Interspecific comparisons of relative assimilation efficiencies for zinc and cadmium in an ecological series of talitrid amphipods (Crustacea)

A dual-labelling radioisotope technique has enabled the relative assimilation efficiencies of an essential (Zn) and a non-essential trace metal (Cd) to be determined in an ecological series of talitrid amphipods from low-shore to fully terrestrial habitats. All species exhibited high assimilation efficiencies for zinc and cadmium (within the range 66.7–96.4%). Interspecific differences in assimilation rates showed no trend with increasing terrestriality of the habitat. Elevated dietary zinc concentrations failed to enhance zinc assimilation efficiency. Incorporation of antibiotics into the diet to eliminate gut microflora did not affect zinc assimilation efficiencies. The implications of having high trace-metal assimilation efficiencies are discussed in terms of land invasion by talitrids.     

Trace metal concentrations in two New Zealand talitrid amphipods: effects of gender and reproductive state and implications for biomonitoring

This is the first in-depth investigation of whether the gender or reproductive state of talitrid amphipods affects the bioaccumulation of trace metals. Concentrations of copper, zinc, and cadmium were measured in the beach flea Transorchestia chiliensis (Milne-Edwards) and the sand hopper Talorchestia quoyana (Milne-Edwards) (Amphipoda: Talitridae) from sites in and near the Avon-Heathcote Estuary, Christchurch, New Zealand. For T. chiliensis, the whole body trace metals concentrations (μg g⁻¹) were generally similar for nonbrooding, brooding, and brooding females that had the embryos removed. Where there were differences between female groups (3 out of 15 samples), concentrations in nonbrooding females were below those for brooding females. The trace metal concentrations of separated embryos did not follow those of their mothers. The body zinc concentration was similar for males and females. For copper and cadmium, body concentrations for females were higher than males at the two most contaminated sites. Cadmium body concentrations were similar between sites, and the lowest concentrations were from amphipods from one of the Estuary sites rather than the reference site. In T. quoyana, the trace metal concentrations in nonbrooding female and male sand hoppers were similar for copper and zinc, but cadmium concentrations were higher in nonbrooding females than in males. Copper and zinc concentrations within amphipod body tissues did not reflect those in the sediment or their food. The implications of these results are discussed in relation to previous studies and the use of beach fleas and sand hoppers as metal biomonitors. The beach flea T. chiliensis is recommended as a suitable trace metal biomonitor in New Zealand coastal waters with the potential to be affected by anthropogenic trace metal contamination.     

Seasonal variation in trace metal concentrations in three talitrid amphipods from the Gulf of Gdansk, Poland

Talitrid amphipod crustaceans are increasingly being used as biomonitors of trace metal bioavailabilities in coastal waters, and it is important to understand how other factors, in addition to metal pollution, might affect their accumulated body concentrations. Seasonal variation (April-October 2000) in body concentrations of copper, zinc, cadmium, iron, manganese, lead and nickel has been investigated in three species, Orchestia cavimana, Talitrus saltator and Talorchestia deshayesii, from the region of the Gulf of Gdansk (including the Vistula Lagoon), Poland, an area with considerable temperature variation between summer and winter. Seasonal variation in the body metal concentrations of talitrid amphipod crustaceans was confirmed in each population, but only copper showed a consistent pattern. Copper concentrations fell from early to late summer, perhaps either as a result of the replacement of the older overwintering generation by the younger spring one, or as a result of the loss of haemocyanin in autumn amphipods entering a period of low metabolic activity. Metal concentration data for T. saltator from Gdynia-Osada Rybacka compared with equivalent data for 1996 and 1998 show a significant drop in metals associated with the influx of the Vistula river water, which occurred in 1998, following a major flood event in 1997.     

Copper and zinc in an ecological series of talitroidean Amphipoda (Crustacea)

Summary Cu and Zn concentrations were determined for the following talitroidean amphipods, Hyale nilssoni (Rathke), Talitrus saltator (Montagu), Talorchestia deshayesii (Audouin), Orchestia mediterranea Costa, O. gammarellus (Pallas), O cavimana Heller and Arcitalitrus dorrieni (Hunt) in September 1986 from sites in W. Britain (mostly Scottish). To minimize size effects, only animals >2mg body dry weight were included in analyses. Only Talorchestia (Cu & Zn) and O. cavimana (Zn) showed any residual relationship between metal concentration and dry weight. Log transformed data for concentrations of each metal against log dry wt. in all species were compared by ANCOVA. Copper and zinc concentrations of males and females were not significantly different in O. gammarellus, O. mediterranea and T. deshayesii, though Cu (but not Zn) concentrations differed with sex in O. cavimana. The order of species when ranked according to an ascending series of Cu concentrations (at standard body weight) reflected their ecological zonation from sea to land closely, with species living proximal to the sea having lowest Cu concentrations. The 6 talitrid species all had similar Zn concentrations but the Zn concentration of H. nilssoni was considerably lower. There was a relationship between Cu and Zn concentrations in individuals of only one species (O. gammarellus). Data on Cu and Zn concentrations for O. gammarellus derived from the same site in September 1983 were almost exctly the same as in September 1986. The possible impact of seasonal variation on haemocyanin levels is discussed.     

Chronic toxicity bioassay and effect of endosulfan,HCH, copper and zinc on the survival and intermoult duration of larvae of mangrove crab Macrophthalmus erato De Man

The effects of insecticides (endosulfan, HCH) and heavy metals (copper and zinc) were studied on survival and duration of the moult cycle of larvae and megalopa of a common mangrove crab, Macrophthalmus erato, that inhabits Pitchavaram mangroves, southeast coast of India. In chronic toxicity test, percentage of survival from hatchling to megalopa stage at different concentrations of endosulfan (0.048 to 0.36 microg/L), HCH (0.32 to 2.4 microg/L), copper (9.0 to 67.5 microg/L) and zinc (15.2 to 139.0 microg/L) were 6, 12, 8 and 12 respectively. Endosulfan, HCH, copper and zinc considerably increased the total period in development from first zoea to megalopa stage from 18 days in the control to 23, 21, 20 and 22 days in the treated specimens. It is concluded that concentrations well below the observed chronic concentrations, may prove to be more deleterious to larva of this species in natural environment leading to reduction in the success of recruitment to the adult population.     

Seasonal variation in copper and zinc concentrations in three talitrid amphipods (Crustacea)

Cu and Zn concentrations were determined for three talitrid amphipods, Orchestia gammarellus (Pallas), O. mediterranea Costa and Talitrus saltator (Montagu), collected at two-monthly intervals in 1987 from sites on Great Cumbrae Island, Firth of Clyde, Scotland. To account for size effects, log transformed Cu and Zn concentrations were regressed against log dry weight for each bimonthly sample of each species, and compared by analysis of covariance. Copper concentrations in O. gammarellus were significantly raised in March 1987, and lowered in November 1987. Copper concentrations in O. mediterranea and T. saltator were significantly lowered in November 1987. Cu concentrations differed interspecifically in the order O. gammarellus > O. mediterranea > T. saltator. There was no significant intraspecific seasonal variation in zinc concentration in any of the three species. Zn concentrations differed interspecifically in the order T. saltator > O. gammarellus > O. mediterranea.     

The timing of gonadal development and moult in three raptors with different breeding seasons: effects of gender, age and body condition

Differences between species in breeding seasons are thought to be mediated through differences in their reproductive physiology. Little is known about how the timing and duration of gonadal maturation varies between raptor species, how the timing of moult relates to the gonadal cycle, whether the timing and degree of sexual maturation varies between juveniles and adults or whether body condition has a significant effect. To address these questions, data on gonadal size and moult for adults and juveniles of both sexes of three raptor species were extracted from the Predatory Bird Monitoring Scheme (based on birds found dead by members of the public). The three species, Sparrowhawk Accipiter nisus, Kestrel Falco tinnunculus and Barn Owl Tyto alba, have different ecologies – diurnal bird predator, diurnal mammal predator and nocturnal mammal predator, respectively. All are single‐brooded but have different breeding seasons. The duration of gonadal maturation was markedly different between the species. Barn Owls showed the earliest maturation and the latest gonad regression, and Sparrowhawks the latest maturation and earliest gonad regression. Kestrels were intermediate. In males of all species, the testes remained fully mature throughout their respective breeding seasons. In females, the ovaries remained partially mature throughout the breeding season. Moult started slightly earlier in Sparrowhawks than in Kestrels and coincided with gonadal regression in the two species. Although females of the two species started to moult earlier than males, moult duration was similar between the sexes. Barn Owls showed no distinct annual pattern of moult. In juveniles of all three species, the gonads were smaller than in adults throughout spring and started to mature later. Gonad size in birds that had starved tended to be smaller than in birds dying from other causes, but did not influence the difference in gonad mass between adults and juveniles and between seasons. Body condition had no effect on moult. Whilst ecology has led to the evolution of different breeding seasons, differences between species, and between adults and juveniles, are mediated through adaptive differences in their reproductive physiology.     

Influence of environmental conditions on the distribution of Amphipoda,Talitridae, in the lagoon complex of Ghar El Melh (north‐east of Tunisia)

The study of the spatiotemporal distribution of talitrid amphipods was carried out along a transect in three stations belonging to the lagoon complex of Ghar El Melh, namely the supralittoral zones of the old harbour of Ghar El Melh, the opposite to Boughaz and Sidi Ali Mekki lagoon. Four species belonging to Talitridae family with two different genera were identified at all stations. These species are Orchestia gammarellus, Orchestia mediterranea, Orchestia stephenseni and Platorchestia platensis. The first two species were collected during the four seasons. The study of the density showed that the most important global mean density in talitrid was found in the supralittoral zone of opposite to Boughaz. In addition, statistical analysis showed a significant difference in the seasonal distribution of amphipods based on plant associations. Furthermore, the highest diversity of talitrid was observed in the winter in the supralittoral zone of opposite to Boughaz and in summer in the supralittoral zones of Sidi Ali Mekki lagoon and the old harbour of Ghar El Melh. Results showed that at all stations, a highly significant correlation of amphipod community with Cymodocea banquette was observed. Moreover, principal component analysis showed that the distribution of the different species depends on climatic and edaphic factors.     

Digestive capabilities reflect the major food sources in three species of talitrid amphipods

Digestive enzyme activities of three talitrid amphipods were examined to investigate the relationship between their digestive capabilities and diet. Laminarinase, cellobiase, carboxymethyl-cellulase, xylanase, alpha- and beta-glucosidase and lipase were detected in all three species suggesting talitrid amphipods can readily digest dietary carbohydrate and lipid, including complex polysaccharides. Relatively high specific enzyme activity (Units (mg(-1) digestive tract protein)(-1)) of laminarinase and lipase was detected in Talorchestia marmorata, a supralittoral kelp feeder which is coherent with the digestion of lipid-esters and beta-glucans (laminarin) which are the main lipid and storage polysaccharides of brown seaweeds. Talorchestia sp., a low shore intertidal feeder, had high enzymatic activity of alpha- and beta-glucosidase, cellobiase and xylanase, which is consistent with the digestion of diatoms. Keratroides vulgaris, a forest litter feeder had a relatively low specific activity of all enzymes. It is possible that leaf litter is partially digested prior to ingestion by bacteria and fungi present in the rotting vegetation, with bacterial and fungal enzymes contributing to this species' ability to hydrolyse its diet. This study provides the first quantitative data on digestive capacity in these three talitrid amphipods and confirms the relationship between dietary preference and digestive enzyme complement.     

Failure of cis-platinum to alter metal concentrations in the liver and kidney of the rat

The anticancer drug, cis-diamminedichloroplatinum, was administered to male rats at a dose of 0.5, 1.0, 2.0 or 4.0 mg platinum/kg body weight. After 48 hrs, the animals were killed and platinum, zinc, copper and metallothionein were measured in renal and hepatic tissue and platinum, zinc and copper were measured in the plasma. Administration of this platinum-containing compound did not induce hepatic or renal metallothionein and did not significantly alter the concentrations of copper or zinc in hepatic or renal tissue or in the plasma.     

The associations of phoretic mites (Acarina: Chelicerata) with sand-hoppers (Amphipoda: Crustacea) on the South Wales coast

Mites of the genera Halolaelaps and Phaulodinychus (Gamasida), together with Histiostoma (Acaridida) (Acarina: Chelicerata), occur amongst tidal debris strandlines on the sandy shores of the South Wales coast. Phoretic deuteronymphs of all three mites are dispersed between strandlines via talitrid amphipods (Talitridae: Amphipoda: Crustacea) which provide two principal advantages over the insect hosts used by most other phoretic Acarina. First, amphipods migrate between strandlines throughout the year allowing continual phoretic mite dispersal, and second, even juvenile Talitridae are sufficiently large to transport several mites. The highly aggregated populations of all three mites are distributed independently of amphipod age, sex and species, suggesting that host selection is primarily influenced by other factors. The most likely factors are those related to host behaviour and, in particular, monthly/diurnal quiescence when the mites encounter, and are boarded by, the desiccation-sensitive phoretic mites. The discrete site selection exhibited by each mite species is at least partly influenced by attachment mechanisms.     

Essential metals in tissues and tumor of inbred C57BL/6 mice during the infective cycle of Lewis lung carcinoma

The variation of tissue copper, zinc, iron, calcium, magnesium, potassium and sodium content of inbred C57BL/6 mice during the infective cycle of Lewis lung carcinoma have been studied. Tissue calcium, magnesium, potassium and sodium concentrations were well maintained during the infective cycle, probably because of their large dietary availability, copper, zinc and iron, however, showed a progressive decrease in their tissue concentrations. Liver zinc increased in parallel with the metastasising process. The important decrease in tissue iron observed agress with the characterized hypoferric response to infection. However, when the losses of metals were considered on a global organism basis, the loss of iron was not paralleled by an increase in tumor iron, but a global loss was observed. The hypoferric response did not deter tumor growth, as this was able to carry on its development with significantly decreasing neoplastic tissue iron content. The only metal actively concentrated by the tumoral mass was sodium.     

MOULT OF BUDGERIGARS MELOPSZTTACUS UNDULATUS

In captive Budgerigars Melopsitticus undulatus moult of primaries started in the middle of the tract and moved progressively inwards and outwards, the inner feathers being replaced faster than the outer ones. Full replacement of primaries took six to eight months and a new cycle of moult usually started before completion of the old cycle. Moult of secondaries followed no clear pattern and occurred less frequently than moult of primaries. Moult of rectrices started with the middle pair and moved progressively outwards on both sides. Complete moult of rectrices took about six months and a new cycle often started before completion of the old. Moult of the head and body occurred intermittently throughout the year. Birds fledged in juvenal plumage, they passed into first basic plumage with a partial moult (head and body feathers) and into definitive basic plumage with a moult of all contour feathers.
In the field in inland mid-eastern Australia, there were some birds replacing feathers and some with complete plumage in most months of the year. Birds with complete plumage may have been between moults or within a moult and between replacement of feathers. The proportion of birds in moult did not increase in intensity after breeding, or cease during breeding or before movements. Some birds of both sexes with gonads in a reproductive condition were replacing feathers. Rirds that were replacing feathers had similar lipid deposits to birds that had a complete plumage.     

Developmental changes in dopamine levels in larvae of the fly Chymomyza costata: comparison between wild-type and mutant-nondiapause strains

Dopamine and two related catecholamines, L-3,4-dihydroxyphenylalanine (DOPA) and N-acetyl dopamine (NADA), were analyzed in whole body and tissue samples taken throughout late larval development of the drosophilid fly Chymomyza costata, which enters facultative diapause as a mature 3rd instar larva in response to short photophase. Wild-type (W) and mutant-nondiapause (M) strains reared under diapause inducing (d) and preventing (nd) photophases were compared. Developmental changes in the whole body of dopamine levels showed some general features irrespective of fly strain and rearing conditions: sharp major peaks during moult from second to third instar larva and during pupariation; lower minor peaks around the middle of both 2nd and 3rd instars. Significant differences between the strains and conditions were also found: dopamine levels were lower throughout the 2nd instar and during the 2nd to 3rd instar moult of mutant strain larvae (M/d) as compared to wild-type larvae (W/nd and W/d); while the late 2nd and late 3rd instar larvae destined to diapause (W/d) maintained relatively high dopamine concentrations, their counterparts destined to continuous development (W/nd and M/d) significantly decreased dopamine levels prior to the 2nd to 3rd instar moult or pupariation. Possible relationship between the dopamine levels and diapause induction/onset in C. costata larvae is discussed. Integument contained more than 90% of the dopamine found in the whole body. The gut and central nervous tissues showed relatively low pools of dopamine, only trace amounts were detected in haemolymph and no dopamine was found in fat body. DOPA levels were low and stable throughout larval development of both W and M strains and under both conditions. NADA levels peaked during second halves of 2nd and 3rd instars of both strains, then dropped to trace levels and were elevated again during 2nd to 3rd instar moult as well as in tanned prepupae. No elevation of NADA levels was recorded in 3rd instar W/d larvae which entered diapause.     

Influence of spontaneous diabetes on tissue status of zinc, copper, and manganese in the BB Wistar rat

The concentrations of zinc, copper, and manganese in liver, kidney, duodenum, pancreas, testes, bone, and serum from control and untreated, spontaneously diabetic BB Wistar rats were compared. Chronic insulin deficiency resulted in significant alterations in the concentrations of one or more of these essential micronutrients in several tissues. The amounts of zinc and copper bound to metallothionein in the liver and kidney of untreated spontaneously diabetic rats were also markedly increased. The tissue trace metal status in diabetic rats was altered similarly in both male and female rats. Daily injections of insulin blocked many of the changes in the tissue concentrations of the metals. The effects of spontaneous diabetes on tissue trace metal status are quite similar to those reported for chemically induced diabetes. Thus, these results demonstrate that chronic endocrine imbalance is responsible for a series of tissue specific changes in the transport and metabolism of zinc, copper, and manganese.     

Effect of dietary copper and zinc levels on tissue copper,zinc, and iron in male rats

The interaction between dietary copper and zinc as determined by tissue concentrations of trace elements was investigated in male Sprague-Dawley rats. Animals were fed diets in a factorial design with two levels of copper (0.5, 5 μg/g) and five levels of zinc (1, 4.5, 10, 100, 1000 μg/g) for 42 d. In rats fed the low copper diet, as dietary zinc concentration increased, the level of copper decreased in brain, testis, spleen, heart, liver, and intestine. There was no significant effect of dietary copper on tissue zinc levels. In the zinc-deficient groups, the level of iron was higher in most tissues than in tissues from controls (5 μg Cu, 100 μg Zn/g diet). In the copper-deficient groups, iron concentration was higher than control values only in the liver. These data show that dietary zinc affected tissue copper levels primarily when dietary copper was deficient, that dietary copper had no effect on tissue zinc, and that both zinc deficiency and copper deficiency affected tissue iron levels.     

Hepatic zinc,copper, and iron in the developing turkey embryo and newly hatched poult

The ontogeny of hepatic tissue growth and trace metal deposition was examined in the developing turkey embryo and newly hatched poult. Hepatic concentrations of zinc and iron in the embryo declined by about twofold between day 16 of incubation and hatching. Hepatic copper concentration increased approximately fourfold by day 23 of incubation and then declined rapidly through hatching. During the post-hatching period, hepatic zinc concentration increased twofold by day 10, whereas a small increase in hepatic iron concentration occurred just prior to hatching and continued through the third day post-hatching. A significant positive correlation existed between hepatic zinc and iron concentrations in the developing embryo. The concentrations of both these metals were inversely correlated with hepatic copper concentration during the same time. Total hepatic zinc and iron content increased throughout the entire time studied, whereas total copper content increased up to hatching and then declined during the first week post-hatching. The most rapid phase of hepatic metal accretion differed for each metal, with zinc being rapidly accumulated during the post-hatching period, copper during the last half of incubation and iron at about the time of hatching and the first few days post-hatching. Each of these metals demonstrated a specific relationship to hepatic tissue growth that changed between the embryonic and neonatal periods of development.     

Metabolism of copper and zinc in the liver and bone of the perinatal guinea-pig

Hepatic copper concentration in the guinea-pig increased markedly during the second-half of gestation, attaining a maximum shortly after birth; thereafter, concentration declined rapidly during the neonatal period. Changes in perinatal hepatic copper concentrations paralleled the binding of copper to a cytosolic metallothionein-like component, and the loss of hepatic copper in the neonates coincided with increases in serum copper concentrations. Zinc concentrations of the perinatal liver were low and showed no dramatic developmental changes. The humerus showed striking increases in zinc concentration with gestational age, attaining peak concentration before term and a marked depletion of tissue zinc during the neonatal period.     

Wild skylarks seasonally modulate energy budgets but maintain energetically costly inflammatory immune responses throughout the annual cycle

A central hypothesis of ecological immunology is that immune defences are traded off against competing physiological and behavioural processes. During energetically demanding periods, birds are predicted to switch from expensive inflammatory responses to less costly immune responses. Acute phase responses (APRs) are a particularly costly form of immune defence, and, hence, seasonal modulations in APRs are expected. Yet, hypotheses about APR modulation remain untested in free-living organisms throughout a complete annual cycle. We studied seasonal modulations in the APRs and in the energy budgets of skylarks Alauda arvensis, a partial migrant bird from temperate zones that experiences substantial ecological changes during its annual cycle. We characterized throughout the annual cycle changes in their energy budgets by measuring basal metabolic rate (BMR) and body mass. We quantified APRs by measuring the effects of a lipopolysaccharide injection on metabolic rate, body mass, body temperature, and concentrations of glucose and ketone. Body mass and BMR were lowest during breeding, highest during winter and intermediate during spring migration, moult and autumn migration. Despite this variation in energy budgets, the magnitude of the APR, as measured by all variables, was similar in all annual cycle stages. Thus, while we find evidence that some annual cycle stages are relatively more energetically constrained, we find no support for the hypothesis that during these annual cycle stages birds compromise an immune defence that is itself energetically costly. We suggest that the ability to mount an APR may be so essential to survival in every annual cycle stage that skylarks do not trade off this costly form of defence with other annual cycle demands.     

Iron and zinc status in rats with diet-induced marginal deficiency of vitamin A and/or copper

The hypothesis was tested that there are interactions of marginal copper and vitamin A deficiency regarding iron and zinc status. Copper restriction (1 vs 5 mg Cu/kg diet) significantly lowered copper concentrations in plasma and tissues of rats and reduced blood hemoglobin, hematocrit, and iron concentrations in tibia and femur, but raised iron concentrations in liver. Vitamin A restriction (0 vs 4000 IU vitamin A/kg diet) reduced plasma retinol concentrations and induced a fall of blood hemoglobin and hematocrit. Neither copper nor vitamin A restriction for up to 42 d affected feed intake and body wt gain. There were no interrelated effects of vitamin A and copper deficiency on iron status. Copper deficiency slightly depressed liver, spleen, and kidney zinc concentrations. Vitamin A deficiency lowered zinc concentrations in heart, but only when the diets were deficient in copper.