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PubMed2003

Magnesium and calcium contents in foods from SE Spain: influencing factors and estimation of daily dietary intakes.

The magnesium and calcium content (fresh weight basis) of 243 food, 69 beverages and 11 potable water samples were determined using flame atomic absorption spectrometry. Analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of this technique. The highest magnesium and calcium levels corresponded to molluscs and crustacea, and dairy products, respectively. Magnesium concentrations found in different food groups were significantly and linearly related with corresponding calcium levels (P<0.001) with the exception of fish products. Significant linear relationships among magnesium and calcium concentrations, and fiber content for cereals, legumes and dry-fruits were found (P<0.001); however, total fat contents of considered foods were not related (P>0.05) with levels of elements considered. Significant linear relationships among magnesium and calcium concentrations in cereals, legumes and fruits, and protein content were found (P<0.001). In meat and by-products, magnesium concentrations found in organ meats were significantly lower (P<0.01); for calcium, levels measured in sausages were significantly higher (P<0.001) than those found in meats and organ meats. In fish products, magnesium levels in molluscs and crustacea were significantly higher than those measured in fish and cephalopoda (P<0.001); for calcium, concentrations in cephalopoda were significantly lower (P<0.001). Mean magnesium and calcium concentrations analyzed in cheese were statistically higher than those determined in other dairy products (P<0.01). In alcoholic drinks, magnesium and calcium levels measured in distilled beverages (whisky, gin, rum, brandy and alcoholic liquors) were statistically lower than those found in fermented types (wine and beer) (P<0.01). The daily intake of magnesium and calcium in the Spanish diet was 366.1 and 1266.6 mg/day per person, respectively. Results revealed that the intake of analyzed elements was similar to recommended dietary allowances.

Animals↗
PubMed2002

Cypermethrin induces glutathione S-transferase activity in the shore crab, Carcinus maenas.

Cypermethrin is a synthetic pyrethroid that is particularly toxic to crustacea. It is therefore applied as a chemotherapeutant in the salmonid aquaculture industry for the treatment of sea lice infestations. After use, cypermethrin is released directly into the marine environment, to be diluted by fresh seawater. The shore crab, Carcinus maenas is found in the vicinity of fish farms, and may come into contact with released cypermethrin. The detoxification enzyme, glutathione S-transferase (GST) has been implicated in cypermethrin metabolism in terrestrial arthropods, but this has not yet been demonstrated in crustacea. In this paper we investigate the response of GST activity in Carcinus to cypermethrin exposure, and also the time course of the induction process. GST activity is significantly increased in Carcinus exposed to nominal concentrations of 50 and 500 ng/l of water-borne cypermethrin. Carcinus demonstrate a significant elevation in GST activity following intra-cephalothoracic injection with 10 ng of cypermethrin. GST activity returns to basal levels after 36 h. The potential application of GST activity in Carcinus as a biomarker of cypermethrin exposure is discussed.

Animals↗
PubMed1999

Behavioural evidence for polarisation vision in stomatopods reveals a potential channel for communication.

Polarisation sensitivity (PS) - the ability to detect the orientation of polarised light - occurs in a wide variety of invertebrates [1] [2] and vertebrates [3] [4] [5], many of which are marine species [1]. Of these, the crustacea are particularly well documented in terms of their structural [6] and neural [7] [8] adaptations for PS. The few behavioural studies conducted on crustaceans demonstrate orientation to, or local navigation with, polarised sky patterns [9]. Aside from this, the function of PS in crustaceans, and indeed in most animals, remains obscure. Where PS can be shown to allow perception of polarised light as a 'special sensory quality' [1], separate from intensity or colour, it has been termed polarisation vision (PV). Here, within the remarkable visual system of the stomatopod crustaceans (mantis shrimps) [10], we provide the first demonstration of PV in the crustacea and the first convincing evidence for learning the orientation of polarised light in any animal. Using new polarimetric [11] and photographic methods to examine stomatopods, we found striking patterns of polarisation on their antennae and telson, suggesting that one function of PV in stomatopods may be communication [12]. PV may also be used for tasks such as navigation [5] [9] [13], location of reflective water surfaces [14] and contrast enhancement [1] [15] [16] [17] [18]. It is possible that the stomatopod PV system also contributes to some of these functions.

Animals↗
PubMed2001

Mitochondrial protein phylogeny joins myriapods with chelicerates.

The animal phylum Arthropoda is very useful for the study of body plan evolution given its abundance of morphologically diverse species and our profound understanding of Drosophila development. However, there is a lack of consistently resolved phylogenetic relationships between the four extant arthropod subphyla, Hexapoda, Myriapoda, Chelicerata and Crustacea. Recent molecular studies have strongly supported a sister group relationship between Hexapoda and Crustacea, but have not resolved the phylogenetic position of Chelicerata and Myriapoda. Here we sequence the mitochondrial genome of the centipede species Lithobius forficatus and investigate its phylogenetic information content. Molecular phylogenetic analysis of conserved regions from the arthropod mitochondrial proteome yields highly resolved and congruent trees. We also find that a sister group relationship between Myriapoda and Chelicerata is strongly supported. We propose a model to explain the apparently parallel evolution of similar head morphologies in insects and myriapods.

Animals↗
PubMed2003

Complete subunit sequences, structure and evolution of the 6 x 6-mer hemocyanin from the common house centipede, Scutigera coleoptrata.

Hemocyanins are large oligomeric copper-containing proteins that serve for the transport of oxygen in many arthropod species. While studied in detail in the Chelicerata and Crustacea, hemocyanins had long been considered unnecessary in the Myriapoda. Here we report the complete molecular structure of the hemocyanin from the common house centipede Scutigera coleoptrata (Myriapoda: Chilopoda), as deduced from 2D-gel electrophoresis, MALDI-TOF mass spectrometry, protein and cDNA sequencing, and homology modeling. This is the first myriapod hemocyanin to be fully sequenced, and allows the investigation of hemocyanin structure-function relationship and evolution. S. coleoptrata hemocyanin is a 6 x 6-mer composed of four distinct subunit types that occur in an approximate 2 : 2 : 1 : 1 ratio and are 49.5-55.5% identical. The cDNA of a fifth, highly diverged, putative hemocyanin was identified that is not included in the native 6 x 6-mer hemocyanin. Phylogenetic analyses show that myriapod hemocyanins are monophyletic, but at least three distinct subunit types evolved before the separation of the Chilopoda and Diplopoda more than 420 million years ago. In contrast to the situation in the Crustacea and Chelicerata, the substitution rates among the myriapod hemocyanin subunits are highly variable. Phylogenetic analyses do not support a common clade of Myriapoda and Hexapoda, whereas there is evidence in favor of monophyletic Mandibulata.

Amino Acid Sequence↗
PubMed2001

Exposure assessment of dioxins/furans consumed in dairy foods and fish.

Dioxins/furans are ubiquitous environmental contaminants whose primary route of human exposure occurs via the consumption of fatty foods of animal origin. The US FDA conducted a market basket survey of dairy products and commercial fish and shellfish to obtain data on levels of 17 dioxin/furan congeners (2, 3, 7, 8-congeners) in the US. The dairy products sampled included various cheeses (American, cheddar, Swiss, cottage), ice cream, yogurt, butter, and milk. The finfish and shellfish (molluscs and crustacea) sampled are those marine species consumed in the greatest amounts and include canned tuna, shrimp, cod, blue crab, and oysters. Catfish was sampled because it is the dominant aquaculture species. Samples were collected in 1995/96 and analysis for 17 dioxin/furan congeners was performed by high-resolution gas chromatography following extraction and clean-up. Limits of detection (LOD) and quantitation (LOQ) for each congener in each food were reported. Point estimates of exposure were calculated using a 3-day (1-day diary plus 2-day recall) food consumption survey for eaters-only and for the general population (USDA/CSFII, 1989-92). Toxicity equivalency factors (TEFs) developed by the World Health Organization (1997) were used to derive overall dioxin/furan toxicity equivalents (TEQ) for each sample food. Mean estimates of TEQ exposure for each food were derived using five values for non-detects (ND = 0; ND = 1/2 LOD or LOQ, ND = LOD or LOQ) on both a total sample and eaters-only basis. Using zero and the LOD provide lower and upper bounds on the range of estimated exposure, respectively. The bounds on mean dioxin intakes (pg/person/day) calculated for consumers of specific foods were estimated as follows (using zero or LOD for non-detects): butter (0.5-11), cheese (1.6-3.2), ice cream (4-19), yogurt (0.8-28), catfish (148-150), fish (other than catfish) (0.03-9), crustacea (32-35), mollusks (16.1-16.6), and shrimp (0.09-4.5). Exposure estimates derived by the five ND-methods are strongly dependent on the LOD and LOQ and represent upper bound estimates of exposure. Uncertainty in the exposure estimates is reduced with refinements in the analytical method.

Adolescent↗
PubMed1996

First molecular evidence for the existence of a Tardigrada + Arthropoda clade.

The complete 18S rDNA gene sequence of Macrobiotus group hufelandi (Tardigrada) was obtained and aligned with 18S rDNA and rRNA gene sequences of 24 metazoans (mainly protostomes). Discrete character (maximum-parsimony) and distance (neighbor-joining) methods were used to infer their phylogeny. The evolution of bootstrap proportions with sequence length (pattern of resolved nodes, PRN) was studied to test the resolution of the nodes in neighbor-joining trees. The results show that arthropods are monophyletic. Tardigrades represent the sister group of arthropods (in parsimony analyses) or they are related with crustaceans (distance analysis and PRN). Arthropoda are divided into two main evolutionary lines, the Hexapoda + Crustacea line (weakly supported), and the Myriapoda + Chelicerata line. The Hexapoda + Crustacea line includes Pentastomida, but the internal resolution is far from clear. The Insecta (Ectognatha) are monophyletic, but no evidence for the monophyly of Hexapoda is found. The Chelicerata are a monophyletic group and the Myriapoda cluster close to Arachnida. Overall, the results obtained represent the first molecular evidence for a Tardigrada + Arthropoda clade. In addition, the congruence between molecular phylogenies of the Arthropoda from other authors and this obtained here indicates the need to review those obtained solely on morphological characters.

Animals↗
PubMed2005

Expression of the reproductive female-specific vitellogenin gene in endocrinologically induced male and intersex Cherax quadricarinatus crayfish.

In oviparous females, the synthesis of the yolk precursor vitellogenin is an important step in ovarian maturation and oocyte development. In decapod Crustacea, including the red-claw crayfish (Cherax quadricarinatus), this reproductive process is regulated by inhibitory neurohormones secreted by the endocrine X-organ-sinus gland (XO-SG) complex. In males, the C. quadricarinatus vitellogenin gene (CqVg), although present, is not expressed under normal conditions. We show here that endocrine manipulation by removal of the XO-SG complex from male animals induced CqVg transcription. The CqVg gene was expressed differentially during the molt cycle in these induced males: no expression was seen in the intermolt stages, but expression was occasionally detected in the premolt stages and always detected in the early postmolt stages. Relative quantitation with a real-time reverse transcriptase-polymerase chain reaction showed that expression of CqVg in induced early postmolt males was an order of magnitude lower than that in reproductive females, a finding that was consistent with RNA in situ hybridization results. The SDS-PAGE of high-density lipoproteins from the hemolymph of endocrinologically induced early postmolt males did not show the typical vitellogenin-related polypeptide profile found in reproductive females. On the other hand, removal of the XO-SG complex from intersex individuals, which are chromosomally female but functionally male and possess an arrested female reproductive system, induced the expression, translation, and release of CqVg products into the hemolymph, as was the case for vitellogenic females. The expression of CqVg in endocrinologically manipulated molting males and intersex animals provides an inducible model for the investigation and understanding of the endocrine regulation of CqVg expression and translation in Crustacea as well as the relationship between the endocrine axes regulating molt and reproduction.

Animals↗
PubMed1986

Colonization of the gut of the blue crab (Callinectes sapidus) by Vibrio cholerae.

Attachment of Vibrio cholerae to the mucosal surface of the intestine is considered to be an important virulence characteristic. Vibrio cholerae, an autochthonous member of brackish water and estuarine bacterial communities, also attaches to crustacea, a significant factor in multiplication and survival of V. cholerae in nature. The ability of V. cholerae to attach to the gut wall of the blue crab (Callinectes sapidus) was examined, and attachment was observed only in the hindgut and not the midgut of crabs, confirming a requirement for chitin in the attachment of V. cholerae to invertebrate and zooplankton surfaces. The new finding of attachment of V. cholerae to the hindgut of crabs may be correlated with the epidemiology and transmission of cholera in the aquatic environment. The crab model may also prove useful in elucidating the mechanism(s) of ion transport in crustacea.

Animals↗
PubMed2002

[Abundance and diversity of littoral invertebrates in the Socorro Island, Revillagigedo Archipelago, Mexico].

Composition, abundance, diversity and distribution of the littoral benthic invertebrates of Socorro Island with transects (parallel to the coast and with 1 m2 quadrats) were analyzed. During the spring of 1991 and 1992 samples were taken from the upper and middle levels of the intertidal zone in Vargas Lozano, Braithwaite, Blanca SW, Blanca NE, Binners, Grayson, Academia and Norte bays. The 161 species found belong to Porifera, Cnidaria, Platyhelmintha, Nemertina, Sipunculida, Annelida, Mollusca, Anthropoda and Echinodermata. Crustaceans and mollusks were the richest groups in both years, as in other rocky shores. Highest total density was found in Blanca NE bay in both samplings, with 281 orgs./m2 in the first and 172 orgs./m2 in the second. Most frequently found species were Isognomon janus (Mollusca, Pelecypoda), Littorina pullata (Mollusca, Gastropoda), Hipponix panamensis (Mollusca, Gastropoda), Pachygrapsus transversus (Crustacea, Grapsoidea) and Turbo funiculosus (Mollusca, Gastropoda). Because of the complexity of the habitat structure, Vargas Lozano was the bay with the highest specific richness (83 species), greatest diversity (4.7 bits/individual) and lowest dominance (0.065). Most species were classified as accidentals with the Dajoz's frequency classification, while the dominant species were accessories and only I. janus, in the spring 1991, was a constant species. Two kinds of bays were distinguished: those with some dominant species (density) and those in which there was no evident dominance by a particular species. Consequently, the diversity and evenness values were set apart: homogeneous communities (Vargas Lozano and Binners) and heterogeneous communities (Grayson bay and others), characterized by intermediate evenness values. The Jaccard similarity index identified two regions: one formed by bays found mainly in the southwest part of the island (Binners, Vargas Lozano, Braithwaite, Grayson and Blanca SW) and the other found in the northern region that included Blanca NE, Academia and Norte; however, Blanca NE had the most diverse species composition because of its physiographic particularities and because the sediment retained by the filamentous algae on the flat stones allow many species to settle down. Isognomon janus, Mitrella baccata (Mollusca, Gastropoda), P. transversus and Xanthodius cooksoni (Crustacea, Xanthoidea) were the most common species in all bays in both expeditions. The dominance-diversity relationship, the high specific richness and the low dominance of coastal invertebrates from the different bays, are indicative that the communities in Socorro Island are little disturbed; their specific richness are similar to those of coral reefs.

Animals↗
PubMed2003

[Recognition of stem cells in the colonial internae of the Rhizocephala Peltogasterella gracilis and Sacculina polygenea at the parasitic life cycle stage].

The colonial internae of two decapod parasites Peltogasterella gracilis and Sacculina polygenea (Crustacea: Cirripedia: Rhizocephala) were studied in vitro by histological, and histochemical methods. We found stem cells, characterized by basophilic cytoplasm, a large nucleus and nucleolus, and a high alkaline phosphatase activity. The cytochemical manifestation of alkaline phosphatase activity in totipotent stem cells of the colonial rhizocephala is the first evidence of commonality in the functional characteristics of embryonic stem cells in vertebrate and invertebrate animals of such different taxa as the mammals and Crustacea.

Alkaline Phosphatase↗
PubMedDate not supplied

[Parasite fauna of the perch fishes Percidae in waterbodies of the Kola Region].

Results of the parasitological investigation of two species of perch fisches (perch Perca fluviatilis and ruff Gymnocephalus cernuus) from Kola Region are given. 63 species of parasites were found on perch in 16 waterbodies belonging to the White Sea and Barents Sea basins (Myxosporea--3, Pleurostomata--1, Suctoria--2, Peritricha--21, Protozoa incertae sedis--1, Monogenea--2, Cestoda--6, Trematoda--10, Nemadota--8, Acanthocephala--4, Hirudinea--1, Bivalvia--1, Crustacea--3). 33 species of parasites were found on ruff in 5 waterbodies belonging to the White Sea basin (Cyrtostomata--1, Hymenostomata--1, Peritricha--8, Monogenea--2, Cestoda--6, Trematoda--9, Nematoda--2, Acanthospehala--2, Bivalvia--1, Crustacea--1). Data on the infestation of perch and ruff by different parasite species are obtained, occurrence of the parasites in the examined waterbodies is shown.

Animals↗
PubMed1990

Shellfish: proximate composition, minerals, fatty acids, and sterols.

Proximate composition, minerals, fatty acids, and sterols were determined for eight species of shellfish commonly marketed in the Northwest. Moisture and total lipid content varied with the size of the species, with more variation in mollusca than in crustacea; total lipid content ranged from 0.7% in sea scallops to 3.1% in blue mussels but only from 1.2% in Dungeness crab to 1.3% in pink shrimp. The mineral content was highly variable; the mineral content of Northwest samples tended to be lower than that reported in other studies. Generally, shellfish are good sources of zinc, and Pacific oysters, blue mussels, and Manila clams are also good sources of iron. Five fatty acids (16:0, 16:1, 18:1, 20:5n-3, and 22:6n-3) represented from 60% to 84% of the fatty acid content. Palmitic acid ranged from 13% to 32% of the total fatty acids. Long-chain n-3 polyunsaturated fatty acids were predominant (37.6% to 54.3%), with sea scallops containing more than 50%; n-6 polyunsaturated fatty acids ranged from 1.5% to 6.5%. In crustacea, cholesterol was the primary sterol, and brassicasterol was the only other measurable sterol. In all mollusca except California squid, cholesterol averaged 37 mg/100 gm and ranged from 23% to 39% of the total sterols. In squid, cholesterol, at 231 mg/100 gm, was the only measurable sterol. We conclude that shellfish vary widely in their nutrient content but, in general, are valuable additions to the diet.

Chromatography, Gas↗
PubMed1964

CAROTENOIDS OF CAVERNICOLOUS CRAYFISH.

Small amounts of beta-carotene and lutein were found in Orconectes pellucidus pellucidus. Cambarus bartonii tenebrosus from the same cave contained much less carotenoid than surface crayfish. Astaxanthin, the principal carotenoid of most Crustacea, was absent from O. p. pellucidus, but accounted for 83 percent of the carotenoid of C. b. tenebrosus. These findings support other observations that pigmentation is dependent on the amount of carotenoid in the diet rather than on the presence of light. Furthermore, they suggest that O. p. pellucidus has lost or has never developed the ability to oxidize dietary carotenoids.

Animals↗
PubMed1975

Bioluminescence: from chemical bonds to photons.

The biological transformation of chemical to photic energy involves an enzyme-mediated chemiluminescent reaction, in which one of the products exists in an electronically excited state, emitting a photon as it returns to the ground state. The colour of bioluminescence differs in different organisms, ranging from the deep blue (460 nm) of certain crustacea, through the bluish green (490 nm) of some bacteria, the green (530 nm) of mushrooms to the red (about 600 nm) of the railroad worm. In one case, energy transfer has been demonstrated from the enzyme system to material that emits light with a longer wavelength. The energies involved range from about 165 to 250 kJ/einstein (40 to 60 kcal/einstein). Boyle first showed that air was involved in bioluminescence in 1668 in his experiments with an air pump. Over the past 100 years, it has become clear that most if not all bioluminescent systems require molecular oxygen. The recent isolation and characterization of an oxygen-containing (peroxide) enzyme intermediate from the bacterial system is described and a reaction mechanism is postulated. This scheme is compared with other hypothetical mechanisms, in particular those involving a four-membered ring intermediate, a dioxetane, in which the simultaneous cleavage of two bonds leaves one product in an excited state. I shall discuss the special role of luciferases in bioluminescence, especially in flashing mechanisms involving 'precharged' intermediates.

Acridines↗
PubMed1988

Quantitative determination of arsenocholine and acetylarsenocholine in aquatic organisms using pyrolysis and gas chromatography/mass spectrometry.

A method for qualitative and quantitative analysis of trace amounts of quaternary organoarsenicals such as arsenocholine and acetylarsenocholine has been developed. The method is based on pyrolysis, gas chromatography/mass spectrometry and use of deuterium-labelled internal standards. Arsenocholine and acetylarsenocholine have been estimated in fish from arsenic-polluted brackish water and compared with the same species of fish from unpolluted water. The investigation also includes some fish and crustacea from marine water. The presence of arsenocholine and acetylarsenocholine in different aquatic organisms indicate the existence of a general metabolic pathway for these compounds in aquatic ecosystems.

Animals↗
PubMed1994

Comparative anatomy of serotonin-like immunoreactive neurons in isopods: putative homologues in several species.

It is now commonly accepted that the arthropod nervous system has evolved only once, and so homologies between crustacean and insect nervous systems can be meaningfully sought. To do this, we have examined the distribution of serotonin (5-hydroxytryptamine)-like immunoreactive neurons in the central nervous system (CNS) of four common British isopods. Two species of terrestrial woodlouse, Oniscus asellus and Armadillidium vulgare, the littoral sea slater, Ligia oceanica, and the aquatic water hoglouse, Asellus meridianus, all possess approximately 40 pairs of serotonin-like immunoreactive neurons, distributed throughout the CNS in a very similar pattern. Interspecific homology is clearly suggested. Serotonin-like immunoreactive neurons in the first (T1) and fourth (T4) thoracic ganglia are particularly prominent in each of the four species studied. Whole-mount immunohistochemistry shows that the pair of T1 neurons have large dorsolateral cell bodies and prominent neurites that project medially and then anteriorly, whereas the pair of T4 neurons have ventrolateral cell bodies and neurites that bifurcate to form a thin axon projecting anteriorly to terminate in T3 and a thick medial axon that projects posteriorly into the abdominal neuromeres of the terminal ganglion. Intracellular cobalt staining of these neurons reveals more of their arborizations: the T1 neurons send three processes anteriorly, which arborize in the brain and exist from the CNS via peripheral nerves, whereas the T4 neurons contribute considerably to the extensive pattern of serotonin-like immunoreactive fibres in T3-T6 ganglia. The overall pattern of serotonin-like immunoreactive neurons in the isopods is similar to that in decapod crustacea, and a number of putative homologies can be assigned. It is more difficult to homologize the isopod serotonin-like immunoreactive neurons with those in the insect CNS, but some stained brain and thoracic neurons share common cell body positions and axon trajectories in isopods, decapods, and insects and may therefore be homologous.

Animals↗
PubMed2000

Development of methods for evaluating toxicity to freshwater ecosystems.

This article presents a summary of a collaborative research program involving five European research groups, that was partly funded by the European Commission under its Environmental Research Program. The objective of the program was to develop aquatic toxicity tests that could be used to obtain data for inclusion at Level 2 of the Risk Evaluation Scheme for the Notification of Substances as required by the 7th Amendment to EC Directive 79/831/EEC. Currently only a very limited number of test methods have been described that can be used for this purpose and these are based on an even smaller number of test species. Tests based upon algae (Chlamydomonas reinhardi, Scenedesmus subspicatus, and Euglena gracilis), protozoa (Tetrahymena pyriformis), rotifera (Brachionus calyciflorus), crustacea (Gammarus pulex), and diptera (Chironomus riparius) were developed. The tests encompassed a range of end points and were evaluated against four reference chemicals: lindane, 3, 4-dichloroaniline (DCA), atrazine, and copper. The capacity of the tests to identify concentrations that are chronically toxic in the field was addressed by comparing the effects threshold concentrations determined in the laboratory tests with those determined for similar and/or related species and end points in stream and pond mesocosm studies. The lowest no-observed-effect concentrations (NOEC), EC(x), or LC(x) values obtained for lindane, atrazine, and copper were comparable with the lowest values obtained in the mesocosms. The lowest chronic NOEC determined for DCA using the laboratory tests was approximately 200 times higher than the lowest NOEC in the mesocosms.

Aniline Compounds↗