced effect was the significant decrease in plasma 17β-estradiol to 19±11%, 27±7%, 63±20% and 61±12% in relation to control fish, respectively, in flounders exposed to 12.5, 2.5 or 0.5 nmol phenanthrene/g food and 0.4 nmol chrysene/g food. Impaired ovarian growth was not observed, most likely because experiments were ended before the period of vitellogenesis, even though a non-significant general decline in total hepatic lipids could be observed. Moreover, all exposed flounders, except fish fed with the highest amount of phenanthrene, showed a negative correlation between plasma 17β-estradiol and 17α-hydroxyprogesterone levels (r=−0.46). One possible explanation is that PAH action may be mediated by a specific inhibition of steroidogenic enzymes. These findings provide evidence that selected PAHs are antiestrogenic xenobiotics with the capability to impair female teleost reproductive function.     

Residues of C-4n-nonylphenol in mosquitofish (Gambusia holbrooki) oocytes and embryos during dietary exposure of mature females to this xenohormone

In order to assess in fish the maternal transfer of alkylphenolic compounds to the progeny, the identification and quantification of the labelled compounds present in oocytes and embryos was conducted after dietary exposure of mature female mosquitofish to ¹⁴C-4n-nonylphenol during vitellogenesis and embryogenesis respectively. Radioactivity found in bile and liver extracts accounted for 0.9–0.6 and 0.2–0.1% of ingested radioactivity for females exposed during vitellogenesis and embryogenesis respectively. The amount of extractable radioactivity present in oocytes and embryos was 0.19 and 0.07% of the ingested dose respectively. The radio-HPLC profiles obtained from bile, liver, oocyte and embryo extracts were similar. They showed the presence of 4n-NP-glucuronide as the major metabolite and traces of unchanged 4n-NP. The other metabolites corresponded to 8-hydroxynonylphenol, 9-(4-hydroxyphenyl)-nonanoic acid and para-hydroxybenzoic acid which is the final product of the alkyl chain oxidation. Our results indicate that exposure of ovoviviparous female fish to 4-NP during vitellogenesis and embryogenesis leads to the contamination of the progeny by 4-NP and its metabolites.     

Uptake and transformation of C-labelled tributyltin chloride by the dog-whelk, nucella lapillus: Importance of absorption from the diet

The importance of the diet as a source of tributyltin (TBT) in Nucella lapillus was studied using [¹⁴C]tributyltin chloride. In N. lapillus provided with prelabelled mussels, Mytilus edulis, in labelled water (mean 20·5 ng/litre TBT) the rate of accumulation of total ¹⁴C was 2–3 times that in unfed animals. Owing to its degradation in the tissues of both fed and unfed animals, concentrations of [¹⁴C]TBT tended to reach a plateau after only 28 days. However, total concentrations of ¹⁴C were still increasing after 49 days. Under experimental conditions (15°C, ample food, no disturbance) the diet accounted for about 50% of the body burden of TBT in N. lapillus after 49 days exposure: concentration factors (dry tissue/water) for [¹⁴C]TBT in both male and female N. lapillus were similar at about 60 000 in fed and 30 000 in unfed animals. It is concluded that the diet may contribute less than half of the body burden of TBT found in natural populations subjected to life-long exposure.     

Trace metal fronts in Scottish coastal waters

Dissolved cadmium and copper concentrations have been determined in 76 surface water samples in coastal and ocean waters around Scotland by anodic stripping voltammetry (ASV). A trace metal/salinity ‘front’ is observed to the west, north and north-east of Scotland separating high salinity ocean water (>35 × 10⁻³) with low concentrations of dissolved Cd and Cu from lower salinity (<35 × 10⁻³) coastal water containing higher concentrations of Cd and Cu. Mean Cd concentrations in ocean and coastal waters are 7 ng dm⁻³ (0·06 n ) and 11 ng dm⁻³ (0·10 n ) respectively; for Cu the respective levels are 60 ng dm⁻³ (0·95 n ) and 170 ng dm⁻³ (2·68 n ). The observed distribution is attributed principally to freshwater runoff and the advection of contaminated Irish Sea water into the study area.     

Toxicokinetics of heavy metals from a mining spill using Carcinus maenas

The knowledge of the reproduction and growth background related to the shore crab Carcinus maenas promotes the use of this crab as a model crustacean to asses the potential for endocrine disruption in crustaceans. In addition, an enzyme linked inmunosorbent assay (ELISA), sensitive to the shore crab vitellogenin in serial hemolymph samples allows determination of the extent of disruption of the process of vitellogenesis in female crabs and its likely impact on reproductive output. Intermoult females Carcinus maenas were exposed to concentrations of Cd: 3 microgl(-1), Cu: 15 microgl(-1) and Zn: 700 microgl(-1) determined at the Guadalquivir estuary after the Aznalcóllar mining spill, during 21 days. Crab hemolymph samples, were taken every seven days, and analyzed through an ELISA for Carcinus maenas vitellogenin. Vitellogenin concentration along the time was fitted to a first order kinetic approach. Results showed a good correlation among experimental values and estimated ones. Metal exposure resulted in an increase in vitellogenin concentration in hemolymph, especially for cadmium.     

Cadmium-binding proteins in the blue crab, callinectes sapidus: laboratory-field comparison

The blue crab, Callinectes sapidus, is distributed along the east coast of the United States from Cape Cod, Mass., through the Gulf of Mexico, including both relatively unpolluted coastal areas and estuaries contaminated with trace metals. Cadmium is of particular concern because it is concentrated in the digestive glands of blue crabs and can be passed on to consumer organisms. Tissue concentrations and partitioning of trace metals from crabs exposed in the laboratory to 10 ppb dissolved cadmium for 40 days were compared with blue crabs collected from two locations on the Hudson River, NY, Foundry Cove and Haverstraw Bay, Foundry Cove and Haverstraw Bay, both of which have elevated trace metal levels relative to estuarine areas near Beaufort, NC. Crab digestive glands, gills and muscle were removed and analyzed for total cadmium, copper, zinc and nickel concentrations using acid digestion and atomic absorption spectrophotometry, and metal-binding (metallothionein-like) proteins were determined by gel-filtration chromatography. In crabs exposed to cadmium in the laboratory, the cytosolic partitioning was similar to previous investigations at our laboratory where higher levels of cadmium (100 ppb) and shorter exposure times (14 days) were used. The similarity in cadmium partitioning from these two separate experiments indicates dose independence. In crabs from polluted environments the digestive glands contained the highest concentrations of trace metals. Chromatograms of the cytosol from the digestive glands and gills from both field and laboratory exposed crabs showed similar distributions of cadmium, copper and zinc. The gills of both field and laboratory-exposed crabs had metal-binding proteins that contained mostly cadmium, and the digestive glands had metallothionein-like proteins that contained cadmium, copper and zinc. Estimated molecular weights for these proteins were similar to the metallothioneins found in other crustaceans and mammals.     

o,p′-DDT induction of vitellogenesis and its inhibition by tamoxifen in Nile tilapia (Oreochromis niloticus)

In order to investigate the mechanism by which o,p′-DDT disrupts endocrine functioning of Nile tilapia in vivo, the estrogenicity of o,p′-DDT was investigated in conjunction with 17β-estradiol (E₂) and tamoxifen. Mature, male tilapia were treated intraperitoneally with o,p′-DDT (60 mg/kg, one dose) or E₂ (5 mg/kg, four doses) in the presence or absence of tamoxifen (5 mg/kg, six doses) for 12 days and then plasma vitellogenin (Vtg) (measured as alkaline-labile phosphorous), E₂, and testosterone (T) were measured. Vtg levels were increased dramatically by E₂ (1744±171 μg/ml) and moderately by o,p′-DDT (82±15 μg/ml) compared with controls (23±3.5 μg/ml). Tamoxifen alone had no effect on Vtg production, but inhibited both E₂ and o,p′-DDT stimulated vitellogenesis. T levels were reduced with E₂ administration (1688±383 pg/ml) and declined further with the combined treatment of E₂ and tamoxifen (281±70 pg/ml), compared with controls (6558±1438 pg/ml). Tamoxifen or o,p′-DDT alone did not affect T levels, but their combined treatment did (2069±647 pg/ml). The results of this study suggest that o,p′-DDT is weakly estrogenic in male tilapia, and that this activity may be mediated through the estrogen receptor.     

Interactions of cadmium with sulfhydryl-containing compounds in striped mullet (mugil cephalus L.)

Interactions between cadmium and sulfhydryl-containing compounds in striped mullet, Mugil cephalus, were examined. Exposure to 10 mg Cd/liter for up to 6 weeks caused an increase in the acid-soluble thiol (AST) content of the liver. Although the AST concentration was elevated at 1·4 weeks, increases in the glutathione and cysteine contents were not observed until after 4 weeks of exposure. Homogenates of livers were fractionated on a Sephadex G-75 column. A homogenate of livers of mullet injected with ¹⁰⁹Cd 2 days prior to sampling had an elution profile for thiols similar to controls. After 3 weeks exposure to 10 mg Cd/liter the 9400 MW thiol peak increased 3·6-fold and the peak with the same retention volume as glutathione increased 4·3-fold. Greater than 70% of the thiols in these two peaks were acid-soluble. In both experiments, almost all the cadmium was associated with the 9400 MW peak. The ratio in the 9400 MW peak declined from 14·1 (controls) to 3·2 after 3 weeks exposure. No cadmium was associated with glutathione in the bile.     

Cadmium in Mytilus spp.: Worldwide survey and relationship between seawater and mussel content

A worldwide literature survey of data on cadmium concentration in the soft tissue of the mussel, Mytilus spp., from 591 stations is presented. These stations are from 13 regions. Geometric means for the regions vary from 0·6 to 3·3 μg g⁻¹ (dry weight) for the Barents Sea and the Northeastern Pacific coast, respectively.The averages of seven of these regions, for which reliable cadmium concentrations in seawater were available, were used to calculate a relationship between cadmium concentrations in seawater and mussel soft tissue. The relationship was highly significant: (Cd) mussel (μg g⁻¹, dry weight) = 0·074 (Cd) water (ng litre⁻¹) + 0·39 (P ≤ 0·0005).This model has been successfully applied in the context of the contamination of the Gironde estuary (France). It can also be used to define a water quality criterion for mussel maturing parks consistent with the quality criterion defined for shellfish for human consumption.     

Toxicological effects of potash brine on bay of Fundy marine organisms

The acute lethality and sublethal heavy metal contamination potential to marine organisms of a waste brine solution from a potash mining operation were determined. The brine was acutely lethal to marine organisms of the Bay of Fundy, Canada, at concentrations between 47 and 55‰ salinity (96-h LC₅₀ values: threespine stickleback, Gasterosteus aculeatus, 47·7‰; polychaete worm, Nephtys incisa, 52·5‰; blue mussel, Mytilus edulis, lethal to whole animal and reduced ciliary activity of gills above 55‰).The brine diluted to sublethal concentrations (≤40‰) contained manganese (≤ 49·5 ×), copper and zinc (≤ 5·2 ×), lead (≤ 2·6 ×) and cadmium (≤ 0·7 ×) in decreasing order of enrichment relative to control seawater. Copper was accumulated in mussels exposed to these solutions over 44 days to the greatest degree (4 ·4 ×), followed by manganese and lead. Tissue lead concentration reached a steady value within 44 days and cadmium was not accumulated.     

Reproductive success as an indicator of genotoxicity in the polychaete worm, Neanthes arenaceodentata

The effects on reproduction of single or chronic exposure to the direct-acting mutagen, radiation, were evaluated using Neanthes arenaceodentata as the model animal. In the first set of experiments, mated pairs were irradiated when oocytes were visible in the female and were given a single dose of either 0·5, 1·0, 2·0, 5·0, 10 or 50 Gy. In the second set of experiments, lifetime exposure was initiated upon the spawning of the P₁ female and was terminated upon the spawning of the F₁ female; the average total doses (0·55, 6·5 and 54 Cy) were delivered at a rate of 0·19, 2·1 or 17 mGyH⁻¹. Our results on embryo abnormalities and mortalities indicated that lethal mutations were most likely induced in the germ cells and had an adverse effect on reproductive success by reducing the survival of early life stages. Except for those mated pairs exposed acutely to 10 or 50 Gy or exposed chronically to 17 mGyh⁻¹, there was no evidence of gamete killing. However, evidence was obtained for mutagen-damage accumulation in developing gametes from continuous exposure to radiation.     

两组不同饲料对中华绒螯蟹(Eriocheir sinensis)卵巢发育及卵黄发生的激素调控

甲壳动物的卵巢发育及卵黄发生受到体内各种内分泌激素的调控。本文研究了两组不同饲料—脂类营养平衡组(A组,含有磷脂和HUFA)和不平衡组(B组,缺乏磷脂和HUFA)对中华绒螯蟹卵巢发育及卵黄发生的激素调控,运用放射免疫法和放射化学法分别测定了处于不同卵黄发生期的中华绒螯蟹的肝胰腺、卵巢、血淋巴中孕酮(PG)、雌二醇(E2)的含量及中华绒螯蟹大颚器(MO)合成与分泌甲基法尼酯(MF)的速率。结果表明:1)中华绒螯蟹体内三种组织(肝胰腺、卵巢和血淋巴)中均存在PG和E2,PG可能为E2的前体;2)早熟蟹的MO合成MF速率远远大于正常发育的幼蟹,MF的大量合成与分泌是促使早熟蟹产生的主要内分泌因素;3)B组饲料(含猪油)喂养的河蟹其MO合成MF的速率均高于A组饲料(含鱼油),且B组饲料的早熟蟹转化PG速度比B组饲料的早熟蟹快;4)PG和E2的脂类结合部位能结合外源性卵黄蛋白原(Vg),通过血淋巴的运输被卵泡细胞胞吞,最终与卵母细胞内的内源性Vg结合,共同形成卵黄体;5)多不饱和脂肪酸(如EPA和DHA)可能会抑制类固醇激素的产生。研究表明,MF是中华绒螯蟹的促性腺激素,具有促使PG合成和E2转化的作用,它们共同诱导河蟹卵巢发育及卵黄发生。     

Measurement of manganese, zinc and cadmium complexation in seawater using Chelex ion exchange equilibria

Equilibria between Chelex 100* and manganese, zinc and cadmium ions were used to determine the complexation of these trace metals in 36‰ Gulf Stream seawater at 25°C and pH 8.2. The method utilized radiotracers (⁵⁴Mn, ⁶⁵Zn, and ¹⁰⁹Cd) to quantify trace metal adsorption from trace metal-amended seawater and from seawater containing a series of ethylenediaminetetracetate (EDTA)—metal ion buffers. Results were consistent with Chelex adsorption of both trace metal ions and trace metal—EDTA chelates. Equilibrium models fitted to the data were used to establish conditional stability constants for Chelex adsorption of manganese, zinc and cadmium ions and for adsorption of EDTA-chelates. These models also yielded ratios of free metal ions to total dissolved trace metal concentrations in seawater: 10^−0.1 for manganese, 10^−0.2 for zinc, and 10^−1.5 for cadmium. Independent measurements with a cadmium ion-selective electrode also yielded a free: total cadmium ratio of 10^−1.5.     

Accumulation of cadmium in extracellular granules in the kidney of the bivalve mollusc Mercenaria mercenaria (L.)

As part of an ongoing investigation of the transport, accumulation and excretion of metals in the infaunal eulamellibranch Mercenaria mercenaria (L.) organisms were exposed to radioactive cadmium followed by an autoradiographic study of the kidney tissue to determine the morphological sites of cadmium accumulation. Preliminary results of these studies indicate that cadmium is associated with large extracellular granules in the lumina of the kidneys. The presence of radioactive cadmium was determined morphometrically by counting developed silver grains on sections coated with a photographic emulsion. The results were statistically significant (99·9 % confidence—Student's t-test) to show that more radioactive cadmium was associated with large granules than with the background tissue.     

A Trophic Flow Model of the Caeté Mangrove Estuary (North Brazil) with Considerations for the Sustainable Use of its Resources

The Caeté Estuary lies within the world's second largest mangrove region, 200 km south-east of the Amazon delta. It has an extension of about 220 km²and is subjected to a considerable human impact through intensive harvest of mangrove crabs (Ucides cordatus) and logging of mangroves. In order to integrate available information on biomass, catches, food spectrum and dynamics of the main species populations of the system, a trophic steady state model of 19 compartments was constructed using the ECOPATH II software (Christensen & Pauly, 1992). Ninety-nine percent of total system biomass is made up by mangroves (Rhizophora mangle, Avicennia germinans andLaguncularia racemosa ), which are assumed to cover about 45% of the total area and contribute about 60% to the system's primary production. The remaining biomass (132 g m⁻²) is distributed between the pelagic and benthic domains in proportions of 10% and 90% respectively. Through litter fall, mangroves inject the main primary food source into the system, which is either consumed directly by herbivores (principally land crabs, Ucides cordatus) or, when already metabolized by bacteria, by detritivors (principally fiddler crabs, Uca spp.). These two groups are prominent in terms of biomass (80 g and 14·5 g m⁻²), and food intake (1120 g m⁻² yr⁻¹and 1378 g m⁻² yr⁻¹respectively). According to the model estimates, energy flow through the fish and shrimp compartments is of relatively low importance for the energy cycling within the system, a finding which is contrary to the situation in other mangrove estuaries reported in the literature. The dominance of mangrove epibenthos is attributed to the fact that a large part of the system's production remains within the mangrove forest as material export to the estuary is restricted to spring tides, when the forest is completely indundated. This is also the reason for the low abundance of suspension feeders, which are restricted to a small belt along the Caeté River and the small creeks which are watered daily. Phytoplankton, temporarily refloating benthic diatoms, neritic zooplankton and small pelagic fish dominate the (low) pelagic biomass. Total system throughput (10 559 g m⁻² yr⁻¹) and mean transfer efficiency between trophic levels (9·8%) calculated by the model fit well into the range reported for other tropical coastal ecosystems. The very high gross efficiency of the fishery (catch/net primary production) of 8·6% and its low trophic level (2·1) is explained by a high harvesting rate of mangroves and the fact that the main animal resource in the system are the mangrove crabs (Ucides cordatus), which feed at the first trophic level. The model was balanced asuming a turnover rate for the land crabs of P/B=0·25 (P/B: production per unit of biomass) which is possibly too high. If this value was replaced by a (possibly more realistic) lower value, the model would not balance, suggesting a situation in which more biomass is being harvested than produced, which hints to an overexploitation of this resource A ranking of the various system components in terms of their contribution to the system function (ascendency sensu Ulanowicz, 1997) revealed that detritus and associated bacteria contribute 34%, mangroves 19%, fiddler crabs 13%, phytoplankton and microphytobenthos 10%, mangrove crabs 10%, and the remaining 14 groups 14% to the total ascendency. Summary statistics of the model are given and compared with those of other coastal ecosystems.     

Influence of cadmium exposure on plasma calcium, vitellogenin and calcitonin in vitellogenic rainbow trout

Effects of cadmium exposure on plasma levels of calcitonin and free and protein-bound calcium were studied in vitellogenic female rainbow trout kept in brackish water (7%(.)). Fish were exposed to 100 μg cadmium litre⁻¹ for four weeks. Exposure of female rainbow trout in the stage of vitellogenesis, with increased total plasma levels of calcium, resulted in a complex hypocalcemic response. Thus, hypocalcemia was found to be due to three different processes: (1) a decrease in the free plasma calcium, and a reduction in protein-bound calcium; due both to (2) decreased plasma levels of vitellogenin; and (3) a reduced binding of calcium to vitellogenin. These findings support the concept of an interference of cadmium with ionregulating tissues as a mechanism for hypocalcemia in rainbow trout. A direct effect on the vitellogenin-binding of calcium was also observed and reproductive function in the females was affected by decreased plasma levels of vitellogenin. In spite of the marked changes of plasma calcium in exposed fish, no significant effects on plasma calcitonin were observed, indicating a lack of a direct relationship between plasma calcium and calcitonin levels in rainbow trout.     

Residues of 14C-4n-nonylphenol in mosquitofish (Gambusia holbrooki) oocytes and embryos during dietary exposure of mature females to this xenohormone

In order to assess in fish the maternal transfer of alkylphenolic compounds to the progeny, the identification and quantification of the labelled compounds present in oocytes and embryos was conducted after dietary exposure of mature female mosquitofish to 14C-4n-nonylphenol during vitellogenesis and embryogenesis respectively. Radioactivity found in bile and liver extracts accounted for 0.9-0.6 and 0.2-0.1% of ingested radioactivity for females exposed during vitellogenesis and embryogenesis respectively. The amount of extractable radioactivity present in oocytes and embryos was 0.19 and 0.07% of the ingested dose respectively. The radio-HPLC profiles obtained from bile, liver, oocyte and embryo extracts were similar. They showed the presence of 4n-NP-glucuronide as the major metabolite and traces of unchanged 4n-NP. The other metabolites corresponded to 8-hydroxynonylphenol, 9-(4-hydroxyphenyl)-nonanoic acid and para-hydroxybenzoic acid which is the final product of the alkyl chain oxidation. Our results indicate that exposure of ovoviviparous female fish to 4-NP during vitellogenesis and embryogenesis leads to the contamination of the progeny by 4-NP and its metabolites.     

Can starvation influence cellular and biochemical parameters in the crab Carcinus aestuarii?

Crustacea experience periods of starvation during moulting or when limited food availability occurs. The effects of starvation on Crustacea physiological responses have been demonstrated, whereas the effects of starvation on Crustacea immune parameters remain to be more fully studied. In the present study the effects of starvation on immune parameters and antioxidant enzyme activities of the crab Carcinus aestuarii were evaluated for the first time. Treated crabs were starved for 7 days, whereas control crabs were fed daily with mussels. Total haemocyte count (THC), haemocyte diameter and volume, haemocyte proliferation, cell-free haemolymph (CFH) glucose and total protein levels, and phenoloxidase (PO) activity in both haemocyte lysate (HL) and CFH were measured in crabs. In addition, superoxide dismutase (SOD) and catalase (CAT) activities were evaluated in both gills and digestive gland from crabs, in order to evaluate whether starvation induced oxidative stress in C. aestuarii. THC increased significantly in starved crabs, with respect to controls, whereas no significant variations were observed in haemocyte diameter, volume and proliferation. In CFH of starved animals glucose concentration significantly increased, whereas total protein concentration significantly reduced. A significantly higher PO activity was recorded in HL from starved crabs, than in control crabs. Conversely, PO activity did not vary significantly in CFH. Starvation did not cause significant alterations in antioxidant enzyme activities in both gills and digestive gland. Results obtained demonstrated that starvation influenced crab immune parameters, but did not induce oxidative stress. Results also indicated that C. aestuarii can modulate its cellular and biochemical parameters in order to cope with starvation.